bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Affecting Sockeye Salmon (Oncorhynchus nerka) Growth in Four Lakes of the Fraser River System
Authors: Goodlad J. C. , Gjernes T. W. , Brannon E. L.
Published: April 2011

Analysis of data from four sockeye rearing lakes of the Fraser River system for periods of up to 20 yr provided information on the relation of estimated fish density (female spawners/ha), temperature, and zooplankton standing crops to growth. The lakes differed widely in all attributes. Growth was inversely related to estimated population density in three of the lakes, but wide variations in growth at low density occurred in the fourth, a cold lake at high elevation with short growing season. In this lake, and to a lesser extent in another lake with short growing season, temperature during fry emergence and early lake residence accounted for much of the recorded fluctuation in growth. Reduced zooplankton abundance was associated with high sockeye density in two of the lakes with intermediate standing crops and greatest sockeye densities, but was not recorded in a lake of low standing crop and intermediate sockeye density. Sockeye feeding was found to be highly selective in one lake, and a limited proportion of the zooplankton standing crop was utilized. It is suggested that reduction in standing crop by grazing of juvenile sockeye, and associated decrease in growth, is greatest as the large zooplankters are progressively reduced in abundance. Further reduction in standing crop and in sockeye growth was suggested to proceed at a slower rate. Competition at high population density was concluded to be the factor most responsible for reducing sockeye growth.
Migrations and Intermingling of Atlantic Cod (Gadus morhua) Stocks of the Newfoundland Area
Authors: Templeman Wilfred
Published: April 2011

Commercial recaptures of 26% (22.5% in years after the tagging year) of 18,822 Atlantic cod (Gadus morhua) 50 cm or more in length that were tagged mainly in the feeding season at 13 localities in the Newfoundland area in 1954–55 elucidated migrations and intermingling of cod of various stocks or stock complexes. Cod of the northern Gulf of St. Lawrence stock migrated southward from the Strait of Belle Isle to winter on the northern side of Cabot Strait and vicinity, mingling there with the Burgeo Bank stock. Cod of the Newfoundland–Labrador complex tagged at three sites mingled along the east coast of Newfoundland and off southern Labrador and with cod of the northern Gulf stock near the Strait of Belle Isle, of the Avalon–Burin stock complex off the Avalon peninsula, and of a Grand Bank stock on the northern part of the bank. Though cod tagged off the Avalon peninsula and on St. Pierre Bank were recaptured mainly near the tagging sites, some moved as far north as Labrador, to the southern Grand Bank, and to Cabot Strait. Fish tagged on the northwestern Grand Bank were recaptured mainly at the tagging site but also elsewhere on the bank and off the east coast of Newfoundland. Those tagged on the Southeast Shoal of the Grand Bank were recaptured mainly on the southeastern part of the bank though some moved as far as southeastern Newfoundland. Those tagged on Burgeo Bank mingled with the Avalon–Burin stock complex, including the St. Pierre Bank component, but mainly with the Northern Gulf stock in winter–spring near Cabot Strait.Cod 90–129 cm long at tagging were recaptured at shorter distances from the tagging sites than 50–89-cm cod. Tagging–recapture distances also increased with increasing age for cod of the smaller length ranges on tagging. In their vertical movements, most tagged cod moved to shallow water in late spring or early summer and retreated gradually to deeper water from late summer to early spring. Some remained in deep water throughout the year.Recapture rates at different size ranges varied with area but were not greatly different at length ranges from 50–59 to 80–94 cm, which included 95% of the tagged cod.
Liver Fat and Protein Metabolism in Rainbow Trout (Salmo gairdneri) Fed Cyclopropenoid Fatty Acids
Authors: Malevski Y. , Montgomery M. W. , Sinnhuber R. O.
Published: April 2011

Effects of cyclopropenoid fatty acid (CPFA) ingestion on fat and protein metabolism in the liver of rainbow trout (Salmo gairdneri) were studied. Three dietary regimens were used: experimental group fed 0.5 mg CPFA/kg body weight per day, pair-fed control, and ad lib. control. CPFA ingestion did not cause a reduction in body weight gain; however, the ratio of liver weight to body weight was elevated. Livers of CPFA-fed trout had higher fat and lower protein levels. Incorporation of 14C labelled amino acids into livers was reduced in CPFA-fed trout. Of the amino acids incorporated into the livers, a higher proportion was found in the liver proteins of CPFA-fed trout than pair-fed controls. The percentage of 14C labelled acetate incorporation into liver fat of CPFA-fed trout was similar to that of the pair-fed controls, whereas acetate incorporation into liver proteins was reduced. Activities of glutamate dehydrogenase (EC 1.4.1.3) and alanine aminotransferase (EC 2.6.1.2) were lower in CPFA-fed trout after 36 days on the diet; acetyl-CoA carboxylase (EC 6.4.1.2) activity was unaffected by the treatment.
A Numerical Study of the Concentration of Some Heavy Metals in Tasmanian Oysters
Authors: Ratkowsky D. A. , Thrower S. J. , Eustace I. J. , Olley June
Published: April 2011

Inferential techniques of numerical classification and principal coordinate analysis have been used to interpret data obtained on the Zn, Cd, and Cu concentration of 48 samples of oysters, comprising 473 individuals, grown at a variety of places around the Tasmanian coastline. A close association was obtained between proximity to heavily urbanized areas and concentration of metals found, oysters growing nearest urban areas having the highest concentrations of one or more of the metals. It appears that areas for commercial oyster growing should be sought in regions far from centers of urbanization and industrialization. Examination of samples of native oysters could be useful in providing an index or measure of environmental pollution.
Biochemical and Serological Differentiation of Several Pigment-Producing Aeromonads
Authors: Paterson W. D.
Published: April 2011

A pigment-producing aeromonad isolated from Atlantic salmon (Salmo salar) was serologically and biochemically indistinguishable from Aeromonas liquefaciens ATCC 14715. Aeromonas salmonicida, whose presence in the Maritime Provinces of Canada has never been confirmed, was clearly differentiated from the pigmented strains of A. liquefaciens.
Pathophysiology of Infectious Hematopoietic Necrosis Virus Disease in Rainbow Trout (Salmo gairdneri): Early Changes in Blood and Aspects of the Immune Response after Injection of IHN Virus
Authors: Amend Donald F. , Smith Lynnwood
Published: April 2011

Juvenile rainbow trout (Salmo gairdneri) were injected with infectious hematopoietic necrosis (IHN) virus and various hematological and blood chemical changes were monitored over 9 days. The packed cell volume, hemoglobin, red blood cell count, and plasma bicarbonate were significantly depressed by day 4. Plasma chloride, calcium, phosphorus, total protein, and blood cell types did not change during the 9 days. Furthermore, plasma [Formula: see text] LDH isozyme was significantly increased by the fourth day, and fish infected with infectious pancreatic necrosis virus, Vibrio anguillarum, Aeromonas salmonicida, and redmouth bacterium did not show specific LDH isozyme alterations. Acid-base alterations occurred at 10 C but not at 18 C. The acid-base imbalance and elevation of the [Formula: see text] LDH isozyme were consistently associated with the early development of the disease.The immune response after injection of IHN virus was determined and protection from disease was tested by passive immunization. Actively immunized fish developed IHN-neutralizing antibodies within 54 days after injection of virus, and the antibodies were protective when juvenile fish were passively immunized and experimentally challenged with IHN virus.
Mixing Within Experimental Enclosures: a Cautionary Note on the Limnocorral
Authors: Boyce F. M.
Published: April 2011

A simple theoretical model was constructed to simulate heat transfer from a stratified lake surrounding an experimental enclosure constructed of a thin, flexible, vertical curtain. It was shown that for realistic dimensions of the apparatus and for modest horizontal turbulent diffusion processes within the enclosure, the vertical temperature profiles inside and outside the enclosure could be expected to be closely similar, and that the similarity was a result of horizontal heat transfers. In this situation, similarity of temperature profiles was not evidence of similarity of vertical transfer processes and experimental results within enclosures which depend on vertical transfers should be extrapolated with caution to the main body of the lake.
Long-Distance Migration of an Atlantic Mackerel (Scomber scombrus)
Authors: Parsons L. S. , Moores J. A.
Published: April 2011

The recapture south of Long Island of an Atlantic mackerel (Scomber scombrus) tagged in Newfoundland waters represents a migration of at least 2259.6 km (1400 miles), the farthest documented migration of mackerel ever reported from the Northwest Atlantic. This recapture supports earlier tagging evidence that overwinter mixing may occur between the northern and southern populations of mackerel.
Empirical Functions Relating Metabolic Processes in Aquatic Systems to Environmental Variables
Authors: Parker Richard A.
Published: April 2011

Two empirical relationships were proposed to describe the metabolic consequences of high and low levels of light intensity, temperature, and nutrients in aquatic systems. Their performance was evaluated for three sets of data taken from the literature.
Toxicity of Phosphamidon to American Lobsters (Homarus americanus) Held at 4 and 12 C
Authors: McLeese D. W.
Published: April 2011

The concentration of phosphamidon that kills 50% of lobsters in 96 h (96-h LC50) at 12 C is 50 μg/liter and the lethal threshold is 18 μg/liter whether determined in static or running water tests. The 96-h LC50 at 4 C is 180 μg/liter and the lethal threshold is 28 μg/liter, or possibly as low as 18 μg/liter. Phosphamidon is 50–60 times less toxic to lobsters than fenitrothion.
Evaluation of the Swimming Performance of Several Fish Species from the Mackenzie River
Authors: Jones D. R. , Kiceniuk J. W. , Bamford O. S.
Published: April 2011

Critical velocities of 17 species of fish from the Mackenzie River have been determined from increasing velocity tests in both field and laboratory, and the effects on critical velocity of different acclimation temperatures and of temperature shock were examined. In five species the relation between fatigue time and swimming speed was investigated.Critical velocity data from 10 species were analyzed by solving the regression equation V = KLe (where V = critical velocity in cm/s, L = fork length, K = constant, e = exponent). Neither acclimation to different temperatures nor temperature shock over a range of ±7 C from acclimation temperature had a significant effect on critical velocity. Intraspecific variation was found to be unrelated to maturity, sex, or condition factor.From a graphical presentation of body length vs. maximum flow rate allowable in a 100-m culvert, it appears that culvert flow rates should be kept below 30–40 cm/s to allow successful passage of the majority of mature individuals of migratory species.
An Inexpensive Multiple Level Water Sampler
Authors: Goodwin M. H. , Goddard C. I.
Published: April 2011

An inexpensive nonmetallic water sampler was designed to secure multiple samples simultaneously from different depths. The device is constructed of readily available materials and may be operated from a small boat.
Feeding Efficiencies of the Polychaete Nereis virens Cultured on Hard-Clam Tissue and Oyster Detritus
Authors: Tenore Kenneth R. , Gopalan U. K.
Published: April 2011

In laboratory experiments, the ecological and assimilation efficiencies of the polychaete Nereis virens cultured on biodeposits of oysters (5.7 and 28.8%) were lower than for worms grown on clam tissue (18.0 and 77.3%). However, a high consumption rate of biodeposits resulted in a growth rate (48% increase in dry wt) higher than for worms fed clam tissue (31% increase). Mucus production by Nereis virens accounted for several percentage points in the calculation of efficiencies. Biodeposits in both natural and aqua-culture environments might be exploited as a food source for this species.
Parasite Fauna of Kokanee Salmon (Oncorhynchus nerka) Introduced into Lake Huron
Authors: Collins J. J. , Dechtiar A. O.
Published: April 2011

In a 7-yr study, the most common parasites of kokanee salmon (Oncorhynchus nerka) introduced to Lake Huron were the acanthocephalans Metechinorhynchus salmonis (in 61% of 228 adult fish examined) and Acanthocephalus jacksoni (15%) and the nematode Cystidicola stigmatura (41%). These also occurred in fish species netted along with kokanee, but many common parasites of other salmonids in Lake Huron were not harbored by kokanee. In addition to evidence of attack by sea lamprey (Petromyzon marinus), 18 species of parasites were found, 13 of which had not been previously recorded for kokanee in the Pacific drainages of North America. The high incidence of M. salmonis and C. stigmatura indicates that amphipods are commonly ingested by kokanee.
Effect of Feeding Brown Trout (Salmo trutta) a Diet Pelleted in Dry and Moist Forms
Authors: Poston Hugh A.
Published: April 2011

Growth rate, body composition, and intake of either dry matter or energy did not differ significantly (P > 0.05) between two groups of juvenile brown trout (Salmo trutta) fed either a low- or high-moisture semipurified diet at different rates to compensate for a diet energy density gradient. Feed/gain efficiency, on an as-fed basis, was significantly greater (P < 0.01) in fish fed the low-moisture diet, but did not differ (P > 0.05) when compared on the basis of dry matter or energy intake.
Fish Farming International
Authors: Saunders Richard L.
Published: April 2011

not available
Redescription of Anonchohaptor anomalum Mueller 1938 and a Description of Icelanonchohaptor fyviei n.sp. (Monogenoidea: Dactylogyridae)
Authors: Dechtiar Alex O. , Dillon William A.
Published: April 2011

Icelanonchohaptor fyviei n. sp., from the gills of quillback, Carpiodes cyprinus (LeSueur), is described and Anonchohaptor anomalum Mueller 1938 is redescribed. A new host record, longnose sucker, Catostomus catostomus (Forster), is reported for Anonchohaptor anomalum Mueller 1938.
Retarded Behavioral Development and Impaired Balance in Atlantic Salmon (Salmo salar) Alevins Hatched from Gastrulae Exposed to DDT
Authors: Dill P. A. , Saunders R. C.
Published: April 2011

Eggs of Atlantic salmon (Salmo salar) were subjected to 0.1, 0.05, 0.01, or 0.005 ppm DDT at gastrulation. Behavior of hatched fish was observed in DDT-free aquaria for about 30 days, and compared with that of controls. Exposure to the two higher concentrations of DDT retarded behavioral development and impaired balance. The consequences of such behavior changes to wild fish are discussed.
Serological Diagnosis of Corynebacterial Kidney Disease of Salmonids
Authors: Chen Peter K. , Bullock G. L. , Stuckey H. M. , Bullock A. C.
Published: April 2011

An immunodiffusion test is described which provides a rapid, sensitive, and definitive diagnosis of corynebacterial kidney disease of salmonid fishes. Specific precipitin lines are formed within 24 h when rabbit antiserum is reacted with kidney disease cell suspensions or internal tissue homogenates containing the specific bacterium. No precipitin lines are formed with tissue homogenates from healthy fish or from those injected with other fish pathogenic bacteria.
The Structure of Marine Ecosystems
Authors: Mann Kennethe H.
Published: April 2011

not available
Systematic Status of a Midwater Population of Freshwater Sculpin (Cottus) from Lake Washington, Seattle, Washington
Authors: Larson K. W. , Brown Jr. G. W.
Published: April 2011

A population of freshwater sculpin from Lake Washington differs from other species of the typically benthic genus Cottus in that individuals migrate nightly to the surface and midwaters. Individuals are phenotypically and biochemically similar to Cottus aleuticus, but have a longer, more terete body, a larger cephalic pore and canal system, shorter pelvic fins, and a higher frequency of individuals with seven branchiostegal rays per side.A close relationship between the Lake Washington population and C. aleuticus seems indicated because of their phenotypic and biochemical similarities and because of the existence of individuals in other Northwest lakes that appear intermediate in character between C. aleuticus and the Lake Washington population. The decision as to the specific status of the Lake Washington population is deferred until more is known of its degree of reproductive isolation from C. aleuticus and of the existence of these possibly intermediate populations.
Effects of the Antimicrobial Furanace on Fundulus heteroclitus Embryos
Authors: Williams Jr. George , Simmonds Richard C. , Boyd John F.
Published: April 2011

Single, 1-h treatments of five stages of Fundulus heteroclitus embryos with Furanace solutions (2.0, 1.0, 0.5, and 0.25 ppm) resulted in no significant increase in either mortality or anomaly rates. We conclude that a 1-h treatment with Furanace may be safely used in the media supporting fertilized eggs. Chronic exposure of F. heteroclitus embryos in 2.0, 6.0, and 10.0 ppm solutions results in high mortality and anomaly rates.
Hybridization in Sunfishes (Lepomis, Centrarchidae) Based on Time-Growth and Static Allometry
Authors: Misra R. K.
Published: April 2011

A statistical method of analyzing for hybridization based on exponential growth curves is presented. It is pointed out that with "truly cross-sectional data" such as those on the sunfishes (genus Lepomis) reported here, it is possible to analyze for hybridization based on static variations separately from that based on the average growths of populations. The technique of statistical linear comparisons is extended to analyze for the degree of intermediacy of the hybrids as an alternative to the hybrid index approach. Applications of the statistical method of analyzing for hybridization based on the constants of exponential curves and of the method based on static allometry are shown on a real set of data for the first time.
Infectious Pancreatic Necrosis Virus and Bacterial Kidney Disease Appearing Concurrently in Populations of Salmo gairdneri and Salvelinus fontinalis
Authors: Yamamoto T.
Published: April 2011

An investigation into disease problems at a hatchery revealed the coexistence of bacterial kidney disease and infectious pancreatic necrosis (IPN) virus in various lots of rainbow (Salmo gairdneri) and eastern brook (Salvelinus fontinalis) trout. During the study, increased mortality rates occurred in yearling brook trout with concurrent infections of bacterial kidney disease and IPN, but the mortality appeared to be primarily associated with the bacterial agent. Evidence is presented to indicate that infection with virus preceded the bacterial infection. Electron microscopic examination of kidney tissues showed that both agents could be found within the same cells.
Selenium Determination on Fish Tissue
Authors: Beal Albert R.
Published: April 2011

A wet-digestion procedure for selenium analysis offish is described. It involves digestion of the fish tissue homogenate in a nitric–perchloric–sulfuric acid mixture and subsequent complexing with 2,3-diaminonaphthalene. Interfering elements are masked with disodium (ethylenedinitrilo)-tetraacetate prior to complexing. The slope of standards is consistent and recoveries range from 85 to 100%.
Trace Analysis of Phenols in Water by Gas Chromatography
Authors: Murray Derek A. J.
Published: April 2011

A method for analysis of low concentrations of phenols, cresols, and xylenols in water samples was developed. O-xylene was added to the sample as an internal standard and the sample was extracted once with chloroform to remove a portion of the total organic material present. The trimethylsilyl derivatives of the phenols were formed and analysis completed by gas chromatography. The method was rapid and required a minimum of sample manipulation. The lower limit of detection was 0.100 mg/liter for phenol, 0.025 mg/liter for cresols, and 0.050 mg/liter for xylenols.
Inhibition of Formation of Free Fatty Acids in Cod Liver with Sodium Hypochlorite Solution (Javex)
Authors: Ke P. J. , Ackman R. G.
Published: April 2011

Inexpensive active chlorine from commercially available Javex has been investigated for the preservation of cod livers at room temperature. Both homogenized and chopped liver samples were treated with preservative solution containing active chlorine concentrations of from 0.01 to 1.35%. After 7 days the formation of free fatty acids in cod livers by hydrolysis of lipids was inhibited by as much as 82 and 72%, respectively, for homogenized and chopped livers. Autolysis was effectively reduced by increasing the concentration of active chlorine, but accelerated markedly after a 10-day storage period. The peroxide value increased slowly in the liver treated with active chlorine solution (0.79%) from 0 to 3.2 meq/kg in a 7-day period and then reached 6.0 after 12 days of storage. About one-half of vitamin A content in the livers was destroyed during a 7-day treatment, but only 24% of vitamin D was lost. Since synthetic vitamin A can be cheaply added to the oil, these results show that active chlorine can be used as a cheap preservative in the fish liver industry, and provide a basis for the development of multiple component preservatives for livers.
Adjustment of Buoyancy by Tadpole Madtom, Noturus gyrinus, and Black Bullhead, Ictalurus melas, in Response to a Change in Water Velocity
Authors: Machniak Kazimierz , Gee John H.
Published: April 2011

Tadopole madtom (Noturus gyrinus) and black bullhead (Ictalurus melas) adjusted buoyancy by altering swimbladder volume becoming less buoyant in current than in still. Extent of adjustment was dependent on size. Tadpole madtom adjusted buoyancy within 96–192 h but partial adjustment occurred within 12–48 h. Year 0 fish made a more rapid decrease in buoyancy than did year 1 or 2. As buoyancy was decreased year 0 and 1 tadpole madtom showed significant changes in internal pressure of swimbladder gases. Black bullhead secreted gases into the swimbladder to increase buoyancy while tadpole madtom showed no such ability.
An Automatic Brine Shrimp Feeder for Aquatic Bioassays
Authors: Schimmel Steven C. , Hansen David J.
Published: April 2011

An electrically operated brine shrimp feeder is described. The device may be set to cycle 1–12 times each day for tests in fish and invertebrate culture and bioassay. Major advantages of the feeder are that it is readily adapted to flow-through bioassay and culture apparatuses which require that equal quantities of food be delivered to animals in two or more test aquaria and that the number of feedings be recorded. The components, all readily available, cost approximately $190.
Estimating Dry Weight of Live, Unanesthetized Fish by Photography
Authors: Hawkes Clifford L.
Published: April 2011

A photographic technique for indirectly estimating the dry weight of live fish is described with an example for fingerling coho salmon (Oncorhynchus kisutch). This technique does not utilize anesthetizing, blotting, or other harsh treatments associated with weighing live fish. It was developed for studies on which size, weight, etc., must frequently be obtained with a minimum of damage to the fish. The example given is the development of the regression equation correlating actual dry weights with photographically measured indices of lateral area. The equation obtained has a coefficient of determination (r2) of 0.954.
The Urohyal in Fishes.
Authors: McAllister D. E.
Published: April 2011

not available
Diseases of fish.
Authors: Wolf Ken
Published: April 2011

not available
Population Dynamics of Limnetic Cladocera in a Beaver Pond
Authors: Kwik Judith K. , Carter John C. H.
Published: April 2011

In a small, shallow, predation free beaver pond near Georgian Bay, Ontario Ceriodaphnia quadrangula was monacmic and Daphnia ambigua and Bosmina longirostris triacmic. Each species peaked and declined rapidly, presumably overshooting the carrying capacity of a food limited environment. Embryonic development times of each species at different temperatures was determined in the laboratory and fitted with Bĕlahrádek’s function. Calculated instantaneous rates of birth and death were normal for D. ambigua and C. quadrangula but too low to account for the rapid fluctuations in numbers of B. longirostris, suggesting occasional gross sampling errors. Bosmina longirostris may periodically abandon the limnoplankton for a benthic existence thus avoiding capture.
Embryonic Development, Early Growth, and Meristic Variation in Rainbow Trout (Salmo gairdneri) Exposed to Combinations of Light Intensity and Temperature
Authors: Kwain Wen-hwa
Published: April 2011

Lowest mortality rates of rainbow trout (Salmo gairdneri) embryos were obtained at temperatures of 7 and 10 C and light intensities of 0.2 and 20 lx. Temperatures of 3 and 15 C and an intensity of 400 lx were near the thresholds for development. Eggs exposed to 0.2 lx required 111 days to reach 50% hatch at 3 C, but 26 days at 15 C; those exposed to 20 lx, 97 days at 3 C and 25 days at 15 C.Growth rates of rainbow trout 145 days after hatch were significantly different (P < 0.05) at 10 and 3 C, and 20, 2, and 0.2 lx. The fastest growth occurred at 10 C and 2 lx, and the lowest growth at 3 C and 0.2 lx. For increment of body weight it was about 23.8%/day of initial weight and 6.6% at 3 C. At light intensities of 20, 2, and 0.2 lx, the rate per day was 24.7, 17.2, and 11.2%, respectively. However, increases in length occurred at a much reduced rate.Variations in numbers of vertebrae, gill rakers, and fin rays were positively correlated with the embryonic development rate. Longer incubation periods were usually associated with more meristic elements, regardless of the environmental factors involved.
Annual Growth Rates of Mooneye, Hiodon tergisus, in the Assiniboine River
Authors: Glenn C. L.
Published: April 2011

Estimates of back calculated lengths at each age for 669 mooneye (Hiodon tergisus) from the Assiniboine River indicate that annual length increments decrease progressively with age. Weight increments, calculated from estimates of weights at corresponding lengths, were greatest for mooneye during their fourth year of life. Both sexes of young mooneye had similar growth rates but after age III females grew more rapidly than male fish.
Canadian Capelin 1972–1973. Fat and Moisture Composition, and Fatty Acids of Some Oils and Lipid Extract Triglycerides
Authors: Eaton C. A. , Ackman R. G. , Tocher C. S. , Spencer K. D.
Published: April 2011

Capelin (Mallotus villosus) taken during exploratory fishing operations in 1972 and 1973 have been examined as sources of edible oil for usages similar to those of herring oil. Samples were obtained from both fat-depleted, spawning stocks from Newfoundland waters and fattening stocks taken in the fall off Labrador. Oils from commercial reduction and triglycerides isolated from laboratory extracts were studied. Moisture and fat contents and detailed fatty acid composition were determined. The commercial oils produced from fat-depleted fish (June–August) had iodine values of 96–112, while oils and triglycerides from fattening fall fish (September–November) had iodine values of 118–128. The basic fatty acid components from Canadian capelin showed remarkably similar percentages in all oils and triglycerides. The total C22 ranged from 21.2 to 26.7% and had a lower proportion of 22:1 than Canadian herring oils. The fatty acid composition suggests that these capelin oils could be used interchangeably with herring oils.
Effect of Dummy Telemetry Transmitters on Stamina of Atlantic Salmon (Salmo salar) Smolts
Authors: McCleave James D. , Stred Kristin A.
Published: April 2011

Effects of three different-sized, internally placed dummy ultrasonic transmitters and one size externally placed dummy radio transmitter on swimming performance of Atlantic salmon (Salmo salar) smolts were determined. Critical swimming speeds were similar for fish in control groups and two of the groups tagged with internal transmitters. The widest internal dummy tag (19 mm long × 10 mm diameter) caused a significant (P < 0.05) decrement in swimming performance; the size representing the smallest available transmitters (33 mm long × 8 mm diameter) did not. Linear regression analysis of this latter group demonstrated that larger smolts carried the transmitter better than smaller smolts. Results indicated that fish longer than about 20 cm can successfully be tagged with the available transmitter. Externally placed dummy radio transmitters caused a highly significant (P < 0.01) decrease in swimming speed compared with that of controls.
Histopathological Changes in Channel Catfish (Ictalurus punctatus) Experimentally and Naturally Infected with Channel Catfish Virus Disease
Authors: Major Ronald D. , McCraren Joseph P. , Smith Charlie E.
Published: April 2011

Two groups of fingerling channel catfish (Ictalurus punctatus), one experimentally infected with channel catfish virus disease by transmission through water, and the other collected during an active epizootic, were examined histologically. Previously unreported pathology of pancreatic and brain tissue is described. The virus elicits a histopathological response similar to that reported for the salmonid viruses.
Effect of DDT and M.S. 222 on Learning a Simple Conditioned Response in Rainbow Trout (Salmo gairdneri)
Authors: McNicholl Patricia G. , Mackay W. C.
Published: April 2011

Rainbow trout (Salmo gairdneri) were force fed, with and without M.S. 222 anesthesia, pellets containing DDT equivalent to 0, 10, and 100% of the 96 h-LD50 dose of 0.03 mg DDT/g body weight. DDT at the LD50 dose significantly increased learning rate 48 and 72 h after treatment. Although the 10% LD50 group did not learn significantly faster than controls, their slightly improved learning rate indicated a dose-dependent response curve. M.S. 222 did not affect learning rate of a simple conditioned response whether or not the anesthetic was combined with DDT.
Aspects of the Winter Ecology of Juvenile Coho Salmon (Oncorhynchus kisutch) and Steelhead Trout (Salmo gairdneri)
Authors: Bustard David R. , Narver David W.
Published: April 2011

The major physical characteristics of overwintering areas for juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri) are described for a small, unlogged, west coast Vancouver Island stream. During the winter months age I+ coho and steelhead were found at a range of depths mainly greater than 45 cm and in deeper water than age 0 of either species. About 45% of age 0 steelhead observed were in water < 15 cm deep. The depth occupied by coho and age I+ steelhead was negatively correlated with water temperature below 8.5 C. Coho were associated less closely with the bottom than were steelhead. At 7 C or less most fish were associated with water velocities of < 15 cm/s. Velocities in which steelhead occurred were positively correlated with rising temperature above 4 C. As water temperature decreased from 9 to 2 C, coho and steelhead moved closer to cover. Cover used by coho and age I+ steelhead most frequently was logs and upturned tree roots, although debris accumulations and overhanging banks were also used. Both age-groups of coho used overhanging brush but steelhead did not. Over 50% of age 0 steelhead were associated with rocks 10–25 cm in diameter. Sidepools and quiet back channels that contained water only in the winter and that had combinations of the above cover types were populated by coho during the winter. A series of unused beaver ponds, dry in the summer, was an important overwintering area for coho with a survival rate about twice as high as the 35% estimated for the entire stream system.
Effects of Water Temperature and Housing Conditions upon the Aggressive Behavior of the Lobster Homarus americanus
Authors: Hoffman Ronald S. , Dunham Philip J. , Kelly Patrick V.
Published: April 2011

Lobsters are more aggressive at 10 C than at 5 C. At 10 C, animals housed communally, and those in physical isolation with visual contact, are less aggressive in a test situation than lobsters housed with no physical or visual contact.
The Shell Makers, Introducing Mollusks.
Authors: Turner Ruth D.
Published: April 2011

not available
Autumn Stranding of a Northern Bottlenose Whale (Hyperoodon ampullatus) in the Bay of Fundy, Nova Scotia
Authors: Mitchell Edward , Kozicki V. Michael
Published: April 2011

A 615-cm male northern bottlenose whale (Hyperoodon ampullatus) stranded in Cobequid Bay, Bay of Fundy, in early October 1969. The skull, mandible, tympano-periotics, and teeth are described and illustrated. Five growth layers in the lower teeth place the animal below a growth curve based on samples from the Labrador Sea taken in May and June. A summary of nine other North American occurrences of 12 individuals, mainly south of Sable Island, indicates a winter migration to waters offshore of Massachusetts and Rhode Island.
Investigation of Small Whale Hunting in Northern Norway, 1964
Authors: Foote Don Charles
Published: April 2011

The author made a field trip to northern Norway in June to September of 1964 to study the techniques and economics of small whale catching. The industry taking small whales exists as a subsidiary to primary producing industries based on fishing or large-scale whale oil production. It takes mainly the minke (Balaenoptera acutorostrata) and northern bottlenose (Hyperoodon ampullatus) whales and other smaller species. The small whale catcher vessel and its equipment is described in detail with specifications given, and an estimate is made of the costs of purchasing and maintaining boat and gear. Good catch and economic statistics are available on the hunt, but not on the packer, wholesaler, and retailer; nor on the separation of those boats used as whalers from March to September from others in the fishing fleet. Whale hunting and food product preparation is described. An economic assessment of costs is made, from hunting through packing, wholesaling and transport, and final retaining of the food products. The purchase, packing, and wholesale of whale meat products operates through a system based on fish production.
Possible Interference in the Isolation of IPN Virus from Carrier Fish
Authors: Nicholson Bruce L. , Dexter Roger
Published: April 2011

This report describes an instance of possible homologous viral interference in the isolation of IPN virus from carrier fish. Brook trout (Salvelinus fontinalis), suspected of being carriers of IPN virus, were examined for the presence of the virus by inoculating monolayer cultures of RTG-2 cells with different dilutions of tissue homogenates of the suspected fish. Cultures of RTG-2 cells infected with concentrated tissue homogenates exhibited little, if any, cytopathic effect (CPE) and yielded little infectious IPN virus at 72 h after infection. However, cell cultures infected with a relatively high dilution of tissue homogenate exhibited extensive CPE and resulted in high yields of infectious virus.
Solubilization of Cod Myofibrillar Proteins at Low Ionic Strength by Sodium Pyruvate During Frozen Storage
Authors: Tran V. D.
Published: April 2011

The effects of adding sodium pyruvate and KCl (0–0.6 M) on protein solubility in cod homogenates were compared. KCl extracted slightly more protein than sodium pyruvate did in samples kept at 0 C for up to 5 days. In contrast, sodium pyruvate extracted more protein than did KCl in samples kept at −20 C for up to 14 days. In the presence of sodium pyruvate, changes occurred during freezing and frozen storage, which caused the myofibrillar proteins to become soluble at ionic strengths as low as 0.1.
Seasonal Characteristics of Water Masses in Muir Inlet, a Fjord with Tidewater Glaciers
Authors: Matthews J. B. , Quinlan A. V.
Published: April 2011

The presence of two distinct seasonal water masses with transitions between them has been revealed in Muir Inlet, a fjord with tidewater glaciers in southeast Alaska. In spring a homogeneous water mass was found in which over 70% of the water fell into the ranges 31.0–31.2‰ salinity and 3.0–3.5 C. Heterogeneous water masses were found in summer and fall. The transition from the homogeneous to the heterogeneous water mass is explained on the basis of an entrainment mechanism during the summer high runoff period. It is suggested that the homogeneous spring condition derives from the intrusion of water from outside the fjord over the entrance sill which continues into early summer. This water exchange is driven primarily by tidal energy and depends upon denser water being available outside the sill during fall and spring. The differences between inlets with and without tidewater glaciers result from the melting of glacial ice in contact with warm, saline water masses. The melting of glacial ice appeared to continue at all seasons in Muir Inlet. The dissolved oxygen content confirms tha almost continuous renewal, showing only relatively small seasonal variations.
Photoreceptor Fine Structure in the Northern Pike (Esox lucius)
Authors: Braekevelt C. R.
Published: April 2011

The morphology of the retinal photoreceptors has been studied in the adult northern pike (Esox lucius) by light and electron microscopy. Three photoreceptor types are seen: rods, single cones, and twin cones. The rod photoreceptors are the most numerous. They are elongate cells basically similar to other vertebrate rod cells described. Twin cones are the more numerous of the two cone types present and are formed by two cone cells lying in close apposition along their inner segments, with a membrane specialization where the two cells are apposed. Each member of the twin cone is morphologically similar to the other and to the single cone. The cone photoreceptors display in addition to the regular outer segment, an accessory outer segment. The ellipsoid of the cone cell inner segment is unusually large. The synaptic region of the cone cells is larger and more elaborate than that of the rods. Synapses in both rods and cones, however, appear to be formed by both superficial and invaginated contacts with bipolar and horizontal cells. The single and double cones are arranged in a well-defined, repeating mosaic pattern.
Historical Changes in Mercury Contamination in Michigan Walleyes (Stizostedion vitreum vitreum)
Authors: Kelly T. M. , Jones J. D. , Smith G. R.
Published: April 2011

Mercury concentrations in Michigan walleyes (Stizostedion vitreum vitreum) are more variable among localities than between recent and historical samples within localities. Increases in mercury concentrations were noted in the recent populations of lakes Cadillac and Mitchell, Lake Gogebic, and western Lake Erie. Walleyes in four of seven localities showed no statistically significant increases in the level of mercury contamination over the past 40 yr. Mercury values over 0.5 ppm are common only on Isle Royale, in Saginaw Bay, and in western Lake Erie. Walleyes from Houghton Lake, Bear Lake, and lakes Cadillac and Mitchell show low levels of mercury contamination.Methods for validly comparing preserved and fresh specimens were established by tests to determine the weight loss through dehydration in preservation. In 74% alcohol, muscle tissue of medium to large walleyes dehydrates to about 70% of the fresh weight in the first year.Mercury concentration in walleye muscle from recent and old museum collections is positively correlated with age and size. Considerable variation in concentration exists not only between geographic localities, but within populations, and even within subsamples of the same tissue.
Presence and Distribution of Polychlorinated Biphenyls (PCB) in Arctic and Subarctic Marine Food Chains
Authors: Bowes Gerald W. , Jonkel Charles J.
Published: April 2011

Polychlorinated biphenyls (PCB), man-made industrial chemicals, have been identified in tissues of polar bears (Ursus maritimus), ringed (Phoca hispida) and square flipper (Erignathus barbatus) seals, and Arctic char (Salvelinus alpinus) of the Canadian arctic and subarctic. All tissues from each species examined contained these compounds. PCB content in tissue, both absolute and relative to the concentration of DDT (p,p′-DDE + p,p′-DDD + p,p′-DDT), generally increased from seals to adult polar bears to polar bear cubs and young. Polar bear milk contained high concentrations of PCB and is the most probable source of the high concentrations in polar bear cubs. Chromatograms revealed a greater accumulation of higher chlorinated PCB isomers in polar bears than in seals, their main food. Residue data suggest that polar bear subpopulations in the eastern Canadian arctic and subarctic have been exposed to higher levels of PCB and DDT than western subpopulations.
Degradation of Phenolic Compounds Downstream from a Petroleum Refinery Complex
Authors: Polisois G. , Tessier A. , Campbell P. G. C. , Villeneuve J. P.
Published: April 2011

Measurements downstream from refinery outfalls in the region of Montreal East have shown that, under favorable temperature conditions, the concentration of phenolic substances in the river water rapidly diminishes with distance from the refineries. Mass balance calculations at different transverse sections show that this decrease in concentration cannot be attributed to dilution only. Laboratory experiments performed on river water samples demonstrate the effects of water temperature and sterilization on the rate of phenol breakdown. Results support the idea that biodegradation is responsible for the self-purification of phenolics in the St. Lawrence River.
Establishment of an Asymptomatic Carrier State Infection of Enteric Redmouth Disease in Rainbow Trout (Salmo gairdneri)
Authors: Busch R. A. , Lingg A. J.
Published: April 2011

The dynamics of establishment, pathogenesis, and continued maintenance of Enteric Redmouth (ERM) disease in rainbow trout (Salmo gairdneri) were examined. Groups were infected by parenteral and oral routes and subsampled at weekly intervals. Both modes of infection were standardized to obtain ID100 levels of infection with an average of 30 bacteria constituting an LD50 dosage when administered parenterally. The clinical course of the disease was monitored up to 102 days postinfection. A clinically asymptomatic carrier state infection was established in the lower intestine of 25% of survivors 45 days postinfection at 14.5 C. Thereafter, regular intestinal shedding of the pathogen, causing recurrent infection and mortality within the population, occurred on acyclic basis of 30–40-day intervals. Clinical recovery, establishment of the asymptomatic condition, and periodicity of intestinal shedding and the clinical course of the disease to convalescence were described.
Effect of Bleached Kraft Mill Effluent on the Survival of Starved Juvenile Coho Salmon (Oncorhynchus kisutch)
Authors: Brown D. A. , McLeay D. J.
Published: April 2011

Starved coho salmon (Oncorhynchus kisutch) fingerlings were exposed to "sublethal" concentrations of neutralized bleached kraft mill effluent (BKME). Time to death was similar in the control group, in fish continuously exposed to BKME concentrations equivalent to 0.05–0.4 of the samples’ 96-h LC50 values, and in fish exposed to a treated (foam-stripped) portion of the samples at a volume equivalent to 0.7 LC50 for untreated effluent. Time to death decreased progressively in groups exposed to effluent concentrations higher than 0.4 of the 96-h LC50.
Experimental Marine Biology
Authors: Fletcher G. L.
Published: April 2011

not available
Optimum Sustainable Yield as a Concept in Fisheries Management. (Proceedings of a symposium held during the 104th Annual Meeting of the American Fisheries Society, Honolulu, Hawaii, September 9, 1974.)
Authors: Westrheim S. J.
Published: April 2011

not available
Physiological Responses of Rainbow Trout (Salmo gairdneri) to Electroshock
Authors: Schreck Carl B. , Whaley Roy A. , Bass Michael L. , Maughan O. Eugene , Solazzi Mario
Published: April 2011

Electroshocking elicited an immediate increase in plasma corticoid and lactate concentrations and thrombocyte:leucocyte ratio in rainbow trout (Salmo gairdneri). Plasma glucose concentrations increased significantly after 3 h. Plasma protein, calcium, magnesium, and androgen levels were not measurably affected. Plasma lactate returned to preshock levels within 3 h, but corticoid and glucose concentrations remained elevated for at least 6 h. The fish coughed violently or did not resume normal breathing rates for 60 s post shocking. Although breathing frequency did not increase, buccal pressure increased substantially and required at least 1 h to return to preshock levels. Cardiac activity was irregular immediately after shocking, but no predictable alterations in rate were evident thereafter. The height of the T wave in ECGs increased markedly 1–3 min after shocking. The electrophoretic patterns of 13 isoenzymes from liver, white muscle, and plasma did not differ between fish captured by dipnet and those captured by electrofishing.Responses exhibited by fish to shocking are most likely attributable to combined effects of trauma, factors associated with paying off of an oxygen debt, and attributes associated with the general adaptation syndrome of stress. A substantial period of time of more than 6 h is required for fish to return to "normal" preshock conditions.
Temperature Tolerance of Young-of-the-Year Lake Whitefish, Coregonus clupeaformis
Authors: Edsall Thomas A. , Rottiers Donald V.
Published: April 2011

The ultimate upper lethal temperature of young-of-the-year lake whitefish, Coregonus clupeaformis, was 26.65 C; this value is closely similar to that reported for yearling bloaters, Coregonus hoyi (26.75 C) and young-of-the-year lake herring, Coregonus artedii (26.0 C).
Changes in Some Hematological Characteristics of Coho Salmon (Oncorhynchus kisutch) in Response to Acute Exposure to Dehydroabietic Acid (DHAA) at Different Exercise Levels
Authors: Iwama George K. , Greer G. L. , Larkin P. A.
Published: April 2011

To determine if changes in some hematological parameters accompanied acute exposure of juvenile coho salmon (Oncorhynchus kisutch) to dehydroabietic acid (DHAA) at three different exercise levels, clotting times, hematocrits, erythrocyte sedimentation rates, red blood cell counts, and white blood cell counts were monitored over 6-, 12-, 24-, and 48-h exposure periods to 0.75 mg/liter DHAA.White cell counts decreased significantly after 24 h exposure and there was a significant increase in clotting times after 48 h exposure to DHAA. In both cases, differences between experimentals and controls were significant only at low and intermediate exercise levels and not at a high exercise level. Hematocrits, erythrocyte sedimentation rates, and red blood cell counts were not significantly different between experimentals and controls for any of the exposure periods or exercise levels.