bluuebunny/crossref_metadata_2025 huggingface dataset:
Histological Effects of 11-Ketotestosterone, 17α-Methyltestosterone, Estradiol, Estradiol Cypionate, and Cortisol on the Interrenal Tissue, Thyroid Gland, and Pituitary Gland of Gonadectomized Sockeye Salmon (Oncorhynchus nerka)
Authors: Overbeeke A. P. van , McBride J. R.
Published: April 2011

Effects of two androgens, two estrogens, and cortisol in gonadectomized sockeye salmon (Oncorhynchus nerka) were investigated. Males were injected with 11-ketotestosterone, 17α-methyltestosterone, or cortisol for 4 or 7 weeks. Females were injected with estradiol, estradiol cypionate, or cortisol for 8 weeks.Both the androgens and the estrogens caused interrenal hypertrophy. The effect of 17α-methyltestosterone was stronger than that of 11-ketotestosterone, and of the two estrogens used, estradiol cypionate exerted the most marked effect. Cortisol brought about a slight atrophy of the interrenal tissue.A pronounced histological activation of the small thyroid follicles was induced by the two androgens. The estrogens exerted no visible effect on the thyroid gland, and cortisol treatment caused a slight reduction in the height of the follicular epithelium.In the gonadectomized control fish of both sexes, gonadotrophs were small and practically all devoid of granules. All four sex steroids induced the appearance of many granulated PAS-positive gonadotrophs, particularly in the anterior part of the proximal pars distalis. This effect is considered on activation of the gonadotrophs. Cortisol administration induced pronounced degranulation and atrophy of the corticotrophs and this effect was strongest in the males. Neither the androgens nor the estrogens visibly affected the corticotrophs.
Accumulation of Yellow Phosphorus by Several Marine Invertebrates and Seaweed
Authors: Fletcher G. L.
Published: April 2011

Lobsters, clams, quahogs, periwinkles, mussels, starfish, and seaweed accumulated yellow phosphorus from sea water containing this element. In an experiment exposing all of the organisms to 15 ± 9 μg/liter yellow phosphorus for 48 hr, the concentration of yellow phosphorus in whole animals ranged from 10 (mussels) to 40 (periwinkles) times the seawater level. The highest concentrations of yellow phosphorus were found in the pyloric caeca of starfish (100 times sea water), and in the ovary and hepatopancreas of lobster (300 and 1000 times sea water). Periwinkles, mussels, seaweed, and a quahog, clam, and starfish contained no yellow phosphorus 7 days after transfer to sea water free of yellow phosphorus.
Effects of Salinity, Temperature, and Dissolved Oxygen on Early Development of the Pacific Cod (Gadus macrocephalus)
Authors: Alderdice D. F. , Forrester C. R.
Published: April 2011

Effects of various combinations of levels of salinity, temperature, and dissolved oxygen on incubation of Pacific cod (Gadus macrocephalus) eggs were investigated in the laboratory. Quantitative relations were determined, by response surface analysis, between the environmental variables and four criteria used to estimate success of egg development. Larval size at mean hatching time, and percentages of total hatch, viable hatch, and postmature eggs that failed to hatch were optimized at intermediate salinities (about 15‰), low temperatures (3–5 C), and over a wide range of dissolved oxygen concentrations. Pacific cod eggs are judged to be euryhaline, euryoxic, and stenothermal. As long as temperatures are within the range of about 3–5 C, the developing egg is tolerant of a wide range of salinities, and of dissolved oxygen levels to a minimum of about 2 or 3 ppm. Below 3 C developmental success decreases precipitously; above 5 C it attenuates more slowly.Distribution and abundance of Pacific cod are reviewed in light of the experimental results. Temperature is suggested to be of major importance to successful egg development in the natural environment; the temperature range associated with reasonable egg viability and incubation success is estimated to extend from about 2.5 to 8.5 C.The distribution of cod in the spawning season appears associated with water temperatures between 2.5 and 8.5 C in Asian waters. Near the southern limit of cod distribution on the North American coast the following associations are suggested in relation to temperatures of the upper mixed layer of coastal waters in the spawning period: limit of commercial abundance, 9 C; extent of limited commercial landings, 10 C; limit of occurrence, 13.5 C.
Food of Two Cohabiting Tide-Pool Cottidae
Authors: Nakamura Royden
Published: April 2011

The organisms found on seven dates in the stomachs of two cottids (Oligocottus maculosus and O. snyderi) cohabiting four rocky tide pools on the west coast of Vancouver Island were the same except for one minor item. Quantitatively, a number of differences were present. For the major food items, the interspecific differences in relative composition of the diets were greatest for amphipods and copepods. Lesser differences are seen for annelids, isopods, and chironomid larvae. However, these were more likely a reflection of differences in microhabitat and behavior rather than interspecific competition for food.
Genetics of Multiple Malate Dehydrogenase Isozymes in Skeletal Muscle of Walleye (Stizostedion vitreum vitreum)
Authors: Clayton J. W. , Tretiak D. N. , Kooyman A. H.
Published: April 2011

Electrophoresis of extracts of white skeletal muscle revealed a total of six phenotypes of malate dehydrogenase (MDH) (L-malate; NAD oxidoreductase, EC 1.1.1.37) isozymes in walleye (Stizostedion vitreum vitreum). The individual MDH phenotypes consisted of four or more MDH isozymes.The heritability of all six phenotypes was tested in a breeding experiment. The results of the breeding experiment provided evidence for the existence of three nondominant alleles at one MDH locus. Subcellular fractionations indicated that these three alleles code for a supernatant (extramitochondrial) form of MDH. The frequencies of these alleles varied in fish from four locations in western Canada.
Quick Statistical Methods for Analysing the Sequences of Fish Counts Provided by Digital Echo Counters
Authors: MacNeill I. B.
Published: April 2011

The data records of digital echo counters consist mainly of sequences of overlapping counts. To estimate target density and the total number of distinct targets present, one should make appropriate allowances for the redundancy induced by overlapping. With this in mind, point and interval estimation methods are suggested for use in the hand analysis of such sequences. The techniques were developed in response to the need for ship-board analysis of data when there is an immediate requirement to gauge variations in target density as fish surveys are being conducted.
Infectious Pancreatic Necrosis Virus: Comparative Frequencies of Isolation from Feces and Organs of Brook Trout (Salvelinus fontinalis)
Authors: Frantsi C. , Savan M.
Published: April 2011

When isolation of infectious pancreatic necrosis (IPN) virus was attempted simultaneously from feces and organs of brook trout (Salvelinus fontinalis), the virus was isolated more frequently from organs than from feces. However, the greater the degree of stress on the fish, the closer the number of isolations from feces appeared to approach that from organs, and the virus was isolated from both organs and feces of each of 10 fish accidentally exposed to low oxygen concentration for 4 days. The findings suggest that masked viral and bacterial infections may be detectable if fish are placed under stress.
A Reconsideration of Aspects of Growth, Reproduction, and Behavior of the White Whale (Delphinapterus leucas), with Reference to the Cumberland Sound, Baffin Island, Population
Authors: Brodie P. F.
Published: April 2011

The beluga or white whale, Delphinapterus leucas (Pallas), was studied in Cumberland Sound, Baffin Island. Layering in teeth and mandibles plus body size were used to determine age. Sexual maturity is attained at 5 years for females and at 8 years for males, with potential life span estimated to be 30 years. Whitening of the skin begins after 6 years.Multiple ovulations and accessory corpora lutea are typical of beluga. The breeding season is in May, and after 14.5 months gestation single births occur in late July or early August. Lactation lasts about 2 years, resulting in a 3-year reproductive cycle. Tooth eruption begins late in the 2nd year with partial eruption by the 3rd. This population appears to have been overexploited by commercial hunting. Productivity estimates for this species are 43% of those implied in previous studies.
Maros-Schulek Technique for Measurement of Carbon Dioxide Production in Fish and Respiratory Quotient in Tilapia mossambica
Authors: Kutty M. N. , Karuppannan N. V. , Narayanan M. , Mohamed M. Peer
Published: April 2011

The technique used by Maros et al. (Anal. Chim. Acta 25: 390–399, 1961) for accurate measurements of total carbon dioxide in small samples has been modified for large samples of water, enabling measurement of carbon dioxide production by small aquatic animals. Data obtained from Tilapia mossambica by using the present technique are discussed. The method is considered to be adequate for obtaining reliable estimates of carbon dioxide production in fish.
Revision of Metavermilia Bush (Polychaeta, Serpulidae), with Descriptions of Three New Species from off Portugal, Gulf of Guinea, and Western Indian Ocean
Authors: Zibrowius Helmut W.
Published: April 2011

The serpulid genus Metavermilia Bush 1904, is emended and revalidated for four species: M. multicristata (Philippi), the type-species and formerly placed in Vermiliopsis, from the Mediterranean Sea and northeast Atlantic, M. annobonensis n.sp. from the Gulf of Guinea, M. taenia n.sp. from the Bay of Portugal, and M. nates n.sp. from the western Indian Ocean. The relationship of Metavermilia to the closely related genera Vermiliopsis Saint-Joseph and Pseudovermilia Bush is discussed. An apparently new form of parasitism (organisms of uncertain systematic position) in serpulid polychaetes was observed on the gill filaments of M. nates.
Descriptions of Sthenelais fusca Johnson 1897 and S. berkeleyi n.sp. (Polychaeta: Sigalionidae) from the Eastern Pacific
Authors: Pettibone Marian H.
Published: April 2011

Two sigalionid polychaete species were found to have been confused under Sthenelais fusca Johnson. The second species is named S. berkeleyi in honor of Dr Cyril Berkeley.
Abyssal Polychaetous Annelids from the Mozambique Basin off Southeast Africa, with a Compendium of Abyssal Polychaetous Annelids from World-Wide Areas
Authors: Hartman Olga
Published: April 2011

Twenty-six abyssal polychaetes are named from the Mozambique basin off southeast Africa. Three species and two genera are new: Progoniada simplex, Berkeleyia profunda, Bruunilla natalensis, and another in Sphaerodoridae to be described elsewhere. A new family Fauveliopsidae is erected, its species previously allied with Flabelligeridae. Three species are known from Indo-Pacific regions: Glycera papillosa, Ammotrypane brevibranchiata, Phalacrostemma elegans. One, Axionice spinifera, is antarctic; another, Scalibregma inflata, is cosmopolitan. Five generic categories are chiefly or wholly abyssal: Ilyphagus, Fauveliopsis, Flabelligella, Monorchos, Potamethus. Nine genera are cosmopolitan: Aphrodita, Euphrosine, Phyllochaetopterus, Chaetozone, Ammotrypane, Nicomache, Myriochele, Serpula. Unidentifiable species are in families Lacydonidae, Onuphidae, and Ampharetidae. A compendium names abyssal species from depths of 2000 m or more; included are nearly 500 species in 240 genera and 51 families.
Associations and Species Diversity in Benthic Macroinvertebrates of Bay of Quinte and Lake Ontario
Authors: Johnson M. G. , Brinkhurst R. O.
Published: April 2011

Three main macroinvertebrate associations were found in the Bay of Quinte, Prince Edward Bay, and the adjacent area of Lake Ontario: a chironomid association of the eutrophic inner and middle bays; an association of many species of sphaeriids, oligochaetes, chironomids, and crustaceans in the mesotrophic lower Bay of Quinte and Prince Edward Bay; and a cold-stenotherm association of the oligotrophic deep basin of Lake Ontario. An additional, but more confined (inner Prince Edward Bay), association consisted of a variety of taxa, whose distribution appeared to be related to the distribution of vascular vegetation. All of the main taxonomic groups contributed to each association and to differences among associations. The lakeward progression of associations in the study area was closely similar to the west to east shifts in Lake Erie reported earlier. Species diversity in Lake Ontario associations apparently was related to degree of eutrophy and to water temperature.
Production of Benthic Macroinvertebrates of Bay of Quinte and Lake Ontario
Authors: Johnson M. G. , Brinkhurst R. O.
Published: April 2011

Production rates (P) by benthic macroinvertebrates, obtained from data on instantaneous growth rate and biomass (B), ranged from 0.26 kcal m−2 day−1 at the inner bay station to 0.80 in the outer bay, 0.19 at the bay mouth, 0.16 outside the Bay of Quinte, and 0.04 in the main basin of Lake Ontario. Respiration rates (R) of the common species were fitted to the general model logeR = a1T + a2 logeW, where T is temperature and W is animal weight. Q10's averaged 3.5 and exponents of animal weight averaged 0.74. Growth efficiencies (production as a proportion of assimilation) declined progressively from about 0.65 at the inner bay station to 0.35 at the Lake Ontario station. Annual turnover ratios (P:B ratios) declined from 13 in the inner bay to about 1 in the deep sediments of Lake Ontario. Turnover ratio (TR) was correlated with mean annual bottom temperature (T), [Formula: see text], and production was predicted by [Formula: see text].
Surges of Winter Flounder, Pseudopleuronectes americanus, into the Intertidal Zone
Authors: Tyler A. V.
Published: April 2011

Movement of winter flounders, Pseudopleuronectes americanus (Walbaum), into the intertidal zone was observed by underwater television situated in a herding fence. Flounders enter the intertidal zone with the rising tide. Peak movement occurs 2–2.5 hr after low tide. Movement generally falls off 3.5 hr after tide begins to rise. Flounders occupy the area for 6–8 hr and then surge back to the sublittoral 2.5–0.5 hr before the next low tide. Small flounders move with the same synchrony as large flounders, but tend to make short movements up and down the beach, with net movement away from shore while tide is falling. Large flounders are more strictly directional. Movements of eight species that occurred with the flounder are compared. Because of the scale of the flounder movement, and because of published observations of pleuronectids feeding in the intertidal zone, it is proposed that the intertidal zone is a major feeding area for northern populations of winter flounder. Actions that interfere with productivity in the intertidal zone (oil pollution, tidal impoundments) are likely to reduce productivity of flounder populations.
Response of Young Sockeye Salmon (Oncorhynchus nerka) to Prolonged Periods of Starvation
Authors: Bilton H. T. , Robins G. L.
Published: April 2011

Young sockeye were held without food for periods of 20 and 30.5 weeks with few mortalities. As was reported in previous experiments, no record of the periods of starvation appeared on the scale, nor did checks form under these conditions. Those fish offered food after 20 weeks of starvation responded immediately and showed significant increases in body and scale growth at the end of 10 weeks feeding. Fish offered food after 30.5 weeks of starvation also responded immediately, but when the experiment ended after 5 weeks of feeding no significant increases in body and scale growth were apparent, indicating insufficient recovery time. A significant increase in the incidence of checks was associated with subsequent feeding. Light period did have some influence on body and scale growth.
Interaction Between Paralytic Shellfish Poison and Melanin Obtained from Butter Clam (Saxidomus giganteus) and Synthetic Melanin
Authors: Price R. J. , Lee J. S.
Published: April 2011

The interaction between paralytic shellfish poison (PSP) and melanin from butter clam (Saxidomus giganteus) and synthetic melanin followed a pattern similar to that reported between PSP and a cation exchanger. The close relation between the anatomical distribution of melanin in butter clams and the distribution of PSP in toxic butter clams suggests that melanin may play an important role in the retention of PSP by these clams.
Temperature Selection of Rainbow Trout (Salmo gairdneri) Fingerlings in Vertical and Horizontal Gradients
Authors: McCauley R. W. , Pond W. L.
Published: April 2011

Preferred temperatures of underyearling rainbow trout (Salmo gairdneri) were determined in both vertical and horizontal temperature gradients. No statistically significant difference was found between the preferred temperatures by the two different methods. This suggests that the nature of the gradient plays a lesser role than generally believed in laboratory investigations of temperature preference.
Acid Phosphatase Activity in Vegetative Cells and Spores of Clostridium botulinum Type E
Authors: Strasdine G. A. , Melville Joanne M.
Published: April 2011

Acid phosphatase activity with a pH optimum of 5 was demonstrated in vegetative cells, spores, and germinated spores of Clostridium botulinum type E (Minnesota). The enzyme was present in the cells during all stages of growth and was insensitive to the orthophosphate concentration of the growth media. Specific activity of the enzyme increased during growth coincident with a loss in inorganic phosphate from the acid-soluble cell fraction. Magnesium or manganese was required for maximum enzyme activity. Acid phosphatase in crude spore extracts was more heat-stable than in extracts obtained from vegetative cells.
Geographic Distribution and Relative Abundance of Salpidae off the Oregon Coast
Authors: Hubbard Jr. Lyle T. , Pearcy William G.
Published: April 2011

Six species of salps were identified from 437 midwater trawl and 202 plankton net collections off Oregon from 1961 to 1964: Helicosalpa virgula, Iasis zonaria, Salpa fusiformis, Pegea confoederata, Thalia democratica, and Thetys vagina. Relative abundance of the species varied in time and space and few distributional patterns were evident. Salpa fusiformis and I. zonaria, the most common species, were found during all seasons of the year, the highest numbers usually during the summer, the upwelling season. Thalia democratica, H. virgula, and T. vagina were found only during 1963, and P. confoederata was most common during 1963. This was an abnormally warm year and the presence of these species off Oregon may have been related to advection from the south or west and the lack of upwelling.
Predation by Rainbow Trout (Salmo gairdneri): the Effect of Experience
Authors: Ware D. M.
Published: April 2011

Rainbow trout (Salmo gairdneri) provided with unfamiliar palatable food changed several components of their feeding behaviour and demonstrated that they can develop searching images for specific prey. Naive fish required an average of 4 days of experience, each of which consisted of exposure to six food particles, before they approached novel prey. After this time the distance from which trout attacked food improved and had doubled by the 12th day of exposure. When conditioned animals were deprived of experience for 90 days, the distance of reaction fell back to the initial naive level. The relation of these results to current work on searching image formation is discussed.
Introduction of Kokanee Salmon (Oncorhynchus nerka) into Lake Huron
Authors: Collins John J.
Published: April 2011

An experimental introduction of kokanee salmon (Oncorhynchus nerka) into Lake Huron from egg stocks obtained from British Columbia and several western states of the United States began in 1964. From 1964 to 1969, about 5.5 million kokanee (eggs, fry, and fingerlings) were planted. Estimated minimum returns of adults were 9000, 1200, and 4000 in 1967, 1968, and 1969, respectively. Although most of the returns were recorded near planting sites, substantial numbers moved into other areas, in some instances spawning in streams that were not planted. Apparently, most kokanee matured in their 3rd year of life (2+) and their lengths ranged from 18 to 49 cm.The incidence of lamprey marks on adults was light (1.6% of 4472 examined) but frequencies of marks tended to increase as fish size increased — from 0.5% for 28–32 cm fish to 16.7% for fish over 40 cm long.Successful stream spawning in 1967 was indicated by the retrieval of live eggs and alevins from redds and the capture of downstream migrant fry. Shore spawning was verified by retrieval of viable eggs from redds in 1969. The potential egg deposition in the two rivers with the largest runs in 1967 was approximately 2.7 million eggs. Fish from British Columbia river-spawning stock spawned both in streams and along shores of South Bay. Since spawning was not restricted to streams, the shore areas of Lake Huron may extend the spawning habitat available to kokanee.Adult kokanee fed mainly on insects and plankton during August and September. Aerial forms of insects predominated in South Bay kokanee. Dieldrin and DDT residues were moderate, averaging between 0.012 and 0.046 ppm for dieldrin and 0.226 and 1.242 ppm for DDT in whole tissue samples.Data from South Bay show that the principal species found in association with kokanee were alewife and smelt. The diet of alewife in August indicated possible competition with kokanee.
Occurrence of the Bowhead or Greenland Right Whale (Balaena mysticetus) in Canadian Arctic Waters
Authors: Mansfield A. W.
Published: April 2011

The action taken in December 1970 by the U.S. Department of the Interior in placing eight species of large whales on an endangered species list has emphasized the need for up-to-date information on their populations. The present paper summarizes a large number of observations on one of these eight species and suggests that the bowhead population of Canada is recovering well after intensive exploitation up till the early years of the present century, though it may amount to only a small percentage of the population present before commercial whaling began.
Physical and Chemical Limnology of the Lakes of Manitoulin Island
Authors: Harvey H. H. , Coombs J. F.
Published: April 2011

Of 51 of the large lakes on Manitoulin Island investigated from 1965 to 1970, 10 were found to be dimictic and 41 polymictic, most of the latter being very shallow. Twenty of the polymictic lakes evidenced one or more trenches in the lake bottom. These trenches may be maintained by wind-induced water currents. In one such trenched lake, Smoky Hollow Lake, winter oxygen declined to less than 1 ppm before surface melt-water entered the lake under the ice sheet. Winter kills of fish such as yellow perch (Perca flavescens) and northern pike (Esox lucius) were observed in three lakes, but the presence of older age-classes of fish in most lakes suggested that extensive winter kills are not common. The survival of fishes in the many shallow lakes is made possible by the continued presence of at least a small amount of oxygen in winter and the timely arrival of surface melt-water under the ice sheet. Most of the lakes had a high pH (7.9–9.1) and were rich in magnesium (mean 17.9 ppm) in relation to calcium (34.2 ppm), consistent with the underlying dolomitic bedrock. Sodium (mean 1.5 ppm) and potassium (0.8 ppm) were present at unusually low concentrations.
Effects of Two Insecticides on the Vulnerability of Atlantic Salmon (Salmo salar) Parr to Brook Trout (Salvelinus fontinalis) Predation
Authors: Hatfield C. T. , Anderson J. M.
Published: April 2011

The experiments were conducted in large outdoor concrete pools in which the salmon had access to a safe haven. After exposure for 24 hr to 1.0 ppm of the organophosphate insecticide, Sumithion, Atlantic salmon (Salmo salar) parr were more vulnerable than unexposed fish to prédation by large brook trout (Salvelinus fontinalis). Sumithion at 0.1 ppm, and DDT at 0.07 ppm, had no noticeable effect. The results, particularly for Sumithion, correlate well with previous laboratory work on the effect of insecticides on the learning ability of salmon.
Chemical Characteristics of Humic Compounds Isolated From Some Decomposed Marine Algae
Authors: Rashid M. A. , Prakash A.
Published: April 2011

The chemical and spectroscopic characteristics of humic compounds isolated from decomposed thalli of Fucus vesiculosus and Laminaria digitata, seaweed exudate, and dissolved organic matter in river water show that, in spite of several differences, their gross structural features are similar to those of humic compounds isolated from marine sediments or soils. Dominant functional groups are carboxyl and carbonyl but phenolic and alcoholic hydroxyl groups are also present in small proportions. Between 20 and 40% of humic acids are represented by fractions having molecular weight greater than 200,000, whereas the fulvic acids do not exceed 10,000. Carbon and nitrogen contents show a direct relation with molecular weight whereas the oxygen is inversely related.
Virucidal Activity of Two Iodophors to Salmonid Viruses
Authors: Amend Donald F. , Pietsch John P.
Published: April 2011

Wescodyne® and Betadine®, organic iodine complexes, were compared in vitro for virucidal activity against infectious hematopoietic necrosis (IHN), infectious pancreatic necrosis (IPN), and viral hemorrhagic septicemia (VHS) viruses. Both iodophors were about equally effective on all three viruses. Each iodophor completely destroyed IHN virus within 30 sec at 12 ppm iodine, and was not affected by water hardness. Virucidal activity, however, was reduced at pH levels above 8.0 and in the presence of organic matter. Wescodyne was also compared with seven disinfectants commonly used in fish hatcheries, for virucidal properties against IHN virus. Wescodyne and chlorine were the only disinfectants to completely destroy the virus. Either Wescodyne or Betadine would effectively destroy the salmonid viruses at less than 25 ppm iodine within 5 min in solutions near neutrality.
Habitat Selection and Spatial Interaction by Juvenile Chinook Salmon and Steelhead Trout in Two Idaho Streams
Authors: Everest F. H. , Chapman D. W.
Published: April 2011

During summer sympatric steelhead trout and summer chinook salmon segregated in Crooked Fork and Johnson creeks. In short-term allopatry, each species occupied the same types of habitat as in sympatry. Most age 0 steelhead lived over rubble substrate in water velocities and depths of less than 0.15 m/sec and 0.15 m, respectively; most age 0 chinook lived over silt substrate in water velocities of less than 0.15 m/sec and depths of 0.15–0.3 m; most age I steelhead resided over large rubble substrate in water velocities of 0.15–0.3 m/sec (near bottom) and 0.75–0.9 m/sec (near surface), and in depths of 0.6–0.75 m. As fish of each species became larger they moved into faster, deeper water. Juvenile chinook and steelhead of the same size used the same physical space. But steelhead spawn in spring and chinook spawn in early fall, and disparate times of spawning create discrete intra- and inter-specific size groups of pre-smolts. The size differences minimize potential for social interaction, both intra- and inter-specific.
Fatty Acids of Channel Catfish (Ictalurus punctatus)
Authors: Worthington R. E. , Boggess Jr. T. S. , Heaton E. K.
Published: April 2011

Representative samples of channel catfish (Ictalurus punctatus Rafinesque) were obtained from five processing plants and analyzed by gas–liquid chromatography for fatty acid composition of muscle tissues. Twenty-three fatty acids were measured. The saturated fatty acids comprised 26.5%, monoenes 48.1%, dienes 13.0%, trienes 3.1%, tetraenes 3.6%, pentaenes 1.3%, and hexaenes 1.9% of total fatty acids. Fatty acid composition varied significantly (P <.01) among fish obtained from the same plant, and in addition, significant variation associated with processing plant was observed for some fatty acids.
Fish Viruses: Histopathologic Changes Associated with Experimental Channel Catfish Virus Disease
Authors: Wolf Ken , Herman Roger L. , Carlson C. P.
Published: April 2011

A histologic examination was carried out on fry with experimentally induced channel catfish virus disease (CCVD). The infection produced a hemorrhagic and necrotic disease with the target organs being the kidneys, liver, digestive tract, and skeletal muscle. The results agree with symptoms of the disease and with published data on quantifications of virus in specific organs.
Changes in Gill Adenosinetriphosphatase Activity Associated with Parr–Smolt Transformation in Steelhead Trout, Coho, and Spring Chinook Salmon
Authors: Zaugg W. S. , McLain L. R.
Published: April 2011

The average Na+- and K+-stimulated adenosinetriphosphatase (ATPase) activity of microsomes from gills of hatchery-reared coho salmon (Oncorhynchus kisutch) increased from about 12 μmoles ATP hydrolyzed/mg protein per hr during February through mid-April to approximately 24 in mid-May. Larger fish developed higher activities than smaller fish. Hatchery-reared spring chinook salmon (O. tshawytscha) exhibited a similar increase 2–3 weeks earlier.In 2-year-old hatchery-reared steelhead trout (Salmo gairdneri), Na+-, K+-ATPase activities were elevated in some, but not all, smolt-appearing animals. Parr-appearing fish, including maturing males, showed no activity increase. When held in fresh water to July, steelhead smolts lost their silvery color and became more parr-like in appearance, and the previously elevated ATPase activity decreased to near pre-smolt levels. Yearling steelhead held at the laboratory showed a more consistent rise in ATPase activity.The increase in transport ATPase (Na+-, K+-stimulated) activity occurring during parr–smolt transformation is probably a preparatory step for saltwater adaption and may also be closely associated with migratory disposition.L'activité moyenne de l'adénosinetriphosphatase (ATPase) stimulée par Na+ et K+ dans les microsomes des branchies de saumons coho (Oncorhynchus kisutch) élevés en pisciculture augmente de 12 μmoles environ d'ATPase hydrolysée/mg de protéine par h de février à la mi-avril à 24 à la mi-mai. Les gros poissons développent une activité plus grande que les petits. Les saumons chinook de printemps (O. tshawytscha) élevés en pisciculture font preuve d'un accroissement semblable deux à trois semaines avant les saumons coho.
Differences in Atlantic Salmon, Salmo salar, from North America and Europe
Authors: Nyman O. L. , Pippy J. H. C.
Published: April 2011

Differences in electropherograms produced by serum proteins and liver esterases were used to identify North American and European Atlantic salmon (Salmo salar) caught at sea. Division of salmon according to continent of origin was supported by mean river age, mean fork length, and abundance of the two parasites Anisakis simplex and Eubothrium crassum. Consistent differences in electrophoretic behaviour of serum proteins and liver esterases in salmon from the two continents support the suggestion that salmon from North America and Europe represent different subspecies.
Preliminary Study of Sablefish Culture, a Potential New Industry
Authors: Kennedy W. A.
Published: April 2011

A new industry may be possible based on capture of second-year juvenile sablefish (Anoplopoma fimbria) weighing about 300 g then rearing them to 4 kg for sale. I found sablefish easy to rear. Under growth-favouring conditions they gained about 150 g per fish per month, used about 5 kg wet weight of feed per kilogram gained, and had mortalities of less than 1% per month. Concentrations of at least 43 kg of fish/m2 or 70 g/liter did not adversely affect growth or mortality.
Comparative Behavior and Habitat Utilization of Brook Trout (Salvelinus fontinalis) and Cutthroat Trout (Salmo clarki) in Small Streams in Northern Idaho
Authors: Griffith Jr. J. S.
Published: April 2011

Individual brook (Salvelinus fontinalis) and cutthroat (Salmo clarki) trout communicated with similar behavioral signals, both in laboratory stream-channels and in northern Idaho streams. Underyearling brook trout were less active socially than equal-sized cutthroat trout in laboratory observations. In study streams, brook trout maintained a 20-mm size advantage over cutthroat of the same age-groups throughout their lives, as they emerged from the gravel before cutthroat. Because of this size advantage, underyearling brook trout of sizes found in study streams in September consistently dominated in experiments the underyearling cutthroat with which they normally lived. But in study streams underyearlings of the two species utilized different microhabitats, particularly with respect to water depth, and so minimized chances for interaction.Yearling and older brook trout initiated 40% fewer aggressive encounters under laboratory conditions than did equal-sized cutthroat trout, and did not displace the cutthroat. In study streams with sympatric populations, cutthroat trout of these age-groups occupied territories with focal points of higher water velocities (averaging 10.2–10.3 cm/sec) than those occupied by brook trout (averaging 7.6–9.6 cm/sec). Considerable interspecific overlap in other habitat characteristics occurred for trout of age-groups I and II. The oldest members of the two species segregated more distinctly, as the brook trout lived closer to overhead cover.
Some Relations of Land Drainage, Nutrients, Particulate Material, and Fish Catch in Two Eastern Canadian Bays
Authors: Sutcliffe Jr. W. H.
Published: April 2011

A year's record of the carbon content of living and of carbon and nitrogen content of nonliving suspended particulate material from St. Margaret's Bay, Nova Scotia, is presented. From considerations of carbon/nitrogen ratios and nutrient data from other sources, the nitrogen budget is briefly considered. The possible importance of land drainage into the bay leads to some positive correlations between runoff and catch of four commercially important species in the Gulf of St. Lawrence.
Bacterial Population of Diets for Aquarium Fishes
Authors: Trust T. J. , Money Vida G.
Published: April 2011

Twenty-five commercial diets formulated and offered for feeding to aquarium fish were examined to determine their microbial burden. The total count of aerobic mesophilic bacteria in 24 of the feeds ranged from 9 × 102 to 1.3 × 106 per gram of diet. Twenty of the diets contained from 7 × 102 to 2.4 × 105 bacteria per gram able to grow anaerobically. One of the feeds was sterile. Species from the genus Bacillus were most numerous, but species of Clostridium (including C. perfringens), enterococci, and members of the Enterobacteriaceae were also present in significant numbers. The fish diets supported the growth of a wide variety of bacteria known to be pathogenic to fish and to man.
Effects of Temperature, Food, and Starvation on Several Physiological Parameters of the Lobster Homarus americanus
Authors: Stewart James E. , Horner G. W. , Arie B.
Published: April 2011

The change in physiological condition of groups of fed and starved lobsters, Homarus americanus, held for 3–8 months at different temperatures was determined. Changes in muscle content and serum protein measurements were strictly temperature dependent in the case of the starved lobsters. Hemolymph nonprotein nitrogen and lactic acid, hepatopancreatic glycogen, lipid, weight, and moisture content varied directly with food, or temperature, or both; hemolymph carbohydrate values apparently vary more directly with temperature than with food quantities.
Mating Behavior in the Spider Crab, Chionoecetes opilio
Authors: Watson J.
Published: April 2011

During the week-long precopulatory embrace, the male spider crab, Chionoecetes opilio, held the female, even when attacking intruding males. Before a 45-min copulation period the male assisted female ecdysis. During the postcopulatory embrace spermatophores flowed onto the pleopods of the female. Polygamous males as small as 60 mm width mated with larger females. More than one fertile egg batch was frequently produced from one mating. Females mated successfully up to 95 hr after molting. Hard-shelled females seemed incapable of mating. The probable mating season is February through April and continued recruitment seems assured.
Effects of Dressing and Cooking on DDT Concentrations in Certain Fish from Lake Michigan
Authors: Reinert Robert E. , Stewart Donald , Seagran Harry L.
Published: April 2011

Concentrations of DDT residues were highest in parts of the body with the highest oil content in four species of fish from Lake Michigan: yellow perch (Perca flavescens), bloater (Coregonus hoyi), lake trout (Salvelinus namaycush), and coho salmon (Oncorhynchus kisutch). Dressing reduced the DDT residues and oil content by more than 90% in yellow perch but had little effect in the other three species. The concentration of DDT residues in bloaters was changed little by smoking but was reduced 64–72% by other methods of cooking: from 8.0 ppm (raw) to 2.2 ppm after frying in corn oil; from 10.7 to 3.9 ppm after frying in lard; and from 9.1 to 3.2 ppm after broiling. The concentration of DDT residues in fillets of yellow perch changed only from 0.3 ppm (raw) to 0.4 or 0.5 ppm after baking, frying, or broiling.
An Experimental Study of Feeding Behavior and Interaction of Coastal Cutthroat Trout (Salmo clarki clarki) and Dolly Varden (Salvelinus malma)
Authors: Schutz D. C. , Northcote T. G.
Published: April 2011

Feeding behavior of cutthroat trout (Salmo clarki clarki) and Dolly Varden (Salvelinus malma) cohabiting a small coastal lake was studied experimentally to examine the importance of food exploitation as a mechanism for spatial and food segregation observed there. The hypothesis that Dolly Varden could feed more successfully on benthic prey, and cutthroat on surface prey was supported by laboratory experiments involving isolated individuals and interspecies pairs exposed to food in benthic, surface, and both locations. Differences between the species were found in resting and orientation positions and in behavior associated with food searching, location, and capture. Dolly Varden also were more successful than cutthroat in capturing benthic prey at low light intensities. Observed differences in feeding between the species were fully expressed in solitary individuals and did not appear to be magnified by interaction. It is suggested that these differences in sympatric stocks of the two species may be inherent and, therefore, that segregation is largely selective rather than interactive, even though the populations still retain considerable plasticity, enabling them to change diets or habitats when necessary or advantageous.
Great Slave Lake: Effects of Exploitation on the Salmonid Community
Authors: Keleher J. J.
Published: April 2011

A 20-year investigation commenced at the inception of the Great Slave Lake commercial fishery, and it is inferred that exploitation has been the sole cause of change in the fish stocks. Background information on the operation of the commercial fishery, the fishing regulations, and the study methods are provided. Lake whitefish, Coregonus clupeaformis, and lake trout, Salvelinus namaycush, have made up 94% of the commercial landings of 119 million lb during the period. Only three other species of the 25 occurring in the lake were usually marketed. Whitefish catches generally were distributed equally between the summer and winter seasons. Trout were caught almost exclusively during the summer season. The annual catch of these two species rose from 1.6 million lb in 1945 to a maximum of 9.4 million lb in 1949 then gradually decreased to about the 5 million lb level. The study data have been partitioned according to 13 statistical areas. Catch has not been in proportion to the extent of these areas. Whitefish catch has predominated in the western, Interior Lowlands, portion of the lake while trout catch has predominated in the eastern, Canadian Shield, portion. In various areas, the peak catches for whitefish were associated with peak catches for trout, indicating that both were the result of fishing down the virgin stocks. Summer catch per unit effort for each species has declined during the 20-year period. CPE varied with the statistical areas. The usual observed reduction for whitefish was 60% in contrast to 93% for trout. Estimated summer fishing effort and whitefish catch showed a direct relation but the relation for trout usually changed from a positive to a negative one. The average size of commercially caught fish has declined to about 2 lb for whitefish and 5 lb for trout. Information on catch per unit effort for other species indicates no evident explosions in their numbers, though ciscoes, Leucichthys spp., appear to have increased in abundance. Although the fishery was regulated in order to provide for maximum annual sustained yields, this has not been achieved for trout. Three opinions for this are offered. Exploitation under a pooled quota system for whitefish and trout is not favoured and a decrease in trout quota is recommended.
Lake Vättern: Effects of Exploitation, Eutrophication, and Introductions on the Salmonid Community
Authors: Grimås Ulf , Nilsson Nils-Arvid , Wendt Curt
Published: April 2011

Vättern, the second largest lake of Sweden, contains 28 species of fish, of which Arctic char (Salvelinus alpinus) and whitefish (Coregonus spp.) are the most important economically. There is both a commercial fishery and a sport fishery. The former has decreased steadily, while the latter is increasing. A modest eutrophication is occurring, due amongst other factors to an increasing input of phosphorus and resulting, for instance, in a decrease in transparency.The lake is, however, still to be characterized as typically oligotrophic. The input of polluting matters is alarming, especially as regards toxic substances. Exploitation of fish populations has on the whole increased, although the number of commercial fishermen decreases. The fishery on the char population and military activity may in the long run result in over-exploitation. An inverse correlation between the catches of char and whitefish has been explained as a result of interaction between the two species. An obvious increase in catches of the Coregonus species (whitefish and cisco) is taken to be the result of eutrophication. Introductions of "exotic" species have only resulted in one recorded case of reproduction of rainbow trout (Salmo gairdneri). Several promising experiments with the release of hatchery-reared fish, e.g. landlocked salmon (Salmo salar), have been carried out. Growth rate of several fish species in Vättern has appeared to be faster than normal.
Vital Statistics, Biomass, and Seasonal Production of an Unexploited Walleye (Stizostedion vitreum vitreum) Population in West Blue Lake, Manitoba
Authors: Kelso J. R. M. , Ward F. J.
Published: April 2011

The population of walleye, Stizostedion vitreum vitreum, (25 cm and greater) in West Blue Lake, Man., in May 1969 decreased from 1090 to 819 in May 1970. During summer and fall, the initial population was supplemented by new recruits, age II+, reaching a maximum of 3451 in September 1969. The total population in May 1970 was 2037. Mean daily mortality for all ages was small for the year, 0.0045, but loss rate was greatest in fall and winter. Growth in length was greatest for age II+ followed by older fish. Growth in weight was similar for ages III–V and lowest for age II+. Mean biomass, approximately 800 kg, was similar in May 1969 and May 1970. Production, 340 kg, coincided with the growing season (June to October) and was greatest from June to September. Greatest contribution to walleye production and biomass was made by age II+ fish. During winter and spring, zero or negative production occurred.
Stability of Elemental Phosphorus in Edible Muscle Tissue of Cod During Processing Including Icing, Freezing and Thawing, Frozen Storage, Salting, and Cooking
Authors: Dyer W. J. , Hiltz Doris F. , Ackman R. G. , Hingley Joyce , Fletcher G. L. , Addison R. F.
Published: April 2011

Elemental phosphorus (Pel) in the white muscle of cod was remarkably stable during processing of the fish by commercial procedures. After iced storage (both as round fish and as fillets), freezing and thawing, frozen storage, or cooking, from about 40 to 100% of the original Pel concentration remained (except for a very few samples) during conditions approximating normal commercial handling. In pickle- and in kench-salted cod, 25% or more of the Pel remained after [Formula: see text] months.At initial values of Pel up to about 500 ng/g, the rate of decrease during iced or frozen storage was very slow, but at higher initial values the rate was much more rapid. The lipid in which the Pel was probably dissolved may have protected the Pel up to the threshold concentration.Commercial processing cannot be relied upon to make cod polluted with Pel safe for use as human food.
Downstream Movements of White Sucker, Catostomus commersoni, Fry in a Brown-Water Stream of Alberta
Authors: Clifford Hugh F.
Published: April 2011

In a brown-water stream of Alberta, white sucker (Catostomus commersonii) fry moved downstream almost entirely at night. During June and July when the fry were moving downstream, their nocturnal "drift" pattern was more pronounced than that of any of the drifting invertebrates; and at this time their total biomass crossing a width transect per 24 hr exceeded the combined total biomass of the drifting invertebrate taxa. As the fry became larger, many more moved downstream near the surface of the water than near the stream's substrate.
Volatile Compounds Produced in Ground Muscle Tissue of Canary Rockfish (Sebastes pinniger) Stored on Ice
Authors: Miller III A. , Scanlan R. A. , Lee J. S. , Libbey L. M.
Published: April 2011

Volatile compounds associated with the progressive degradation of ground muscle tissue of canary rockfish (Sebastes pinniger) stored on ice were determined by combined gas–liquid chromatography and mass spectrometry. Compounds positively identified included dimethyl sulfide, n-propyl alcohol, acetaldehyde, propionaldehyde, acetone, ethyl alcohol, 2- and 3-pentanone, diacetyl, hexanal, 1-pentene-3-ol, 3-methyl-1-butanol, acetoin, trimethylamine, and dimethylamine. The following compounds were tentatively identified: propenal, octenal or octadienal, butyraldehyde, 3-methyl butanal, 2-butanone, and methyl vinyl ketone.
Morphological and Myogen Comparison of Johnny and Tessellated Darters and Their Hybrids, Genus Etheostoma, Near Ottawa, Canada
Authors: McAllister Don E. , Jolicoeur Pierre , Tsuyuki Hiroshi
Published: April 2011

Ten morphological characters and two electrophoretic characters were studied in nearly 200 specimens of johnny and tessellated darters from the Ottawa area. The data were analyzed using a simple character index and principal component analysis. The frequency distribution of the character index was trimodal, and specimens could be resolved into three groups: those typical of johnny and tessellated darters, and a group of intermediates. The two extreme groups were interpreted as representing two valid species, Etheostoma nigrum Rafinesque and Etheostoma olmstedi Storer, and part of the intermediate group was inferred to consist of interspecific hybrids. Hybrids were estimated to constitute less than 7.6%. There was no clear evidence of backcrossing. Most specimens could be clearly identified with one or the other of the two species. A key is provided.
Acute Toxicity of Spent Sulphite Liquor to Atlantic Salmon (Salmo salar)
Authors: Wilson R. C. H.
Published: April 2011

Ninety-six-hour static bioassays, with daily toxicant replenishment, were performed on Atlantic salmon (Salmo salar) parr to test for the acute toxicity of spent sulphite liquor (SSL). The LC50 of two batches of fresh SSL varied from 2000 to 2400 ppm, while the LC50 of SSL which had been previously oxidized for 5 days was 2750 ppm. Test fish responded differently to oxidized than to fresh SSL. Caution is urged in the application of 96-hr bioassay results on sulphite pulp mill wastes to field situations.