bluuebunny/crossref_metadata_2025 huggingface dataset:
Aggressive Behavior in Juvenile Coho Salmon as a Cause of Emigration
Authors: Chapman D. W.
Published: April 2011

Large numbers of coho fry (called nomads) move downstream from shortly after emergence through early fall. These fry are smaller than residual coho. Study of behavior showed coho to be aggressive and territorial or hierarchical. Nomadic coho placed in stream aquaria barren of resident fish tended to remain in the aquaria rather than continuing downstream movement, while nomads added to resident groups of coho were dominated by the resident dominant fish and tended to leave the channels. Hierarchies were organized on the basis of fish size, with larger fry having better growth opportunities. Feeding of coho in excess of requirements did not alter holding capacity of stream aquaria. Aggression observed in natural stream areas was frequent, probably virtually continuous. Nomads transferred to natural stream areas barren of other coho remained there, while nomads added to resident populations tended to move downstream. It was concluded that aggressive behavior is one important factor causing downstream movement of coho fry.
Machine Computations of Mass Transport in the North Pacific Ocean
Authors: Fofonoff N. P.
Published: April 2011

Recently, a series of computer programs was developed by the Fisheries Research Board of Canada Pacific Oceanographic Group to enable more intensive studies to be carried out of the effects of winds over the ocean surface on the circulation in the ocean. The programs are used to compute geostrophic velocities and mass transports from oceanographic station data, Ekman and total transports from mean sea-level atmospheric pressure.The theoretical background for the programs is developed and examples of the results obtained are given. More complete discussions of the results will be given as processed information is accumulated.
The Bound Nucleotides of Freshly Frozen and Severely Denatured Frozen Lingcod Muscle
Authors: Tomlinson Neil , Geiger S. E.
Published: April 2011

The bound nucleotides of lingcod (Ophiodon elongatus) muscle have been examined in relation to the denaturation of muscle proteins during frozen storage. No difference between the quantity of adenine nucleotides (principally adenosine diphosphate) bound in washed muscle residues from freshly frozen (pre-rigor) and in those from muscle severely denatured during frozen storage could be detected. Somewhat more adenosine triphosphate was found bound in crude actin extracts prepared from undenatured frozen muscle than in similar extracts from denatured frozen muscle. Heating lingcod muscle resulted in almost complete release of bound nucleotide.
Some Aspects of Olfactory and Visual Responses in Pacific Salmon
Authors: Brett J. R. , Groot C.
Published: April 2011

Past and current research by the Fisheries Research Board of Canada related to olfactory and visual responses in Pacific salmon is reviewed, including comments on some of the sensory and behavioural relations important in migration.An innate ability to perceive highly dilute odours supports the view that olfaction can be instrumental in detecting a distant source, but the problems of following a well directed course indicate likely support from other sensory paths including visual and acoustico–lateralis responses.A threshold visual sensitivity of about 1/300 that of bright moonlight and an ability to orient at night, with view of the sky only, provide evidence that retinal images may be useful as migratory cues as long as turbidity does not interfere.
Movements, Growth and Survival of Marked and Tagged Lobsters Liberated in Egmont Bay, Prince Edward Island
Authors: Wilder D. G.
Published: April 2011

The average straight line distance between release and recapture points of 253 tagged lobsters free 10 to 12 months was 7.3 nautical miles (13.5 km). Carapace-length growth increments per moult among 870 punch-marked lobsters recovered from the fishing grounds were independent of size and averaged 0.47 inches (11.9 mm) for males and 0.42 inches (10.7 mm) for females. Weight increments per moult varied from 4.0 to 7.5 ounces (113–213 g) for males and from 3.3 to 5.4 ounces (94–153 g) for females. Of the males, 17.8% moulted twice; of the females, 7.4%. Survival over a 10-month period was estimated to be 76.4%.
The Movement of Tagged Great Slave Lake Fish
Authors: Keleher J. J.
Published: April 2011

At Great Slave Lake, N.W.T., 3629 fish marked with Petersen tags were released during 5 years from 1946 to 1955. The time at large and movement of 505 recoveries, mostly lake whitefish, Coregonus clupeaformis, and lake trout, Cristivomer namaycush, are analyzed. Most of the tagged fish were caught in the summer commercial fishery; returns during the fall and winter were scarce. The median recapture time was 268 days; the maximum, for a lake trout, was 4027 days. Movement was generally limited; its median was 5 statute miles (8 km). A few fish travelled relatively long distances. There was no overall directional pattern to the movement, but some aggregation of the recaptured fish was noted. The fish populations are regarded as sedentary rather than mobile.
Respiration of the Atlantic Cod
Authors: Saunders Richard L.
Published: April 2011

Measurements of routine and standard rates of oxygen consumption of various sized cod at temperatures between 3 and 15 °C revealed a well-marked size effect; small cod consume oxygen at a greater rate per unit weight than do large ones. Increases in temperature raise oxygen consumption in starved and fed fish. The increase in rate of oxygen consumption of starved fish between 3 and 10° is proportionately greater than that between 10 and 15 °C. Feeding of cod which have previously been starved increases the rate of oxygen consumption by 40–90%. The rate subsides to the starvation level in 4–7 days depending on temperature and amount of food eaten. Handling cod causes them to increase their rate of oxygen consumption; rates return to normal levels in 3–5 hours. Crowding reduces the rate of oxygen consumption apparently by reducing the space for movement and thus restricting activity. Reducing the ambient oxygen from about 10 to 3 mg/l lowers the rate of oxygen consumption slightly, but the respiratory volume (volume of water pumped over the gills per unit time) is markedly increased. This suggests there is added stress because the increased metabolic cost of irrigating the gills is not met by increased rates of oxygen consumption.
Resistance of Four Freshwater Crustaceans to Lethal High Temperature and Low Oxygen
Authors: Sprague J. B.
Published: April 2011

The crustaceans studied were the isopod Asellus intermedius Forbes, and the amphipods Hyalella azteca (Saussure), Gammarus fasciatus Say, and Gammarus pseudolimnaeus Bousfield.Resistance to high temperature decreased with size in A. intermedius and G. fasciatus, but no difference was found for H. azteca. Female Gammarus, were more resistant than males, there was no difference for A. intermedius, and a variable relation in H. azteca. Acclimation temperature could be raised at rates of 2.5 to 5 °C per day, at temperatures above 14 °C. Raising acclimation from 10 to 20 °C increased the lethal temperature (50% mortality in 24 hours) by 1.9 °C in G. fasciatus, 1.3 °C in A. intermedius, 0.5 °C in G. pseudolimnaeus, and apparently not at all in H. azteca. There was no seasonal variation in resistance after A. intermedius was acclimated in the laboratory.Two difficulties encountered were mortality during acclimation and short survival of controls, but careful checking showed that neither greatly affected the reported resistance.Estimates of the ultimate 24-hour lethal temperatures were 34.6 °C for A. intermedius and G. fasciatus, 33.2 °C for H. azteca, and 29.6 °C for G. pseudolimnaeus. The concentrations of low oxygen causing 50% mortality in 24 hours, with acclimation and testing at 20 °C, were.0.03 mg/l for A. intermedius, 0.7 mg/l for H. azteca, 2.2 mg/l for G. pseudolimnaeus, and 4.3 mg/l for G. fasciatus. Lethal temperatures would seldom seem to affect distribution under natural conditions, but resistance to low oxygen fits field observations fairly closely.
Biological Changes in Herring Stocks Following An Epizootic
Authors: Tibbo S. N. , Graham T. R.
Published: April 2011

Herring landings in the Chaleur Bay area of the Gulf of St. Lawrence declined from 25 million lb (11,340 metric tons) in 1947 to 12 million lb (5443 metric tons) in 1959. The decline is attributed to lower levels of abundance resulting from mortalities caused by a fungus (Ichthyosporidium hoferi) disease which reached epidemic proportions during the mid 1950's. Data obtained during the periods 1946–48 and 1960–61 are compared and show mean lengths of herring have remained unchanged, mean ages have decreased, growth rates have increased, fewer year-classes are represented and relative abundance of autumn-hatched fish has increased.
Some Effects of Simultaneous Variation in Salinity, Temperature and Dissolved Oxygen on the Resistance of Young Coho Salmon to A Toxic Substance
Authors: Alderdice D. F.
Published: April 2011

Median resistance times of juvenile coho salmon (Oncorhynchus kisutch) acclimated to fresh water at 12 °C were investigated at 3 mg/l of sodium pentachlorophenate over combinations of levels of salinity, temperature and dissolved oxygen using factorial schemes developed by Box and associates. For the relationship:[Formula: see text]a true response ς is regarded as a function of combinations of levels of k quantitative factors x1, x2, x3, …, xk. The relationship was approximated by a polynomial in x for the three coded factors—salinity (x1), ‰; temperature (x2), °C; and dissolved oxygen (x3), mg/l. The experimental data were fitted to a second-order polynomial:[Formula: see text]This was transformed to its canonical form, from which ellipsoidal response surfaces were constructed. Alternative levels of salinity, temperature and dissolved oxygen were computed for general evaluation of the manner in which these variables altered the response to the pentachlorophenate. A maximum response time was computed for the response surfaces, associated with levels of the three variables at 17.68‰ salinity, 4.86 °C and 7.66 mg/l, O2.The use of multivariate experimental techniques is discussed as a means of considering the significance of alteration in the levels of associated environmental factors in evaluation of experimental or environmental situations involving water quality alteration.
Seasonal Movements of the Winter Flounder, Pseudopleuronectes americanus (Walbaum), on the Atlantic Coast
Authors: McCracken F. D.
Published: April 2011

Winter flounders occur from Labrador to Georgia and yield large catches off southern New England. This paper relates their distribution and seasonal movements to environmental factors.In spring immature and mature flounders are alongshore with spawning fish concentrated in shallow water. During "summer", winter flounders leave the shore zone in areas where water temperatures rise above about 15 °C but not where bottom temperatures do not reach this level. This movement toward cooler water does not continue into depths at which temperature is below about 12 °C. Flounders return to the shore zone in fall after temperature decreases below 15 °C. These temperatures are well below the upper incipient lethal for flounders of about 26 °C.Flounders remaining alongshore in summer are distributed in depth according to size and maturity. Small, immature fish are in the shallowest water, the region of highest light intensity, immatures of medium size deeper, and mature fish in both regions. Under experimental conditions immature fish of medium size moved into shade at lower light intensities than either small immatures or large matures.North of Cape Cod flounders move deeper in "winter" as the shallow water becomes colder than the deeper. To the south spawning condition is reached earlier and mature flounders remain in shallow water during the cold-water period.Off southern New England a large, sustained fishery denotes a large population of flounders. In the Bay of Fundy and off the coast of Nova Scotia winter flounders are restricted to a narrow depth zone, and good exploratory catches there probably do not indicate large populations. In the broader shallow zones of the southern Gulf of St. Lawrence similar catches suggest a larger population. Exploitation will depend on increased efforts by small otter trawlers or possible development of marine sport fishing.
Effects of Temperature on Growth of Zooplankton, and the Adaptive Value of Vertical Migration
Authors: McLaren Ian A.
Published: April 2011

Existing theories of the adaptive value of vertical migration are examined and found wanting. Adult size and generation length are negative functions of temperature. It is shown that Bělehrádek's temperature function gives a close fit to size and development rate of several species of zooplankters growing in adequate food supply, although conclusions do not depend on the theoretical content of this equation. Fecundity is an exponential function of adult size, and enough data are available for two quite different zooplankters — the copepod Pseudocalanus minutus and the chaetognath Sagitta elegans — to depict relative rates of increase as generally positive functions of temperature. Diurnal migrants are known to feed nearer the surface, which is almost universally warmer. Increased fecundity gained by spending part time in deeper, cooler waters, might be offset by slower development, although interrupted or seasonal breeders could sacrifice development rate for greater ultimate fecundity. However, an animal which does all necessary feeding in warm surface waters and "rests" in cooler waters gains an energy bonus which may be put into fecundity. A model of the effect on fecundity is derived from a much-generalized version of von Bertalanffy's growth equation. From the most probable range of solutions it is deduced that migration in thermally stratified waters would be disadvantageous when surface waters were cool, but increasingly advantageous as surface waters warmed up, and this is supported by empirical evidence. The theory accounts for many geographical, seasonal, systematic and ontogenetic regularities in the large and confusing literature on vertical migration.
Observations on Behavior of Juvenile Brown Trout in a Stream Aquarium During Winter and Spring
Authors: Hartman G. F.
Published: April 2011

Observations were carried out in February–March and May–June periods during which water temperature ranges were 0.0–0.5 °C and 8.5–12.5 °C, respectively. Responses of fish to structures representing simplified environmental features, e.g. visual reference points, support against which fish could brace themselves in current, areas of slow water, overhead cover and areas of shade, were studied at three different water velocities. Winter and spring responses to illuminated and dark cover and to areas of rocky bottom were compared. Fish associated progressively more with experimental structures as more environmental features were incorporated into them. Degree of association with such structures and with other types of cover was much greater during winter. Degree of association increased with water velocity during both spring and winter. Increasing water velocities modified aggressive behavior. Fish displayed relatively more at low water velocities and nipped more at high velocities. It is possible that the association with and defence of specific locations on the bottom of a stream has selective value that alternates seasonally, providing the species with protection from predation and from displacement by current in winter, and with an efficient mode of food utilization in spring and summer.
First Record of the Thornback Sculpin, Paricelinus hopliticus, Eigenmann and Eigenmann, in British Columbia Waters
Authors: Barraclough W. E. , Ketchen K. S.
Published: April 2011

not available
Observations on the Migration of Young Sockeye Salmon (Oncorhynchus nerka) through a Large, Complex Lake System
Authors: Johnson W. E. , Groot C.
Published: April 2011

The seaward migration of sockeye salmon smolts through the Babine Lake system to its outlet is examined by extensive tagging, direct observations and experimental orientation tests. The migration appears to be a well-oriented, non-random movement; it apparently commences from all lake regions at about the same time, suggesting a common triggering stimulus. When migrating, the smolts swim at a speed of 0.65 to 1.0 feet per second. The migration appears to take place primarily at near-surface depths; diurnally, most of the migration activity appears centered around the evening dusk period. There is a consistent increase in rate of travel as the season progresses; in large part this appears a result of increasing migration drive. Orientation tests with a view of only the sky show the smolts capable of time-compensated orientation in relation to celestial phenomena, and such tests at various points along the migration route show the preferred direction of smolts to correspond with the direction of most direct route to the outlet. Most smolts of the system show a constant preference for the northwesterly direction which would lead them rather directly to the outlet. However, one group which in the course of its migration to the outlet must make a 180° turn clockwise from southeast to northwest is found to have a corresponding shift in directional preference with time. Simple one-direction orientation, in one case shifting with time, is sufficient to account for ability to find the outlet. A positive relation is shown between rate of travel of tagged smolts and the hours of sunshine on days subsequent to their release.
The Effect of Tagging with Petersen Disc Tags on the Swimming Ability of Fingerling Steelhead Trout (Salmo gairdneri)
Authors: Clancy Dan W.
Published: April 2011

Fingerling steelhead trout were given individual performance tests in an experimental flume. Barriers confined the fish to a 10-foot (1 foot = 30.48 cm) testing section where they swam against a constant velocity of 2.5 feet per second. The end point of each test was reached when the fish was fatigued enough to allow itself to be impinged by the water flow on a net barrier. The study was designed to test what effect the application of Petersen disc tags had on swimming endurance, by comparing tagged, handled, and control groups.No permanent reduction of swimming endurance was experienced by the handled group (tag pin inserted, then removed). The tagged group experienced a permanent drop of about 50% in their swimming endurance due to the presence of the tag.
Temperature, Salinity and Plankton in the Eastern North Atlantic and Coastal Waters of Britain, 1957.: II. The Relationships Between Species and Water Bodies
Authors: Bary B. McK.
Published: April 2011

Occurrences of seventeen species of zooplankton from near-surface oceanic and coastal waters about Britain have been correlated with temperatures and salinities, in temperature-salinity-plankton (T-S-P) diagrams, for the 12 months of 1957. Species exhibit distinctive relationships to the several water bodies, as these have been defined in temperature-salinity (T-S) diagrams. Similar relationships between species have been used as a basis to group species together and 6 such groups are discussed. The species of three of the groups are oceanic; one of these groups is restricted to warm water, but the others are less restricted. A fourth group consists of species confined to coastal waters. The remaining two occur in oceanic, mixed oceanic-coastal and coastal waters. The relationships to the water bodies are shown to persist throughout the seasonal fluctuations of properties in the waters.
A Further Record of the Blacktail Snailfish, Careproctus melanurus Gilbert, from British Columbia Waters
Authors: Forrester C. R. , Wilson R. M.
Published: April 2011

not available
An Occurrence of Opah, Lampris regius (Bonnaterre), in the Northwest Atlantic
Authors: McKenzie R. A. , Tibbo S. N.
Published: April 2011

not available
Pycnogonida of the North American Arctic
Authors: Hedgpeth Joel W.
Published: April 2011

This report concerns 22 species of pycnogonids found between Point Barrow and the Baffin Bay–Davis Strait region, based on collections by the Calanus expeditions since 1947 and by G. E. MacGinitie at Point Barrow. One new species, from Point Barrow, is described. Three basic distribution patterns are recognized: a boreal, circumarctic or panarctic distribution, a high arctic and deeper boreal distribution related to the North Atlantic–Norwegian sea areas, and a Pacific boreal distribution. Neither of the latter two have circumpolar components. No relationship between arctic and antartic Pycnogonida can be demonstrated, and several arctic species carry their young until they are much more advanced than do antarctic species.
Gamma Irradiation as a Means of Extending the Storage Life of Haddock Fillets
Authors: Power H. E. , Fraser D. I. , Neal W. , Dyer W. J. , Castell C. H.
Published: April 2011

Studies of the storage life of iced haddock (Melanogrammus aeglefinus) fillets after treatment with doses of gamma radiation of 75,000, 150,000, and 250,000 rads, have shown that a useful extension of the storage life is made possible by irradiation. The fillets irradiated with the 75,000-rad dose and assessed after cooking became unacceptable after about 25 days at 0 °C. The unirradiated control became unacceptable after 12 days. Fillets irradiated at the two higher levels were of lower quality initially than the fillets irradiated at the 75,000-rad level but showed no significant decrease in acceptability up to 27 days storage in ice. Raw fillets developed an objectionable odour and appearance just prior to becoming unacceptable to the taste panel.
A Morphometric Description of Blue Shark (Prionace glauca) from Canadian Atlantic Waters
Authors: McKenzie R. A. , Tibbo S. N.
Published: April 2011

not available
A New Species of Parasitic Copepod, Caligus clemensi sp. nov. (Caligoida: Caligidae), from Pelagic Fishes in the Coastal Waters of British Columbia
Authors: Parker R. R. , Margolis L.
Published: April 2011

Adult females and males of Caligus clemensi sp. nov. from the body surface of British Columbia fishes are described. The known hosts are Oncorhynchus kisutch, O. gorbuscha, O. keta, Clupea pallasi, Gasterosteus aculeatus, Hexagrammos sp. and Theragra chalcogrammus. This is the only species of Caligus known from the coastal waters of British Columbia. "Caligus gurnardi Krøyer" of Fraser, 1920, is synonymous with the new species.
Preliminary Observations on the Vertical Distribution of Pacific Salmon (Genus Oncorhynchus) in the Gulf of Alaska
Authors: Manzer J. I.
Published: April 2011

The vertical distribution of Pacific salmon in the high-seas areas of the Gulf of Alaska was investigated from mid May through July in 1959 and 1960 by fishing with gillnets (constructed from 41/2–inch nylon web and measuring 40 ft in depth and initially 400 fathoms in length) at five depth intervals from the surface with the deepest between 160 and 200 ft.Sockeye salmon exhibited diurnal and seasonal differences in their vertical distribution while chum salmon showed diurnal differences. The downward movement of sockeye salmon appeared limited by the thermocline, especially during late June and July. This relationship was observed for chum salmon during hours of darkness only in late June and July. Other factors must also influence seasonal and diurnal vertical movements of sockeye and chum salmon. Within the conditions of the experiment, no consistent differences in the vertical migrations between fish of different age were apparent. Catches showed pink and coho salmon were nearer the surface than either sockeye or chum salmon.
Ocean Growth and Mortality of Pink and Chum Salmon
Authors: Ricker W. E.
Published: April 2011

Records of length of pink and chum salmon computed from scale annuli are summarized, and are converted to show rate of growth in weight. Information is available on 11 pink stocks or groups of stocks originating at points from the Strait of Georgia to Sakhalin and Primorye, and for 7 chum stocks taken from Tillamook Bay to the Amur River and Sakhalin. Estimates of increase in weight from the time of formation of the final annulus to time of capture near shore vary from 190% to 590% for pinks maturing at age 1+, and from 60% to 92% for chums maturing at age 3+. At the end of the first year, pinks are computed to average 356 g in weight, and chums 287 g. Average instantaneous rate of growth per month in the final year is 0.28 for pinks and 0.12 for chums, each available locality being given equal weight. The seasonal distribution of growth in the final year has been estimated for pink salmon of the Bering Sea (by Birman) and for those of the central British Columbia coast (by LeBrasseur and Parker); for chum salmon an approximate seasonal distribution can be deduced from comparisons of growth rates. Combining these with the best available estimate of natural mortality (0.02 per month for salmon more than 30 cm long), calculations of net yield from high-seas fishing can be made for any desired date, and compared with the yield from a purely coastal fishery (the same escapement being provided in both cases). In all situations the catch taken on the high seas is less than that taken from the survivors of the same fish in coastal waters. The loss of yield exceeds 50% for pinks taken early in their final season, and also for chums taken early in their penultimate season.
Estimation of Sea Mortality Rates for the 1960 Brood-Year Pink Salmon of Hook Nose Creek, British Columbia
Authors: Parker Robert R.
Published: April 2011

Seaward migrating pink salmon fry at Hook Nose Creek, British Columbia, were estimated to total 1,153,000 in 1961. Of these, 41.5% or 479,000, were marked by amputation of both ventral fins (BV). Following this marking 36,900 fingerling were captured in the marine environment and marked by removal of the adipose and right ventral fins (ARV). During the 1962 fishing season 1,160,645 adult pinks were examined and 7050 BV and 184 ARV marks recognized. For the Hook Nose Creek stock, survival at sea from natural causes is shown to approximate 22% and the rate of exploitation was 95%. This stock is shown to be more exposed to fishing than the Bella Coola stock, for which a rate of exploitation of 69–80% is estimated. Rate of exploitation for Dean Channel stocks is even lower. These differences are explained as due to times of entry and rates of travel through the fishery. The two-stage marking experiment failed to estimate the natural mortality rate of juvenile pinks during the initial 5 weeks of sea life because of this dissimilarity between rates of exploitation on the stocks in the area.
Dispersion of Kraft-Mill Effluent from a Submarine Diffuser in Stuart Channel, British Columbia
Authors: Waldichuk Michael
Published: April 2011

Stuart Channel is a stratified, estuarine region typical of British Columbia coastal "inside" waters. Tidal currents are mostly less than 1 kt at all depths, and set to the northwest on the flood and southeast on the ebb, along the axis of the channel. Effluent released by a submarine diffuser, from the kraft pulp mill at Crofton, mixes in a ratio of about 1:22 with sea water as it rises to the surface. The entrainment of cold, saline water in the ascent gives the effluent–sea water mixture at the "boil" above the diffuser a density usually greater than that of surface sea water. Therefore, the mixture generally sinks and spreads in a thin sheet at a depth between 3 and 10 m. Non-tidal currents at the surface and at 9–10 m depth could be expected to give the effluent present in these layers a net displacement seaward through Sansum Narrows. Effluent at a depth of 4–5 m would receive a net transport in the opposite direction (northwest) and could be expected to be retained in the channel much longer.
Redd Superimposition and Egg Capacity of Pink Salmon Spawning Beds
Authors: McNeil William J.
Published: April 2011

A study of egg recruitment to pink salmon spawning beds in two southeastern Alaska streams (Indian Creek and Harris River) has shown that egg loss during spawning increases as the density of female spawners increases. Mortality was caused for the most part by superimposition of redds.A mathematical model of spawning success is derived. The model assumes that the curve describing the recruitment of eggs to a spawning bed is asymptotic and that pink salmon females spawning within any denned spawning ground select the sites of their redds at random. The model is used to estimate the asymptotic limit of the egg recruitment curve for a Harris River spawning bed. Levels of mortality associated with various densities of spawning female pink salmon are predicted for Harris River from the model.
The Volatile Sulphur Compounds of Oysters
Authors: Ronald A. P. , Thomson W. A. B.
Published: April 2011

The compound responsible for the characteristic odour of fresh Pacific oysters, Crassostrea gigas (Thunberg), has been identified as dimethyl sulphide [(CH3)2S], by the formation of mercury salts, and by infrared analysis and gas chromatography. The effect of bacterial action on the oysters has been observed and a number of the volatile organo-sulphur decomposition compounds, produced during room storage at 20–21 °C, have been identified by gas chromatography and by the formation of their lead and mercury salts.
Ascidians of the Canadian Arctic Waters
Authors: Trason Winona Bethune
Published: April 2011

The ascidians of the Canadian Arctic collected by the Eastern Arctic Investigations and Arctic Unit of the Fisheries Research Board of Canada from the years 1947 to 1962 inclusive have been identified and the numbers collected tabulated. Information relevant to collecting stations is presented in tables and on maps.
Carbonyl Compounds in Salted Cod.: II. Separation and Identification of Volatile Monocarbonyl Compounds from Heavily Salted Cod
Authors: Yurkowski M. , Bordeleau M.A.
Published: April 2011

Volatile monocarbonyl compounds were isolated from heavily salted cod (Gadus morhua) as the 2,4-dinitrophenylhydrazones. These compounds were separated by thin-layer chromatography first into classes and then according to chain length. n-Alkanals C1–5 and n-alk-2-enals C5–6 were conclusively identified. n-Alkanals C8,10 and n-alk-2-enals C4,7,8 were tentatively identified. An unknown compound corresponding to n-hexanal, except in the melting point, was isolated. Formaldehyde, and to a lesser extent, acetaldehyde and propanal, were the major monocarbonyls present in salted cod.
The Salinity of Baker Lake, N.W.T., Canada
Authors: Johnson Lionel
Published: April 2011

not available
Rare Skates of the Newfoundland and Neighbouring Areas
Authors: Templeman Wilfred
Published: April 2011

Raja erinacea is reported from the east coast of Newfoundland, a first record from the Newfoundland area. Raja hyperborea is recorded from east of Baffin Island, 60 nautical miles south of the most southerly previous record on this coast. Raja jenseni and Raja mollis have been found on the southwest slope of the Grand Bank, and Raja mollis on the continental slope off northeast Newfoundland and Baffin Island. These are northward and eastward extensions of range from the southern part of the Nova Scotian Shelf. Two individuals of Raja lintea are recorded from Flemish Cap, the first record of this species west and south of West Greenland. Body proportions and other characteristics of the rare skates are discussed in relation to those reported by previous authors.
Lethal Levels of Mixed Copper–Zinc Solutions for Juvenile Salmon
Authors: Sprague J. B. , Ramsay B. Ann
Published: April 2011

The toxicity of copper and zinc sulphates to juvenile Atlantic salmon (Salmo salar L.) was tested in very soft water at 17 °C. The salts were tested separately and in mixtures. Incipient lethal levels were 32 μg/litre of copper alone or 420 μg/litre of zinc alone.Concentrations were expressed in "toxic units" by taking them as proportions of incipient lethal levels. Compared this way, resistance-times were similar for the two metals. Experiments showed that the incipient lethal level for mixtures was attained when addition of toxic units contributed by each metal reached a total of 1.0. The lethal threshold was therefore governed by simple additive effect of the two toxicants. This result is useful for applying to pollution problems in the field.In stronger mixtures totalling 2 and 5 toxic units, fish died faster than would be expected from their resistance to the metals separately. This type of potentiation in short-term tests seems to account for more-than-additive effects previously reported in the literature.
Life History and Ecology of American Plaice (Hippoglossoides platessoides F.) in the Magdalen Shallows
Authors: Powles P. M.
Published: April 2011

Males reach marketable size (32 cm) at age 10, and females at age 8. Sexual maturity is attained at 25 cm (age 6) for males and 41 cm (age 10) for females, and maximum spawning occurs annually from mid April to mid May. Commercial fishing has reduced the number of year-classes in the fishery from about 26 in 1957 to 17 in 1961, but has not affected the rate of growth.The main summer fishery occurs in the Chaleur Bay, Shippegan Gully, and North Bay regions in depths of 40–100 m. In winter, American plaice were most abundant in depths of 180–460 m (bottom temperature 3–6 °C), although a few immatures remained in the cold inshore waters. In spring (April), plaice were taken mostly from 75 to 150 m depths (−1.0 to 5.0 °C).Adult plaice feed mainly on molluscs and echinoderms, and young plaice on polychaetes and small Crustacea. Feeding ceases almost completely during January–March. The main food competitor of plaice in the Magdalen Shallows is the Atlantic cod, which has the same general distribution during the summer. Atlantic cod, particularly those over 78 cm long, are also the main predators of small plaice, but mortality due to cod grazing has decreased in recent years because of declining numbers of large cod.Tagging and meristic studies indicate that Magdalen Shallows plaice are a discrete stock made up of two main groups. The groups are maintained by the tendency of plaice (excluding very old individuals) to return to the same areas each summer. The northern or "Miscou–Magdalen" group includes fish of Chaleur Bay, Shippegan Gully, and Orphan Bank regions. The southern or "Cape Breton" group occurs from George Bay to St. Paul Island.
Are Killifish Poisonous?
Authors: White H. C. , Medcof J. C. , Day L. R.
Published: April 2011

not available
Browning of Freeze-Dried Fish
Authors: Tarr H. L. A. , Gadd R. E. A.
Published: April 2011

Lingcod (Ophiodon elongatus) and sole (Parophrys vetulus) muscle were treated in different experiments with a dilute solution of ribose, or with a particulate enzyme preparation capable of oxidizing both ribose and glucose before freeze-drying at low temperature. Freeze-drying did not occasion loss of free glucose or ribose. Various experiments in which the freeze-dried fish was stored at −30, 25, 33, or 37 °C and relative humidities (RH) of 0, 5, and 10% showed that browning proceeded rapidly at all RH values except in samples held at −30 °C, and developed more rapidly at the higher temperatures. Browning was accelerated in samples containing added ribose, and retarded in those in which a large proportion of the sugars was removed by enzyme treatment. Storage in nitrogen retarded development of browning but did not eliminate it, indicating that oxidation is responsible for much of the discolouration.
Myxosporidian Parasite from Salmon
Authors: Boyd J. W. , Tomlinson N.
Published: April 2011

not available
Ketone Bodies in the Blood of Salmonoid Fishes
Authors: Jonas R.E.E. , Bilinski E.
Published: April 2011

The concentration of acetoacetate expressed as acetone in the blood of rainbow trout (Salmo gairdnerii) was generally in the range of 0.3–1.0 mg/100 ml and long periods of starvation did not appear to affect this level to any appreciable extent. In sockeye salmon (Oncorhynchus nerka) in the pre-spawning stage of migration the concentration of acetoacetate was within the range found for rainbow trout. Higher concentrations of acetoacetate, amounting to approximately 1.5 mg/100 ml of blood, were present in sockeye salmon at the spawning grounds. Rainbow trout, which had been exercised, yielded greater value for β-hydroxybutyrate, and it was shown that under these conditions lactic acid interfered with the determination of β-hydroxybutyrate. Starvation of rainbow trout did not affect the concentration of β-hydroxybutyrate to any appreciable extent. In spawning salmon β-hydroxybutyrate showed some increase, as compared with fish in the pre-spawning stage of migration.
Some Resemblances and Differences Between Raja erinacea and Raja ocellata, Including a Method of Separating Mature and Large-Immature Individuals of These Two Species
Authors: Templeman Wilfred
Published: April 2011

Raja erinacea Mitchill and Raja ocellata Mitchill are now distinguished by differences in tooth count and, in larger specimens, by size, size at sexual maturity, and eye spots when present in R. ocellata. The presence of distinct eye spots in the typical R. ocellata position in some R. erinacea was recorded. Separation of mature and large-immature male and female individuals of these two species was achieved by means of ventral pelvic denticles located in different positions in the two species, closer to the cloaca in female R. erinacea and more laterally on the pelvic fins in female R. ocellata. These pelvic denticles occur also in mature and maturing male R. ocellata but not in male R. erinacea. The denticles are much smaller and more numerous in R. erinacea and have relatively smaller sharp-angled bases with usually 4 and occasionally 5–6 rays. In R. ocellata the bases of the denticles are usually much larger, have 4–11 or more rays, usually with rounded tips.
Effect of Temperature on Mortality and Rate of Development of the Eggs of the Windermere Char (Salvelinus alpinus)
Authors: Swift D. R.
Published: April 2011

Rate of development and mortality of eggs of the Windermere char (Salvelinus alpinus willughbii) were investigated. Excessive mortality occurred at temperatures above 8 C, total mortality above 12 C. Rate of development varied with the water temperature, eggs taking on an average 45 days to hatch at 10 C and 95 days at 4 C.
The Role of Behavior in the Ecology and Interaction of Underyearling Coho Salmon (Oncorhynchus kisutch) and Steelhead Trout (Salmo gairdneri)
Authors: Hartman G. F.
Published: April 2011

Two similar salmonids, coho and steelhead, cohabit many coastal rivers of British Columbia. Field collections reveal that the distributions of underyearling coho and steelhead are similar along the length of these streams. However, the micro-distribution of the two species is different. In spring and summer, when population densities are high, coho occupy pools, trout occupy riffles. In autumn and winter, when numbers are lower, both species inhabit the pools. Nilsson (1956) stated that segregation (such as that shown by coho and trout in spring and summer) may be indicative of competition resulting from similar ecological demands. To test this hypothesis the distribution and behavior of coho and steelhead were compared in a stream aquarium at different seasons with gradients of light, cover, depth or depth/velocity, and in experimental riffles and pools. Distributions and preferences of the two species in the experimental environments were most similar in spring and summer, the seasons when segregation occurred in nature, and least similar in autumn and winter, the seasons when the two species occurred together in nature. Spring and summer segregation in the streams is probably the result of interaction which occurs because of similarities in the environmental demands of the species and which is accentuated by dense populations and high levels of aggressiveness. The species do not segregate in streams in winter because certain ecological demands are different, numbers are lower, and levels of aggressiveness are low. When the two species were together in the experimental riffle and pool environment, trout were aggressive and defended areas in riffles but not in pools; coho were aggressive in pools but less inclined to defend space in the riffles. These differences in behavior probably account for the distribution of trout and coho in natural riffles and pools.The data support the basic contention of Nilsson (1956) and illustrate the role of behavior in segregation produced by competition for space.
Preliminary Results on the Seasonal Size Distribution of Mytilicola orientalis and the Effect of this Parasite on the Condition of the Pacific Oyster, Crassostrea gigas
Authors: Chew K. K. , Sparks A. K. , Katkansky S. C.
Published: April 2011

not available
Paralytic Shellfish Poison in Sea Scallops (Placopecten magellanicus, Gmelin)
Authors: Bourne N.
Published: April 2011

Bioassays for paralytic shellfish poison were carried out in sea scallops (Placopecten magellanicus, Gmelin) from the major scallop producing areas off the Canadian Atlantic coast. There was very little or no toxin in Georges Bank or southern Gulf of St. Lawrence scallops. In Bay of Fundy scallops, adductor muscles and gills were poison-free but livers and mantles remained toxic the year round. The highest score of roes in these scallops was 43 μg of toxin per 100 g of roe.
Method of Rapid Measurement for Large Samples of Fish
Authors: Davenport D. , Hakling W. R.
Published: April 2011

not available
Lymphocystis Disease in American Plaice of the Eastern Grand Bank
Authors: Templeman Wilfred
Published: April 2011

Lymphocystis infection is described and figured, both for gross appearance and for microscopic sections of American plaice, Hippoglossoides platessoides (Fabricius), from the eastern slope of the Grand Bank. This infection was first noticed in American plaice from this area in September 1960. Between July and early October 1964 about 1% of the American plaice of commercial size caught on the southern part of the eastern slope of the Grand Bank showed lymphocystis nodules, usually between 0.6 and 2.0 mm diameter, on the surface of the skin, on the upper and lower surfaces and on the fins, either separate or in tumours made up of individual nodules surrounded by connective tissue and covered externally by epidermis.
Influence of Photoperiod on Growth of Green Sunfish, Lepomis cyanellus
Authors: Gross W. L. , Roelofs E. W. , Fromm P. O.
Published: April 2011

Four 6-week experiments were conducted to evaluate the effect of photoperiod on growth (total length and weight), food consumption, and food conversion efficiency by green sunfish. Fish were held at constant temperatures in light-tight aquaria under four photoperiods (8-hr constant; 16-hr constant; variable, increasing from 8 to 16 hr; and variable, decreasing from 16 to 8 hr).Growth, food consumption, and food conversion efficiency were all influenced by photoperiod. Food consumption varied directly with the amount of light to which fish were exposed. Fish growth and food conversion efficiency were closely correlated and were generally highest in the increasing, lowest in the decreasing, and intermediate in the two constant photoperiods, but higher in the longer daylength. The results suggest that photoperiod influences growth through increasing conversion efficiency and also possibly through stimulating food consumption.Varying daylength exerts a greater influence on fish growth than a constant daylength. Increasing photoperiod stimulates growth and decreasing photoperiod inhibits growth. This result suggests that the lack of growth of warmwater fish in fall when water temperatures and average daylength correspond to those of spring is largely due to the influence of decreasing daylength.
Estimation of Sea Mortality Rates for the 1961 Brood-Year Pink Salmon of the Bella Coola Area, British Columbia
Authors: Parker Robert R.
Published: April 2011

A two-stage marking experiment was designed to estimate natural mortality rates of pink salmon during their early (coastal) and later (oceanic) periods of sea life. Difficulty was encountered because of disproportionate representation of various stocks in the marked populations, the stocks being subject to dissimilar rates of exploitation. Several assumptions were made for which the error introduced could not be fully evaluated. Under these assumptions, the results indicate (approximate values) that 55.7 million fry, resulting from the 1961 Burke Channel–Bella Coola stocks brood year, entered the sea. Of these, 77% died during the initial 40-day period of life in the enclosed marine waters. The following stage, from the time of seaward migration to adult return, a period of about 410 days, 78% of the remaining population died. The adult return was subjected to a rate of exploitation of 0.85 which produced a catch of 2.5 million fish. The spawning escapement was approximately 450,000 fish. It is established that the rate of natural mortality during the initial short period was much more severe than that during the remaining period of sea life.
Relative Rates of Degradation of Some Organisms Consumed by Marine Salmon
Authors: LeBrasseur R. J. , Stephens K.
Published: April 2011

not available
Precocious Sexual Development in Male Post-Smolt Atlantic Salmon Reared in the Laboratory
Authors: Saunders Richard L. , Henderson Eugene B.
Published: April 2011

not available
Inter-Species Relationships Within the Genus Oncorhynchus Based on Biochemical Systematics
Authors: Tsuyuki H. , Roberts E.
Published: April 2011

The species specific muscle myogens of Salmo gairdnerii, Oncorhynchus masou, O. masou ishikawae, O. kisutch, O. tshawytscha, O. keta, O. nerka, and O. gorbuscha are compared by starch gel electrophoresis. Plasma proteins of these same species are also examined by polyacrylamide disc electrophoresis. The range of usefulness of muscle myogens in species identification, and equally significantly, their value in establishing phylogenetic relationships of closely related groups, as the genus Oncorhynchus, are discussed. The myogen patterns of O. keta and O. gorbuscha from the Asiatic and North American coasts were found to be identical, further supporting the concept of absolute species specificity of these patterns.
A Method of Fitting Growth Curves of the von Bertalanffy Type to Observed Data
Authors: Allen K. Radway
Published: April 2011

A method is described for obtaining the best least-squares estimates of the parameters L∞, k, and t0 when von Bertalanffy curves of the type[Formula: see text]are fitted to observed data. This method imposes no restrictions on the number or size of the samples or on the time intervals between them. It also provides estimates of the limits of error of the parameters. The amount of computation is fairly large, but a method of systematizing it is described which makes manual computation practicable for moderate-sized sets of data. The method has been used to develop a computer program which seems to have advantages over some existing methods.A numerical example is worked out in full to illustrate application of the method.