bluuebunny/crossref_metadata_2025 huggingface dataset:
Rancidity in Lean Fish Muscle.: II. Anatomical and Seasonal Variations
Authors: Castell C. H. , MacLean Jill
Published: April 2011

In a study of copper-catalyzed rancidity of cod fillets it has been found that: (1) muscle from the tail section goes rancid faster than muscle from the head or centre sections; (2) there is no apparent difference in the development of rancidity in the inner and outer halves of fillets that have been sliced lengthwise; and (3) sensitivity to rancidity changes with the season and is greater in the winter and early spring than in the summer and fall.
Activity Coefficient of the Magnesium Ion in Sea Water
Authors: Platford R. F.
Published: April 2011

Sodium hydroxide was added to carbonate-free sea water and the point at which Mg(OH)2 precipitated was detected optically. At this point the hydroxyl ion activity was calculated from the measured pH of the solution and the magnesium ion activity was calculated from the activity product for Mg(OH)2.From a knowledge of the magnesium ion activity and other data, it was estimated that about 3% of the total magnesium in the sea water was in the form of [Formula: see text].
The Species Specificity and Constancy of Muscle Myogen and Hemoglobin Electropherograms of Oncorhynchus
Authors: Tsuyuki H. , Roberts E. , Vanstone W. E. , Markert J. R.
Published: April 2011

not available
Nucleotides and Related Compounds, Sugars, and Homarine in Shrimp
Authors: Tarr H. L. A. , Comer A. G.
Published: April 2011

Pink shrimp (Pandalus borealis) frozen promptly after capture were extracted with perchloric acid and the clear extract, after neutralization with KOH and removal of potassium perchlorate, was subjected to ion exchange chromatography. Glucose, ribose, inosine, inosinic acid, adenylic acid, and a small amount of hypoxanthine were detected. Only traces of hexose phosphates appeared to be present. Homarine was present in moderate concentration and was isolated as crystalline homarine hydrochloride.
Effects of Fish Introductions and Hydroelectric Development on Fishes in the Kananaskis River System, Alberta
Authors: Nelson J. S.
Published: April 2011

Changes occurred in the abundance and distribution of fishes in the Kananaskis River system, Alberta, in conjunction with fish introductions and hydroelectric development. Data from surveys from 1936 to 1961 indicate the probable chronology of events.Dolly Varden (Salvelinus malma), brook trout (S. fontinalis), cutthroat trout (Salmo clarkii), and rainbow trout (S. gairdneri) decreased in abundance, probably due to the introduction of brown trout (Salmo trutta), longnose suckers (Catostomus catostomus), and white suckers (C. commersonii), to the cooling of the Kananaskis River from reservoir construction, and to sport fishing. Hybridization between rainbow and cutthroat trout was also important in the decrease of the latter species. After introduction by man, brown trout, rainbow trout, longnose suckers, white suckers, lake chub (Hybopsis plumbea), and longnose dace (Rhinichthys cataractae) greatly increased in abundance. Prior to the increase in numbers of white suckers, a reduction in the numbers of longnose suckers occurred in Lower Kananaskis Reservoir. Little change in the distribution of mountain whitefish (Prosopium williamsoni), longnose dace, and brook sticklebacks (Culaea (= Eucalia) inconstans) occurred over the 25 years. Changes in the physicochemical environment and invertebrate fauna in the reservoirs appeared to be of secondary importance to the interaction among fish in causing the changes in species abundance and distribution.
Post-Spawning Death of Pacific Salmon: Sockeye Salmon (Oncorhynchus nerka) Maturing and Spawning in Captivity
Authors: McBride J. R. , Fagerlund U. H. M. , Smith M. , Tomlinson N.
Published: April 2011

It has been shown that sockeye salmon, Oncorhynchus nerka, will start to eat soon after capture during their freshwater spawning migration. Some will continue to eat up to, during, and after spawning, while others stop eating shortly before spawning. The effect of feeding has been investigated histologically in a number of tissues by comparison of feeding fish, unfed controls, and fish spawned in the wild. Atrophy, and often degeneration of the liver, stomach, and intestine in post-spawned unfed controls and fish spawned in the wild was equally marked, but was absent or much less pronounced in fed fish.
Sedimentation in a Salmon Stream
Authors: Shapley S. Philip , Bishop Daniel M.
Published: April 2011

Sediment was artificially added to a small southeastern Alaskan salmon stream. Observations in sedimented and control riffles indicate that the amount of sediment settling to the stream bottom decreases exponentially with distance downstream. The dissolved oxygen content of intragravel stream water remained high in sedimented riffles. The added sediment was removed from stream-bed gravels by fall freshets and floods.
Partial Freezing as a Means of Preserving Pacific Salmon Intended for Canning
Authors: Tomlinson N. , Geiger S. E. , Kay W. W. , Uthe J. , Roach S. W.
Published: April 2011

Proteolysis of the flesh surrounding the visceral cavity ("belly-burn") can cause serious spoilage in Pacific salmon. The condition usually occurs in uneviscerated fish that were feeding when caught and develops during storage at temperatures above freezing when storage must be prolonged beyond a few days.The possibility that the proteolysis might be prevented by partial freezing of the fish in salt-reinforced refrigerated sea water at various temperatures between 25 and 29 F was investigated. Round fish, containing large quantities of food in the stomach and intestine could be held at 25 F for 2 weeks without the appearance of belly-burn or bacterial spoilage. Between 25 and 29 F there was a delay in the appearance and a reduction in the incidence of belly-burn.Partial freezing was effective in preventing a darkening of the flesh adjacent to the visceral cavity, a defect that is sometimes observed in fish canned after being stored in an uneviscerated condition for several days at temperatures above freezing. This darkening is apparently the result of the diffusion of pigment from the kidney, liver, and spleen into adjacent flesh.The lipid of the red lateral muscle in partially frozen fish was found to be very susceptible to rancidity, but this defect was overcome by excluding air from the storage tank.Free drip from partially frozen fish after storage (3.2–4.5%) was approximately double that from unfrozen fish, while weight increases during storage tended to be a little greater in unfrozen than in partially frozen fish. Spoilage odours that developed in unfrozen fish during storage were greatly reduced or eliminated in partially frozen fish. Sodium uptake and potassium loss during storage were similar in fish stored under either condition, but magnesium uptake was less in partially frozen than in unfrozen fish.A comparison of the influence of prior storage of the fish, either unfrozen in refrigerated sea water or partially frozen in salt-fortified, refrigerated sea water on the quality of the canned product, showed that each method had some advantages over the other. When the fish were of initially good quality, those stored partially frozen yielded a product quite comparable in quality to those stored unfrozen. Judgment of quality was based on the results of a number of organoleptic and objective tests, including colour, curd formation, firmness of flesh, quantity of free oil, and odour.
Distribution, Ecology, and Biology of the Salmonid Leech, Piscicola salmositica (Rhynchobdellae: Piscicolidae)
Authors: Becker Clarence D. , Katz Max
Published: April 2011

Piscicola salmositica Meyer 1946 is widely distributed throughout the Pacific coast of North America from central British Columbia to northern California. Habitual ectoparasites of teleost fishes, these piscicolid leeches are ordinarily encountered in association with spawning adult salmon (genus Oncorhynchus) and other Salmonidae; the common name "salmonid leech" is therefore applied. Piscicola salmositica, in common with its teleost hosts, occurs in a characteristic lotic environment — streams with moderate to swift currents, generally low temperatures, high dissolved oxygen content, and gravelled beds.An annual cycle of abundance is evident. Salmonid leeches appear in early fall attached to their hosts as they ascend into hatchery and natural spawning areas. From late September to February, during a period of feeding, growth, and reproduction, the leech populations attain a great abundance. By late winter, subsequent to the death of their hosts, the leeches have become virtually nonexistent, apparently as a result of high mortality among the mature individuals, some downstream displacement, and limited prédation by sculpins (Cottus sp.). Only the small, immature leeches are believed to survive the summer and return attached to spawning salmon the following fall.During the period of abundance in Soos Creek, a western Washington study stream, the lengths of feeding leeches increased at a rate of 2–3 mm per week. Weight, in relation to length, was dependent upon the amount of salmon blood ingested.Reproduction of salmonid leeches in Soos Creek was correlated with low water temperatures. Breeding began in temperatures of about 12 C in October and continued during December and January even in temperatures dropping to 5 C. The leeches attained sexual maturity at a length of about 15 mm; mature individuals then copulated and fastened cocoons to the lower surfaces of stones in the streambed. Deposited cocoons were dark brown and averaged 1.4 by 1.2 mm. In the laboratory, the average rate of reproduction ranged from 1.6 to 2.5 cocoons per leech per day, but the largest leeches (23–30 mm) produced the greatest number of cocoons. One young leech developed in each cocoon, emerging at a length of about 5.3 mm. Complete embryonic development and hatching occurred in about 7 days.
The Food of the Pike, Esox lucius, in Heming Lake, Manitoba
Authors: Lawler G. H.
Published: April 2011

The stomach contents of 29,477 northern pike (Esox lucius) captured mainly in gill nets at Heming Lake, Manitoba, between 1950 and 1962 were examined. The food consisted almost exclusively of fish: trout-perch (Percopsis omiscomaycus) and yellow perch (Perca flavescens). Other fish included common suckers (Catostomus commersoni), spottail shiners (Notropis hudsonius), sticklebacks (Eucalia inconstans and Pungitius pungitius), pike, burbot (Lota lota), whitefish (Coregonus clupeaformis), tullibee (Leucichthys sp.), yellow walleye (Stizostedion vitreum), cottid (Cottus cognatus), and darters (Etheostoma nigrum). Among invertebrates were crayfish, mayflies, dragonflies, caddisflies, and leeches. Ducks, small mammals, and frogs formed an insignificant part of the diet. Seasonal variation in food content and annual variation in the degree of feeding were evident. Trout-perch were important as food items in May and June, the spottail shiner in July, the yellow perch in August and September, and stickleback between October and March. Coregonine fishes, important in the life-cycle of Triaenophorus crassus but of minor importance as pike food, occurred in higher concentrations in October. There appeared to be annual differences in the degree of feeding, possibly related to differences in temperature. The frequency of empty stomachs from pike caught by angling and in gill nets was approximately the same. No obvious differences were noted in feeding habits of male and female pike, but there were some minor differences in the food of pike from shallow and deeper water habitats. Over an 11-year period of intensive fishing, there did not appear to be any unusual changes in the food habits of pike. The size of the prey is related to the size of the pike. There is a marked increase in the number of small perch, trout-perch, and spottail shiners consumed by pike of increasing size. The possible effects of the predator (pike) on other prey species is discussed. Relative abundance and seasonal availability appeared to determine the incidence of prey consumed. The reduction in the average size of the pike appears to have had some effect on the survival of other species of fish.
Effort Metabolism of Lateral Muscles in Carp
Authors: Wittenberger C. , Diaciuc I. V.
Published: April 2011

Effort induced by direct electrical stimulation of the lateral musculature of the carp led to effects which differed from one muscular tissue to another. With moderate effort, in the white muscle the glycogen concentration decreased and the pyruvate concentration increased; in the red muscle, the glycogen and pyruvate concentration did not change, but the amount of lactate and the oxygen consumption increased. With exhausting effort, the white muscle showed a decrease of glycogen and pyruvate, a great increase of lactate, without any significant modification of oxygen consumption; in the red muscle, there was a slight decrease of glycogen, an enormous rise of lactate, and a slight decrease of oxygen consumption. The sole modification observed in the liver was the increase of the lactate content after stimulation. Hypoxic conditions induced a great increase of the lactate:pyruvate ratio in the liver and in the red muscle, but not in the white. The findings suggest that the red muscle is a "burning place" of catabolites produced in the white muscle.
Widow Rockfish, Sebastodes entomelas, New to British Columbia Waters
Authors: McAllister D. E. , Westrheim S. J.
Published: April 2011

not available
Oxygen Dissociation Curves of the Blood of Brook Trout (Salvelinus fontinalis) Acclimated to Summer and Winter Temperatures
Authors: Black Edgar C. , Kirkpatrick Donald , Tucker Harold H.
Published: April 2011

The respiratory function of the blood of brook trout, acclimated to summer and winter conditions, was investigated at various temperatures and at various tensions of carbon dioxide. The marked sensitivity of hemoglobin to carbon dioxide served to offset the influence of lower temperature upon the equilibrium of oxygen and hemoglobin. There did not appear to be any adaptation of the Bohr effect to differences in acclimation temperatures.
Dependence of Total Annual Growth in Yellow Perch on Temperature
Authors: Coble Daniel W.
Published: April 2011

Total yearly growth of female yellow perch, Perca flavescens (Mitchill), in South Bay, Lake Huron, estimated by the distance along the lateral radius from last annulus to scale edge, showed a marked relationship to mean water temperature at a depth of 20 ft. When published data on growth of perch in Lower Red Lake, Minnesota, were compared with mean air temperatures for the period June through September at Redlake, no such relationship could be demonstrated. The reasons for the different results obtained in these and in other studies could not be determined.
Rancidity in Lean Fish Muscle. V. The Effect of Amino Acids
Authors: Castell C. H. , MacLean Jill , Moore Barbara , Neal Wanda
Published: April 2011

Addition of free amino acids to blended cod muscle affected the subsequent development of rancidity. In the presence of trace amounts of Cu++, the aromatic, heterocyclic, and sulphur-containing amino acids exerted varying degrees of antioxidant acitivity. In the absence of added metallic ions the aliphatic amino acids and cysteine showed strong pro-oxidant activity. Tests were carried out to determine the effect of pH and the concentration of amino acid on these reactions.Amino acid-induced rancidity was inhibited by the commercial antioxidants NDGA, PG, and BHT and by the chelating agent, EDTA; but not by tocopherol; ascorbic acid enhanced the oxidation. A limited number of tests indicated that the fish muscle did not undergo a seasonal variation in sensitivity to the amino acid-induced rancidity, and thus differed from the Cu++-induced rancidity.Those amino acids which inhibited metal-induced rancidities did not retard rancidity induced by the addition of sodium chloride.
The Coregonus autumnalis Complex in Alaska and Northwestern Canada
Authors: McPhail J. D.
Published: April 2011

The systematic status of ciscoes of the Coregonus autumnalis complex in Alaska and northwestern Canada is discussed. Two forms of "autumnalis" ciscoes occur in this area: a form with 26–30 gill rakers on the lower limb of the first gill arch is found in the Beaufort and Chuckchi Seas, and a form with 21–25 gill rakers on the lower limb of the first gill arch is found in the Gulf of Alaska, the eastern Bering, and the Chuckchi Seas. Both forms occur along the arctic coast of Alaska, apparently without intergrading, and therefore are considered valid species. The form with the high gill raker number is Coregonus autumnalis (Pallas) (sensu stricto), and that with the low gill raker number is Coregonus laurettae Bean.
Underwater Observations on Fish in an Off-Bottom Trawl
Authors: High William L. , Lusz Larry D.
Published: April 2011

not available
The Effect of Intermittent Exercise on Carbohydrate Metabolism in Rainbow Trout,Salmo gairdneri
Authors: Stevens E. Don , Black Edgar C.
Published: April 2011

The effect of intermittent severe exercise of short duration on carbohydrate metabolism was examined using unanesthetized, intact rainbow trout. The levels of muscle glycogen, muscle lactate, blood lactate, and liver glycogen were determined in fish sampled immediately after severe exercise of 3 sec to 5 min, after recovery of 3 min to 60 min, and after re-exercise of 3 sec to 5 min. It appears that rainbow trout are not well adapted to tolerate frequent exercise of short duration.
Preparation and Properties of Trout Myosin
Authors: Buttkus H.
Published: April 2011

Myosin from the white, dorsal muscle of trout was isolated by a modification of the method of Mackie and Connell (1964). This myosin was homogeneous in the ultracentrifuge at 5 C. The corrected sedimentation coefficient, S°20,w = 6.50, was similar to those for cod and rabbit myosin. The isolated protein had two enzymatic activities, an adenosine triphosphatase (ATPase) and an acetylcholinesterase. The rate of inactivation of the acetylcholinesterase activity at 45 C was approximately equal to the rate of inactivation of the ATPase activity at 25 C. Inactivation of the ATPase was a first-order process with respect to time and 0.6th order with respect to protein concentration. The energy of activation was 46 kcal mole−1 at pH 6.8, lower than values reported for rabbit myosin. Using the loss of enzyme activity as a measure of denaturation, trout myosin was about 23 × more stable than cod myosin, but lost its activity about 25 × more rapidly than rabbit myosin. Some of the mechanisms active in denaturing myosin are briefly discussed.
A Record of Bathypterois dubius Vaillant from the Western North Atlantic, and Review of Status of the Species
Authors: Templeman Wilfred
Published: April 2011

A specimen of Bathypterois dubius Vaillant, 204 mm standard length, trawled by the A. T. Cameron at a depth of 750–805 m on the southwestern slope of the Grand Bank on May 2, 1959, is apparently the first record for the western North Atlantic. The specimen is illustrated and its characteristics described and compared with those of other B. dubius from the eastern Atlantic and the Mediterranean.
A Simple Technique for Obtaining Chromosomes from Teleost Fishes
Authors: McPhail J. D. , Jones R. L.
Published: April 2011

not available
Variability of Oceanographic Conditions Between Ocean Station P and Swiftsure Bank off the Pacific Coast of Canada
Authors: Fofonoff N. P. , Tabata S.
Published: April 2011

Oceanographic observations taken along the line between Ocean Station P (50°N, 145°W) and Swiftsure Bank (48°32′N, 125°00′W) from January 1959 through January 1962 showed that the annual variation of temperature was determined primarily by the heat exchange across the surface and only secondarily by currents. Salinity variations were related to freshwater runoff from land and the component of Ekman transport normal to the coast. Variations of depths of isopycnal surfaces appeared to be related to the curl of wind stress, except near the coast. However, the observed vertical movement of isopycnal surfaces was much larger than that calculated from the wind stress. Near the coast, the vertical movement was related to the component of Ekman transport normal to the coast.The average total transport through the section, as calculated from the curl of the wind stress, was 5.8 million metric tons per second and was directed northward. The average baroclinic flow was 13 million metric tons per second. These transports were consistent if the mean depth of no motion was at 1400 m with southward flow in the bottom portion.
Use of Overhead Cover by Rainbow Trout Exposed to a Series of Light Intensities
Authors: McCrimmon Hugh , Kwain Wen-Hwa
Published: April 2011

Fingerling and yearling trout (Salmo gairdneri Richardson) responded differently when exposed to a series of artificial daylight illuminations. Fingerling trout showed no apparent response to the overhead cover, being randomly distributed at all light intensities. Yearling trout, except in total darkness, exhibit a positive response to the overhead cover, but their pattern of behaviour differed with the light intensity and the positioning of the cover.
Pigments in the Belly Skin of Coho Salmon (Oncorhynchus kisutch)
Authors: Markert J. R. , Vanstone W. E.
Published: April 2011

not available
Effects of Oxygen in Relation to Temperature on the Development of Embryos of Brook Trout and Rainbow Trout
Authors: Garside E. T.
Published: April 2011

Embryos of the brook trout (Salvelinus fontinalis Mitchill) were incubated in reduced levels of dissolved oxygen of approximately 2.5 ppm, 3.5 ppm, 4.5 ppm, and a control level near air-saturation (10 ppm) at each four temperatures, 2.5, 5.0, 7.5, and 10.0 C, from fertilization to a late stage of development. Embryos of the rainbow trout (Salmo gairdneri Richardson) were incubated in a similar experiment at levels of oxygen approximating 2.5 and 3.5 ppm and a level near air-saturation at each of the four temperatures, to a similar, late stage of development. A third small experiment was conducted in which embryos of rainbow trout were incubated at 12.5, 15.0, and 17.5 C, at a level of dissolved oxygen near air-saturation. In all instances for both species the velocity of embryonic development, measured by the times required to attain a series of selected embryonic stages, was accelerated by increasing temperature. The velocity of development was increasingly retarded by progressively lower levels of dissolved oxygen. The times required to affect hatching and the lengths of the periods of hatching were similarly influenced by temperature and by the level of dissolved oxygen. These findings are discussed in the light of pertinent literature.
Depth Distribution of Oceanic Shrimps (Decapoda; Natantia) off Oregon
Authors: Pearcy William G. , Forss Carl A.
Published: April 2011

Sixteen species of oceanic shrimps, seven Penaeidea and nine Caridea, appeared in 244 collections made within the upper 1500 m at one station in the northeast Pacific off Oregon. Most of the species were primarily mesopelagic in distribution.The most abundant species, Sergestes similis, was the only shrimp common in epipelagic waters at night and the only species clearly demonstrating diel vertical migrations. Night catches exceeded day catches in near-surface waters, while day catches exceeded night catches at mid-depths. Sergestes similis migrated into the upper 50 m at night and on one occasion was collected at the surface.
Biology of the Atlantic Argentine (Argentina silus Ascanius) on the Scotian Shelf
Authors: Emery A. R. , McCracken F. D.
Published: April 2011

On the Scotian Shelf, Argentina silus Ascanius was found mainly along the continental slope but extended into the deep-water basins of the central shelf. It was not found in the Bay of Fundy, and only a few were found in the Gulf of St. Lawrence. It was found in largest numbers in depths between 100 and 150 fath (183–275 m) and at temperatures between 4 and 10 C.Although larger fish were usually found deeper, in general argentines from the slope region had a modal length of 21–28 cm and were from 2 to 7 years of age. Argentines taken from Emerald Basin had a modal length of 18–22 cm and were 1 or 2 years of age in autumn, but had a modal length of 30–36 cm and were 6–11 years of age in winter.Spawning occurred in the spring in Emerald Basin with males maturing around 25 cm and females around 30 cm.Since argentines grow slowly after the first few years and do not mature until several years after growth slows down, it is possible that heavy fishing might quickly reduce stocks and catches below current levels.
Distributions and Comparisons of Centrolophus niger (Gmelin) and Centrolophus britannicus Günther (Centrolophidae) from the North Atlantic
Authors: Templeman Wilfred , Haedrich Richard L.
Published: April 2011

The general distribution of Centrolophus niger in the North Atlantic is reviewed including the first two records from the Canadian area and two additional records off the New England coast to add to the four previously recorded from this area. Two new records from the Dana collections extend the distribution of this species westward in the oceanic area between Iceland and the Azores. All known records of the rarely captured Centrolophus britannicus are presented. These include 34 previously published records from the northeastern Atlantic, eight new records from the northeastern Atlantic and the first seven records from the northwestern Atlantic, from Flemish Cap and the southern Grand Bank to North Carolina.In separating C. niger and C. britannicus some meristic characters are useful: C. niger, D. 35–41, A. 23–25, P. 20–23, gill-rakers on lower limb 1st arch, 13–15; C. britannicus, D. 44–51 (one, 55), A. 27–33 (one, 25), P. 18–21 (one, 16), gill-rakers on lower limb 1st arch, 11–13. Some body proportions are also important: the bases of the dorsal and anal fins are longer in C. britannicus and the distance from the snout to the anterior base of the dorsal fin usually greater. The length of the caudal peduncle is distinctly greater in C. niger.In C. niger the flesh is firm and the skin tough whereas in C. britannicus the flesh is flabby and the skin delicate. The peritoneum of C. britannicus is usually dark and that of C. niger usually light.
Perception of Surface Waves by the Blackstripe Topminnow, Fundulus notatus
Authors: Schwartz Erich , Hasler Arthur D.
Published: April 2011

The function of the cephalic lateral line in perceiving surface waves and its ecological significance was examined in the topminnow, Fundulus notatus (Rafinesque), a fish which frequents the surface waters. The sense organs are located in groups on the dorsal surface of the flatish head and are prominently visible on the skin. The individual organs of each group form a specific angle when related to the fish's midline. These organs perceive the force of slight surface waves and the perceptional field is omnidirectional. A great number of enucleated fish respond spontaneously, but when trained they orient toward the source of the disturbance on the surface up to a distance of 15 cm. The fact that the radiating wave is curved enables fish to locate the origin accurately. Fundulus notatus does not distinguish between two waves of equal strength striking simultaneously; it does so, however, if a time or intensity difference is present. A fish with sense organs removed from one side of the head deviates at a constant angle from the wave source. The perceptional field of individual organs or canals circumscribes a line drawn through the longitudinal axis of the organ or canal. A wave, therefore, traveling parallel to the longitudinal axis of the oval sense organ and hence the cupula, stimulates to the greatest extent whereas a wave perpendicular to it does not. The individual organs possess a directional property and, therefore, their arrangement on the head is functionally meaningful. The lateral line supplements the vision of the fish in finding its prey at the water surface.
Open-Water Movements of the Cutthroat Trout (Salmo clarki) in Yellowstone Lake After Displacement from Spawning Streams
Authors: Jahn Lawrence A.
Published: April 2011

Cutthroat trout were taken from their spawning streams (June–August 1964 and 1965). A Styrofoam float was attached and fish were tracked from two release points. They moved generally shoreward (eastward). Of 120 fish tracked when the sun was visible, 68% went toward shore, 19% went away from shore, 4% showed random movement, and 8% were lost. Of 20 fish released when the sun was obscured, 30% went toward shore, 30% went away from shore, 30% showed random movement, and 10% were lost. Movement toward the eastern shoreline was less pronounced for fish liberated at a mid-lake release point. No directional preference was shown with respect to surface currents. There was no evidence that specific landmarks were used for orientation, but the sun may have served as a reference point since fish traveled farther and showed a stronger shoreward tendency on sunny days.
Amount of Organic Matter Lost to a Lake by Migration of Eels
Authors: Smith M. W.
Published: April 2011

not available
Distribution of Lecithinase in the Subcellular Fractions of Rainbow Trout (Salmo gairdnerii) Lateral Line Muscle
Authors: Bilinski E. , Jonas R. E. E.
Published: April 2011

not available
Digestion of Fat by Cod
Authors: Brockerhoff H.
Published: April 2011

The gut contents of two cod were analysed for isomeric glycerides. Ten times more α,β-diglyceride than α,α′-diglyceride was found, and five to ten times more β-monoglyceride than α-monoglyceride.A fat labelled with tritiated oleic acid in position 1 and with C-14-oleic acid in position 2 of L-glycerol was fed to two cod, and the diglycerides were then isolated from the gut content. Radioactive analyses showed them to be mixtures of the 1,2 and the 2,3 isomers.In cod, therefore, dietary fat is degraded to diglycerides and monoglycerides by a digestive lipase which preferentially attacks the α-bound fatty acid esters but is not stereospecific. This enzyme corresponds in its action to the pancreatic lipase of mammals and of skate.
Comparative Limnology of Lakes in the Southern Rocky Mountain Trench, British Columbia
Authors: Sparrow R. A. H.
Published: April 2011

Within a restricted geographical area of British Columbia, detailed examination in 1960 and 1961 of nine lakes having similar morphometric and climatic characteristics but exhibiting a wide range in dissolved nutrients (50 to 1463 ppm) suggested that, standing crops of plankton were related to oxygen deficits and perimeter-to-area ratios of the lakes. Total dissolved solid contents of the lakes were not closely correlated to standing crops of plankton, bottom fauna, or fish. Ranking by selected physical or chemical indices of productivity failed to agree with ranking based on standing crops or various biological measurements of productivity. Water level fluctuation, perimeter-to-area ratios, lake basin shape, and the size and nature of the drainage area are discussed as some of the possible factors which interact to modify the expression of the primary factors in productivity.
Northeastern Pacific Pleistocene Sea Otters
Authors: Mitchell Edward
Published: April 2011

Previously known by only one fossil bone from Oregon, the record of the sea otter is supplemented by description of 11 bones newly found in Late Pleistocene deposits at San Pedro and on Santa Rosa Island and one tooth from an Early Pleistocene deposit at San Pedro, southern California, all considered representative of the living species Enhydra lutris. Faunal associations suggest that the animals lived with cool-water faunas in areas of shallow to moderate depth near islands. The long-accepted hypothesis that E. lutris evolved from "Lutra reevei" during the Pliocene in the North Atlantic and migrated to the North Pacific is rejected on chronologic and zoogeographic grounds. The sea otter may be a North Pacific endemic autochthon.
Effect of Pasteurizing Doses of Gamma Radiation on Storage Life of Cooked Lobster Meat
Authors: Power H. E. , Fraser D. I. , Dyer W. J. , Neal W. , Castell C. H.
Published: April 2011

Irradiation of cooked lobster (Homarus americanus) meat with a dose of gamma radiation of 75,000 rads extended the storage life, in ice, to between 28 and 35 days for both tail and claw meats from 14 to 21 days for unirradiated iced samples. Higher irradiation levels caused an immediate loss of quality due to toughening and loss of flavour. The growth of trimethylamine-producing bacteria was inhibited 10 days longer on irradiated samples than on the unirradiated iced control.
The Biology of an Ampeliscid Amphipod Crustacean Sibling Species Pair
Authors: Mills Eric L.
Published: April 2011

The amphipod sibling species Ampelisca vadorum and A. abdita have an overwintering generation and a summer generation. Breeding begins above 8 C. In A. abdita, breeding is probably correlated with the full moon. Curves of growth in length are linear, except where growth slows in winter. Length–weight curves are exponential, and A. vadorum is slightly heavier than A. abdita at any given length. The slope of the length–weight curves is the same in both species. Growth in weight is not isometric; weight increases less rapidly than does length. In some allometric features the two species stop growth at different points on the same line, but other morphological features develop out of phase due to genetic differences in patterns of development. The two species differ in a number of biological features including egg size, metabolic contribution in egg production, relative gill area, and probably egg number. Reported "intersexes" are actually subadult males. The sex ratio in both species is always 1:1. Gonad growth and somatic growth have different temperature limits.Tubes, tube building, and feeding are described. Three major functional groups of ampeliscids show marked morphological adaptations to feeding type and sediment. Free swimming occurs at times of breeding, ensuring fertilization of eggs and dispersal of young to new and favourable environments.Ampelisca vadorum occurs on course sand, A. abdita on fine sand to mud. Range, temperature, and depth preferences of these and other North American Ampelisca species are outlined. The fauna associated with A. vadorum and A. abdita is described. The unique microtopography of Ampelisca areas affects the nature of the association. Ampelisca abdita is successful in a crowded environment because it grows fast and breeds early. Ecological, life history, and taxonomic evidence all indicate that A. vadorum and A. abdita are sibling species.
Serological Differences between two Populations of Oysters (Crassostrea virginica) from the Atlantic Coast of Canada
Authors: Li M. F. , Flemming Carol , Stewart James E.
Published: April 2011

not available
Pelage Patterns and Population Distributions in the Pacific Harbour Seal (Phoca vitulina richardi)
Authors: Stutz Sherwood S.
Published: April 2011

not available
Dimethyl-β-Propiothetin Dimethyl Sulphide in Labrador Cod
Authors: Ackman R. G. , Hingley J. , May A. W.
Published: April 2011

not available
Reproductive Isolation Between the Sunfish Lepomis gibbosus and L. macrochirus
Authors: Clark Francis W. , Keenleyside Miles H. A.
Published: April 2011

Reproductive isolation appeared to be complete between pumpkinseeds (Lepomis gibbosus) and bluegills (L. macrochirus) when equal numbers (1:1 sex ratio) were stocked in each of two similar ponds near London, Ontario, and observed during the breeding seasons of 1964 and 1965. Ethological isolation, through visual recognition of potential conspecific mates, was probably the major barrier to hybridization. Interspecific courtship and attempted spawning were not seen; intraspecific courtship and spawning were frequently observed. No clearly identifiable hybrids were found among large numbers of yearling and 2-year-old offspring collected in both ponds in 1965 and 1966.Pumpkinseeds began nesting about 3 weeks before bluegills, but spawning by the two species broadly overlapped in time both years. Individual pumpkinseeds occupied nests for an average of 18.5 days; bluegills for 8.7 days. Duration of pumpkinseed nest occupancy appeared to vary directly with surface water temperature, whether eggs or fry were in the nests or not, whereas bluegills tended to remain on nests containing eggs or fry, regardless of temperature fluctuations. Bluegills nested in deeper water and further from shore than pumpkinseeds, and bluegills tended to nest in colonies whereas pumpkinseeds did not. Interspecific differences were not found in nest site selection with respect to substrate or vegetation.
Morphology of Phrixocephalus cincinnatus Wilson, 1908 (Copepoda: Lernaeoceridae)
Authors: Kabata Z.
Published: April 2011

The morphology of Phrixocephalus cincinnatus Wilson, 1908 (Copepoda: Lernaeoceridae) is described and discussed, with special reference to the structure of the antennae, hitherto almost unknown. Mention is also made of the mode of attachment and of its possible effect on the host.
A Tumorlike Growth on the Foot of a Freshwater Mussel (Anodonta californiensis)
Authors: Pauley Gilbert B.
Published: April 2011

A freshwater mussel, Anodonta californiensis, was found which possessed a small tumorlike growth on the foot that measured 3 mm in diameter and 2 mm in height. This abnormal growth, thought to be an adenomyoma, was located laterally near the ventral edge of the foot. The growth consisted of dark basophilic glandular cells and muscle fibers with a deeply convoluted epithelial covering. The cause of the lesion is not known.
Purines in the Integument of the Atlantic Salmon (Salmo salar) During Parr–Smolt Transformation
Authors: Johnston C. E. , Eales J. G.
Published: April 2011

During the parr–smolt transformation in Atlantic salmon, silvery materials were found beneath the scales (scale layer) and deep in the dermis adjacent to the muscle (skin layer). Both layers were thicker in smolts than in parr and both layers contained guanine and lesser amounts of hypoxanthine.Changes in levels of guanine, hypoxanthine, and the ratio between them (G/H) were measured from late December to late May on 2-year-old parr held in the laboratory under natural photoperiods and at temperatures varying from 6.0 in December to 9.5 C in late May. The change from parr to silvery parr during February and March accompanied sharp increases in guanine, hypoxanthine, and G/H values in the skin layer with less marked increases in the scale layer. The change from silvery parr to smolts during April and May accompanied sharp increases in guanine, hypoxanthine, and G/H values in the scale layer but no change occurred in the trend already established in the skin layer.Parr held all winter under stream conditions and examined in early April possessed purine levels and G/H ratios in the skin and scale layers comparable to those in laboratory fish during the previous December.Silvery parr captured migrating seaward in early June had purine levels and G/H ratios in the scale layer similar to those in laboratory smolts in late May but skin guanine values were much lower and the G/H ratio in the skin was extremely low.
The Teeth of Lampreys (Petromyzonidae): Their Terminology and Use in a Key to the Holarctic Genera
Authors: Vladykov Vadim D. , Follett W. I.
Published: April 2011

not available
Growth and Hypothetical Age of the Newfoundland Bait Squid Illex illecebrosus illecebrosus
Authors: Squires H. J.
Published: April 2011

Length measurements of a migrant ommastrephid squid Illex illecebrosus illecebrosus (Le-Sueur), in Newfoundland east coast waters indicated that only one modal class was present except in November of some years. Average lengths and weights of random samples taken monthly from May to November indicated also that growth was very rapid during this period. The majority of the population, averaging 140 mm in mantle length (54 g whole weight) in both sexes in May, reached maximum mantle lengths of 260 mm in males and 300 mm in females by October (weights of 360 and 550 g in males and females respectively). By fitting growth curves to these data, and by observations on sexual maturity, the approximate times of birth and mortality were extrapolated. Spawning and probable subsequent mortality of this squid was estimated to be at not more than 2 years and most probably at only 1 year of age.
A New Apparatus for Measuring Maximum Swimming Speeds of Small Fish
Authors: MacLeod J. C.
Published: April 2011

An apparatus and method were developed to obtain comparative measurements of maximum swimming speeds of small fish. The present method is considered useful in bioassays for measuring sublethal effects of pollutants. The fish swim in an open-topped oval channel with a circumference of 1.48 m. A variable speed [Formula: see text] motor turns two paddle wheels and creates measured currents up to 30 m per minute. Fish are not required to swim at the same velocity as the water in the chamber. Rather, they swim in a current which is greater than their maximum swimming speed and which moves them backwards in the channel. The average maximum swimming speed for a group of four to six fish is calculated from the current velocity, circumference of the channel, and the number of laps lost during a specific time period.Tests with fathead minnows, Pimephales promelas, showed that different current velocities gave the same swimming speed as long as the current was greater than the swimming speed of the fish. A swimming period of 3 min gave consistent results.Largemouth bass fingerlings, Micropterus salmoides, which were conditioned by exposing them once daily to the standard test in the chamber, showed a marked increase in swimming ability after 3 days. Fed and unfed fish showed equal increases in performance and the conditioned fish developed a slightly higher active metabolism.
Numerical Changes and Population Regulation in Brook Trout Salvelinus fontinalis
Authors: McFadden James T. , Alexander Gaylord R. , Shetter David S.
Published: April 2011

A brook trout population in a stable stream environment was studied for 14 years. Population estimates were made each September, the catch of fish by anglers was recorded, and collections of fish were made to determine sex ratio, age at sexual maturity, and fecundity.The sex ratio was close to 1:1 for all age-groups. Some male trout were sexually mature at the end of the 1st year of life, most were mature at the end of the 2nd year, and all were mature at the end of the 3rd. No females were mature at the end of their 1st year, most were mature at the end of the 2nd, and all were mature at the end of the 3rd year of life. The regression of egg content on total length of female trout was determined.On the average 132,000 eggs were produced annually by the population in the study area, from which 4813 fish survived to the end of the 1st year; 1966 to the end of the 2nd; 356 to the 3rd; 29 to the 4th; and 0.6 to the end of the 5th year.The growth rate of the fish varied little during the period of study. Annual egg production varied between 80,000 and 212,000; the number of age-group 0 fish between 2809 and 6703; age-group I fish between 1589 and 2653; age-group II between 175 and 685; age-group III between 13 and 68; and age-group IV fish between 0 and 2.During the 14 years of observation, survival of adult fish tended to increase, leading to larger numbers of spawners. The larger egg complements which resulted tended to experience lower survival, thus largely preventing substantial increases in population size. Positive serial correlations exist in some of the series of estimates of numbers and of survival. No biological explanation is advanced for these serial correlations.Life tables and age-specific fecundity rates were calculated for 11 successive cohorts of brook trout. Net reproduction rates varied from 0.74 to 1.88, averaging 1.14. The lx components were about three times as variable as the mx components, indicating that changes in death rates rather than changes in birth rates have been the principal immediate cause of fluctuations in the population.The mx values were not related to population density in any way that would tend to regulate population size. Survival from the 12th to the 24th month of life was directly density-dependent. The pattern of survival from the 24th to the 36th month of life suggested an inverse density-dependent relationship.The number of 12-month-old progeny surviving varied from 2809 to 6703, and the parental egg complement varied from 80,000 to 212,000. The form of the relationship between these two variables could not be defined, partly because of the relatively small range of values of parental egg complement.Even though the form of the density-survival relationship was defined for several stages of the life history, no relationship between the size of a parental egg complement and the lifetime egg production of the progeny could be established, again partly because of the small range of values of the former variable.
Thermal Acclimation and Temperature Selection in Atlantic Salmon, Salmo salar, and Rainbow Trout, S. gairdneri
Authors: Javaid M. Yaqub , Anderson John M.
Published: April 2011

The selected temperature for Atlantic salmon and rainbow trout, as determined in a horizontal gradient, increases with acclimation temperature over the acclimation range 5–20 C for salmon and 10–20 C for trout. The final preferendum for salmon is about 17 C. The results for rainbow trout suggest that the type of gradient used, i.e. vertical or horizontal, has a marked influence on the experimentally determined relation between acclimation temperature and selected temperature.
Swimming Performance of Sockeye Salmon (Oncorhynchus nerka) in relation to Fatigue Time and Temperature
Authors: Brett J. R.
Published: April 2011

Further studies on the swimming performance of fingerling sockeye salmon at fixed velocities have been conducted in relation to fatigue time. The method of probit analysis, commonly used in dealing with bioassay data, was found to be suitable for determining times to 50% fatigue and in providing a measure of variance despite the presence of some erratic behaviour. For sockeye acclimated to 15 C (mean length = 13.6 cm) the velocity at which 50% fatigued was 54.4 cm/sec or 4.0 lengths/sec (L/sec). The 5% and 95% fatigue velocities were 3.1 and 4.8 L/sec, respectively. Larger fish required longer exposure times for determining maximum sustained speeds, extending from approximately 120 min for fingerlings to 500 min for adults.Using the method of increasing velocity steps the effect of temperatures from 5 to 27.5 C was examined. When acclimated to 15 C fingerling sockeye exhibited only a 4% reduction in swimming speed at 10 and 20 C. Temperatures above the lethal level caused a rapid decline in swimming ability approaching the extinction point at 27.5 C.Recommendations for standard procedures in the study of swimming speeds are made.
A Pumping System for Sampling Small Plankton
Authors: Beers John R. , Stewart Gene L. , Strickland John D. H.
Published: April 2011

not available
Effect of Ovine Prolactin on Tissue Electrolyte Composition of Hypophysectomized Freshwater Eels (Anguilla rostrata)
Authors: Butler D. G.
Published: April 2011

not available
An Audiogram of the Atlantic Cod, Gadus morhua L.
Authors: Buerkle Udo
Published: April 2011

Auditory thresholds were determined by means of a conditioned response to sound stimuli at frequencies 17.6, 35.3, 70.7, 141, 283, and 400 cycles/sec for 10 cod, Gadus morhua. The conditioned response was a change of cardiac rhythm. It was established through an electric shock as unconditioned stimulus, and could be monitored on an oscilloscope.The thresholds indicated cod to have high sensitivity to sounds up to 283 cycles/sec. At 400 cycles/sec they were relatively deaf. Background noise in the experimental tank was high enough to influence thresholds; an absolute threshold could therefore not be determined.
Wintering of Pilot Whales, Globicephala melaena, in Newfoundland Inshore Waters
Authors: Mercer M. C.
Published: April 2011

not available