bluuebunny/crossref_metadata_2025 huggingface dataset:
Stomach Contents of Adult Starry Flounder and Sand Sole in East Sound, Orcas Island, Washington
Authors: Miller Bruce Stuart
Published: April 2011

Starry flounder fed mainly on priapulids, nemerteans, polychaetes, and lamellibranchs. Sand sole fed on fish, mysids, shrimp, and squid. Both species appeared to be daytime feeders.Starry flounder ceased feeding during the months of lowest water temperature. This indicates that the local commercial fishery for starry flounder takes fish when they are in poor physical condition. Sand sole showed little reduction in feeding during the cold-water months.The stomach of the starry flounder appeared to be used primarily as a holding organ and was emptied in about 9 hr. The sand sole stomach was used for digestion, which, for forage fish, took longer than 24 hr to complete.
Genetic Control in the Lakeward Migrations of Sockeye Salmon (Oncorhynchus nerka) Fry
Authors: Raleigh Robert F.
Published: April 2011

Eggs of sockeye salmon taken from tributary, outlet, and beach spawners at Karluk, Alaska, were treated identically from time of egg fertilization through time of testing as fry in a laboratory. Test lots were released during the day and at night in a central release pool from which the fry could migrate either upstream or downstream through simulated stream channels. Oxygen-saturated water at 50 F (10 C) was pumped through the 40-ft (12.2-m) gravel-bottomed simulated stream at about 0.3 ft/sec (9.1 cm/sec).Test results showed that directions (upstream or downstream) and times (day or night) of migration differed substantially between fry from the tributary and those from the outlet. Fry from beach spawning reacted in a manner similar to that of the tributary fry. These differences were concluded to be of genetic origin. The possible interaction of innate behavior and environment in controlling the migratory movements of salmonid fry is discussed along with the significance of choosing a donor stock with appropriate innate responses to make best use of a new environment.
Behavior and Distribution of Spawning Sockeye Salmon on Island Beaches in Iliamna Lake, Alaska, 1965
Authors: Kerns Jr. Orra E. , Donaldson John R.
Published: April 2011

In 1965, spawning was studied on the island beaches of the eastern part of Iliamna Lake from a 5.5-m tower mounted on a 9.1-m boat and with the use of scuba. Over 3 million sockeye salmon, Oncorhynchus nerka (Walbaum), utilized nearly 130 ha of the beaches surveyed during the period August 8–21. The total spawning population and utilized area of shoreline of all the islands in the lake were greater since each area was surveyed only once and possible multiple waves of spawners were not taken into account, and not all of the island shoreline was surveyed by the above methods. The salmon generally spawned in dense groups, over immovable rock, in exposed areas with no upwelling ground water, and with little display of territorial defense. Density ranged from less than 0.1 fish to more than 5 fish per 0.84 m2 (1 yard2). The latter density prevailed on reefs and outside points of the islands. Seventy-three per cent of spawning took place over bottom with irregular rocks from 102 to 305 mm (4–12 inches) in diam, and over 90% at depths from 2 to 6 m (6–20 ft) on bottom with slopes from 15 to 25°. Commonly, in a group of fish, one or more of the females were seen with their vents down in rock interstices, emitting eggs, while the males in close proximity were observed releasing milt. Eggs on the beaches are probably aerated by wind-generated lake currents and seiches. Of 3553 eggs collected from several island beaches, 6.8% were infertile.Several features of the spawning behavior and environment are favorable to the survival of eggs and fry. The bottom is not scoured. Most eggs are deposited between immovable rocks and are thus not disturbed by subsequent spawners. Fry emerging from the beaches have immediate access to the large food supply in the lake. Some hazards are predation on eggs by fishes, freezing, and ultraviolet radiation of eggs in shallow water, and smothering of eggs in areas with a high density of eggs or algal growth.
Inheritance of Muscle Proteins in Hybrids Between the Redside Shiner (Richardsonius balteatus) and the Peamouth Chub (Mylocheilus caurinum)
Authors: Aspinwall Nevin , Tsuyuki H.
Published: April 2011

Selected muscle proteins were examined in artificially reared redside shiners, Richardsonius balteatus, peamouth chubs, Mylocheilus caurinum, and in their F1 and backcross hybrids to determine if they would be useful in identifying suspected natural hybrids. In reference to the proteins studied, Mylocheilus possesses a single zone designated "3"; Richardsonius also possesses a single zone designated "1," but of slower mobility. Artificially reared F1 hybrids possess, in addition to both parental zones, a unique zone designated "2" which was assumed to be composed of components of zones 1 and 3. Some naturally occurring individuals suspected of being hybrids on the basis of morphological characters possessed a pattern identical to that of the experimentally produced F1 hybrid (zones 1, 2, 3). Other suspected hybrids possessed either zones 1 and 2 or zones 2 and 3. These types of pattern corresponded to some of those produced by backcrosses to Richardsonius and Mylocheilus, respectively.The presence of both parental protein zones in the F1 hybrid indicates that each polypeptide can be synthesized when only half the alleles of each parent is present. This characteristic of codominance can be useful in identifying suspected hybrid offspring of parents having different protein zones.Evidence is presented which supports the hypothesis that the proteins in question are genetically controlled by two loci, A and B, each of which exists in two allelic forms.
Effect of Metopirone on Pituitary–Interrenal Function in Two Teleosts, Sockeye Salmon (Oncorhynchus nerka) and Rainbow Trout (Salmo gairdneri)
Authors: Fagerlund Ulf H. M. , McBride J. R. , Donaldson Edward M.
Published: April 2011

Metopirone (SU 4885), an inhibitor of 11β-hydroxylation of adrenocorticosteroids, was administered intramuscularly to adult castrated sockeye salmon (Oncorhynchus nerka) and intact rainbow trout (Salmo gairdneri). Marked hypertrophy of interrenal cells pointed to an increase in the activity of the interrenal tissue of both species. Increased cortisol concentrations in trout at low dosage levels of metopirone suggested that the drug was stressful. However, decreased concentrations at higher dosage levels in trout, and decreased cortisol concentrations in all salmon indicated that the drug was also exerting a marked inhibitory effect on 11β-hydroxylation. In salmon, a repository ACTH preparation (acthar) brought about interrenal hypertrophy similar to that produced by metopirone. Metopirone also induced degranulation and hyperplasia of the cells of the palisade-like layer in the rostral region of the pars distalis in both species of fish. These cells were the only cell type of the pars distalis that were stained with lead-haematoxylin. The evidence indicates that they are the corticotrops.
Tattoo-Marking of Fingerling Salmonids with Fluorescent Pigments
Authors: Duncan Richard N. , Donaldson Ivan J.
Published: April 2011

not available
Effectiveness of the Integument and Gastric Fluid as Barriers Against Transmission of Gaffkya homari to the Lobster Homarus americanus
Authors: Stewart James E. , Dockrill April , Cornick John W.
Published: April 2011

A rupture of the integument was shown to be essential for the transmission of Gaffkya homari to the lobster Homarus americanus. The acidity of the lobster gastric fluid was bactericidal for G. homari and was an adequate barrier against transmission of gaffkemia by the oral route. Lytic activity associated with the larger protein molecules of lobster gastric fluid, but not with the bactericidal effect of the acid condition, was weakly active against Micrococcus lysodeikticus but was not active against G. homari. The acidity of the lobster stomach is a function of the acidic protein molecules rather than a result of an excess of small, acidic molecules.
Variants of Lactate Dehydrogenase Isozymes in Sera of Sockeye Salmon (Oncorhynchus nerka)
Authors: Hodgins H. O. , Ames W. E. , Utter F. M.
Published: April 2011

Three phenotypes of lactate dehydrogenase (LDH) isozymes were found in sera of sockeye salmon (Oncorhynchus nerka), presumably representing B′B′, B′B, and BB genotypes. No association was obvious between LDH phenotype of sera and sex or total body length.Of 1006 sera from Asian, Bristol Bay, and Gulf of Alaska stocks, 826 were B′B′ and 180 were B′B or BB. Of 591 sera from Washington and British Columbia stocks, 589 were B′B′ and 2 were B′B; both of the B-allele phenotypes were found in fish captured at the Skeena River in northern British Columbia. These findings suggested that LDH isozymes should be useful in studies on ocean distribution of sockeye salmon and in characterizing certain Asian and Alaskan sockeye salmon populations.
Planktonic and Benthic Bacteriovorous Protozoa at Eleven Stations in Puget Sound and Adjacent Pacific Ocean
Authors: Lighthart Bruce
Published: April 2011

Bacteriovorous Protozoa and heterotrophic bacteria quantitatively cultured from 31 samples collected at eight stations in Puget Sound and three in the adjacent Pacific Ocean (one station being 1520 m deep) ranges from undetectable to approximately 1000 Protozoa per ml and 5–80,000 bacteria/ml. Flagellates in the genera Bodo, Oikomonas, Monas, Rynchomonas, and Actinomonas were the most prevalent forms cultured. One ciliate and several sarcodinoids were also grown. The regression of predatory Protozoa on prey bacteria in sediment samples was calculated to be 580 bacteria for every bacteriovorous protozoan. Population densities of both bacteriovorous Protozoa and heterotrophic bacteria in the samples decreased from sediment to the water column, and from shore seaward. The ecological role of bacteriovorous Protozoa in the shallow and deep sea is discussed.
Phenotypic Variation in Threespine Sticklebacks (Gasterosteus aculeatus) of the Chignik River System, Alaska
Authors: Narver David W.
Published: April 2011

Four phenotypes of the threespine stickleback, Gasterosteus aculeatus Linnaeus, were identified from the two Chignik lakes, Alaska: unplated (2–6 anterior plates); half-plated (7–15 anterior plates); fully plated (18–22 plates) lacustrine; and fully plated (18–22) estuarine. Distinctions lie in number and size of lateral plates and extent of lateral keel development on the caudal peduncle. Composition of the three lacustrine phenotypes in either lake population was similar among the years 1962–64 for both age I and age II in Black Lake but dissimilar in Chignik Lake. The Black Lake population contained a higher proportion of the unplated and half-plated phenotypes but fewer of the fully plated phenotypes than the Chignik Lake population. The life history of the estuarine phenotype is outlined. The mechanisms responsible for the maintenance of the four phenotypes in the Chignik River system have not been determined.
Studies on the Blood Morphology of Three Estuarine Cyprinodontiform Fishes
Authors: Gardner George R. , Yevich Paul P.
Published: April 2011

Specimens of Fundulus heteroditus, Fundulus majalis, and Cyprinodon variegatus were bled in the field at the site of capture. Blood was obtained during all seasons and in the laboratory at intervals over a 30-day period from specimens held in two types of holding aquaria. The circulating blood elements of these three estuarine species consist of erythrocytes, small and medium lymphocytes, eosinophils, and thrombocytes. The observations were made using both stained and fresh blood preparations.Variations occurred seasonally in the morphology of erythrocytes, eosinophils, and thrombocytes. Cytoplasmic inclusions were visible in erythrocytes prior to, and at the beginning of, the new breeding season. There were changes in the refringent properties of thrombocytic and eosinophilic granules, and cyclic variations in the number of eosinophilic granules. Seasonal variations occurred in the ratio of immature to mature thrombocytes, but there was little overall variation in the ratios of leucocytic cell types. The thrombocytes were characterized by thrombocytic granulation and nuclear indentations. Thrombocytes were capable of altering their form; mature cells formed thrombocytic networks.The concentration of eosinophils gradually increased to 18% above the usual level in Fundulus heteroditus held 30 days in 20-liter circular aquaria. The eosinophil level remained at the usual 2% in specimens held in 189-liter aquaria for the same time period. Values for specimens captured in a natural environment were also 2%. It is therefore plausible to relate the rise in eosinophils with an environmental stress associated with the circular holding containers.
Some Parasites from Elasmobranchs in Newfoundland
Authors: Threlfall William
Published: April 2011

One blue shark (Prionace glauca (L.)), 107 spiny dogfishes (Squalus acanthias L.), and 17 thorny skates (Raja radiata Donovan) were examined for parasites during the period August 1967–August 1968. All fish were obtained in Newfoundland waters. Four species of cestodes were recovered from the blue shark. The spiny dogfishes were infected with 13 species of parasites, and the thorny skates with 11 species. A total of 18 species of parasites were recovered from the spiny dogfishes and thorny skates, namely, two species of Monogenea, four of Digenea, six of Cestoda, four of Nematoda, one of Hirudinea, and one of Copepoda. Several new host records were noted.
Parasite Fauna of Pink Salmon (Oncorhynchus gorbuscha) of the Bella Coola River, Central British Columbia, During Their Early Sea Life
Authors: Boyce Norbert P. J.
Published: April 2011

The acquisition of parasites by pink salmon during their initial phase of marine life is described. The parasites found were the trematodes Lecithaster gibbosus, Parahemiurus merus, and Pentagramma petrowi, the cestode Phyllobothrium sp. larva, and the nematode Contracaecum sp. larva. An attempt is made to account for the occurrence of the more predominant species, particularly the trematode L. gibbosus.
A Revision of the Genus Cystidicola Fischer, 1798 (Nematoda: Spiruroidea) of the Swim Bladder of Fishes
Authors: Ko Ronald C. , Anderson Roy C.
Published: April 2011

The systematics of the species of the genus Cystidicola Fischer, 1798, parasites of the swim bladder of physostomous fishes, is revised. Cystidicola farionis Fischer, 1798, C. cristivomeri White, 1941, and C. stigmatura (Leidy, 1886) Ward and Magath, 1917, are considered to be the only valid species in the world. These three species are redescribed. Cystidicola farionis is morphologically indistinguishable from C. stigmatura but the two species are tentatively regarded as distinct until more data on their biology are available. Cystidicola brevicauda Fujita, 1939, and C. mesopi Fujita, 1940, are not members of Cystidicola but they cannot be assigned to any other genus. Cystidicola lepisostei Hunter and Bangham, 1933, is a member of Cystidicola but should be regarded as a species inquirendae. Cystidicola minuta Rhodhain and Vuylsteke, 1934, and C. serratus (Wright, 1879) Railliet, 1916, are regarded as species inquirendae of the genus Rhabdochona. The literature on numerous other species assigned at various times to Cystidicola is reviewed. The host and geographical distribution of the valid members of Cystidicola are reviewed.
Some Physiological Consequences of Aortic Catheterization in the Brook Trout (Salvelinus fontinalis)
Authors: Houston A. H. , DeWilde Mary Anne , Madden Jane A.
Published: April 2011

The effects of aortic catheterization upon the hematology and water-electrolyte regulation of brook trout have been followed for a period of 72 hr after completion of the procedure. The data indicate the markedly traumatic character of techniques of this general type, and the need for much longer recovery periods than have generally been allowed in studies on the cardiovascular physiology of salmonids.
Aspects of the Anatomy of the Winter Flounder Ovary with Hypotheses on Oocyte Maturation Time
Authors: Dunn R. S. , Tyler A. V.
Published: April 2011

Ovarian tissues of mature winter flounders have distinct groups of oocyte types which suggests that a minimum of 2 or 3 years pass from the time that oocytes become histologically recognizable until they are spawned.
Newfoundland Capelin Lipids: Fatty Acid Composition and Alterations During Frozen Storage
Authors: Ackman R. G. , Ke P. J. , MacCallum W. A. , Adams D. R.
Published: April 2011

Total lipids, triglycerides, and phospholipids from several lots of beach-spawning capelin and one lot of prespawning, offshore capelin have been determined and examined in detail for fatty acid composition. Generally, but not invariably, female fish contain more fat, the difference being apparent in the triglycerides. These are also usually of higher iodine value than triglycerides in the males. During frozen storage the lipids, including triglycerides, in most samples of male capelin undergo more severe hydrolysis than in the females. It is believed that these phenomena are related to bioenergetic relationships by which the males require very rapid catabolism of depot fat and hence nonspecific hydrolysis of fatty acids, whereas the less active females show some selectivity and preferentially catabolize the longer-chain monounsaturated fatty acids.When allowances are made for 16:1 and 18:1 being interchangeable, Newfoundland capelin triglycerides are shown to be essentially similar to eastern Atlantic commercial capelin oil, and may be distinguished by certain composition characteristics from other Canadian commercial oils of comparable iodine value. Details of fatty acid compositions are summarized for nutritional evaluation of capelin and capelin products.
Olfactory Discrimination of Natural Waters by Salmon
Authors: Oshima Kiyoshi , Hahn William E. , Gorbman Aubrey
Published: April 2011

Three sets of experiments are described, all based on the electrical responses recorded in the olfactory bulb of salmon (Oncorhynchus tshawytscha and O. kisutch) when various natural waters, or modified natural waters, were infused into the nostril.In the first experiments it was found that, generally, the most vigorous response was evoked by the home spawning area water and relatively less vigorous responses were evoked by waters in which the tested salmon had never been. However, an exceptional situation was found in which a strange water (Issaquah River) evoked olfactory responses in Soos Creek and University of Washington salmon that could not be distinguished from the home water response.Chinook salmon that had been reared in a freshwater hatchery for 2 years and then placed in sea water for 2 weeks retained their home water response in sea water. Placing chinook salmon in a small volume of fresh water, which had previously evoked only a slight bulbar electroencephalographic (EEG) response, rendered the water highly stimulatory. Keeping coho salmon under the same conditions did not make the water as stimulatory.Two-year-old adult chinook salmon placed in a new environmental water that was relatively weakly stimulatory at first developed a bulbar EEG response to the novel water in 3 days that was not distinguishable from the home water response.
Preliminary Investigation of the Exploitation of Some Potential Nutritional Resources by Three Sympatric Tubificid Oligochaetes
Authors: Brinkhurst Ralph O. , Chua Kian E.
Published: April 2011

Eight heterotrophic aerobic bacteria were identified in samples from Toronto Harbour. The three tubificid species present seem to ingest most if not all of these, but different species survive passage through the gut. One of the three worm species absorbs amino acid from solution in the absence of bacteria in the gut. It is suggested that the results indicate differences in the utilization of the potential nutritional resources by the worms, which may be reflected in the ability of three unspecialized sediment feeders to coexist in the same microhabitat.
Some Effects of Shape and Structure of Fish on Selectivity of Gillnets
Authors: McCombie A. M. , Berst A. H.
Published: April 2011

Selectivity curves for three species of fish taken in South Bay, Manitoulin Island, and in Georgian Bay during 1954–59 with gangs of nylon gillnets differed with respect to mode, skew, and kurtosis. A graphic method was developed to describe one aspect of body shape, namely the relation between girth and distance from the snout, which would affect selectivity. Surprisingly, the shapes of mature (but not gravid) and immature perch and suckers of both sexes could be described by the same curve. Hence, differences in body shape did not account for differences in the selectivity of these species. In contrast, the taper for gravid female perch was markedly different from that for nongravid, as might be expected. Catches in which the positions where caught were carefully identified showed that most of the fish were caught either on the opercle or near the position of maximum girth. That the fish could be caught at different positions accounted for most of the skew in the selectivity curves based on maximum girth. Selectivity curves plotted on the basis of girth where caught, rather than on maximum girth or length, show that efficiency of capture was maximal when the girth of the fish was 1.0–1.2 times as great as the perimeter of the mesh. Efficiency was negligible at girth/perimeter ratios smaller than 0.8 or 0.9 and it declined rapidly at ratios greater than 1.2. However, a few fish were taken at ratios up to 1.5 or 1.6.
Hypertrophy of the Interrenal Tissue in Sexually Maturing Sockeye Salmon (Oncorhynchus nerka) and the Effect of Gonadectomy
Authors: McBride J. R. , Overbeeke A. P. van
Published: April 2011

Sockeye salmon (Oncorhynchus nerka) develop marked hypertrophy of the interrenal tissue during the period of sexual maturation and spawning. No differences were found between fish held in captivity and those that matured in their natural habitat. Feeding appeared to have an inhibitory effect, but did not prevent the hypertrophy. Gonadectomy of sexually mature fish resulted in a rapid involution of the hyperplastic interrenal tissue. On the other hand, gonadectomy, when performed in an early stage of sexual maturity, prevented the development of interrenal hypertrophy. The interrenal hyperplasia was not accompanied by apparent changes in the ACTH cells of the pituitary gland. Gonadectomy, however, led to increased affinity of these cells for lead-hematoxylin, but this effect did not take place until after interrenal involution had commenced. The results are discussed and it is concluded that the hypertrophy of the interrenal at this time is caused by gonadal hormones, which may act directly on the adrenal homologue without mediation by the pituitary gland.
An Improved Extender for Freezing Atlantic Salmon Spermatozoa
Authors: Truscott B. , Idler D. R.
Published: April 2011

A solution of chemical composition based on that of seminal plasma was an effective extender for Atlantic salmon spermatozoa; semen diluted to 20 volumes could be maintained at 4 C in an inactive but potentially motile condition for several days. Propylene glycol at concentrations between 7.0 and 12.5% protected sperm cells against freeze–thaw damage. The addition of glycine or albumin to the basic extender containing 7–12.5% propylene glycol or 10% dimethyl sulphoxide provided an extender meriting further development for the cryopreservation of salmonid spermatozoa. Fertilities of 5–19% were achieved with 10 frozen sperm samples diluted with such extenders. For frozen samples a method of fertilization with simultaneous addition of water and sperm to the eggs is proposed.
Effects of Metal Poisoning on Five Liver Enzymes in the Killifish (Fundulus heteroclitus)
Authors: Jackim Eugene , Hamlin Janice M. , Sonis Stephen
Published: April 2011

Activities of five liver enzymes (acid and alkaline phosphatase, catalase, xanthine oxidase, and ribonuclease) from Fundulus heteroclitus surviving exposure to 96-hr TLm concentrations of salts of six metals (lead, copper, mercury, beryllium, cadmium, and silver) differed markedly from those of unexposed fish. Changes in enzyme activity produced by the exposures were not necessarily the same in magnitude or direction as those observed when the salts were introduced directly into the enzyme preparations. It is proposed that changes in liver enzyme activity may be useful as a kind of biochemical autopsy tool for diagnosing sublethal metal poisoning in fish.
A Review of the Morid Fish Genus Lepidion of the North Atlantic With First Records of Lepidion eques from the Western North Atlantic
Authors: Templeman Wilfred
Published: April 2011

Seventeen specimens of Lepidion eques (Günther) taken by the Fisheries Research Board of Canada St. John's, Nfld., Biological Station are apparently the first records of the species from the western Atlantic west of West Greenland. Comparison with specimens from the northeast Atlantic shows some differences in averages of meristic and morphometric characters, but with overlapping ranges in these characters.Comparison of these North Atlantic L. eques with the Mediterranean Lepidion lepidion (Risso) revealed that although closely related, these species are separable on the bases of the smaller orbit diameter in relation to the head length and especially by the relatively larger postorbital length in L. lepidion. Lepidion guentheri (Giglioli) is distinctly different from these two species in some meristic and many morphometric characters. Lectotypes of L. eques and L. guentheri are designated. Various incorrect or doubtful records of Lepidion are discussed. Two giant lepidions reported recently from the northeast Atlantic as L. guentheri are tentatively assigned to Lepidion schmidti Svetovidov, a species hitherto known only from Japan.The distributions of the North Atlantic species of Lepidion are discussed and information is provided on sexual maturity.
An Electrophysiological Basis for Olfactory Discrimination in Homing Salmon: A Review
Authors: Hara Toshiaki J.
Published: April 2011

Past and current researches relating to olfactory acuity and discrimination in fishes, with special reference to homing salmon, are reviewed.When the nasal sac of spawning Pacific salmon is stimulated with water from the spawning site a high amplitude electroencephalographic response of characteristic pattern is recorded from the olfactory bulb. This electrical response is specific in the sense that it cannot be evoked by water from spawning sites of other groups of breeding salmon. Further, the salmon respond clearly to water taken from places along their migratory routes below the spawning sites. These findings suggest that olfaction is an important factor in guidance during the final phases of homeward migration of salmon. It is also possible that salmon retrace sequentially a trail of stimuli that is the reverse of that imprinted in the young fish on their seaward migration.Although the available data do not delineate the sensitive period, or the duration of the imprinting process, there is accumulating evidence that only a short period is necessary for imprinting, which may occur when the smolts are in their freshwater life.Recent study on the effect of antimetabolites (puromycin, actinomycin D, or cycloheximide) on olfactory bulbar discrimination in homing salmon suggests that long-term olfactory memory in these fish depends upon continued metabolism of RNA and continued protein synthesis. The possibility that the imprinting process in young fish may be affected by polluted water, which has recently become a serious problem in fisheries, is discussed. The need for electrophysiological as well as biochemical studies at a macromolecular level of the imprinting process is emphasized.Finally, the hypothesis is discussed that a home stream odour may act most effectively as a simple "sign stimulus," which, through the release of a positive rheotropic response, induces the fish to move upstream toward home. This is largely based on the recent experimental observations of the orientation mechanism in several species of teleost fishes.
Gas Exchange in Rainbow Trout (Salmo gairdneri) with Varying Blood Oxygen Capacity
Authors: Cameron James N. , Davis John C.
Published: April 2011

The effects of large changes in hemoglobin concentration were studied in rainbow trout in fresh water between 8 and 14 C. Anemia was produced by injecting phenylhydrazine hydrochloride or by replacing blood with either saline or plasma.No significant changes were observed in the rate of oxygen consumption, arterial or venous oxygen tensions, ventilation volume, inspired and expired water oxygen tensions, or dorsal aortic blood pressure. The primary compensatory mechanism invoked was an increase in the cardiac output, which was accomplished almost entirely by increases in stroke volume. Although the viscosity of the blood was reduced, there must also be large changes in the peripheral resistance to blood flow, since greatly increased cardiac output was achieved without significant increase in blood pressure.The change in blood oxygen capacity and increase in cardiac output caused significant lowering of the ventilation–perfusion ratio, but the capacity–rate ratio of water to blood varied only a little. A small rise occurred at low hematocrit values, due to small changes in a number of parameters.The experiments illustrate what happens when blood oxygen capacity is reduced, but do not elucidate the mechanism for control of stroke output of the heart. They also indicate that a species' hemoglobin level is maintained at a level that allows cardiac output to vary over an optimal range of its efficiency curve.
Influence of Temperature and Salinity Acclimation on Temperature Preferenda of the Euryhaline Fish Tilapia nilotica
Authors: Beamish F. W. H.
Published: April 2011

When Tilapia nilotica was acclimated to temperatures of 15–35 C and salinities of 0–30‰ in a vertical gradient tank, maximum temperature preferenda occurred at acclimation temperatures of 20 and 25 irrespective of salinity. Preferenda declined as acclimation temperature was increased above 25 C and, except at 0 and 7.5‰, declined as acclimation temperature was decreased below 20 C. The pattern of the relation between final temperature preferenda and salinity was similar to that reported between oxygen consumption for a given sustained swimming speed and salinity. The final preferendum was lowest at 15‰, close to the isosmotic salinity of T. nilotica, and highest at the extremes, 0 and 30‰. Final temperature preferenda are in general agreement with optimum temperatures reported for growth, reproduction, and swimming performance.
Marine Trematode Tubulovesicula lindbergi (Digenea: Hemiuridae) from Resident White Sturgeon in the Columbia River
Authors: Becker C. Dale
Published: April 2011

An infection with a marine trematode, Tubulovesicula lindbergi (Layman, 1930) (Digenea: Hemiuridae), was discovered in a resident white sturgeon, Acipenser transmontanus Richardson, taken in the central Columbia River, Washington, USA. Tubulovesicula lindbergi is normally restricted to marine environs by virtue of essential (but still unknown) invertebrate intermediate hosts, but may occur in migratory fish that enter fresh water. Since hydroelectric dams on the Columbia are now effective barriers to the passage of sturgeon, it is postulated that T. lindbergi was transported into the river system by a maturing, anadromous teleost. After the postspawning death of the "transport" teleost host, the sturgeon presumably acquired the infection when scavenging. Consideration of basic synecological relationships supports the hypothesis. The white sturgeon is a new host record for T. lindbergi.
An Occurrence of Male Predominance Among Repeat Spawning Atlantic Salmon (Salmo salar)
Authors: MacDonald J. Rod
Published: April 2011

An unusual case of male predominance among Atlantic salmon (Salmo salar) repeat spawners was observed in the Saint John River, N.B., in 1967. A sample of 947 Saint John River salmon (416 grilse and 531 older salmon) contained 91 repeat spawners, 50 (55%) of which were males.
Changes in the Blood of Brook Trout (Salvelinus fontinalis) After Short-Term and Long-Term Exposure to Copper
Authors: McKim J. M. , Christensen G. M. , Hunt Evelyn P.
Published: April 2011

Seven blood characteristics — red blood cell count (RBC), hematocrit (Hc), hemoglobin (Hb), plasma chloride (Cl), plasma glutamic oxalacetic transaminase (PGOT, L-aspartate:2-oxoglutarate amino transferase), osmolarity (Os), and total protein (TP) — were measured in brook trout (Salvelinus fontinalis) that had been exposed to three concentrations (67.5–69.2, 38.2–39.0, and 22.8–24.0 μg/liter) of Cu(II) for 6 and 21 days. Concentrations of 67.5–69.2 and 38.2–39.0 μg/liter caused statistically significant increases in RBC, Hc (6-day only), Hb, PGOT, and TP (6-day only), whereas Cl and Os decreased during both exposure periods. Five blood characteristics (RBC, Hb, Hc, Cl, and PGOT) were also measured in brook trout, which were exposed for 337 days to Cu(II) concentrations of 32.5, 17.4, 9.5, 5.7, and 3.4 μg/liter. After this long-term exposure, no changes were observed in the blood except for a measurable decrease in PGOT values at 32.5 and 17.4 μg/liter. The disappearance of initial blood changes, after extended exposure, suggests the transient nature of these early responses. Application of this study to the evaluation of the physical condition of fish and the possible long-range forecasting of reproductive success and survival of a species is discussed.
Ecological Energetics and Natural History of Hedriodiscus truquii (Diptera) in Two Thermal Spring Communities
Authors: Stockner John G.
Published: April 2011

The interrelations of flora and fauna of the Ohanapecosh Hot Springs, Mount Rainier National Park, Washington State, were studied during a 4-year period commencing in 1963. The flow of energy and efficiency of its transfer were measured in two springs, one with an annual mean temperature of 35 C (SD 2.0) and the other a constant 47 C. In addition to temperature differences, each spring contained a different flora and fauna.Primary production estimates were obtained together with data relative to many aspects of the natural history of the dominant dipteran herbivore Hedriodiscus truquii (Bellardi), hitherto undescribed in the larval stage, and common to both springs. Aspects of the natural history of Hedriodiscus pertinent to the energetic approach are discussed, including a detailed caloric investigation. Information about the seasonal variation in lipid composition during larval growth was used to explain much of the observed caloric variation. Energy budgets for three of the four instars of Hedriodiscus were determined from estimates of growth, respiration, and rates of food ingestion. This information together with population census data permitted calculation of population energy budgets. Efficiencies of energy transfer in both spring communities are compared and discrepancies in the allocation of assimilated energy between populations are attributed to variation in diel behavior patterns and differences in food ingested. Export of Hedriodiscus larvae and spider predation on newly emerged adults inflicted heavy mortality and were considered the most important sources of population regulation. The annual energy balance for the two springs was tabulated from estimates of energy income and export. The springs fixed far more energy than was expended in any given year. Greatest losses are attributed to algal export, respiration, and travertine deposition; tree leaves represented a significant income of energy to the springs. Primary production accounted for better than 90% of total income and only 0.5–1.0% of algal primary production was channeled to the dominant herbivore, Hedriodiscus. Of algal gross production 20–25% was exported from the system. Photosynthetic efficiency was 1.06% utilization of visible light available to algae.
Light, Temperature, and Oxygen Regimes of Selected Lakes in the Experimental Lakes Area, Northwestern Ontario
Authors: Schindler D. W.
Published: April 2011

Light was measured in several Experimental Lakes Area (ELA) lakes in 1968 and 1969, using a Secchi disc, a standard photometer (cadmium sulfide cell), and a 16-channel spectroradiometer. The results of some checks upon the standard procedure usually used for making subsurface light measurements are presented. Light penetration at several wavelengths and total energy flux at several depths are given for a number of lakes. Oxygen and temperature isopleths, winter rates of oxygen depletion, annual heat budgets, and data on work of the wind are also presented. Vertical extinction coefficients (average of all visible wavelengths) ranged from 0.285 for lake 161 to 1.732 for lake 227, and Secchi disc visibility from 1.2 to 10.1 m. The wavelength of maximum transmittance shifted toward long wavelengths, as expected, when transmission coefficients and Secchi disc visibility decreased.Annual heat budgets ranged from 8400 to 24,200 cal/cm2. From 3700 to 16,000 cal/cm2 of this were summer heat income. Summer and annual heat budgets were larger for larger lakes. Annual and summer heat incomes were related to mean depth, surface area, and volume of the lakes by simple linear regression equations.The work of the wind and its efficiency in distributing summer heat income are discussed. The depth of the thermocline in ELA lakes was set early in the year, and did not change during the summer until well after the lake had reached maximum heat content. The temperature of the epilimnion followed the mean daily air temperature closely during the summer though remaining several degrees higher, probably as the result of radiant heating. It is concluded that wind work calculated by Birge's method (Trans. Wis. Acad. Sci. Arts Lett. 18: 341–391, 1916) is of little value, unless corrections for back-radiation and evaporation can be made.Rates of oxygen depletion under ice were compared in several lakes. Values ranged from 15.0 to 73.8 mg O2/m3∙day and from 36 to 253 mg O2/m2∙day.
Preliminary Characterization of Lakes in the Experimental Lakes Area, Northwestern Ontario, Using Diatom Occurrences in Sediments
Authors: Stockner John G.
Published: April 2011

Diatoms in deepwater surface sediment from 16 Experimental Lakes Area (ELA) lakes of varying size and morphometry were separated for analysis on the basis of their generally understood habitat preference into littoral and planktonic groups. The lakes were ranked in order of increasing relative abundance of littoral diatoms recovered from deepwater surface sediment. A significant correlation was found between the abundance of littoral diatoms in deepwater sediments and the morphometric variables: lake surface area (Ao), and shoreline length to lake volume (L/V), and percent littoral development in each lake. The Centrales was the dominant planktonic group in most of the ELA lakes examined. Species of Cyclotella and Melosira were the dominant diatoms in most ELA lakes. The ratio of the two planktonic groups—Araphidineae and Centrales (A/C)—calculated from sediment counts, agreed closely with the A/C ratio enumerated from 1969 phytoplankton counts in two lakes compared. Based on a lake classification scheme using values of the A/C ratio from sediment diatom counts, the majority of ELA lakes were classed as oligotrophic. Analysis of a 155-cm core from lake 240 showed little change in diatom species composition over the past 3000–4000 years. Centrales was the dominant diatom assemblage at all sediment depths. The dominant diatoms in the sediment of lake 240 and the majority of ELA lakes examined were similar to those dominant in the deepwater sediments of well-studied oligotrophic lakes in other lake districts. On the basis of calculated A/C ratios in surface sediment in several lakes at temperate latitudes, a lake trophic classification is proposed.
Dissolved Oxygen Requirements for Embryonic and Larval Development of the Hardshell Clam, Mercenaria mercenaria
Authors: Morrison George
Published: April 2011

Eggs and larvae of Mercenaria mercenaria were exposed to various levels of dissolved oxygen for varying time periods. Larval growth was normal in levels of dissolved oxygen at or above 4.2 mg/liter, but was essentially curtailed in levels at or below 2.4 mg/liter. Larvae survived extended exposures of 1 mg/liter, but showed little growth. Growth rates of larvae transferred to conditions of high dissolved oxygen after various periods of exposure to low dissolved oxygen became normal. Eggs developed normally at oxygen levels down to 0.5 mg/liter. One hundred percent mortality was experienced at 0.2 mg/liter.
High Tide Movements and Homing Behaviour of the Tidepool Sculpin Oligocottus maculosus
Authors: Green John M.
Published: April 2011

Tagging studies show that the tidepool sculpin Oligocottus maculosus Girard shows fidelity to specific tide pools and will return to their pools when displaced. The results indicate that the navigational ability of O. maculosus is not solely dependent upon familiarity with geographical features of the intertidal zone. It is suggested that homing behavior functions as a mechanism stabilizing the spatial distribution of this species.
The Red-Water Ciliate Mesodinium rubrum and its "Incomplete Symbionts": A Review Including New Ultrastructural Observations
Authors: Taylor F. J. R. , Blackbourn D. J. , Blackbourn Janice
Published: April 2011

The authors provide the first ultrastructural description of the marine holotrich ciliate Mesodinium rubrum and of its unusual "incomplete symbionts," consisting of numerous functional chloroplasts associated with distinctive nonciliate mitochondria but apparently lacking associated nuclei. The pigment characteristics suggest a cryptomonad origin for the chloroplasts but they are traversed by lamellae that are either ungrouped or in groups of three's, this being contrary to ultrastructural observations on cryptomonads to date. Unusual ultrastructural features of the ciliate include the lack of alveoli in the very thin pellicle and two types of ciliary differentiation: the presence of lateral packing material in some of the cilia grouped to form cirri, and narrow distal portions from which the nine peripheral microtubule duplets are excluded. The cytostome is greatly reduced and the ciliate usually swims backwards. The problem as to the degree of permanence reflected by these features, including whether the symbiotic state is obligate or not, was not resolved. The authors discuss the evidence bearing on this question.The paper also reviews the ecology and taxonomy of the ciliate. Fifty instances of its occurrence, often in conjunction with nontoxic "red water," are summarised. The species has an extremely wide geographic distribution, including both polar and equatorial waters. Red water caused by the species occurs either within extreme coastal localities (bays, inlets) or in the vicinity of offshore upwelling. Field studies demonstrated that the ciliate–chloroplast consortium is a functional autotroph capable of playing the role of primary producer.Taxonomic difficulties are summarised. Previous designations of the species to the genus Cyclotrichium are considered inappropriate. Detailed study of widely spread populations is needed to determine the degree of taxonomic confusion involved.
Nitrogen Excretion and Protein Consumption of the Bluegill Sunfish (Lepomis macrochirus)
Authors: Savitz J.
Published: April 2011

Nitrogen excretion rates increase with an increase in protein consumption levels. A mathematical description of this relation was formulated from the data. Estimates of the effect of specific dynamic action on nitrogen excretion were also calculated.
Effects of Androgens, Estrogens, and Cortisol on the Skin, Stomach, Liver, Pancreas, and Kidney in Gonadectomized Adult Sockeye Salmon (Oncorhynchus nerka)
Authors: McBride J. R. , Overbeeke A. P. van
Published: April 2011

A study was made of the histological changes occurring in the skin, stomach, liver, pancreas and kidney of adult gonadectomized male and female sockeye salmon in response to hormone treatments. The males received 11-ketotestosterone, 17α-methyltestosterone or cortisol for 4 or 7 weeks, and the females received estradiol, estradiol cypionate, or cortisol for 8 weeks.In the males, androgen injection evoked a highly significant increase in the thickness of the epidermis, a marked atrophy of the stomach, and a degeneration in the liver and kidney. In the pancreas, the exocrine portion showed characteristics of cytolysis in the acini, whereas the islets of Langerhans were hypertrophied. These changes were generally more pronounced after 7 weeks than after 4 but, in the skin, no further increase in the thickening of the epidermis was noted after the 4th week of treatment. No differences between responses of these tissues to 11-ketotestosterone and 17α-methyltestosterosne were detected.Estrogen administration in the females evoked similar, albeit weaker, responses in the skin, stomach, pancreas, and kidney than those recorded in the androgen-treated males. The liver of the females exhibited the characteristics of a hyperactive organ, which probably reflects estrogen-induced vitellogenesis.The effects of cortisol were similar in both sexes: little, if any, change was noted in the skin; atrophy or degeneration was observed in the stomach, liver, kidney, and in the exocrine portion of the pancreas, and the islets of Langerhans were hypertrophied. The cortisol-induced alterations were not, however, as pronounced as those noted in either the androgen- or estrogen-treated fish.These changes are discussed in relation to the changes observed in normal sexually maturing and reproducing Pacific salmon.
Factors Influencing Scope for Activity and Active and Standard Metabolism of Rainbow Trout (Salmo gairdneri)
Authors: Dickson I. W. , Kramer R. H.
Published: April 2011

Scope for activity was similar for hatchery and wild rainbow trout (Salmo gairdneri), except at 25 C where values for wild trout were significantly higher than those for hatchery trout. In hatchery and wild rainbow trout, respectively, scope for activity was highest at 15 and 20 C. Active metabolism increased with temperature to 570 and 592 mg O2/kg per hr at 15 and 20 C, respectively. At 25 C, active metabolic rates of wild trout were higher than those for hatchery trout. In hatchery and wild trout, respectively standard metabolism increased from 36 and 42 mg O2/kg per hr at 5 C to 138 and 120 mg O2/kg per hr at 25 C.Scope for activity of hatchery trout was highest after 6 days starvation. Starvation had no effect on active metabolism of hatchery trout, but decreased their standard metabolism after 2 days.Scope for activity and active and standard metabolism of wild trout were similar during forenoon to those during afternoon when light simulated natural day and night and also when lighting was constant for 24 hr.Active metabolism of hatchery trout was higher during the spawning period than other periods of the year and was consistently the higher for males throughout the year.
Temperature Requirements for Growth and Survival of Larval Ciscos (Coregonus artedii)
Authors: McCormick J. Howard , Jones Bernard R. , Syrett Roll F.
Published: April 2011

Temperatures above 13 and below 18 C are recommended as most suitable for sustained production of larval cisco, as indicated by instantaneous rates of growth, mortality, and net biomass gain in cisco reared at seven constant temperatures from 3 to 21 C. Growth rates increased in the temperature range from 3 through 18 C. Mortality rates were low from 3 through 13 C, but increased significantly between 13 and 18 C. Net rates of biomass gain were maximum at 13 through 18 C. The 24-hr median lethal temperature for ciscos acclimated to 3 C was calculated to be 19.8 C.