bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Inlet and Outlet Spawning Runs of Rainbow Trout in Loon Lake, British Columbia
Authors: Hartman G. F. , Northcote T. G. , Lindsey C. C.
Published: April 2011

Rainbow trout (Salmo gairdneri) entering and leaving inlet and outlet spawning streams were trapped and marked during three years. Spawners entered the outlet stream at approximately the same time each year despite considerable differences in time of lake ice breakup. Spawners entered the inlet stream 3 to 5 weeks later than outlet spawners and at water temperatures several degrees higher. The inlet spawning run was later in years when disappearance of lake ice was delayed. Comparative statistics are presented on size, sex ratio, survival and diel movement of spawners in both streams. Effects of several types of marking were compared; removal of adipose fins produced much lower mortality than tagging with Petersen discs. In the outlet stream an inverse correlation existed between number of spawners and survival, condition, and length of stay of spawners in the stream. Factors which may be responsible for differences in timing of spawning migrations are discussed.
Changes in Glycogen, Pyruvate and Lactate in Rainbow Trout Salmo gairdneri) During and Following Muscular Activity
Authors: Black Edgar C. , Connor Anne Robertson , Lam Kwok-Cheung , Chiu Wing-Gay
Published: April 2011

Experiments upon muscular fatigue in [Formula: see text]-year-old rainbow trout (Salmo gairdneri) were carried out at the trout hatchery at Summerland, British Columbia during the summers of 1958 and 1959. Observations were made on hemoglobin, water content of muscle and whole blood, muscle and liver glycogen, and pyruvate and lactate in muscle, blood and liver. Experimental conditions included 30 min moderate activity, 2–15 min severe exercise, and recovery up to 24 hr following 15 min severe exercise. The results for hemoglobin, muscle and liver glycogen and blood lactate were similar to those reported earlier. Muscle glycogen was depleted 50% or more in the first 2 min of severe activity. Correlated with this rapid depletion of glycogen was a sudden accumulation of muscle pyruvate and lactate. Pyruvate and lactate likewise increased in the blood. While the disappearance of both pyruvate and lactate from muscle began immediately upon cessation of activity, resting levels were not approached until the 8th hr of recovery. During recovery, the levels of pyruvate and lactate in the blood after severe exercise continued to increase for the first hour, remained elevated for at least 8 hr and did not return to the resting level until the 12th–24th hr. Muscle glycogen was not restored above half the resting level at the end of 24 hr. Interpretations of the data in relation to metabolism in rainbow trout are discussed.
Blood pH and Mortality in Rainbow Trout (Salmo gairdnerii) and Sockeye Salmon (Oncorhynchus nerka)
Authors: Jonas R. E. E. , Sehdev Harcharan S. , Tomlinson N.
Published: April 2011

Rainbow trout (Salmo gairdnerii) under light anaesthesia with MS 222 (tricaine methanesulphonate) died when their blood pH was lowered into the range of 6.8 to 6.9 by injection of either lactic acid or hydrochloric acid. When injection of the same quantities of either acid did not lower the blood pH into this range, fatalities did not result (one exception in 56 fish injected). The injection of much larger quantities of lactate or chloride ions in the form of sodium salts did not cause fatalities.Very limited data for sockeye salmon (Oncorhynchus nerka) suggest a similar association between blood pH and mortality for this species.
Effect of Food Quantity on Fecundity of Rainbow Trout, Salmo gairdneri
Authors: Scott D. P.
Published: April 2011

Studies of histology and development of rainbow trout ovaries indicate that the degree of follicular atresia is associated with degree of starvation during the maturation period. Experimental stocks raised under varying starvation regimes showed that the greater the starvation, the higher the proportion of maturing follicles which regressed. Thus the result was a lower number of eggs brought to maturity in starved fish.Observations on natural populations indicate wide differences in egg size, with corresponding inverse differences in egg number at maturity. Egg size is apparently not effected by diet, but rather through natural selection depending on intraspecific competition. There appeared to be little correlation between egg size and fish size, but some difference did exist between age classes. Variations in egg number are therefore attributable to fish size, egg size and adequacy of diet. Starvation has also a lasting effect on the proportion of a given age-class which matures.
Relation Between Water Temperature and Gastric Digestion of Largemouth Bass (Micropterus salmoides Lacépède)
Authors: Molnár Gyula , Tölg István
Published: April 2011

The rate of gastric digestion of largemouth bass (Micropterus salmoides Lacépède) was measured at 5, 10, 15, 20 and 25 °C temperature by the X-ray method of the authors. Bleak (Alburnus alburnus L.) of 8.0–8.5 cm length were force-fed to largemouth bass of 25–27 cm length. There was a more rapid increase in the rate of digestion in the range between 5° and 10° than at higher temperatures. In the stomach of bass the food fish was rolled up into the shape of a spiral during digestion. Because these measurements, unlike in vitro experiments, were made under circumstances similar to those existing in nature, they may serve as an indication of rate of digestion in the wild.
Some Considerations in the Study of Respiratory Metabolism in Fish, Particularly Salmon
Authors: Brett J. R.
Published: April 2011

A general review of the basis and measurement of respiratory metabolism in fish is presented, with particular reference to sources and magnitudes of influence (error) which various major factors can impose. There is a continuing need for precise measures of metabolism, including quantitative estimates of excretory products, both intrinsically and as a basis for assessing the effect of environmental change. The metabolic cost of locomotion at all levels of performance requires exact definition. Efficiency of performance for fish cannot be determined without a suitable means of relating energy expended to work performed. It is suggested that comparisons be made on the basis of energy required for a propulsion rate of 1 body length per second.
The Relative Efficiency of Nylon and Cotton Gill Nets for Taking Lake Trout in Lake Superior
Authors: Pycha Richard L.
Published: April 2011

The change from cotton to nylon twine for gill nets in 1949–52 resulted in a sharp increase in the efficiency of the most important gear used for taking lake trout in Lake Superior, and, consequently, biased estimates of fishing intensity and abundance severely.From early May to the end of September 1961, short gangs (2000 or 4000 linear feet) of cotton and nylon nets were fished in parallel sets for lake trout. A total of 343,000 feet of gill netting was lifted. Nylon nets were 2.25 times as efficient as cotton nets for taking legal-sized fish and 2.8 times as efficient for undersized lake trout. The average lengths of legal, undersized, and all lake trout taken in nets of the two materials did not differ greatly. The percentage of the catch which was undersized (less than 1.25 lb, dressed weight) was 20.8 in nylon nets and 17.7 in cotton. The relative efficiency of cotton and nylon nets showed no trend during the season. The efficiency ratio determined in this study was closely similar to that obtained by earlier workers.Correction of estimates of fishing intensity and abundance for the greater efficiency of the nylon nets used since 1951 has not been attempted. The drastic decline of the lake trout fishery has forced fishermen to make changes in fishing practices in the past few years that cause new bias of an unknown extent to estimates of fishing intensity.
The Enzymic Digestion of Cod Tropomyosin
Authors: Truscott B. , Hoogland P. L. , Odense P. H. , Waddell A. E.
Published: April 2011

Tropomyosin from cod muscle can be oxidized with performic acid to cleave disulphide bonds without degradation of other amino acid residues. The ε-amino groups of lysine within the molecule can be substituted readily with carbobenzoxy-groups for protection against digestion by trypsin. The digestions by trypsin of carbobenzoxy-substituted tropomyosin, and by chymotrypsin of oxidized tropomyosin, have been shown to be reproducible, providing peptides suitable for amino acid sequence studies. The peptides so obtained were separated by ion-exchange chromatography using a Beckman/Spinco Amino Acid Analyzer.After treatment with urea, cod tropomyosin does not yield a free N-terminal amino acid as has been reported for rabbit tropomyosin.
Observations on the Morphology and Optical Properties of the Adipose Eyelid of Fishes
Authors: Stewart Kenneth W.
Published: April 2011

not available
Additional Note on the Oceanic Puffer Lagocephalus lagocephalus (L.)
Authors: Templeman W.
Published: April 2011

not available
Causes of Mass Mortalities of Scallops (Placopecten magellanicus) in the Southwestern Gulf of St. Lawrence
Authors: Dickie L. M. , Medcof J. C.
Published: April 2011

In 9 of the years since 1928 there have been midsummer mass mortalities of scallops in the southwestern Gulf of St. Lawrence. There is evidence that sudden, great increases in water temperature sometimes exceeded the upper incipient lethal temperatures of scallops and that these were directly responsible for the more devastating, sudden and widespread mortalities (up to 80%).Unusual and unexplained concentrations of predators, mainly starfish, are considered to have been responsible for several of the slower and less spectacular mass mortalities (up to 25%). Aquarium tests showed that, in spite of well developed escape reactions, scallops are nevertheless often killed by starfish.Smaller, sudden temperature increases (too small to be lethal) and sudden decreases are common in the southwestern Gulf and both can cause temperature debility in scallops. Presumably debility hampers escape from enemies, and magnifies effects of prédation. It probably helped to produce the minor mass mortalities but so far its importance has not been assessed.
Extent of Atresia in Maturing Ovaries of the Eastern Brook Trout, Salvelinus fontinalis (Mitchill)
Authors: Henderson Nancy E.
Published: April 2011

Counts were made of the number of developing ova during the secondary growth phase of the oogenetic cycle in several groups of brook trout. An adjustment was made for the growth of the females since they increase appreciably in length during the secondary growth phase of the ova. Fecundity counts were then corrected to fish of a mean adjusted length. The results indicate that there is no major reduction in the number of developing ova during the secondary growth phase.
Source of Paralytic Shellfish Toxin in the Bay of Fundy
Authors: Prakash A.
Published: April 2011

Seasonal rise in shellfish toxicity in the Bay of Fundy in 1961 was coincident with increased abundance of a marine dinoflagellate, Gonyaulax tamarensis, and the appearance of toxin in plankton extracts. Experiments with unialgal cultures of G. tamarensis isolated from the Bay of Fundy provided overwhelming evidence that it is the primary source of toxin in shellfish in this area and the Gulf of St. Lawrence. G. tamarensis is widely distributed in the North Atlantic and there is evidence of toxic and non-toxic strains of this species.
Accelerated Cooling of Wet, Heavily Salted Fish
Authors: Wood A. L.
Published: April 2011

"Green" heavily salted split fish may be pre-cooled within a cold storage area with ice and salt, without imposing an excessive load upon storage refrigeration facilities and with little additional labour. Twelve pounds of ice plus 4 lb of salt per 100 lb of fish, uniformly applied between 3- to 4-inch thick layers of fish, will reduce the bulk fish temperature by 25°F (14 °C) in less than 8 hours.No mechanical equipment is required if flake ice be deemed a commodity. The direct cost may be estimated at less than 15 cents per 100 lb of finished (dried) fish.Pre-cooling is not essential under normal conditions but is recommended for heavily salted fish in which the degree of red bacterial contamination is unknown or suspected to be critical, and the storage refrigeration is not adequate to cool the product in a sufficiently short time.
An Investigation of Herring (Clupea harengus L.) Spawning Using Free-Diving Techniques
Authors: Tibbo S. N. , Scarratt D. J. , McMullon P. W. G.
Published: April 2011

Free-diving (Scuba) techniques were used to survey a herring spawning bed near Blanchard Point, Chaleur Bay, N.B., in May 1962. The spawning bed occupied a long, narrow area running parallel with and near the shore in depths of 4–20 feet (1.3–6 m). The total area surveyed was 448,800 square yards (375,200 sq m) and the total number of herring eggs was estimated to be 35.46 × 1011. The number of spawning herring was calculated to be 185 million fish (54.7 million pounds or 24,812 metric tons). The commercial fishery took 2.2 million pounds (998 metric tons) in the vicinity of the survey area which represents a fishing mortality rate of 4.0%. Hatching started about May 24 when large numbers of herring larvae 5–7 mm long were captured with plankton nets.
Vertebral Numbers of American Plaice, Hippoglossoides platessoides (Fabricius), in the Northwest Atlantic
Authors: Pitt T. K.
Published: April 2011

Vertebral numbers of American plaice in the Northwest Atlantic are compared. Counts ranged from 42 to 48 vertebrae excluding the urostylar half-vertebra.No significant difference was found between vertebral averages of males and females.Averages for an area extending from the Northeast Newfoundland Shelf southward over the whole of the Grand Bank and inshore to include St. Mary's Bay are statistically similar. The average for this area is significantly higher than averages for the Gulf of St. Lawrence, the Labrador Shelf, Flemish Cap and Fortune Bay. However, over the whole area differences are not very great, the range of averages being (for a sample of 30 or more) 45.273–45.806 vertebrae.The possible effects of differences in the time of spawning, larval drift and the inclusion of a large number of year-classes in the various samples are discussed as possible explanations for the low degree of variability in the whole area.The vertebral averages of the year-classes 1942–1953 from St. Mary's Bay are not statistically different.
Tidal Calibration of the Hecate Model
Authors: Bell W. H. , Boston N.
Published: April 2011

A semi-empirical method for the tidal calibration of oceanographic models with two ocean approaches is developed. The same method may be extended to models with more than two approaches. Tidal functions (amplitude and phase) at reference stations are expressed in terms of the amplitudes and phases of the tide generators. A Taylor expansion is made about an initial set of conditions imposed on the generators. The result is a set of simultaneous equations, whose coefficients can be found experimentally. Then, knowing the response at the reference points to the initial generator conditions, corrections can be made to obtain any desired tide.The method is applied to the particular case of the Hecate Model. Examples of single- and multiple-component tides are given.
An Occurrence of Mako Sharks, Isurus oxyrinchus, Rafinesque 1810, in the Canadian Atlantic
Authors: Tibbo S. N. , McKenzie R. A. , Scott W. B.
Published: April 2011

not available
Use of Coloured Tags in Fish Population Estimates
Authors: Lawler G. H. , Smith G. F. M.
Published: April 2011

Transparent colourless and opaque yellow tags of several types were applied to small perch, less than 15 cm in length, and larger suckers, 17 cm and greater, in Heming Lake, Manitoba, Canada. The return of opaque yellow tags was significantly smaller than that of clear transparent tags (less than one-half) for the small fish only. Tag type was relatively unimportant. This is interpreted as a higher predation rate, by pike, on small fish with opaque yellow tags.
Minke Whales, Balaenoptera acutorostrata Lacépède, of the Western North Atlantic
Authors: Sergeant D. E.
Published: April 2011

Minke whales Balaenoptera acutorostrata support a shore-based fishery in eastern Newfoundland. The appearance of minke whales here parallels the spawning concentration of capelin (Mallotus villosus) and lasts from late May to late July, the whales eating chiefly capelin with some cod and herring and other organisms. Summer distribution extends north to Ungava Bay. A return migration is not noted in Trinity Bay before catching ends in late October but reports from the Labrador coast indicate that many whales pass through just before freeze-up in November or December. The catch in Newfoundland consists mainly of large mature animals, and there is some evidence that many calves may remain in summer in more southerly waters. Body form, colouration and life cycle show no differences from minke whales of European seas. Ear plugs were rarely found to show readable growth layers in minke whales.
Temperature, Salinity and Plankton in the Eastern North Atlantic and Coastal Waters of Britain, 1957.: III. The Distribution of Zooplankton in Relation to Water Bodies
Authors: Bary B. McK.
Published: April 2011

The distributions of 17 species of marine zooplankton from near surface waters are discussed relative to the areas occupied by water bodies (as characterised by surface temperature-salinity diagrams) in the eastern North Atlantic and the coastal waters of Britain. The species' distributions are delimited by the area occupied by the water bodies with which they were associated in the temperature-salinity-plankton diagram, or for some species, by the extended influence of the water pursuant on mixing with another. Oceanic species show distributional features interpreted as indicating movements from north and south towards mixed (transitional) water; species occurring in both oceanic and mixed oceanic-coastal water demonstrate distributional features considered not at variance with movements from the ocean towards the inshore waters. Other, coastal species, are restricted in distribution to water lying shorewards of the position of the shelf-edge. Interspecific variation in relationships to water bodies among species within a group is reflected in more or less limitation of their geographic ranges.
Further Information on Sustained Yields from Fluctuating Environments
Authors: Larkin P. A. , Ricker W. E.
Published: April 2011

The conclusions of Ricker (1958) are confirmed in series of 200 generations in which environment effects are simulated. The best constant rate of exploitation is very close to the maximum equilibrium rate when there is no environmental variation. A higher catch is obtained when an optimum portion of the stock is reserved for escapement and the remainder is harvested up to the level of the maximum equilibrium rate. Still higher catches are associated with reserving an optimum portion of the catch for escapement and harvesting all of the remainder. In general, these kinds of benefits are greatest at higher levels of environmental variability.
Variations in the Growth of Atlantic Cod (Gadus morhua L.)
Authors: Kohler A. C.
Published: April 2011

Growth rates of Atlantic cod vary both between populations in the same year and within a population over a series of years. The latter type of change is selected for detailed study, using an example found in the population resident in the western Gulf of St. Lawrence (ICNAF Division 4T). A real change in growth is verified by examining ageing methods, selectivity of sampling, tagging returns, and by measuring increments on the otoliths. Laboratory experiments showed that, when food supply is unlimited, food consumption increases with increasing temperature, and that growth increases with increasing food consumption. Direct correlation between temperature and growth changes is not established.Cod growth changes in Division 4T are found to be the result of changes in abundance and availability of herring as food, plus changes in competition for food resulting from density changes in fish-eating members of the cod population.
Marine Phytoplankton Photosynthesis as a Function of Light Intensity: A Comparison of Methods
Authors: McAllister C. D. , Shah N. , Strickland J. D. H.
Published: April 2011

An apparatus is described in which the constant for exponential algal growth has been determined as a function of light at controlled temperature. Studies were made of bacteria-free cultures of Skeletonema costatum and Dunaliella tertiolecta grown at the optimum temperature for cell division in media with and without adequate nitrate and phosphate. Less complete studies were made of the behaviour of Monochrysis lutheri and Amphidinium carteri. In all experiments the growth constants were determined at known light intensities, expressed in the energy units, langlies/minute, using light of a known spectral distribution similar to sunlight shining through a few metres of coastal sea water.Growth constants were determined for the following processes: increase of cellular carbon, chlorophylls a, b or c, carotenoids, cell numbers and photosynthesis measured both by oxygen evolution (net and gross) and by the uptake of C-14 labelled carbonate.The rate of maximum photosynthesis occurred when the illumination reached about 0.1 ly/min and little or no light inhibition occurred when the intensity was increased to as high as 0.4 ly/min. Respiration was about 10% of maximum gross photosynthesis. This fraction increased when cells were nitrogen deficient but decreased in phosphate deficient cultures because a phosphate shortage inhibited respiration more severely than photosynthesis.Gross photosynthesis at low light intensities was proportional to the total number of molecules of all plant pigments added together, irrespective of species or of culturing conditions. By contrast, the rate of maximum gross photosynthesis was poorly related to pigment composition, the best correspondence being with the amount of chlorophyll a in the cultures.The uptake rate of C-14 varied with time. There was an apparent "leakage" of labelled organic matter which eventually reached a near-equilibrium with 14CO2 uptake, after which the C-14 method measured the production of particulate carbon but not necessarily net or gross photosynthesis. The rate of particulate carbon production was the same as that of cell division but about 40% less than net photosynthesis in cultures of Skeletonema. Agreement between C-14 rates and net photosynthesis was better in cool-white fluorescent light than in the imitation submarine sunlight used in this work. At high light intensities there was apparently no excretion from Dunaliella "shade" cells but when these became changed to "sun" cells they behaved more like Skeletonema.Various observations are recorded of the effect of growth conditions on cell composition, especially with regard to pigments.The relatively low C-14 rates found with Skeletonema costatum may be explicable in part by an abnormally low counting efficiency for this species even when present as a "weightless" source but the problem requires further study.
Nessorhamphus ingolfianus Schmidt, An Oceanic Eel, Recorded in Canadian Continental Waters
Authors: Rees E. I. S.
Published: April 2011

not available
A Technique for Prolonged Blood Sampling in Free-Swimming Salmon
Authors: Smith Lynwood S. , Bell Gordon R.
Published: April 2011

A technique is described for insertion of a cannula in the dorsal aorta of salmon for long-term blood sampling or vascular injection while the fish is confined, but free-swimming. Previous methods for single injections into the dorsal aorta are improved by a modified cannulation technique. The practicality of the technique was tested by introducing Evans Blue (T-1824) into the dorsal aorta of immature pink salmon (Oncorhynchus gorbuscha) in sea water and mature sockeye salmon (O. nerka) in fresh water to make preliminary estimates of blood volumes. It was shown that the technique can also be applied to angiography of salmon.
Stomach Contents of Blue Shark (Prionace glauca L.) Taken in the Gulf of Alaska
Authors: LeBrasseur R. J.
Published: April 2011

not available
Thermal Resistance of Pike (Esox lucius L.), Muskellunge (E. masquinongy Mitchill), and their F1 Hybrid
Authors: Scott D. P.
Published: April 2011

Comparison of thermal resistances of pike, muskellunge, and their F1 hybrid indicates close similarity between the two species. There appears to be some hybrid vigour in that the hybrids tend to be more resistant to thermal stress at the average acclimation and test temperatures encountered in the experiments. The greatest difference between the hybrids and parents occurred at the lowest test temperatures. Differences between the parent species were apparent only in their response to acclimation temperature, the slope of the curve of resistance time on acclimation temperature being much steeper for muskellunge than that for pike.
The Respiratory Metabolism and Swimming Performance of Young Sockeye Salmon
Authors: Brett J. R.
Published: April 2011

The rate of oxygen consumption in young sockeye salmon (Oncorhynchus nerka) was determined for various swimming speeds, including fatigue levels, at temperatures of 5, 10, 15, 20, and 24 °C. A logarithmic increase in oxygen demand with increase in swimming speed characterized each acclimation temperature. Extrapolation to zero activity (standard metabolism) and maximum activity (active metabolism) provided differences of the order of 10 to 12 times the minimum rate.The greatest scope for activity occurred at 15 °C with an average active metabolic rate of 895 mg O2/kg/hr for a swimming speed of 4.1 body lengths per second, just maintained for 1 hr. Above 15 °C active metabolism was limited, apparently by oxygen availability.Rate of replacement of oxygen debt following fatigue was determined by tracing the return to a resting state of metabolism, and confirmed by re-tests at fatigue velocities. In most instances the rate declined logarithmically with time; in some there was an initial or secondary slump. Times to recovery (return of spontaneous activity) averaged 3.2 hr, independent of acclimation temperature.Swimming speed–fatigue tests indicated a sustained level of performance at about 200–300 min. Comparison with other fish suggests a marked change in slope of the fatigue curve at about 20 sec. The effect of temperature was greatest on sustained speeds and least on burst speeds.
Further Information on Spawning Stock Size and Resultant Production for Skeena Sockeye
Authors: Shepard M. P. , Withler F. C. , McDonald J. , Aro K. V.
Published: April 2011

not available
Polyphosphate Treatment of Frozen Cod. 3. Taste Panel Evaluation, Chemical Assessment and Thaw-Drip in Once-Frozen Newfoundland Trap-Caught Cod
Authors: MacCallum W. A. , Chalker Dorothy A. , Lauder J. T. , Odense P. H. , Idler D. R.
Published: April 2011

Sodium tripolyphosphate treatment before packaging and freezing of fillets of trap-caught cod (Gadus morhua L.) in-rigor was compared with treatment in plain water.The once-frozen treated fillets, evaluated by an analytical taste panel after frozen storage at −12°F (−24.5 °C) for periods up to 27 weeks, had significantly better texture characteristics than did the untreated control fillets.Thaw-drip was significantly smaller in treated samples but this effect was less pronounced after extended frozen storage.Lipid hydrolysis proceeded at the same rate in both treated and untreated fillets.There was no significant difference between the electrophoretic patterns of the proteins found in the treated and untreated samples. In both cases the muscle albumins constituted the major portion of the proteins in the drip.Results indicate that polyphosphate-treated fillets prepared from trap cod could have greater market acceptance than untreated fillets. The producer would benefit from improved quality of product and from increased yield.
Demersal Quality of Fertilized Eggs of Rock Sole (Lepidopsetta bilineata Ayres)
Authors: Forrester C. R.
Published: April 2011

not available
On Passive Features in the Osmoregulatory Adaptation of Anadromous Salmonids to Sea Water
Authors: Houston Arthur Hillier
Published: April 2011

not available
A Northern Pike, Esox lucius, with an Accessory Fin
Authors: Lawler G. H.
Published: April 2011

not available
A Solution of the Catch Equation
Authors: Murphy Garth I.
Published: April 2011

A method is described for explicit solution of the catch equation yielding year-by-year estimates of the population at the beginning of the fishing season and the coefficient of fishing mortality of fully recruited members of the population. A method of obtaining similar statistics for less than fully recruited ages is also given. Other types of information that can be derived if fishing effort is measured are discussed. A minimum program for solution of a fishery is described. As an example, the method is applied to the catch statistics of the Antarctic fin whale population.
Retinal Structure in the Arctic Char (Salvelinus alpinus L.)
Authors: Ali M. A.
Published: April 2011

not available
Comparative Study of the Intraperitoneal Alimentary Tract of Parasitic and Nonparasitic Lampreys from the Great Lakes Region
Authors: Battle Helen I. , Hayashida Kaye
Published: April 2011

The macroscopic and microscopic anatomy of the intraperitoneal alimentary tract of two parasitic species of lamprey, Petromyzon marinus and Ichthyomyzon unicuspis, and two nonparasitic species, Entosphenus lamottenii and Ichthyomyzon fossor, are described and compared. In adults of both parasitic species a diverticulum of the anterior mid-gut occurs at the level of the posterior oesophagus; and longitudinal mucosal folds or rugae greatly increase the internal surface of the mid-gut. The course of the mid-gut spiral valve shows species variation, and is more complex in parasitic than nonparasitic adults. Throughout most of the tract tall cilia occur on epithelia over the tips of folds, whereas short cilia form tracts in the fornices. Extra-epithelial tunics are composed of fibro-elastic connective tissue, circular smooth muscle, and a serosa. The four species can be distinguished on the bases of the mucosal folds, spiral valve, and the lining epithelium of the oesophagus.Atrophy of the tract of both parasitic species commences with the spawning migration, when the epithelium exhibits a characteristic cytolysis with vacuolation of the cytoplasm and peripheral migration of the nuclei. In Entosphenus lamottenii atrophy involves initial necrosis of the epithelium and subsequently of the extra-epithelial tunics, both accompanied by massive infiltration of lymphocytes, whereas in Ichthyomyzon fossor it is resultant upon autolysis of some of the epithelial cells with progressive reduction in the diameter of the tract without interruption of the lining layer.
A Comparison of Catches by 3- and 4-Inch Rings on Offshore Scallop Drags
Authors: Bourne Neil
Published: April 2011

Comparative fishing with offshore scallop drags, knit with 4-inch (102-mm) and the standard 3-inch (76-mm) inside diameter rings, was carried out on Georges Bank in 1959 and 1961. Catches of the two drags were measured to determine the possibility of increasing the annual yield of scallop meats by delaying capture of 5-year-old scallops until they are 6 years old (96–108 mm, shell height). The difference in catches of scallops of this size-range by the two drags was small: the larger ring caught 90% as many as the smaller ring caught. The effect of increased linkage on catches was also measured. A mesh regulation enforcing the use of a 4-inch ring would not give the desired selection.
Drift Bottle Observations in Northumberland Strait, Gulf of St. Lawrence
Authors: Lauzier L. M.
Published: April 2011

Drift bottles have been released at fixed stations and during cruises in Northumberland Strait from 1960 to 1963. From the 2741 releases, there have been 1213 recoveries before the winter seasons. The overall high percentage recovery (44%) and the large number of returns not far from the point of release and within a short time after releases are featured.The drift bottle recoveries suggest a surface non-tidal drift through Northumberland Strait from the northwest and west to the southeast and east. An outward drift into the Gulf of St. Lawrence, along the northwest coast of Prince Edward Island is inferred.The speeds of the drift were generally greater than 3 miles a day on the average. They reached 5 miles a day (0.2 knot).
Survival of Lobsters, Homarus americanus, out of Water
Authors: McLeese D. W.
Published: April 2011

Median resistance times (MRT) in moist air at 0, 5, 10, and 15 °C were determined for lobsters acclimated at 0, 10, and 20 °C. At temperatures above 4–8°C depending on acclimation, there was an inverse relationship between median resistance time and temperature. A break in the relationship occurred at 4–8 °C and further lowering of temperature to 0 °C had no effect on MRT. Survival time was not increased by continuous sprays of sea water. Exposure to an air–oxygen mixture containing 40% oxygen by volume had no effect; however, lobsters died faster at 55–85% oxygen. Fed lobsters died faster than starved ones. An inverse relationship between MRT and metabolic rate was indicated.
Preliminary Trials of a Tag for Salmon and Lobsters
Authors: Scarratt D. J. , Elson P. F.
Published: April 2011

A description is given of a new design of toggle tag which can be easily embedded in the musculature of small marine animals. A brief account is included of preliminary trials on Atlantic salmon, cod, and lobsters.
Migrations of Harp Seals Pagophilus groenlandicus (Erxleben) in the Northwest Atlantic
Authors: Sergeant D. E.
Published: April 2011

Some 1300 harp seal pups were marked with four types of tags over 5 years from commercial sealing ships at the breeding patches off eastern Canada. Recovery rates from individual taggings ranged up to 20%. The greatest age at recovery was 4 years, 10 months. The recoveries and observational evidence show that the young seals at 4–6 weeks move out to the ice edge, drift passively with the prevailing current, and at 8–10 weeks begin to migrate northward, independently of and somewhat later than the herds of older animals. Tag recoveries in summer come from West Greenland and eastern Baffin Island. The southward migration begins in late September at high latitudes and reaches the Strait of Belle Isle by late December. Many immatures remain in arctic waters much later than the main herds, but the majority have moved south to join them in the breeding areas by April, when moulting takes place. Harp seals born in the Gulf of St. Lawrence and on the ice east of Belle Isle separate to their home areas to moult as immatures, although they mix in their summer range and on the southward migration. Probably, breeding and moulting adults remain distinct also. In the Gulf of St. Lawrence, most moulting takes place in the water, but east of Belle Isle, on ice. Moulting groups east of Belle Isle are composed at first of adult males and immatures, and are joined in the later part of April by the adult females which have given birth.
Trends in Catch, Age, and Size of Cod from the Commercial Longline Fishery at Bonavista, Newfoundland, 1952–62
Authors: Fleming A. M.
Published: April 2011

A commercial longline fishery for cod was begun from Bonavista in 1952. Catches remained high until 1956, particularly on the deep-water grounds but thereafter decreased rapidly because of (a) the intense fishery, especially by European otter-trawlers and longliners after 1956, and (b) irregular recruitment to the fishery. The decrease in catch per unit of effort was marked by wide changes in the age and size compositions of the catch. The cod in deep-water catches tend to be older and larger than in the shallow-water catches.
Chalkiness in Halibut in Relation to Muscle pH and Protein Denaturation
Authors: Tomlinson N. , Geiger S.E. , Dollinger E.
Published: April 2011

Chalkiness in halibut, a condition in which the flesh is dull, white, opaque, soft and flabby in contrast to the normal shiny, translucent, and firm appearance, has been found to be a postmortem development; the flesh of normal and potentially chalky fish being indistinguishable in appearance when they are caught. The change to the chalky condition was shown to be dependent on the pH of the muscle, taking place only if it fell to about 6.0 or lower, and to be accompanied by a marked decrease in extractability of both myofibrillar and sarcoplasmic protein. Denaturation of these proteins is probably the direct cause of chalkiness. Possible reasons for the rather wide range of muscle pH found in halibut taken in the British Columbia fishery are discussed.
First Transponding Oceanographic Buoys in the Pacific
Authors: Favorite F. , Fisk D. , Ingraham Jr. W. J.
Published: April 2011

Three transponding oceanographic buoys were released off the Washington coast during May 1964. One drifted over 320 miles 155° T at a speed of almost 5 miles per day. Two buoys, 1000 yards apart on May 29, were recovered 58 miles apart on July 17. Attempts to track the buoys at 10-day intervals by aircraft were unsuccessful. Communications using a frequency of 2690 kc were unsatisfactory at ranges in excess of 200 miles, but an interrogation and transponding range of 900 miles was obtained using 4134.5 kc.
Distribution and Morphology of the Medusa, Calycopsis nematophora, from the North Pacific Ocean
Authors: Renshaw R. Ward
Published: April 2011

The medusa, Calycopsis nematophora, is reported from the North Pacific for the first time since its original description. It is restricted to arctic-subarctic surface waters. Radial canal variation and other morphological characters are discussed.
Orange-Red Meats in Sea Scallops
Authors: Bourne Neil , Bligh E. G.
Published: April 2011

not available
Candling for the Detection of Triaenophorus crassus Cysts in Whitefish
Authors: Budde W.
Published: April 2011

not available
Rancidity in Lean Fish Muscle.: IV. Effect of Sodium Chloride and Other Salts
Authors: Castell C. H. , MacLean Jill , Moore Barbara
Published: April 2011

Sodium chloride accelerated rancidity in blended cod muscle at 0 C. This salt-induced rancidity was retarded by commercial antioxidants and chelating compounds. The active agent appeared to be the Na+rather than the whole salt or the Cl−.Other metal salts had similar pro-oxidant action on the cod muscle when used in relatively high concentrations (0.1 N and above). The relative activity, using metal chlorides, was as follows: Fe > Co > Cd > Li > Ni > Mg > Zn > Na > K. Ca and Ba had no effect.Many of these "pro-oxidant" salts also had a strong antioxidant effect on the development of copper-induced rancidity in the muscle.The relationship between TBA values and the type and intensity of odours is not the same for sodium chloride-induced and copper-induced rancidities. Some of the reasons for this have been discussed.It has been suggested that one mechanism by which sodium chloride influences the rate of lipid oxidation in the fish muscle is by the changes it produces in the accompanying proteins.
Distribution of Certain Crustaceans and Fishes in the Region of Algonquin Park, Ontario
Authors: Martin N. V. , Chapman L. J.
Published: April 2011

Senecella calanoides, Limnocalanus macrurus, Mysis relicta, Pontoporeia affinis, and Myoxocephalus quadricornis were found in 63 lakes in the Algonquin Park region of Ontario. Their distribution results from direct coverage by glacial Lake Algonquin, outlet channels from this lake and Nipissing Great Lakes to the Ottawa valley, and inundation by the Champlain Sea. Their occurrence in 12 high-altitude lakes resulted from their transport to these waters by proglacial lakes.
Carbon Balance Experiments with Marine Phytoplankton
Authors: Eppley Richard W. , Sloan Phillip R.
Published: April 2011

Carbon budgets were prepared for eight species of marine phytoplankton organisms in culture and one natural red tide population during 5-hr experiments at 21 C and light intensity 0.07 cal/cm2/min. Net cell carbon increase, dissolved organic carbon excretion, and respiration were each determined by two or more independent methods.In diatoms, net oxygen production gave higher estimates of carbon assimilation than did direct carbon measurements, which were not accounted for by excretion of dissolved organic matter. Carbon-14 assimilation agreed well with the increase in oxidizable particulate carbon and with decrease in dissolved CO2 of the medium, the latter after correcting for excreted organic carbon.Dunaliella tertiolecta excreted a constant fraction of its assimilated carbon regardless of its physiological activity. In diatoms excretion increased as cells became physiologically inactive.Thalassiosira rotula excreted similar amounts of carbon in light and dark. In two other diatoms excretion increased on darkening. In these short-term experiments carbon-14 sometimes gave low estimates of excretion by diatoms probably because both labelled and nonradioactive compounds were released by the cells.
Limnological Aspects of Some Saline Lakes in West-Central Manitoba
Authors: Driver E. A.
Published: April 2011

During the summer of 1963 a qualitative and quantitative survey of the total dissolved solids of six lakes, Crawford, Raven, Beauford, Shoal, Horseshoe, and Eighteen in west-central Manitoba, was conducted to establish the chemical type. The lakes ranged in decreasing salinities respectively from approximately 10,300 ppm to approximately 4000 ppm. The predominant anion was sulphate and the predominant cation was magnesium in each lake. With considerations of information for certain physical and morphometric features a trophic status was derived. These lakes are eutrophic-saline-glacial lakes of the sulphate type.
Hybridization in the Family Esocidae
Authors: Crossman E. J. , Buss Keen
Published: April 2011

Of 11 possible hybrids of species in the family Esocidae, six were known from nature and they are reviewed. The occurrence of a seventh, Esox lucius × Esox americanus americanus, is recorded. Of 22 possible reciprocal combinations of these species, five were previously known, five are still unknown, and 12 are newly described here. These 12 are based on artificial hybrids of known gametic constitution. Data are given on: description (young and oldest material available); growth; fertility; vitality and meristics are compared with parent populations. The low level of interspecific sterility was surprising. Some interspecific sterility exists between the two largest (Esox masquinongy Mitchill, Esox lucius Linnaeus) and the two smallest (Esox americanus Gmelin) forms. Total sterility does not exist as artificially one or other of the reciprocals was successful in each cross, including Esox masquinongy × Esox americanus. The hybrids exhibited the blending and intermediate nature usual in fish hybrids but colour pattern seemed tied to a particular parent. In nature only certain species hybridize, but it would appear that incompatibility of gametes has proceeded only to a limited extent. Other factors such as distribution, habitat, size, and behavior may be preventing hybridization.
Effect of Thermal Acclimation and Sublethal Heat Shock Upon Ionic Regulation in the Goldfish,Carassius auratusL.
Authors: Heinicke Elizabeth Anne , Houston A. H.
Published: April 2011

Goldfish acclimated to 20 and 30 C exhibited no significant differences in plasma sodium level, tissue chloride, potassium and water content, and chloride space. Plasma chloride varied inversely and plasma potassium directly with temperature. Tissue sodium levels tended to be slightly lower at the higher acclimation temperature. The shock response following abrupt transfer from 20 to 30 C was characterized by a complex sequence of changes in water–electrolyte balance. Following a lag period plasma chloride rose sharply, peaking some 48 hr after transfer, and subsequently declining. Plasma sodium varied in substantially similar fashion. Changes in plasma sodium/chloride ratio suggested the possible occurrence of a transient condition of alkalosis following thermal shock. Plasma potassium levels increased rapidly, and appeared to stabilize within 24 hr. By contrast, little variation in tissue levels of sodium, potassium, and chloride was observed. Tissue water content, on the other hand, tended to increase steadily for several days after transfer. Changes in chloride space suggested that an increase in extracellular phase volume, in part at the expense of the cellular fluids, accompanied thermal shock. It is concluded that while thermal shock induces marked initial deviations in iono- and osmoregulatory ability the goldfish can, during the acclimatory process, carry out compensatory changes in regulatory activities which permit restoration of virtually the original ionic status. Possible mechanisms underlying the shock and acclimatory responses are discussed, and the bearing of studies of this general type upon the estimation of thermal acclimation rates is considered.
Effect of Retention of Spermatozoa and Ova of Sockeye Salmon, Oncorhynchus nerka, in Water and Without Addition of Water, on Fertility
Authors: Foerster R. E.
Published: April 2011

Viability of ova and of spermatozoa was retained after considerable exposure to water and to air before fertilization. Fertilization occurred when spermatozoa were held in water for 8 hr (10.9% ova fertilized) and in air for 72 hr (4.4%), and when ova were held in water for 28 min (3.4%) and in air for 96 hr (73.7%). Great variation in results suggested that little importance could be attached to the actual percentage of eggs fertilized.
Alkaline Phosphatase in Fish Scales
Authors: Coble Daniel W.
Published: April 2011

not available
Swimming Speeds of Sockeye and Coho Salmon on Spawning Migration
Authors: Ellis Derek V.
Published: April 2011

The speed at which sockeye and coho salmon swim while on spawning migration through a river was determined by direct timing of individual fish over measured river sections and by measurement of opposing water velocities. Migration was accomplished by two locomotory patterns: dart and steady swimming. For steady swimming there was a critical opposing water velocity from 1.1 to 1.7 ft/sec (mean 1.4 ft/sec). Against currents slower than the critical range steady swimming to a maximum speed of approximately 3.4 ft/sec (1.7 body lengths (L)/sec) was sustained through the observation areas, but against currents faster than the critical range salmon broke into position-holding behaviour at intervals. The calculated inter-decile range of swimming speeds (excluding slowest 10% and fastest 10%) against water velocities below the critical range was 1.75–3.18 ft/sec (0.9–1.7 L/sec) for sockeye salmon and 1.70–3.14 ft/sec (0.9–1.7 L/sec) for coho salmon. These swimming speeds were below maximum sustained values which have been determined experimentally.
Occurrences of the Fishes Pholis schultzi and Liparis mucosus in British Columbia
Authors: Peden Alex E.
Published: April 2011

not available
Exploitation in a Type of Predator–Prey Relationship
Authors: Larkin P. A.
Published: April 2011

The properties are explored of the response to exploitation of the predator–prey system defined by the equations:[Formula: see text]This type of equation is perhaps a suitable representation of the type of natural situation in which a predator (N2) is not wholly dependent on one species of prey (N1) for food, and in which factors other than predators may regulate prey abundance. Yield- and value-isopleths are presented for sample values of the above parameters and for various rates of fishing.
An Occurrence of Capelin (Mallotus villosus) in the Bay of Fundy
Authors: Tibbo S. N. , Humphreys R. D.
Published: April 2011

not available