identifier: Wang, Zhilan <https://research.library.mun.ca/view/creator_az/Wang=3AZhilan=3A=3A.html>   (1996) A study of reproductive physiology in the male ocean pout Macrozoarces americanus.  Masters thesis, Memorial University of Newfoundland.

abstract: To provide more information on the reproductive biology of an internally fertilizing marine species, a two-year study of the reproductive physiology of the male ocean pout (Macrozoarces americanus) was undertaken. The physiological characteristics of the spawning season and sperm physiology, including the changes in the gonadosomatic index (GSI), plasma androgenic steroids, the timing of spermiation, sperm motility and sperm concentration, and the variations of pH, osmotic pressure and the biochemical composition of seminal plasma during the spawning season were investigated. The spermiation response began in June, and by July all mature males spermiated. Spermiation ended in late September or early October. Sperm motility rose and fell in a similar manner from June to September. Compared with the milt of most investigated male teleosts, ocean pout milt had a low sperm concentration (0.91 - 6.81 x 10⁸ spz/ml), and was correlated with spermatocrit values during most of the spawning season (r²-0.79, p<0.0001). The GSI of the males was relatively low, ranging between minimum values in September and October (0.26 - 0.31%) and a maximum in July (1.9%). Plasma testosterone levels rose rapidly seven weeks in advance of spermiation and peaked one week before the onset of spermiation, and decreased thereafter. Plasma levels of 11- ketotestosterone paralleled those of testosterone during the spawning season and reached a peak coincident with onset of spermiation.  -- Biochemical composition of seminal plasma also varied through the spawning season. The pH of seminal plasma increased from 7.4 to 7.9 during the period of spermiation, and the average pH (7.78±0.03) for the spawning season remained close to an experimentally determined optimum pH range for ocean pout sperm motility (pH 8-9). Although the values for seminal plasma osmolality fell from 416 to 339 mmol/kg during the reproductive season, the average osmolality value (356±3 mmol/kg) was within the optimum for ocean pout sperm motility (300 - 400 mmol/kg). In comparing fluctuations in sperm motility with the biochemical composition of ocean pout seminal plasma during the spawning season, this study showed that increased Mg levels were correlated with the summer period of maximum sperm motility. A seasonal decline in Na and Cl ion levels was reflected in lower seminal plasma osmolality values.


identifier: Bhat, Krishna Moorthi <https://research.library.mun.ca/view/creator_az/Bhat=3AKrishna_Moorthi=3A=3A.html>   (1986) Incorporation of plasma proteins during oocyte growth and its hormonal control in winter flounder, Pseudopleuronectes americanus (Walbaum).  Masters thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

format: application/pdf application/pdf

abstract: Direct evidence is provided for ovarian incorporation of plasma proteins other than vitellogenin in winter flounder Pseudopleuronectes americanus. Two major polypeptides of molecular weights 70 K and 28 K from Peak A protein(s) of the plasma were demonstrated to be incorporated into ovarian  proteins. Both the polypeptides were structurally different from vitellogenin and were found to exist in the oocyte as polypeptide fragments of molecular weights 28 K, 70 K and 76  K. Vitellogenin was shown to occur as 96 K and 86 K fragments in the oocyte. The ovarian polypeptides of molecular weight 96 K fragment from vitellogenin, and 28 K fragment from Peak A protein(s) appear to be completed together and are classified here as lipovitellin 1 and lipo-vitellin II. This is similar to the molecular organization of yolk in Xenopus laevis [Berridge, M.V., and Lane, C.D. (1976). Cell, 8, 283-297]. In addition, the presence of the 70 K and 28 K polypeptides of Peak A protein(s) in the testicular proteins has been established. -- Carbohydrate-poor pituitary proteins stimulated the ovarian incorporation of vitellogenin and the non-vitellogenin plasma proteins, Peak A protein(s) and Peak E protein(s). A biologically active peptide (Rf 0.72 protein) was obtained from the carbohydrate-poor proteins; this has a molecular weight of 14.3 K by polyacrylamide gel electrophoresis containing sodium dodecyl sulphate and elutes in the region of 28 K on Ultrogel AcA 44 together with prolactin and growth hormone. A regulatory role of this gonadotropin in the ovarian uptake  of Peak A protein(s) was established. These findings were in  agreement with the earlier studies on the duality of gonadotropins in many species of teleosts, reported from this laboratory (see Idler and Ng, 1983).


identifier: Bryant, Shelley L. <https://research.library.mun.ca/view/creator_az/Bryant=3AShelley_L=2E=3A=3A.html>   (1993) Influences of Larus gulls and nocturnal environmental condition on Leach's storm-petrel activity patterns at the breeding colony.  Masters thesis, Memorial University of Newfoundland.

abstract: The risk of predation is perhaps the most serious pressure an animal must contend with during its lifetime. Predation risk has played a strong selective force in many aspects of life history, including the activity patterns of prey species. Leach's Storm-Petrels (Oceanodroma leucothoa) arrive and depart from breeding colonies only at night. Anecdotal reports suggest that storm-petrels return to the colony later on bright nights than on overcast or foggy ones, and that fewer birds are seen at the colony on bright nights. These are considered predator avoidance behaviours as diurnal gulls prey on storm-petrels, especially on bright moonlit nights. -- This study examined the effects of the presence of predators on the activity and parental care patterns at two Leach's Storm-Petrel colonies - one with gulls (Gull Island) and one without (Green Island). Data were collected on storm-petrel flight and vocalization activity, reproductive chronology, chick interfeed interval,  and gull activity and predation on Leach's Storm-Petrels. A model gull experiment was conducted on Green Island to determine storm-petrel responsiveness to gulls at this colony. In addition, fledging mass and winglength measurements were collected from five colonies; four in Newfoundland and one in Maine. -- Differences were found in storm-petrel responses to nocturnal environmental condition both between the colonies and between the reproductive phases of incubation and chick rearing. At both colonies, and over the entire reproductive season, storm-petrels arrived and began to vocalize later on bright evenings than on intermediate or dark ones, and under clear versus cloudy or foggy skies. Leach's Storm-Petrels on Gull Island were also quiet on arrival for a longer period than those on Green Island. Once at the colony, the behaviour of the storm-petrels was similar under a variety of nocturnal environmental conditions at Gull and Green Islands, although the storm-petrels at Green Island were apparently less affected by nocturnal environmental condition. Storm-petrels  tended to be most affected by nocturnal environmental condition during incubation on Gull Island and during chick rearing on Green Island. The activity of Leach's Storm-Petrels at both colonies was affected by the presence of gulls (model gulls on Green Island). Gulls had a higher level of activity under those conditions that were more conducive to nocturnal hunting (i.e. brighter nights), and more storm-petrel remains were found after bright or moonlit  nights. The reproductive season was somewhat attenuated at Gull Island compared to Green Island, and fledging mass and winglength tended to be lower at colonies with gulls, and at  larger colonies compared to smaller ones. The results of this study indicate that many factors contribute to the ultimate decision an individual storm-petrel makes to return  to and land at the colony: a number of these factors are outlined in a model of offshore, colony, and underlying influences.


identifier: Acharya, Kashmira P. <https://research.library.mun.ca/view/creator_az/Acharya=3AKashmira_P=2E=3A=3A.html>   (1986) Initial steps in the degredation of 1, 3, 5-trihydroxybenzene by Bacillus sp. BPG-8.  Masters thesis, Memorial University of Newfoundland.

abstract: Gram postitve, sporulating, aerobic rods (Bacillus BPG-8) isolated from local soil sample were found to grow on 1,3,5-trihydroxybenzene (Phloroglucinol, PG) when this substance was used as a sole source of carbon and energy. The optimal growth was reached at a substrate concentration of 0.1%; the  pH optimum for the gtowth in mineral salt medium was pH 5.5 and the optimum temperature was 25°C. Phloroglucinol reductase (PGR), the initial enzyme in the metabolic pathway  appeared to be an inducible enzyme. High elevated levels of this enzyme were prsent in cells grown on either PG alone or  on other carbon substrates (like succinate, pyruvate etc.) mixed with PG. Besides PG, the isolate also grew on pyrogallol and orcinol as sole sources of carbon. The oxidation of PG by cell suspension in minimal salt medium was easily demonstrable and the cell suspension was found to  metabolize about 100 mg of the substrate in about five hours. The generation time of BPG-8 was calculated to be 3.75 hours. -- The PGR required electron donors such as reduced NADP⁺ and NAD⁺ for the reduction of the substrate. Metal ions such as Zn²⁺, Fe²⁺, Mn²⁺, Mg²⁺ and Cu²⁺ did not stimulate the PGR activity. Some metal ions inhibited the activity to varying degrees. The PGR activity was inhibited by potassium phosphate, sodium chloride, sodium phosphate, imidazole and poly buffers. -- The PGR and resorcinol hydroxylase (RH) activities were unseparable by ammonium sulphate treatment, gel filtration and ion exchange column chromatography. The activity of PGR was always higher than that of RH in all enzyme preparations. The Km values for PGR  was 2 x 10⁻⁴ M and molecular weight was found to be 155,000 daltons. The PGR and RH activities from BPG-8 reached a peak  in about 18 hours. The pH optimum for the enzyme activity was found to be 7.4. -- Freezing and thawing had little or no effect on the PGR and RH from BPG-8. When the crude extract stored at 4°C for two days, a 90% loss of the RH activity resulted. Increasing concentrations of glycerol to (15%) offred protection to the PGR and RH. -- The spectral changes observed during chemical reduction of PG by sodium borohydride indicated the formation of dihydrophloroglucinol. Evidence is presented to show that enzymic reduction of PG in the presence of NADPH forms a product with a similar spectrum. -- The data presented suggest that BPG-8 may carry an enzyme complex with two separate activities, namely PGR and RH.


identifier: White, Ellen Mary Patricia Rahal <https://research.library.mun.ca/view/creator_az/White=3AEllen_Mary_Patricia_Rahal=3A=3A.html>   (1985) A taxonomic and zoogeographical study of the haemoproteidae and leucocytozoidae of the avian family Pycnonotidae.  Masters thesis, Memorial University of Newfoundland.

abstract: An extensive collection of blood film from the avian family Pycnonotidae, collected across the range of their distribution from Africa to the Philippines, provided an opportunity to survey the blood parasites of this host family and to study the taxonomy and zoogeography of the Haemoproteidae and Leucocytozoidae.  -- Of the 9834 bulbuls of 69 species examined for blood parasites, 23.0% harboured haematozoa. Haemoproteus was the most commonly occurring blood parasite, recorded from 15.7% of the total pycnonotids examined, followed in prevalence by Leucocytozoon (4.6%), microfilaria (3.1%), Plasmodium (1.1%) and Trypanosoma (0.7%).  -- Five species of Plasmodium (P. circumflexum, P. polare, P. relictum, P. rouxi and P. vaughani) and three species of Trypanosoma (T. avium, T. Calmettei and T. paddae) were identified. Three haemoproteid species were found in the bulbuls. Haemoproteus sanguinis Chakravarty and Kar 1945 was resurrected from synonymy with Haemoproteus otocompsae de Mello 1935 and both species were redescribed. A new species, Haemoproteus philippini sp. n., was described for the first time. Leucocytozoon brimonti Mathis and Leger 1910, Leucocytozoon dubreuili and Leucocytozoon majoris were also identified. It was recommended that Leucocytozoon brimonti be considered a valid species and that Leucocytozoon molpastis de Mello 1936 be synonymized with it. -- when the haemoproteid species were examined by host genera, H. otocompsae and H. sanguinis were found to occur more often in Pyhchonotus while H. philippini sp. n. occurred more frequently in Hypsipetes and Criniger. -- The zoogeographic distribution of Haemoproteus and leucocytozoon were examined. As evidenced by prevalence rate, H. otocompsae was more common in bulbuls towards the western end of their range, particularly in India; H. philippini sp. n. was a more easterly parasite, reaching its peak prevalence in pycnonotids in the Philippines; and H. sanguinis was fairly evenly distributed across the range of the host family. Leucocytozoon prevalence showed an upward trend from the eastern end of the pycnonotid range to the western end.


identifier: Caines, Jennifer R.  <https://research.library.mun.ca/view/creator_az/Caines=3AJennifer_R=2E_=3A=3A.html>   (1991) A taxonomic study of the haemoproteidae (Apicomplexa: Haemosporina) of the avian families Fringillidae, Emberizidae, Parulidae, Thraupidae and Icteridae.  Masters thesis, Memorial University of Newfoundland.

abstract: The haemoproteids (Haemosporina: Haemoprotcidae) of the avian families Fringillidae, Emberizidae, Parulidae, Thraupidae and Icteridaesensu Edwards (1986) were reviewed, and eight species determined to be valid, all of the basic halteridial or microhalteridial form as defined by Bennett and Peirce (1988). Haemoproteus fringillae (Fringillidae), H. mazzai (Emberizidae), H. chloris (Emberizidae) and H. quiscalus (Icteridae) were redescribed from hapantotype or neohapantotype material from a wider range of hosts and/or locations than in the original descriptions. Haemoproteus loxiae, H. acanthis and H. emberiza were declared nomina inula. H. globulosus, H. macropigmentatus, H. serini, and H. tarkakovskyi were declared synonyms of H, chloris, and H. Iiedymelis was declared a synonym of  H. mazzai. The new haemoproteid species Haemoproteus coatneyi (Emberizidae), H. paruli (Parulidae), H. coereha (Parulidae), and H. thraupi (Thraupidae) were described. All hapantotype, neohapantotype and parahapantotype material was deposited in the collection of the International Reference Centre for Avian Haematozoa, Department of Biology, Memorial University of Newfoundland.


identifier: Houston, Kimberly Anne <https://research.library.mun.ca/view/creator_az/Houston=3AKimberly_Anne=3A=3A.html>   (1984) Food sources for deep-sea fishes from the upper continental slope of the Grand Banks off Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Stomach contents and parasite faunas of 464 specimens of demersal fishes in 14 species were examined from the Carson Canyon region of the upper continental slope of the Grand Banks off Newfoundland. Individual species tended to feed either primarily on benthic invertebrates or on pelagic food items. Most pelagic predators also fed on benthopelagic organisms. Prevalence of parasites was 46 percent, with an average of 5.5 worms per fish. Prevalence of parasites was higher in benthic feeders (53.1%) than in pelagic fedders (28.9%). Relative abundance by group among benthic feeders was: Digenetic Trematoda 5.8%. Nematoda 53.1% and Acanthocephala 40.9%. Percent occurrence by group among pelagic feeders was: Digenetic Trematoda 27.8%, Nematoda 72.2% and Acanthocephala 0%. There were more species of benthic feeders (5) than pelagic feeders (3), but pelagic feeders were more abundant (pelagic 70.9%, benthic 20.5%). Benthic feeders were on average larger (x̄ = 270.6 g) than pelagic (x̄ = 130.6), but pelagic feeders represented a larger proportion of the biomass (pelagic 43.3%, benthic 25.94%).


identifier: Flynn, Shawn R. <https://research.library.mun.ca/view/creator_az/Flynn=3AShawn_R=2E=3A=3A.html>   (1996) Gametogenesis in the Capelin, Mallotus villosus (Müller) from the Northwest Atlantic.  Masters thesis, Memorial University of Newfoundland.

abstract: Capelin, Mallotus villosus (Muller), from the Northwest Atlantic were examined to describe the anatomical structure of the gonads and their positioning in the body cavity in relation to that of other fish. The testes of immature fish were thread-like, elongate, smooth and clear without obvious internal divisions in histological cross section. Those of maturing fish were elongate and smooth but much more robust, flattened and white. -- In maturing fish the final stages of spermatogenesis begin in the Fall of the year before spawning and are easily recognized as primary spermatogonia begin a process of division. This results in the division of the testes into lobules containing cysts. Within the cysts cells develop synchronously but the development of cells from different cysts is asynchronous. Sperm cells first appear in October and as development continues cysts filled with sperm break down and form larger pools of sperm starting in February. Fish examined immediately after spawning had gonads that were distended and contained only small amounts of residual sperm. -- The ovarian anatomy is unusual in that ovarian wall covers only the medial half of the organ and the oocytes develop in lamellae that extend freely into the body cavity. This type of ovarian structure was previously described by Brock, 1878 and Huxley, 1883. -- Four potential year classes of oocytes develop in the capelin ovary simultaneously and can be distinguished on the basis of size and cytological character. In immature fish all four are previtellogenic, but in maturing fish the fourth year class begins vitellogenic growth during the fall (September - October) of the year prior to spawning. This year class will mature over the winter passing through several developmental phases until final ovulation in June - August Mature eggs are ovulated directly into the body cavity and spawned through the gonopore located just posterior to the anus. The previtellogenic stages continue to develop during this time but at a slower rate. Their slight increase in size is accompanied by changes in the density of cytoplasm and the occurrence of such organelles as Balbiani bodies. -- Post-spawned capelin were captured at Middle Cove and maintained in aquaria at the Ocean Science Centre in Logy Bay. All the male fish died within several weeks but some female fish survived until the following year. Samples of these fish were taken in the winter and spring and showed clear evidence of development of gonads for the upcoming spawning season. The ovaries of recovering fish, soon after spawning, are distended and histological cross sections reveal thickened areas of folded tissue in the ovarian wall as well as loosely packed previtellogenic oocytes and residual eggs. These features have been used to develop a method to distinguish recovering females from first time spawners. -- The timing for the sequence of developmental steps of gametogenesis occurring in the last year before spawning, for both male and female capelin, was documented. It was shown that fish of different lengths have different rates of reproductive development.


identifier: Bates, Jennifer Ann <https://research.library.mun.ca/view/creator_az/Bates=3AJennifer_Ann=3A=3A.html>   (1992) Genetic and morphological variation in the mussel Mytilus in Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The genus Mytilus in Newfoundland is thought to be differentiated into two taxa, presently called M. trossulus and M. edulis. In the present study a survey of the distribution of these two taxa was undertaken. Ten sites along the east coast of Newfoundland were sampled; two of these sites were sampled on a finer scale. Four partially diagnostic enzyme loci, Pgm, Est, Lap, and Ap differentiated two groups. Both groups were found at most sites. Heterozygote deficiencies (relative to Hardy Weinberg Equilibrium) were found in one or more loci at all but one site. However the presence of some heterozygotes suggests that the two taxa interbreed. Pgm, Est, and Lap genotypes were significantly associated and together were useful in separating the two taxa. -- Inner shell colour was correlated with enzyme genotype, M. trossulus being relatively darker than M. edulis, but this failed to be a robust taxonomic character across all sites. In a fine scale analysis at Traytown, genotype frequency was found to be correlated with increasing shell length. This suggests variation in recruitment, growth and/or mortality between the two taxa.


identifier: Hicks, Shawn A. <https://research.library.mun.ca/view/creator_az/Hicks=3AShawn_A=2E=3A=3A.html>   (1996) Genetics, phylogeny, and biogeography of the marten (Martes americana).  Masters thesis, Memorial University of Newfoundland.

abstract: The purpose of this study was to examine the genetic variation within a small reintroduced population of American  pine marten (Martes americana) in Terra Nova National Park, Newfoundland, as well as the variation and diversity within and among other North American pine marten and closely related species. DNA sequencing of several hundred base pairs of the 5' most end of the cytochrome b gene of the mitochonrdial DNA was completed and the sequences analysed. -- It was determined that a reintroduced population and the source population shared identical DNA, based on 307 base pairs of data. A 401 base pair data base was compiled from samples of 12 subspecies of American pine marten (Martes americana) as well as European pine marten (M. martes), sable (M. zibellina), and American badger (Taxidea taxus). Genetic diversity was detected between certain subspecies of  Martes americana as well as between all species of Martes studied. Two distinct lineages of Martes americana are apparent in North America ["americana" and "caurina" groups]  whose pairwise sequence divergence is 1.5%. The two genetic groups correspond to the two former North American pine marten species Martes caurina and Martes americana. The average nucleon diversity (h) within the "americana" group is 0.22 and within the "caurina" group is 0.72.


identifier: Bacon, Gregory Scott <https://research.library.mun.ca/view/creator_az/Bacon=3AGregory_Scott=3A=3A.html>   (1994) Feeding activity, energy balance and scope for growth in the juvenile sea scallop Placopecten magellanicus (Gmelin) in Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The physiological responses of juvenile sea scallops (Placopecten maqellanicus) (Gmelin.) exposed to experimental food rations, that varied in concentration and quality, were evaluated using techniques of physiological energetics. This included: 1) the pre-ingestive feeding activity such as clearance rate, pseudofaeces production and preferential selection; 2) energy gained through ingestion and absorption; 3) energy losses associated with respiration and excretion; and 4) the integration of these energy gains and losses to predict scope for growth. -- To accomplish this, scallops were exposed to laboratory experimental diets with qualities (at 12° C) set at 25%, 50%, and 80% particulate organic material (POM) and diet concentrations set at approximately 1, 3, 7, and 14 mg 1⁻¹ using varying proportions of the microalgal diatom Chaetoceros muelleri and inert silica particles (SiO₂) . These conditions mimicked the range of seston conditions this species is exposed to in the natural environment in eastern Newfoundland. -- Juvenile sea scallops exposed to the above conditions were able to regulate ingestion rate by reducing clearance rate and increasing the amount of material rejected in pseudofaeces, all in order to maintain a high absorption efficiency. An increase in scope for growth by this species with particle concentration was facilitated by maintaining relatively constant oxygen consumption and ammonia excretion rates. -- P. maqellanicus showed no relative difference in scope for growth at concentrations greater than 3 mg 1⁻¹ when fed a 50% organic mix of algae and silica when compared to a ration consisting of 80% organic content (i.e. 100% algae). A direct grow out experiment would be required to confirm that scallops could grow as effectively on a 50% diet as on an 80% diet, but these results suggest the cost of rearing algae and the hatchery/nursery stage of culturing this species of scallops could be reduced by supplementing algal food with inorganic particles such as silica.


identifier: Steel, Deborah Anne <https://research.library.mun.ca/view/creator_az/Steel=3ADeborah_Anne=3A=3A.html>   (1986) Feeding rates of appendicularians (Oikopleura spp.) in coastal Newfoundland waters : results of in situ studies.  Masters thesis, Memorial University of Newfoundland.

abstract: Appendicularian populations were observed in Logy Bay, Newfoundland over a two year period to quantify their feeding behavior and to elucidate their role in energy flow in a cold ocean environment. Populations were observed to fluctuate rapidly in apparent response to wind-induced changes in water mass characteristics. Very large individuals of Oikopleura vanhoeffeni dominated very cold waters (< 0°C) while warmer waters (> 8°C) were characterized by higher densities of the smaller Oikopleura labradoriensis. -- Radioactively labelled algae were used to  measure in situ ingestion and clearance rates of individual Oikopleura over a wide range of animal sizes, temperatures and ambient food concentrations. Multiple regression analysis indicated that animal body size (measured as tail length) explained 11.3% of the variance in ingestion rate and 46% of the variance in clearance rate. Temperature was not a significant variable, while the biomass concentration of phytoplankton < 2 μm explained an additional 8% of the variation in clearance rate. Animal activity, estimated from  tail beat observations, explained 60% of the variation in ingestion rate for a sublet of the data but was not significantly correlated with temperature, body size or ambient food concentrations. Oikopleura populations were estimated to clear a maximum of 2% of the water column per day at observed densities, while literature estimates of densities for nearby Conception Bay yielded clearing estimates up to 64% per day.


identifier: Kuhlenkamp, Ralph <https://research.library.mun.ca/view/creator_az/Kuhlenkamp=3ARalph=3A=3A.html>   (1990) Field and culture studies on the Tilopteridales (Phaeophyceae) in Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The family Tilopteridaceae (Tilopteridales, Phaeophyceae) consists of three monospecific genera of which two species, Tilopteris mertenaii and Haplospora globosa, occur throughout the North Atlantic and Arctic Ocean. The third species, Phaeosiphoniella cryophila} is restricted to four localities in Newfoundland and, aside from its initial description, is little known. Both Phaeosiphoniella and Haplospora develop prostrate systems when their rhizoids come in contact with the substrate. These prostrate discs are functionally, and to some degree also morphologically, equivalent to crusts of species of the Sphacelariales or Scytosiphonales and serve as perennating structures during the summer. Upright filaments are produced from the prostrate systems only under winter conditions. Combined culture and field studies showed that uprights of Phaeosiphoniella are restricted to water temperatures of less than 10°C and light intensities of less than 8 μmol m⁻² s⁻¹ while prostrate discs withstand up to 20°C. -- Phaeosiphoniella reproduces exclusively through fragmentation and abscission of branch systems. The sporadically occurring antheridia or sporangia are functionless and the reproductive system is more reduced than in the other two species.  -- Quantitative DNA fluorometry confirmed that Tilopteris and Phaeosiphoniella exhibit only one level of ploidy, whereas the two generations in Haplospora show different ploidy levels, although the number of chromosomes does not change. -- The reduced life cycles shown in Tilopteris and Phaeosiphoniella might indicate that both species are derived forms and have formerly possessed a sexual life cycle with an alternation of generations such as seen in Haplospora. This study suggests that Phaeosiphoniella represents a relic species which exists only at the extremes of its former area of distribution. Members of the Tilopteridaceae, especially Phaeosiphoniella, might be regarded as species with weak competitive capabilities, but with the ability to live in areas of high physical disturbance where competition with other algae is low.


identifier: Rodway, Michael S. <https://research.library.mun.ca/view/creator_az/Rodway=3AMichael_S=2E=3A=3A.html>   (1994) Intra-colony variation in breeding success of Atlantic puffins : an application of habitat selection theory.  Masters thesis, Memorial University of Newfoundland.

abstract: Theoretical models of habitat selection generally assume that organisms behave optimally, that population density correlates with resource abundance, and that increasing density reduces habitat quality.  My purpose was to determine whether current models could explain the distribution of Atlantic Puffins (Fratercula arctica) breeding on Great Island, Newfoundland and, if not, to propose a model that could.  Theoretical models have rarely been applied to explain the distribution of a colonially-nesting species that may gain fitness benefits from increasing density. -- I used breeding success as a representative measure of fitness that I compared among three habitats, maritime slope, maritime level, and inland slope, sampled at three locations, north, east and south on Great Island in 1992 and 1993.  Based on results of previous studies, I predicted that distance from the shore edge of the colony, slope, and aspect would be the most important habitat variables that discriminate habitat quality for puffins on Great Island. -- Nest density was highest in maritime slope and lowest in inland slope habitat and was best predicted by distance from the shore edge of the colony.  Breeding success, as measured by the proportions of burrows that fledged chicks, was highest in maritime and inland slope habitats and lowest in maritime level habitat and was related to distance from the edge and slope.  Aspect was an important predictor of timing of breeding but was not significantly related to breeding success.  Thus, it appeared that preferred areas were close to shore, while optimal areas were on slopes. -- High breeding success and nest density in maritime slope habitat was predicted by current habitat selection models, but high success at low density in inland slope habitat was not.  Breeding success increased with density within habitats, also contrary to model predictions.  Current models proved unable to explain the distribution of puffins if breeding success was used as the sole measure of fitness.  A cost-benefit model is proposed that acknowledges habitat related fitness costs that are not accounted for by typical measures of breeding success.  Unique cost-benefit ratios for different habitats can explain observed patterns of dispersion and breeding success.


identifier: Shantharam, Sivramiah <https://research.library.mun.ca/view/creator_az/Shantharam=3ASivramiah=3A=3A.html>   (1980) Interaction between the nitrogen fixing bacterium Rhizobium japonicum and soybean (Glycine max L.) involving specificity and recognition.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The initial cell surface interaction between legumes and rhizobia during infection, is believed to be mediated by legume seed lectins.  The specificity and host-recognition are the two important prerequisites for the successful infection of legumes by rhizobia.  The present study deals with the involvement of soybean lectin in the interaction between soybean and Rhizobium japonicum. -- Using biochemical and cytological techniques, soybean lectin binding properties of a non-mucoid strain of R. japonicum under two different laboratory culture conditions were studied.  The primary lectin binding sites were localized in the capsular extracellular polysaccharide (EPS) of the bacteria using ferritin and colloidal gold labeled soybean lectin at the ultrastructural level.  It was also possible to show the secondary soybean lectin binding sites to be the outer cell wall of the bacterial cells.  Further, the lectin specific cells were characterized as coccoid forms embedded in a capsular matrix and rod forms having a polar capsule.  In experimental studies both capsulated coccoid and rod forms were found to attach to the root hair surface with the rod forms showing distinct polar attachment. -- Differential centrifugation was used to fractionate the rod and coccoid forms which were then further characterized.  Both the forms were clearly distinguishable at the light and electron microscope levels.  The rods were often found aggregated by their polar ends to form 'stars’.  The coccoid forms were found to be either capsulated or non-capsulated.  The coccoid and rod cells when allowed to grow separately in fresh nutrient medium were shown to undergo interconversion.  The lectin binding kinetics of both the types of cells were studied.  The nodulation capacity of these two types against soybean were carried out. -- Gas chromatographic analyses of EPS and LPS fractions of the bacteria grown in yeast extract mannitol medium did not reveal any detectable quantity of lectin specific receptors (galactose or N-acetylgalactosamine).  However, when the bacteria were grown in soil extract medium, galactose, a soybean lectin specific sugar, was found to be one of the components in both EPS and LPS.  This induction of galactose synthesis was accompanied by increases in cell size, percentage of coccoid forms and in the amount of lectin bound to the bacterial cells.  These results indicate that more lectin binding receptors can be induced in rhizobia grown in soil extract medium. -- The study leads to the following conclusions:  (1) the lectin binding sites are located in the capsular extracellular polysaccharide (primary lectin binding site) and in the lipopolysaccharide of the outer cell wall envelope (secondary binding site) of the bacteria; (2) there are distinct rods and coccoid forms of bacteria in the broth culture reflecting the different phases of growth; and (3) that the lectin receptor sites are induced in Rhizobium when culture conditions simulate the natural environment (soil) of the bacteria.


identifier: Baggs, Eric M. <https://research.library.mun.ca/view/creator_az/Baggs=3AEric_M=2E=3A=3A.html>   (1988) Selected aspects of the life history of Salvelinus fontinalis (Mitchill) in Big Northern Pond, an acid headwater pond of the Topsail-Manuels watershed, Avalon Peninsula, Newfoundland, Canada.  Masters thesis, Memorial University of Newfoundland.

abstract: A five-year ecological investigation into the life history of Salvelinus fontinalis (Mitchill) was undertaken to evaluate its growth in an acidic, dystrophic, headwater habitat and to determine the seasonal aspects of  feeding,  reproduction and parasitism. -- Young of the year fish were found to hatch and grow in water with a stream pH of 4.7 and were subject to parasitism at the onset of exogenous feeding.  The growth of these fish was rapid but subject to a great deal of variation due to environmental conditions and initial times of egg deposition.  Condition factors of this age group were extremely low. -- Fish of age greater than zero were found to be robust, having very high condition factors (greater than 1.00).  The condition was variable with season, peaking during July of most years but displaying two low periods associated with fall and spring water temperature changes. -- The changes in condition were attributed to change in food supply and physiological demands.  Analysis of parasites revealed only four enteric helminth species which were cyclical in nature, responding to seasonal changes in temperature and intermediate host densities.  Metechinorhynchus lateralis, an acanthocephalan, was the only parasite maintained at high numbers throughout the year.  This parasite was also the only one which showed increases in prevalence with increase in fish age.  Routes of infection for M. lateralis were established.  Parasite burden was not found to be associated with condition factor. -- Growth of older fish was comparable to that of fish downstream in the watershed and either habitats which have higher pH values. -- The diets of young of the year fish and that of older fish were similar with the exception of fish eggs which were found only in the stomachs of older fish.  These fish utilized all available aquatic insects, molluscs, and crustaceans as well as any available terrestrial food sources.  There were no cases of empty stomachs in older fish.  Exogenous feeding usually began in May for young of the year fish.  They showed a preference for chironomids, coleopterans, trichopterans and ceratopogonids whereas the older fish showed the highest preference for the Odonata, prey size corresponding with an increase in fish age (thus size).  Feeding was affected by season and prevalence for some food items and modified by prey availability.  The abundance of some food items was correlated with increases in parasitism. -- S. fontinalis was the sole user of the only fluvial habitat available for spawning but was also seen utilizing redds in the pond environment.  The initiation of spawning was earlier in the fluvial environment.


identifier: Appadoo, Chandani <https://research.library.mun.ca/view/creator_az/Appadoo=3AChandani=3A=3A.html>   (1997) Some aspects of the biogeography and ecology of intertidal and shallow subtidal marine gammaridean amphipods of Mauritius (Indian Ocean).  Masters thesis, Memorial University of Newfoundland.

abstract: Sixty-nine species of marine gammaridean amphipods were reported from 34 sites (486 samples with 34,441 specimens) of varying exposure in the intertidal/shallow-subtidal zones  of Mauritius (19° 59' E-20°32' E; 57°18' S-57°47' S, Indian Ocean) in April-July, 1995. Two sites, Souillac, a wave exposed site on the south coast, and Trou aux Biches, a sheltered site on the north-west coast were sampled most intensively. -- Sand, coral rubble, debris, seagrass and algal substrates were sampled both qualitatively and quantitatively (10 cm x 10 cm quadrat). The occurrence and abundance of amphipods on algal substrates were studied in detail. -- Forty-one of the 69 species are new records for the island and 19 of these are undescribed. One hundred and thirty species are now known from Mauritius and of these 32% appear to be endemic. Many Mauritian amphipod species are widely distributed in the Indo-Pacific. About 50% of the amphipod species are shared with Madagascar (the closest large land mass). -- Amphipod species showed varying patterns of occurrence on sand, seagrass, coral rubble and algal substrates with some being specialists and others generalists. The frequency of occurrence of 35 amphipod species on 17 algal taxa showed that some species occurred on only a few, while others were more ubiquitous. Mean abundance of individuals per 10 cm x 10 cm quadrat was significantly different for 7 of the amphipod species on 12 algal taxa analysed at Souillac. At Souillac, only the mean number of individuals per quadrat for Hyale grandicornis was  significantly different among algal morphological categories  with the highest mean number occurring on foliose forms. Only mean numbers of individuals of Hyale grandicornis and Mallacoota subcarinata were significantly different among algal toughness categories. -- The amphipod assemblages on algal substrates were compared in terms of total abundance and species diversity. The amphipod community on Ulva lactuca at an exposed and sheltered site were not significantly different in total numbers; species richness, however, was higher at the exposed location. Cluster analysis showed that exposed sites have different amphipod assemblages than protected/moderately exposed sites.


identifier: Graham, Jeri L. <https://research.library.mun.ca/view/creator_az/Graham=3AJeri_L=2E=3A=3A.html>   (1992) Spatial distribution of female Tabanidae and Simuliidae (Diptera) among different terrestrial habitats in central Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The spatial distribution of female Tabanidae and Simuliidae among terrestrial habitats was investigated during June-July of 1988 and 1989 in central Newfoundland. Tabanid collections from modified Manitoba and Box traps consisted predominantly of Chrysops species (>93%) with a much lower proportion of Hybomitra species. The four most common species in both years were C. excitans, C. frigidus, C. furcatus and C. zinzalus. In blackfly collections, sampled using dry-ice-baited sticky traps or a combination of landing counts and sweep netting, there was a predominance (>95%) of Eusimulium euryadminiculum, an ornithophilic species; Simulium venustum/verecundum complex and Prosimulium mixtum were also present. -- Tabanids were collected from five different habitat types: black spruce forest, fen, bog, regrowth and dirt road. Tabanid abundance was generally lowest on the bog and road, in 1988, and lowest on the regrowth and road in 1989. In both years, tabanids were most abundant in the fen. Factors affecting spatial distribution, including distance from larval habitat, dispersal ability of adults and presence of nectar sources or hosts in a habitat are discussed, as well as the effect of trapping methods on relative abundance and species  composition. -- Of the four most common tabanid species, C. excitans and C. furcatus appeared to locate the traps more efficiently in open habitats while C. frigidus and C. zinzalus were trapped most often in a wooded habitat. Clearing of forested land during clear-cut logging operations will likely cause a shift in species composition from the preferentially sylvan species to those preferring open habitats. -- Blackflies were collected from three different habitats: fen, woods and regrowth area. These collections support the idea of habitat preferences for some  species of biting flies, since blackflies, almost exclusively Eusimulium euryadminiculum, were trapped primarily in the fen and rarely in the woods.


identifier: Hudak, Kathi A. <https://research.library.mun.ca/view/creator_az/Hudak=3AKathi_A=2E=3A=3A.html>   (1990) The development of xylem within the tomato and its influence on the movement of water and calcium into the fruit.  Masters thesis, Memorial University of Newfoundland.

abstract: Functional associations of xylem vascularization, calcium transport, and water flux were studied in Lycopersicon esculentum Mill. "Tiny Tim". Xylem formation of the pedicel and fruit was traced from the emergence of the floral primordia through to the development of mature fruit. Berberine hemi-sulphate, an apoplastically mobile dye, was used to follow water movements through the xylem systems of intact stems and trusses. ⁴⁵Ca was used to identify areas of calcium localization within the plant and correlated with transpiration rates measured for the selected plant parts. -- Water flow and calcium distribution in the plant were not uniform and the pattern was dependent on the extent of xylem vascularization. Leaves, sepals, and the smallest immature fruit (<30 mm³), which were all well supplied with xylem, showed the greatest accumulations of calcium. Fruit in this class also showed the highest transpiration rates. In contrast, calcium concentration was lowest in mature fruit, which also had the lowest proportion of xylem vascularization and lowest transpiration rates. -- These findings bear on the mechanism of induction of blossom end rot, a phytopathological condition regarded as a calcium-deficiency disease of tomatoes. The suggestion that the deficiency might first occur in very small fruit as a result  of their early, rapid increase in volume is not supported by  the present data which demonstrate that such fruit, due to high water flux and transpiration rate, accumulate large amounts of calcium. The distal portion of larger fruit may become calcium deficient because apoplastic water does not reach the far blossom end of these fruit.


identifier: Pittman, Robert Charles <https://research.library.mun.ca/view/creator_az/Pittman=3ARobert_Charles=3A=3A.html>   (1974) The ecology of some tidepools of the Avalon Peninsula, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The relationships between plants, animals and physical factors of the tidepool environment were examined.  Seasonal  and diurnal observations were made in six tidepools, three of which were located on an extremely exposed coast and three on a moderately exposed coast. -- Pools located on moderately exposed coasts were subject to less extreme wave exposure.  The decrease in wave exposure was positively correlated with the number of species found in pools.  However, larger numbers of fewer species were often found in pools on highly exposed coasts. -- Elevation of pools above sea level was also correlated with a reduction in the number of species and stratification in pools.  Temperature, salinity and oxygen stratification were frequently found in pools of high elevation. -- Variations in tidepool physical factors were found.  Over a 12 hour period the tidal cycle caused variations in temperature pH and Oxygen content of the pool water. -- Faunal and floral species were subject to extreme pool conditions resulting in seasonal and daily fluctuations in number or coverage in a tidepool.  Plants of spring flora and animals whose population increased due to breeding cycles were observed in the tidepools. -- Biomass of tidepools was found to be highest in pools of the mid-littoral.  Thus, pools which can provide moderated conditions of exposure and submergence are most likely to produce greatest biomass.


identifier: Pinsent, David L. <https://research.library.mun.ca/view/creator_az/Pinsent=3ADavid_L=2E=3A=3A.html>   (1995) Hatch date and 0-group growth rate comparisons for cod (Gadus morhua) in Newfoundland waters: support for the match hypothesis.  Masters thesis, Memorial University of Newfoundland.

abstract: Lapillus otoliths of 0-group cod (Gadus morhua) were used to determine the day of hatching and length at age of individuals collected along the northeast coast of Newfoundland and on the southern Grand Bank in 1989 and 1991.  Spatial pattern in the distribution of hatch dates was examined for latitudinal trends analogous to those of the spawning times in the area.  Length at age analysis allowed the identification of specific areas and times where 0-group growth was greatest. -- Geographic distribution of cod hatching dates is neither consistently synchronous nor sequential in Newfoundland waters.  A homogeneous pattern of hatch date distributions existed from the northeast coast of Newfoundland to southern Grand Bank in 1989, a year with average spring and summer water temperatures.  In contrast, hatching dates during 1991, a year with below average spring and summer temperatures, exhibited a latitudinal progression from south to north.  Hatching in the early part of a site-specific distribution resulted in first-feeding-larvae emerging at the onset of Calanus peak abundance.  These larvae were characterized by a prolonged period of relatively slow growth.  Those which began feeding later maintained rapid instantaneous growth for a short period.  The result was that slower-growing, early larvae were actually larger than faster growing, later feeding larvae, by the end of their first year.  Consequently, those that hatch early achieve a larger size at the end of one year.


identifier: Bartlett, Francis M. <https://research.library.mun.ca/view/creator_az/Bartlett=3AFrancis_M=2E=3A=3A.html>   (1987) Heat-stable extracellular proteases of psychrotrophic pseudomonads : purification and physicochemical properties.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: There is a trend in the dairy industry towards the storage of bulk raw milk at refrigerated temperatures for attended periods of time before processing. This practice has the disadvantage of providing conditions favourable for the growth of psychrotrophic (cold-tolerant) microorganisms. Most raw milk psychrotrophs are heat sensitive Gram-negative  bacteria, many of which produce heat-resistant extracellular  proteaes. The heat-stability of these enzymes enables them to retain some activity in milk following conventional pasteurization, as well as ultra high temperature (UHT)  pasteurization. The heat-resistant proteases have been implicated in such defects as the development of off-flavours, gelation and clearing of milk, and reductions in cheese yields. -- The heat-stable extracellular proteases of  six psychrotrophic pseudomonads isolated from raw milk were purified to homogeneity by affinity chromatography using CBZ-DL-phenylalanine TETA Sepharose-4B. The yields of purified enzymes were 38 to 59% before concentration by ultrafiltration. The molecular weights, which were determined by gel-filtration, were 38 to 40kD, and the proteins had isoelectric points (pI) from 5.7 to 6.2. The optimum pH for proteolytic activity was between 7 and 8, while the optimum temperature ranged from 30 to 40°C. A dramatic loss of activity was noted for each protease at 45°C. -- Each of the proteases were metalloproteases as indicated by their sensitivity to the metal chelating agent EDTA. Restoration of activity to EDTA-treatcd proteases was achieved by the addition of Mg, Mn or Ca ions. The predominant metal ion present in the three proteases examined was Ca (5-8 g-atoms/mole) followed by Mg and Zn, with trace amouts of Mn. The amino acid content of each of the proteases were similar, with high numbers of aspartic acid, serine, glycine, and alanine residues. The N-terminal amino acid determined for three of the proteases was found to be threonine. The T16 protease contained two aminosugars,  glucosamine and galactosamine, and was classified as a glycoprotein. -- Five of the six proteases exhibited a preference for α-casein as a protein substrate, while T16 showed greatest activity towards κ-casein. None of the proteases was able to break down the whey proteins, α-lactalbumin, or β-lactoglobulin. Collagenase and elastase activities were noted for each protease. The T16 protease was quite stable, with a D-value at 150°C of 2.2 min. The presence of Ca or Mg ions stabilized the T16 protease against inactivation at 90°C for 10 min while lactose had no  effect. The secondary structure of the T16 protease consisted of "random coil" (67%) and β-structure(33%) with no α-helix. Upon heating from 45 to 55°C the secondary structure-tended to become more random. -- All of the proteases cross-reacted with the anti-serum to the T16 protease, including the protease of psychrotrophic pseudomonads from Ontario, British Columbia, Ireland, U.S.A., Australia and the Neterlands. An enzyme-linked immunosorbent assay (ELISA) was developed using anti-Tl6 IgG, which was sensitive to a minimum concentration of 720 μg/ml of purified T16 protease. The mole % G+C content of the DNA psychrotrophic pseudomonads from different geographical regions were similar (58 to 62%) with the exception of 015 (44%).


identifier: Villagarcia, Maria Guadalupe Del Mar <https://research.library.mun.ca/view/creator_az/Villagarcia=3AMaria_Guadalupe_Del_Mar=3A=3A.html>   (1995) Structure and distribution of demersal fish assemblages on the northeast Newfoundland and Labrador Shelf.  Masters thesis, Memorial University of Newfoundland.

abstract: Multivariate analysis of 14 years of scientific survey data has distinguished four groundfish assemblage areas on the Northeast Newfoundland and Labrador Shelf. The assemblages were characterized by an homogeneous faunal composition, and relative abundance and persistence over time. From 1978 to 1986, their spatial distribution was maintained within certain geographical boundaries which followed bottom topography and exhibit characteristic bottom temperature ranges. Starting in 1987 and coincident with a decline in the commercial fisheries, there was a shift of three of the assemblages towards the east. Further analysis revealed a decrease in biomass in all of the more abundant species as well as in some of the less abundant. Rare species were found to decrease earlier than dominant ones, perhaps acting  as indicators of major changes taking place across the continental shelf. Increasing density of certain species near the shelf/slope break has produced groupings of fish offshore of the main banks which has made them more vulnerable to the fishery. Possible causes for this behaviour, e.g. varying bottom temperature and lost of stability in the main species, are investigated. Intense exploitation of groundfish is the most likely explanation for the decline of fish biomass on the Northeast Newfoundland and Labrador Shelf. Less abundant species distribution may also be affected by discard or as by-catch of the commercial species. The homogeneous fish assemblages found could be used as the basic units to manage the shelf in a smaller scale basis from a biological perspective and to define highly sensitive areas where fish tend to aggregate that might need to be protected.


identifier: Mullins, Conrad <https://research.library.mun.ca/view/creator_az/Mullins=3AConrad=3A=3A.html>   (1995) State of sexual maturity of Atlantic salmon (Salmo salar L.) caught at sea, in commercial fisheries off Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The state of maturity of male and female Atlantic salmon harvested at sea during 1990 and 1991 at three sites in Newfoundland was investigated. Salmon landed at St. Barbe Bay, Conche and Twillingate were sampled throughout the commercial fishing season (June - August). The methods used to determine the state of maturity in male and female salmon were histological examination of gonadal development and radioimmunoassay of plasma steroid hormone levels. The gonad  stage development, gonadosomatic index (GSI), hepatosomatic index (HSI), condition factor (CF), testosterone (T), 11-ketotestosterone (11-KT), vitellogenin (Vg) and 17β-estradiol (E2) levels measured in commercially caught salmon  were compared with those of cage-reared and wild salmon of known background to verify the maturity classifications. Stages of gonad development, the levels of T, E2, 11-KT, Vg,  and GSI, HSI and CF measured in male and female salmon of known state of maturity were used to develop discriminant functions for predicting the state of maturity in commercially caught salmon. Salmon sampled in St. Barbe Bay in the Gulf of St. Lawrence were 100% spawners-of-the-year, whereas, samples from Conche and Twillingate on the northeast coast of Newfoundland consisted of salmon that would not have returned to their native rivers to spawn. Differences in biological characteristics of salmon from the  commercial fishery locations tend to support the maritime origin of the non-maturing component of commercial landings in Newfoundland. Male and female Atlantic salmon that are not spawners-of-the-year can be recognized by discriminant analysis techniques on the basis of the stage of gonad development, plasma hormone levels, and GSI.


identifier: Bridgland, James Parsons <https://research.library.mun.ca/view/creator_az/Bridgland=3AJames_Parsons=3A=3A.html>   (1987) The flora and vegetation of Cape Herschel, Ellesmere Island, N.W.T.  Masters thesis, Memorial University of Newfoundland.

abstract: Botanical explorations at Cape Herschel, a small peninsula on the relatively oceanic coast of eastern Ellesmere Island, Northwest Territories, have yielded a flora which includes 68 species of vascular plants, 121 species of mosses, and 44 species of lichens. -- Field typification of seven vegetation types was tested with cluster analysis and the seven types were divided into eleven plant communities.  Diagnostic species were identified for each community using species constancy and mean abundance in each cluster.  Environmental factors determining the distribution of plant communities at Cape Herschel were tested with direct gradient analysis and with topographic analysis. -- Floristic comparison of plant communities at Cape Herschel with those described from elsewhere in the Queen Elizabeth Islands identified 11 communities which appear to correspond directly enough to be useful for the purposes of regional vegetation mapping.  A twelfth community was identified it Cape Herschel but it was not comparable to communites described elsewhere. -- Moisture, snowcover, and substrate texture have the greatest influence, in that order, on the distribution of vegetation types at Cape Herschel.  Altitude and aspect were also found to control the distribution of vegetation. -- Cassiope heath, cottongrass and sedge meadows, and Luzula confusa steppe were the communities at Cape Herschel which were floristically most similar to communities described from other areas of the Queen Elizabeth Islands, but two barrens communities, two tundra communities, and a marsh community also show some similarity to communities described elsewhere.


identifier: Boland, J. Todd (Jeffrey Todd) <https://research.library.mun.ca/view/creator_az/Boland=3AJ=2E_Todd_=28Jeffrey_Todd=29=3A=3A.html>   (1993) The floral biology of Platanthera dilatata (Pursh) Lindl. (Orchidaceae).  Masters thesis, Memorial University of Newfoundland.

abstract: The floral ecology of Platanthera dilatata (Pursh) Lindl. in St. Phillip's, Newfoundland, was investigated during the 1990-1992 flowering seasons.  For comparison, two additional populations from eastern Newfoundland and a population from southwestern Alberta were also examined.  Pollinators were restricted to the nocturnal Noctuidae and diurnal Hesperiidae.  While pollinators were rarely observed, pollination exclusion experiments indicated that insect vectors are required for capsule set.  Percentage capsule set for the St. Phillip's site was similar in all three seasons (range = 47.7-56.0%).  Two populations from eastern Newfoundland showed similar capsule set values while the population in southwestern Alberta had significantly higher capsule set (66.8%).  Capsule set was determined to be pollinator-limited.  Microhabitats had no effect on capsule set.  P. dilatata has a number of physical characteristics which increased its opportunity for pollination.  These include an extended blooming period, sequentially-produced flowers which are long-lived, long receptivity-time for flowers and continual odour production.  The adaptations are particularly advantageous during periods of unfavourable weather and low pollinator activity.  Additionally, it was observed that some populations can have seed production dramatically reduced due to insect damage and fungal infection.


identifier: Orr, David Cameron <https://research.library.mun.ca/view/creator_az/Orr=3ADavid_Cameron=3A=3A.html>   (1990) The food and feeding habits of the white Indian prawn, Penaeus (Fenneropenaeus) Indicus H. Milne Edwards, 1837.  Masters thesis, Memorial University of Newfoundland.

abstract: There is disagreement within the literature as to whether Penaeus indicus feeds selectively.  Few studies deal with the dietary importance of the various items that this prawn ingests.  A comprehensive study of the potential food items was made then electivity indices and indices of relative importance were estimated.  The indices indicate that P. indicus become more carnivorous as they grow and that members of the family Nereidae (Polychaeta) and Mesopodopsis orientalis (Crustacea: Mysidacea) were selected.  In terms of ingested volume and frequency of occurrence, detritus was the most important food item.  Examination of faecal pellets indicated that diatom frustules, long strands of Oscillatoria spp., woody plant tissue and harpacticold copepod exoskeletons were difficult to digest.  Plant matter and micro-crustaceans may therefore be of limited nutritional value to P. indicus.


identifier: Hawryluk, Mark Douglas <https://research.library.mun.ca/view/creator_az/Hawryluk=3AMark_Douglas=3A=3A.html>   (1995) The effects of grazing by littorinid gastropods on the structure of algal communities in Newfoundland tidepools.  Masters thesis, Memorial University of Newfoundland.

abstract: Grazing by the littorinid gastropods, Littorina littorea and L. saxatilis, significantly affected the structure of algal communities in 10 intertidal pools on the Avalon Peninsula of insular Newfoundland.  Pools were sampled approximately monthly between February and November of 1987.  Diversity of the algal communities was highest at intermediate levels of grazing and lowest when a given species of algae formed a monoculture in the absence of grazing.  Diversity was also low in pools with very large grazer populations which overgrazed the macrophytes.  The diversity was relatively stable in moderately and heavily grazed pools but fluctuated widely in lightly grazed pools. -- The greatest effect that the grazers had on the algae was to increase the amount of bare substrate and calcareous algae by removing the filamentous and blade-forming algae.  Littorina littorea and Littorina saxatilis prevented blade-forming algae from establishing by grazing settling propagules but only L. littorea was able to significantly reduce the abundance of the adult thallus of filamentous algae which settled before the grazers became active in the spring. -- The population of L. saxatilis increased to a peak in mid summer as individuals moved from nearby upper intertidal emergent substrata and offspring were produced in the pools.  Large populations of L. littorea in two of the pools declined during the course of the study.  The cause of this decline is not known.


identifier: Reynolds, John Jeffrey <https://research.library.mun.ca/view/creator_az/Reynolds=3AJohn_Jeffrey=3A=3A.html>   (1997) Population ecology, home range size, and caching behavoiur of red squirrels (Tamiasciurus Hudsonicus) in Terra Nova National Park, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The population ecology, home range size, and caching behaviour of red squirrels was studied in black spruce habitat in Terra Nova National Park, Newfoundland.  Density was almost twice as high during summer 1995 (a year of heavy cone crop) than in 1994, but densities in both years were similar to those reported in other studies.  Densities ranged from 0.4 - 1.3 squirrels /ha in 1994 and 1.0 - 2.7 /ha and 0.8 - 3.7 /ha on grids 95-1 and 95-2 respectively in 1995.  Transients (animals captured only once) were a minor component of the population in both years.  The larger number of spring recruits and higher summer body weight in 1995 indicate that the greater density was due to higher overwinter survival during 1994/1995.  Total adult sex ratios (based on all animals captured) were significantly biased in favour of males in 1994 and for the combined adults in 1995. -- Summer home range size in 1995 ranged from 0.34 - 4.1 ha (95-1) and 1.8-2.4 ha (95-2) using the minimum convex polygon method and from 0.34 - 4.8 ha (95-1) and 4.3 - 8.0 ha (95-2) using the adaptive kernal method.  These values are generally larger than home range and territory sizes reported in other studies.  The presence of deciduous food and the breeding season, may have contributed to the larger home range size.  Home ranges were not exclusive and all showed signs of overlap. -- North American red squirrels exhibit variation in caching behaviour across their range.  Larderhoarding dominates in the west and scatterhoarding dominates in the east.  One proposed explanation for this variation is predation risk.  If safe feeding and caching sites are unavailable, then moving to, and eating at scattered caches may elevate the risk of predation for the caching individual.  It was predicted that in areas of low understory shrub cover, predation risk is higher and safe caching sites are rare.  Therefore, creating larger caches at one or a few low-risk sites would be the better strategy. -- The caching behaviour of red squirrels was documented in 1995 in grids 95-1 (high cover) and 95-2 (low cover).  In both grids, both single cone and large caches (11+ cones) occurred more frequently than expected, but cache size frequency distributions did not differ significantly between grids.  The mean (± SE) number of cones in large caches (30.9 ± 2.5) was significantly greater in low cover than in high cover (18.3 ± 2.6).  Large caches accounted for 65% and 20% of all cones stored in the low and high cover grids respectively.  The size of the cache (single or multiple cones) was not dependent on the distance from the nearest tree in low cover, but in high cover, single cone caches were found farther from a tree (mean ± SD: 1.5 m ± 1.3) than multiple cone caches (1.0 m ± 0.67).  It appears that the amount of cover may be one component of red squirrel caching behaviour.


identifier: Copeman, Douglas Gordon <https://research.library.mun.ca/view/creator_az/Copeman=3ADouglas_Gordon=3A=3A.html>   (1973) Population diversity in the rainbow smelt, Osmerus Eperlanus Mordax (Mitchill, 1814) (Salmonoidea: Osmeridae) as revealed by canonical and discriminant function analyses on morphometric, meristic and esterase data.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The rainbow smelt, Osmerus eperlanus mordax was first described by Mitchill in 1814.  It can live entirely in a freshwater or marine environment.  Freshwater smelt may spawn in streams, on beaches or in relatively deep water (Rupp, 1959; Delisle, 1969).   Marine smelt are usually anadromous although they may spawn on the bottoms of quiet brackish bays.  There has been considerable debate as to whether or not two forms exist, one large and the other small. -- There is a great deal of evidence indicating that the smelt exists in rather isolated populations.  Therefore, they could be expected to be subjected to different sets of selective factors.  These, presumably, would exhibit their different effects by modifications in the characteristics of the populations.  Conversely, if populations of smelt from different areas are found to be different, then the populations' proposed attributes (isolation and different selective pressures) are substantiated. -- Thirteen smelt populations were sampled during their spawning runs.  Morphometric, meristic and biochemical data were recorded for each population.  These data were analysed separately and together to obtain a measure of the degree of difference between the populations.  Appropriate statistical methods were employed throughout the study. -- It was found that there were differences between the samples on the basis of any type of data and that the differences were real.  Individuals could be identified as to population of origin with an average accuracy of 93.4 per cent.  The differences between small and normal forms were very large and the marine and freshwater smelt were also distinct.  There were also indications that smelt populations vary, not only from place to place but from year to year.  Classifications derived from the data indicated that environmental factors may be important in accounting for the observed differences between populations.  A considerable amount of redundancy was observed in the data. -- The work forms a comprehensive model for the investigation and identification of populations of a species.  Methods are proposed for handling data for which the standard analyses of population genetics are not applicable.


identifier: Murphy, Francis Edmund <https://research.library.mun.ca/view/creator_az/Murphy=3AFrancis_Edmund=3A=3A.html>   (1974) Quantitative aspects of the food of Littorina Littorea (Linnaeus).  Masters thesis, Memorial University of Newfoundland.

abstract: Two series of feeding experiments were carried out on Littorina littorea, each using three groups of 33 snails.  At Bonne Bay, each group was fed one of Ascophyllum nodosum, Fucus vesiculosus, and Lami'naria longicruris.  Algae used at Logy Bay were the same, except that the third was Laminaria digitata.  Controls were of two kinds.  An initial group of 33 was measured and weighed, then killed to obtain dry weights, caloric content and ash content.  The second control was a group of 100 marked snails, weighed and measured, then released upon the shore.  At the end of six weeks, 15 of these were recovered alive.  Data and discussion are provided for the 13 identifiable snails. -- The experimental animals were marked, weighed and measured.  During six weeks, record was kept of the amount of food ingested and the amount of feces produced.  At the end of the experiment, animals were again measured and weighed; they were then killed to obtain dry weights, caloric content and ash content. -- The results generally show a decrease in all measurements.  Shell length remained unchanged in four groups, increased slightly (but significantly) in two.  Wet weights decreased in four groups, significantly in one, and increased in two groups, significantly in one.  'Dry weight decreased in all groups, significantly in two.  Highly significant decreases in caloric content occurred in all six groups.  With other factors considered, the Bonne Bay Laminaria group showed a gain in caloric content.  Factors causing this gain are discussed. -- Lack of growth is considered to be due to conditions of captivity, natural periods of decrease in growth, and especially to the probable unsuitability of the algae used as food.


identifier: Bradbury, Helen Elizabeth <https://research.library.mun.ca/view/creator_az/Bradbury=3AHelen_Elizabeth=3A=3A.html>   (1970) Observations on the functional anatomy of the Ommastrephid, Illex Illecebrosus (Leseur, 1821) (Coleoidea: Cephalopoda), with emphasis on musculature and the blood vascular systemQuantitative aspects of the food of Littorina Littorea (Linnaeus).  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The ommastrephid Illex illecebrosus, has escaped analysis by anatomists for the almost 150 years since its first description by Lesueur in 1821.  During the mid-1880's, A. E. Verrill, in his studies on Northeastern Atlantic cephalopods, gave excellent descriptions, with detailed illustrations of this particular oegopsid.  Also incorporated in Verrill’s descriptions are recorded observations on certain behavioural aspects such as the feeding and colour changes of this squid.  It was for Leonard Williams (1909) to give zoologists an accurate and detailed study of the anatomy of a decapod cephalopod, the species being Loligo pealei Lesueur.  This work has since become the standard source of squid anatomy, particularly in North America.  Too often, however, squid structure and function is interpreted on basis of knowledge of octopods or sepioids, whether it applies or not. -- Wherever possible, this thesis departs in large measure from previous squid anatomical studies in that it incorporates functional aspects of the anatomy with gross and microscopic structural features of selected organs and organ systems of lllex illecebrosus. -- The musculature of the mantle complex, the hyponomal complex and the brachial cone complex are elucidated and described from a functional viewpoint.  Greatest effort was made in the use of a variety of techniques to trace the blood vascular system and observe its several parts in vivo.  The system, really a double system, is closed and blood always passes through endothelial lined vessels.  Consideration was also given to the cartilaginous and structural skeletal features of the squid, as well as gross, microscopic and in vivo anatomical studies of the alimentary canal and its associated organs.  These morphological investigations are enhanced by related behavioural investigations conducted primarily on locomotion and feeding. -- The results of these studies are the basis of discussion on the molluscan structural nature of the squid, its divergence from the basic ancestral molluscan body plan, and subsequent evolution into a pelagic oceanic niche.


identifier: Williams-Ryan, Kathryn Anne <https://research.library.mun.ca/view/creator_az/Williams-Ryan=3AKathryn_Anne=3A=3A.html>   (1997) Occurrence, histopathology and fine structural studies on Hematodinium sp. (Dinoflagellida: Syndinidae) parisitizing the snow crab (Chionoecetes opilio).  Masters thesis, Memorial University of Newfoundland.

abstract: Snow crabs exhibiting macroscopic evidence of Hematodinium sp. infection were collected off the east coast of Newfoundland during the period 1993 to 1996.  Infected crabs were collected over a large area but prevalence of infection was low.  Pathology of the internal organs in affected crabs was observed in association with the developmental stages of Hematodinium sp.  The parasite invaded hemal spaces causing disruption of normal tissue morphology, and ultimately mortality of the host.  Hematodinium sp. developed through three distinct morphological stages during the progress of infection: vegetative, multinucleate prespore and dinospore.  The latter is the final stage within the crab.  These stages of the parasite developed synchronously and sequentially within any one crab, but might differ between individual crabs.  The ultrastructure of these stages was examined using electron microscopy, which revealed the following characteristics in all developmental stages: the presence of many trichocysts, mitochondria with tubular cristae and vacuoles with lipid-like material.  In the dinospore stage, flageila and micropores were observed in addition to the other common features.  The morphological characteristics of Hematodinium sp. described in this investigation conform to previous descriptions of Hematodinium spp. reported from a variety of crabs inhabiting different geographic regions.


identifier: Urban, Juanita <https://research.library.mun.ca/view/creator_az/Urban=3AJuanita=3A=3A.html>   (1992) Seasonal changes in the chemical and physical characteristics of Calanus finmarchicus and Oikopleura vanhoeffeni fecal pellets.  Masters thesis, Memorial University of Newfoundland.

abstract: Fecal pellets from Oikopleura vanhoeffeni and Calanus finmarchicus were analyzed in the spring, summer, fall and winter to determine if there were changes in their physical (size, phytoplankton content & density) or chemical (particulate organic carbon & particulate silicate) characteristics. Changes in phytoplankton content due to seasonal succession were observed in both feces types which resulted from a change from a diatom based food chain in the spring to one based on the microbial loop in the fall. Changing phytoplankton content also resulted in seasonal changes in the dynamic density of the fecal pellets, due to the differential compactness of the component particles. Changes in the dynamic density resulted in changes in the potential of both fecal pellet types to exit the upper mixed layer and contribute to vertical nutrient and particle flux.  -- Current literature equations used for predicting the settling velocity of fecal pellets gave correct trends for my data but overestimated the actual rates by 2-100 times. Empirical settling velocity equations were developed for the  two fecal types based on their physical characteristics. The  resulting equations for both C. finmarchicus and 0. vanhoeffeni were modified Stokes equations. For O. vanhoeffeni, the settling velocity (Ws) can be expressed as:  -- [special characters omitted] -- and for C. finmarchicus as: -- [special characters omitted] -- where μ is the viscosity of the water, ps is the density of the fecal pellet, p is the density of the water, g is gravity (981 cm s⁻¹, Dn is the diameter of an equivalent sphere, and L and D  are the length and diameter of the fecal pellet. Using these  equations, seasonal settling velocities were calculated for the copepod fecal pellets. Fall C. finmarchicus fecal pellets had the fastest settling velocities (25-95 m day⁻¹), indicating that these feces have a greater potential in contributing to the nutrient flux than do spring feces (7-35 m day⁻¹). The higher measured sinking velocities for 0. vanhoeffeni fecal pellets suggests that they are more likely  to leave the upper mixed layer and contribute to the nutrient flux than are copepod feces. -- The decay rate for C. finmarchicus fecal pellets was the same in the spring, summer and fall in the field, suggesting that the seasonally dependent nutrient flux due to fecal pellets is determined not by how fast they decay, but by their ability to leave the upper mixed layer. Decaying and fragmenting fecal pellets release dissolved free amino acids (DFAA) into the surrounding water. Changes in the physical characteristics of the fecal pellets resulted in the fall C. finmarchicus fecal pellets and the winter O. vanhoeffeni fecal pellets having the greatest potential to leave the upper mixed layer. This implies that, seasonally, the microbial loop can  contribute to the nutrient and particle flux through copopod  and tunicate feces.


identifier: Mungkaje, Augustine Japeieni <https://research.library.mun.ca/view/creator_az/Mungkaje=3AAugustine_Japeieni=3A=3A.html>   (1995) Seasonal patterns of diversity in marine fish communities.  Masters thesis, Memorial University of Newfoundland.

abstract: This study used exploratory analysis to discover and describe seasonal patterns of diversity in marine fish communities.  Many small-scale studies have shown that seasonal patterns of diversity do exist in fish communities; there have been no comparisions to investigate large-scale patterns. -- The specific objectives of this comparative study were to: (i) use published data sets to discover seasonal patterns of diversity in marine fish communities; (ii) describe these seasonal patterns; (iii) separate general seasonal patterns from specific ones; (iv) develop further testable hypotheses about the possible causes and mechanisms of these patterns of diversity; and (v) discuss these seasonal patterns and any relationships among richness, heterogeneity and equitability components of diversity in order to enable researchers in applied fields such as fisheries management and marine pollution, where diversity statistics are often used, to design and execute more sensitive tests. -- Published fish catch data sets were compiled and analysed for seasonal patterns in the diversity indices S, H’ and E which measure richness, heterogeneity and equitability, respectively.  Three principal patterns were observed. -- A broad geographical pattern was that two major seasonal peaks in the three indices occurred in fish communities from higher latitudes (> 41°10'N) while two to three such peaks were frequent at lower latitudes (≤ 41°10’N) in the North American East Coast.  The time of occurrence of the first peaks in H’ and E showed a latitudinal trend in this region; the first peaks in H' and E occurred earlier at lower latitudes than at higher latitudes. -- Two major patterns of seasonal tracking in S, H’ and K observed were an 'in-phase’ (peaks in species number coincide with peaks in H' and E) and an ‘out-of-phase' pattern (peaks do not coincide).  The ‘in-phase' pattern was more prevalent than the ‘out-of-phase' pattern, which typically results from the influx of large numbers of one or two species.  An additional pattern observed was that the means of S and H' within studies were higher in data sets with more species while that of E was higher in those with fewer species. -- Autocorrelation analysis of the temporal resolution of the peaks in the seasonal patterns showed that for all data sets that had ‘smooth correlograms’, the time interval between peaks was longer (≥ five months) at latitudes ≥ 33°37'N than at latitudes < 33°37'N. -- Two hypotheses were formulated from these results: (i) “Plankton and Fish Phenology hypothesis; and (ii) Instability-Dominance hypothesis.  The potential application of these patterns and hypotheses in fisheries management and marine pollution monitoring are discussed.


identifier: Cuthbert, Fiona M. <https://research.library.mun.ca/view/creator_az/Cuthbert=3AFiona_M=2E=3A=3A.html>   (1990) Selected aspects of the ecology of nematodes in Butterpot Provincial Park, Avalon Peninsula, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: A total of 46 nematode taxa, from seven orders and 21 families, were collected from three habitats (a black spruce-moss forest, a Dryopteris-white birch forest, and a dry Kalmia heath-barren) in Butterpot Provincial Park, Avalon Peninsula, Newfoundland.  These nematodes represent four feeding groups:  microbial feeders, plant feeders, omnivores and predators.  The vertical distribution, abundance, and seasonal dynamics of the four feeding groups, as well as selected species, are discussed. -- Principal Components and Multiple Regression analyses revealed two environmental factors which correlate positively with increasing nematode numbers.  Soil productivity (inferred from PC1) may have been the main factor governing nematode abundance in this study.  The second Principal Component is a function of soil particle size and soil temperature. -- The habitat rankings in terms of total nematode abundance were:  Dryopteris-white birch forest > black spruce-moss forest > Kalmia heath barren Dryopteris].  The most abundant nematode populations, in all feeding groups, were in the topmost soil layer of all sites, although plant feeding nematodes comprised a larger percentage of the total nematode fauna in the lower soil layers.  Within the topmost soil layer, nematode numbers from all feeding groups peaked in late spring/early summer and again in autumn. -- Five distinct nematode assemblages within the three habitats were identified, by Cluster Analysis.  Composition of the nematode fauna from the Kalmia heath-barren was clearly distinct from that found in the two forest habitats.  These latter habitats were similar in overall nematode species composition, but different soil layers within these habitats appeared to have different nematode assemblages.  Discriminant Functions Analysis gave clear evidence that the five nematode species assemblages had an ecological basis.


identifier: Lewis, D. J. (David James) <https://research.library.mun.ca/view/creator_az/Lewis=3AD=2E_J=2E_=28David_James=29=3A=3A.html>   (1973) The Simuliidae of insular Newfoundland and their dynamics in small streams on the Avalon Peninsula.  Masters thesis, Memorial University of Newfoundland.

abstract: Three genera and twenty-one species of simuliids are recorded from Newfoundland, viz., three species of Prosimulium, two of Cnephia, and sixteen of Simulium.  S. croxtoni, S. excisum, and S. gouldingi are new records for Newfoundland.  A key to the simuliids of insular Newfoundland is provided for the mature larvae, pupae, males, and females. -- Sampling of 212 streams across Newfoundland indicated that species of Prosimulium and Cnephia overwinter as larvae, and species of Simulium overwinter as eggs.  P. fuscum, P. mixtum, and S. venustum were the most abundant mammalophilic species, while S. latipes was the most abundant ornithophilic species. -- Nine species of simuliids were found in the complex of streams in Pickavance Creek and its six tributaries.  Pickavance Creek is a small, shallow, permanent stream about 16 km west of St. John's. -- Sampling in the Pickavance Creek area was accomplished using 10 x 10 x 0.8 cm ceramic tiles.  These facilitated collecting of specimens and were of convenient area for population density studies. -- The effects of the following factors on simuliid larval and pupal populations have been investigated:  rate of flow, temperature, depth, substrate, light, shade, drift, water chemistry, parasites and predators. -- The seasonal succession of simuliids in Newfoundland is similar to that in other regions of North America, but it occurs later in the year in Newfoundland.  The number of generations of multivoltine species of simuliids is usually less in Newfoundland due to the short summer.  Apart from these two differences, the habits and biology of Newfoundland simuliids are similar to those of other areas on the continent, and the insular habitat apparently does not affect the ecology and bionomics of these blackflies.


identifier: O'Connell, M. F. (Michael Francis) <https://research.library.mun.ca/view/creator_az/O=27Connell=3AM=2E_F=2E_=28Michael_Francis=29=3A=3A.html>   (1982) The biology of anadromous Salvelinus fontinalis (Mitchill, 1815) and Salmo trutta Linnaeus, 1758 in river systems flowing into Placentia Bay and St. Mary's Bay, Newfoundland.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The biology of anadromous brook trout (indigenous) and brown trout (introduced) was studied for several river systems flowing into Placentia and St. Mary's Bays, Newfoundland. Outward movements of brook trout were observed from April to June; inward movements occurred in July-August. Movements between fresh and salt water in Northeast and Southeast Arms, Placentia appear to occur throughout the year. Outward  movements of brown trout occurred concurrently with brook trout (North Harbour River, S.M.B.) while inward movements were observed from July through September. Smolt age of brook trout ranged from 1.⁺ to 7.⁺ years and that of brown trout from 1.⁺ to 8.⁺ years. Modal smolt age of brook trout ranged from 2.⁺ to 4.⁺ while for brown trout it was 2.⁺ to 3.⁺. The great majority of all samples for both species were comprised of smolt/post-smolt. It is possible that specimens of brown trout with a history of sea life leave North Harbour River, S.M.B. in a discrete run prior to the one observed in April-May which was comprised almost exclusively  of smolt. There was some indication that homing occurs to Southeast River and its tributary Beaver River for brook trout. -- Growth in freshwater was slower than previously reported for the freshwater form of each species in lakes on the Avalon Peninsula. Growth in freshwater and salt water was slower than that reported for anadromous populations elsewhere in North America (brook trout) and in Europe (brown trout). The slow growth of brown trout in salt water could partially result from the relatively small portion of the yearly increment attained during the winter with temperature being the dominant determining factor. Newfoundland populations overwintering in estuarine and coastal areas likely experience temperatures of 0°C and less  compared with 5-6°C for certain European populations. There was a dramatic increase in growth rate in salt water compared with freshwater for both species; also there was a tendency towards attainment of a greater ultimate size the younger the smolt age. -- All age groups of smolt on North Harbour River, S.M.B. were significantly smaller than observed for the other areas. This appears to be the result; of overwintering in flowing water on that river as opposed to lakes for the others. Lakes afford better temperature and  feeding regimes as well as more living space. Based on the fact that the growth increment attained at the end of the growing season for parr remaining in North Harbour River, S.M.B. is similar to that of the other areas, it does not appear that the size difference in smolt has an adaptive basis but rather reflects a homeostatic compensatory response to temporal environmental conditions. -- While size  has been reported to be an important factor in smoltification and the development of salinity tolerance, it is not the only one. Smolt in the present study were substantially smaller than those reported in the literature as suffering high mortality upon direct transfer to seawater. These phenomena appear to be the result of a synergistic process involving several variables such as temperature, photoperiod, water level and living space. -- Except for some differences in percent occurrence of items in gut contents, the food of brook trout and brown trout were similar in both fresh and salt water. -- Spawning time varied with area for brook trout (first three weeks in October for North Harbour River, S.M.B, and first three weeks in November for Southeast River); no spawning concentrations of brown trout were located. Sex ratio was significantly in favor of females for brook trout in virtually all cases, no significance and no consistent trend  in favor of either sex was found for brown trout. Age at first maturity for brook trout was 2⁺ for both sexes; for brown trout it was 2⁺ for males and 3⁺ for females. The percentage of brook trout males reaching maturity in a given  age group was higher than than of females in the majority of  cases; there was no consistent trend for brown trout. For both species there was a tendency for a lower percentage of anadromous fish to reach maturity in a given age group than reported for their counterparts in freshwater. Both sexes of  brook trout appear to be alternate spawners; there was evidence for the same for female brown trout. For brook trout, parr and specimens with a sea history spawn together;  kelts of each sex showed evidence of spawning and parr. Male  brown trout can spawn as parr. -- Reproduction in anadromous  brook trout and brown trout is spread over the maximum number of years. Delay of maturity until a larger size is attained probably results in a higher reproductive effort and juvenile survival. Atlantic salmon cohabiting the same rivers are more r-selected in that the overall life span is shorter and they probably produce a higher reproductive effort. Salmon are consecutive spawners as opposed to alternate spawners. -- Brown trout introduced to Newfoundland were mainly British and were of the freshwater form. They have since become anadromous in Newfoundland waters. Growth rate in freshwater and salt water is lower than that published for British anadromous populations (as already pointed out) and age at first maturity and longevity  are greater. Alternate spawning is exhibited instead of consecutive spawning. Differences in exploitation between Newfoundland and Great Britain over the years could compound  any assumptions based on life history theory predictions. -- Since their introduction in the 1880's through early 1900's, the spread of brown trout (colonization by means of the sea) was rather slow. This could be the result of a combination of the following factors: (1) straying rate, (2) slow growth and hence low egg deposition potential, and (3) the fact that a relatively large number of specimens of both sexes may not mature after entering a river. For one of the rivers  studied, the establishment of a population of brown trout has been to the detriment of  brook trout. It is not possible in light of present data to say if resource competition in freshwater has contributed to an observed decline in numbers of anadromous brook trout concomitant with an increase in numbers of brown trout on that river. However, there is evidence to suggest that a combination of greater vulnerability to angling on the part of brook trout,  angler preference and adjustments in the length and timing of the licenced angling season have in part brought about this result.


identifier: Clark, Donald Stuart <https://research.library.mun.ca/view/creator_az/Clark=3ADonald_Stuart=3A=3A.html>   (1989) Temperature preference and activity of juvenile cod in Broad Cove, Conception Bay, Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: Field tracking studies conducted in Conception Bay, Newfoundland employing ultrasonic telemetry, determined the activity patterns of juvenile (3 year old) cod (Gadus morhua L.) on a daily and seasonal basis.  In conjunction with the tracking study, the temperature preference of juvenile cod throughout the year was determined in the laboratory, and the influence of holding temperature on temperature preference was assessed.  The results of the temperature preference studies were compared with water temperatures inhabited by juvenile cod in the field to assess the role that water temperature might play in mediating movement and activity. -- Juvenile cod exhibited seasonal variation in both temperature preference, and activity patterns.  Temperature preference was highly correlated with seasonal changes in the temperature of the inshore waters inhabited by juvenile cod, both for fish acclimated to ambient temperature water, and those maintained at 10°C overwinter.  This indicated that seasonal variation in temperature preference was initiated by factors other than changes in ambient water temperature.  However, the temperature preference of these two groups differed significantly, indicating that thermal history also influenced temperature preference. -- The tracking studies showed that during summer (May - September) juvenile cod were wide ranging, conducting a diel migration from deep cold water where they remained inactive diurnally, to shallow warm water where they actively fed nocturnally.  In autumn (September - December) these fish were diurnally active within a restricted home range in shallow water over a sandy substrate.  At night they were inactive and remained in a consistent night-resting site over a rocky substrate in close proximity to their diurnal home range. -- The summer diel migration may result in increased growth since the movement of juvenile cod into deep cool water during non-foraging hours would effect a lower metabolic rate, and hence lower maintenance costs.  In September when the water column becomes isothermal their switch to a non-migratory diel activity pattern is consistent with what would be predicted on the basis of energetic efficiency.  It is unclear what selective factors may be involved in the switch in September from nocturnal to diurnal activity.  However the most parsimonious hypothesis is that juvenile cod time their activity to reduce predation risk.


identifier: Boothroyd, Frank Albert <https://research.library.mun.ca/view/creator_az/Boothroyd=3AFrank_Albert=3A=3A.html>   (1990) The biology of lobsters (Homarus Americanus Milne-Edwards) transplanted to St. Michael's Bay, Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract: In 1982, 1983 and 1985 the Newfoundland and Labrador Department of Fisheries transplanted a total of 4484 adult lobsters (Homarus americanus) to St. Michael's Bay, Labrador with the intention of creating a self-propagating population.  Studies done during the summers of 1986 to 1988 were designed to assess whether or not the population is propagating and were concentrated on the lobsters of the 1982 and 1985 transplants. -- The 1985 transplants had few molting events to 1987, and no spawning events to 1988.  The stress associated with the transplant caused the paucity of molting and the lack of spawning observed in 1986.  Low water temperature is thought responsible for prolonging the effects of the initial stresses.  The 1982 transplants were undergoing more molting events than expected.  Possible reasons for this are suggested.  The percentage of females that were potentially ovigerous was high, but the percentage of ovigerous lobsters was low; of the latter, the fecundities tended to be low and embryo development retarded.  Low temperature is probably responsible; however, the possibility of other complicating factors is also discussed. -- The potential reproductive output of the St. Michael's Bay lobsters is too low for the population to become self-propagating.  This suggests the physiology of Homarus americanus dictates the southerly limit for the species.


identifier: Roy, Nicole A. <https://research.library.mun.ca/view/creator_az/Roy=3ANicole_A=2E=3A=3A.html>   (1986) The breeding biology and behaviour of great black-backed gulls (Larus marinus L.) in Newfoundland.  Masters thesis, Memorial University of Newfoundland.

abstract: The application of Game Theory to the study of behaviour has shown that it is possible, in theory, to have stable equilibria with individuals in a population behaving in different ways.  In order to test for colony type selection or nesting strategies in this species, breeding success, site tenacity and mate selection should be monitored on a long term basis.  An investigation of the reproductive biology and behaviour of Great Black-backed Gulls was undertaken to provide preliminary data to design such project. -- The effects of habitat or colony type selection on reproductive output was assessed in a one year study by comparing the breeding biology and behaviour of Great Black-backed Gulls in two different environments, namely a mono-specific and a mixed-species colony.  Many aspects of the breeding biology of Great Black-backed Gulls were similar between colonies but important behavioural differences were observed. -- There is some evidence that colony type selection fits the model of “ideal free distribution (Fretwell and Lucas, 1970) and acts as a breeding strategy in Great Black-backed Gulls.  However, energetic studies should be undertaken to assess costs and benefits of the proposed strategies.