bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrographic and Meteorological Factors Affecting Shellfish Toxicity at Head Harbour, New Brunswick
Authors: Prakash A. , Medcof J. C.
Published: April 2011

Toxicities recorded from 1944 to 1958 in blue mussels (Mytilus edulis) from Head Harbour, N.B., are examined in relation to some hydrographic and meteorological factors. Within-year variations in toxicity are correlated with summer rises in water temperature. Year-to-year variations are directly correlated with springtime insolation and salinity and inversely correlated with springtime river discharge and winter water temperature. The probable role of these factors in regulating the abundance of the causative organism, hence, levels of toxicity, is discussed.
Growth and Reproduction of the Longnose Sucker, Catostomus catostomus (Forster), in Great Slave Lake
Authors: Harris Roy H. D.
Published: April 2011

A biological investigation of the longnose sucker, in Great Slave Lake, was carried out in 1950 and 1951. Specimens were obtained by use of gill nets and seines. Suckers taken along the south shore had a faster rate of growth than those in the more northern area. In both areas, males and females grew at the same rate in length and weight. Females lived longer and thereby became heavier. The average annual survival rate was 45%. The growth exponent was 2.88; the length-weight relationship, W = 0.000252 L2.88. Longnose suckers spawned in Hay River from the ice cover break-up in May to June 15. The water temperature did not exceed 59°F (15 °C). The majority of spawning-run fish were 10 to 12 years old. Although sexually mature at 7 years, no suckers younger than 9 years of age were found in the spawning run. Females contained from 17,000 to 60,000 eggs but may not spawn each year. Fingerlings from Hay River were 33 to 80 mm in length, and were in their first summer. They all had scales.
Fat Hydrolysis in Frozen Fillets of Lingcod and Pacific Gray Cod
Authors: Wood J. D. , Haqq S. A.
Published: April 2011

not available
Enumeration of Coliform Bacteria in Light Salted Fish Brines
Authors: Dussault H. P.
Published: April 2011

For the enumeration of the coliform bacteria present in light salted fish brines, the most probable number (MPN) procedure has been applied. Results have shown that lactose fermentation is inhibited when the inoculation of brine aliquots into plain lactose broth produces a final NaCl concentration higher than 3%. Thus erroneous low counts are obtained. It was found that this inhibitory effect could be obviated by diluting commercial fish brines with an equal volume of sterile distilled water before inoculation. The total number of coliform bacteria was determined in a number of brine samples collected at three different fish processing plants. The recommended dilution has resulted in an average 40-fold increase in total counts. All the samples collected contained significant numbers of coliform bacteria indicative of faecal contamination.
Observations on the Isopod Mesidotea entomon in the Western Canadian Arctic Ocean
Authors: McCrimmon Hugh , Bray Joseph
Published: April 2011

The collection of Mesidotea entomon (Linnaeus) during the 1960 cruise of the Salvelinus in the western Canadian Arctic ocean has expanded the recorded distribution of the species. Population densities were highest in mud-bottomed areas where water temperatures ranged from −1.3 to +10.0 °C. No specimens were collected at depths greater than 24 fathoms (44 m). Sexual dimorphism of M. entomon became apparent at lengths of 25 mm, males reaching a larger size than females at maturity in the second year of life. The majority of the population apparently died after reproducing once.
Trichodinids from the Gills of a New Host, the Lingcod Ophiodon elongatus
Authors: Bell Gordon
Published: April 2011

not available
Proteins in Fish Muscle: 17. Fractionation of Aqueous Extracts with Zinc Acetate
Authors: Dingle J. R. , Hines J. A. , Neelin J. M.
Published: April 2011

Zinc acetate in low concentrations has been used to fractionate aqueous extracts of cod and haddock muscle. Approximately 18% of the cod proteins extracted remained soluble after addition of 0.1M zinc acetate and subsequent treatment with KH2PO4 buffer. This fraction consisted largely of two components of the original cod extract, and the same fraction from haddock was very similar. Fractionation on DEAE-cellulose removed the minor components, but failed to separate the main ones. The protein of the cod fraction contained an unusually large proportion of phenylalanine.
Conversion of the Free Fatty Acids of Cod Oil to Methyl Esters in situ
Authors: Ackman R. G. , Gallay L. R. , Jangaard P. M. , Hughes M. L.
Published: April 2011

The application of 2,2-dimethoxypropane to the in situ conversion of the free fatty acids of cod oil to methyl esters is successful in reducing the free fatty acid content to the order of 1%. This material, in the presence of a suitable acid catalyst, serves both as a water scavenger and a source of methanol for the esterification. Of the catalysts examined, methanolic HCl gives the best results. Purification procedures giving a stable product are outlined.
Distinctions Between the Broad Whitefish, Coregonus nasus, and Other North American Whitefishes
Authors: Lindsey C. C.
Published: April 2011

176 specimens of C. nasus and 121 of "humpback" whitefish (allied to C. clupeaformis) were examined from 15 North American localities where the two kinds occurred sympatrically. No previously published criteria were effective in separating the two kinds at all sizes in all localities, but combinations of certain pairs of measurements chosen to compensate for non-isometric growth allowed identification of all individuals examined. Length of longest gill raker was less than 20% of the interorbital width in all C. nasus, more in all "humpbacks". Means of 15 other proportional or meristic characters differed consistently between sympatric species pairs. C. nasus is a distinct and widespread species. Its distribution and nomenclature are reviewed.
Seasonal Changes in Feeding of Coho and Chinook (Spring) Salmon in Southern British Columbia Waters
Authors: Prakash A.
Published: April 2011

Food study based on the stomach analyses of 551 chinook salmon (Oncorhynchus tshawytscha) and 659 coho salmon (O. kisutch) collected from the various localities along the southern British Columbia coast during the summer of 1957 revealed that herring followed by crustaceans formed the most important items of the diet of the two species. Coho salmon exhibited a more pelagic and varied diet than chinook salmon caught in the same area. Definite seasonal fluctuations in the composition of food and feeding intensity were noticed. Considerable amounts of Crustacea were taken in early summer months and after that fish assumed importance.Qualitative and quantitative differences in the feeding of these two species on the east and west coasts of Vancouver Island appear to warrant the establishment of two food type areas, Although herring constitute the major food item of both spring and coho salmon, evidences are presented in support of the hypothesis that a change in herring stock is not likely to affect salmon abundance in British Columbia coastal waters.
Possible Effects of Passamaquoddy Power Project on Clams, Scallops and Shipworms in Canadian Waters
Authors: Medcof J. C.
Published: April 2011

Only three molluscs in the Passamaquoddy region of the Bay of Fundy have economic significance. The annual soft-shell clam (Mya arenaria) production now at 4 million lb will drop 2 million and fishermen's earnings will drop to $100,000 because the area of clam flats in the High Pool will decrease 95%. Annual scallop (Placopecten magellanicus) production, now at 60,000 lb, will increase to about 90,000 lb and fishermen's earnings will increase to about $36,000 because reduced water exchange in the High Pool will favour survival of larvae and recruitment of scallop stocks. The shipworm (Teredo navalis), no problem now, will become an expensive pest in the Low and High Pools because higher water temperatures will encourage the build-up of heavy breeding populations.
Annual Cyclic Changes in the Physical Oceanography of a British Columbia Fjord
Authors: Gilmartin Malvern
Published: April 2011

Indian Arm (49°30′N, 122°53′W), one of the characteristic fjords of the coast of British Columbia, was intensively studied during 35 approximately monthly cruises during 1956 through 1959, with the main objective of determining the annual cycle of its oceanographic features. Unique in its duration of a British Columbia fjord study, this observational time series of the distributional patterns of salinity, temperature, density, dissolved oxygen and climate is presented, and used to analyze the circulation pattern and replenishment mechanism of fjord waters.
Temperature and Salinity in the Quoddy Region of the Bay of Fundy
Authors: Trites R. W.
Published: April 2011

not available
Predator-Prey Relationships in Pikes (Esocidae)
Authors: Crossman E. J.
Published: April 2011

not available
Oceanography of the Subarctic Pacific Ocean
Authors: Uda Michitaka
Published: April 2011

All available oceanographic data observed from 1951 through 1958, north of Lat. 35° N in the Pacific Ocean, the Sea of Okhotsk, and the Bering Sea, together with the relevant literature, were examined. There were sufficient data from 1955 through 1958 to prepare composite charts of salinity, temperature, dissolved oxygen and transparency of the near-surface waters in the Subarctic Region from Asia to America.The Subarctic Pacific is defined as the region in which there is a marked halocline separating a low salinity upper zone from a more saline lower zone. It includes all areas having dichothermal temperature structure. Definite boundaries for the region are established. The Subarctic characteristics are limited to the upper zone and halocline. The lower zone characteristics are continuous from the Subtropic into the Subarctic.From the data the principal features of structure of the properties have been shown, as well as the differences from one locality to another. The seasonal variations and also some non–seasonal variations have been discussed. The persistent current systems have been traced and their components named.The processes for the maintenance of the structure by precipitation, evaporation, dissipation of upper zone water, and entrainment from the deep zone are discussed. A relation between the barometric pressure distribution and the transport in the non–persistent current systems is proposed.
Apparatus for Measuring the Energy Input in Cutting Fibers of Fish Muscle
Authors: Buttkus Hans
Published: April 2011

The construction and operation of an apparatus for measuring the amount of energy expended in cutting muscle fibers is described. The measured energy permits a quantitative comparison of the toughness of different samples. Measurements on a model system of paraffin wax show a variation of ±5%. With muscle fibers of raw and cooked salmon, lingcod and beef, the variation in these measurements was sometimes as high as ±20%.
Systaltic Muscular Action of the Kidney Tubules of Flounder
Authors: Townsley P. M. , Scott M. A.
Published: April 2011

not available
Big Effects from Small Causes: Two Examples from Fish Population Dynamics
Authors: Ricker W. E.
Published: April 2011

1. A population which, before exploitation, includes upwards of 12–15 age-groups in appreciable quantities, is very sensitive to fishing. For example, even as little as 5% catch per annum eventually causes a major reduction in the relative weight of older fish in the stock. With unchanging recruitment the absolute size of the total stock also declines markedly, or even catastrophically, under moderate exploitation—so much so that it seems likely that recruitment must usually increase when the stock is first thinned, partly compensating for the removals.2. A population that produces its greatest sustained yield at a high rate of exploitation—say 75% or more at average recruitment—is then close to a point where recruitment will fall off rapidly if utilization becomes only slightly more intensive. This fact, and the aggravating effect of environmentally-caused variations in recruitment, suggest that any really close approach to the point of optimum yield will usually be too dangerous to be practical.
Summer Food of Lake Whitefish, Coregonus clupeaformis Mitchill, from Heming Lake, Manitoba
Authors: Watson N. H. F.
Published: April 2011

During the summer months of 1956 to 1959 inclusive, the stomach contents of 2963 Heming Lake whitefish from 5–15 inches in length were examined. Data on stomach contents of 194 whitefish taken in 1945 were examined and included in this analysis. Most stomachs contained food, but lesser quantities of food per stomach and many empty stomachs were found in July and August of each year. Mayfly nymphs occurred in the stomachs most often. Other, insects eaten included dipterous larvae, especially Chaoborus and chironomids. Incidental items, constituting a smaller though important part of the fish's diet, included aquatic coleopterans, hemipterans, trichopteran larvae, cladocerans, Hyalella, hydrachnids, gastropods and, seasonally, aerial insects from the surface of the lake, and small fish. Cyclopid and calanoid copepods were found in about 1% of the stomachs. This apparently low incidence of cyclopids in the diet is considered to be sufficient to establish the relatively high infection levels of Triaenophorus found in Heming Lake fish. Some differences in diet between fish of different sizes and between seasons were shown.
Lethal Temperatures of the Developmental Stages of the Sea Lamprey, Petromyzon marinus L.
Authors: McCauley R. W.
Published: April 2011

Of all stages of the sea lamprey, the eggs have the most exacting thermal requirements. The range of constant temperatures necessary for successful hatching is narrow, being 15–25 °C. This range may be extended to 12–26 °C and possibly beyond, if the eggs have developed to the head stage before they encounter temperature extremes.The ability to withstand high temperature characteristic of the post-embryonic stages of the species appears shortly before or after hatching.The role of temperature in the development of eggs under natural conditions is discussed.
Effects of Artificial Propagation and the Weather on Recruitment in the Lake Ontario Whitefish Fishery
Authors: Christie W. J.
Published: April 2011

No significant relationship could be found between variations in the level of fry planting and ensuing variations in the level of catch in the long-term statistics of the Lake Ontario whitefish gill-net fishery. An alternate-year planting experiment in which fry were planted in the even-numbered years 1944 through 1954, similarly failed to show a detectable level of contribution of the hatchery fish to the fishery. The supported year-classes averaged larger than those not given hatchery support but this was judged coincidental because of a phasing with an alternate-year periodicity which characterized the catch statistics over the whole series examined, and was present in the six years prior to the start of the alternate-year plantings. Estimates of spawning stock were calculated and it was not found that the progeny-per-parent ratios were significantly affected by the fry plantings.A possible explanation for the periodicity was suggested by a significant correlation between air temperatures at the times of spawning and hatching, and the strengths of the produced year-classes. Cold Novembers followed by warm Aprils appeared to provide conditions associated with the production of larger year-classes, with the opposite combinations relating to the weaker broods.The disappearance of lake trout and ciscoes from the commercial catch resulted in increased fishing pressure directed towards the capture of the whitefish. Increases in the efficiency and intensity of the fishing were observed during the period of the study and these were likely responsible for the reduction of the average age of the fish in the catch by almost one year, and the resultant restriction of the annual catch to one year-class in recent years. Probably because most of the fish are currently caught before first spawning, a decline in spawning stock was almost continuous during the study period. The year-to-year fluctuations in the level of the catch increased both because of the reduced average age, and because of a greater variation in year-class strength. The year-classes produced in favourable years tended to increase, down to quite low levels of stock. This gave a configuration similar to Ricker's Type C reproduction curve, and which differed chiefly in that the limiting diagonal representing minimum reproduction fell below the replacement diagonal. It was suggested that the whitefish may require more than one spawning, to achieve stock replacement. The present instability of the catch, and the potentially serious effect of any sustained break in the rhythm of the climatic conditions suggest a condition of over-exploitation in this case.
Amino Acid Composition of Representatives of Eight Bacterial Genera with Reference to Aquatic Productivity
Authors: Stewart James E. , Hoogland P. L. , Freeman H. C. , Waddell A. E. J.
Published: April 2011

Representatives of eight bacterial genera were grown under identical conditions and the harvested, washed cells were analyzed quantitatively for eighteen amino acids using chemical methods. All of the bacteria contained the eighteen amino acids and, although quantitative differences were noted, variation in composition was not great. Cell nitrogen content averaged 11.91% of the dry weight. Some of the nutritional implications of the data are discussed.
A Note on the Upper Lethal Temperature of Eggs of Two Species of Triaenophorus
Authors: Watson N. H. F.
Published: April 2011

not available
On the Demersal Quality of the Fertilized Eggs of Pacific Cod, Gadus macrocephalus Tilesius
Authors: Thomson J. Arthur
Published: April 2011

not available
Body Fluid Regulation in Smolting Atlantic Salmon
Authors: Houston Arthur H. , Threadgold Lawrence T.
Published: April 2011

Parr–smolt metamorphosis in yearling Atlantic salmon was accompanied by variations in plasma and tissue electrolyte levels, and in tissue water distribution. Plasma chloride declined sharply with the onset of smoltification, but recovered to values somewhat higher than those seen in parr with the attainment of the silvery parr stage. Some decrease, with no evidence of a secondary increase, was observed in tissue chloride concentrations. Changes in chloride space values suggested that parr–smolt metamorphosis is also characterized by a shift of tissue fluids from the extracellular to the cellular phase. These variations in water–electrolyte balance are thought to reflect a premigratory activation and secondary suppression of the extrarenal salt excretion systems employed for osmotic and ionic regulation in sea water. Their occurrence in fish estimated upon the basis of morphological characters to be large parr suggests that the metamorphic process may occur earlier in the life cycle of this species than is generally recognized.
On the Problem of Maximum Yield from North Pacific Sockeye Salmon Stocks
Authors: Parker Robert R.
Published: April 2011

If it is assumed that rates of exploitation, regardless of where fishing takes place, can be adjusted to the needs for reproduction, maximum yield from stocks of north Pacific sockeye salmon (Oncorhynchus nerka) will then be a function of growth and natural mortality rates. Events during the last decade have demonstrated the vulnerability of this species to pelagic fishing during the penultimate and ultimate years of life. The instantaneous growth rate on a per-month basis (g) is estimated from diverse data by back calculation, tag and recapture, and size-at-time methods. A general consistency of results is apparent regardless of the method utilized. For 2-ocean annuli life history types, penultimate [Formula: see text], ultimate [Formula: see text]. For 3-ocean annuli types, penultimate g = 0.059, ultimate [Formula: see text]. Ocean mortality models and rates derived by several researchers are reviewed and discussed. Using those proposed by the author, it is shown that the stock mass, hence the allowable yield, increases throughout the penultimate and ultimate years in the sea and reaches a maximum when the stocks approach the coast on the spawning migration. A conservative estimate of the potential increment, based on the 1957–1959 pelagic catches, is 14.2%. It is concluded that the yield of these stocks is seriously depressed by pelagic fishing.
Studies on the Life History and Ecology of the Bigmouth Buffalo, Ictiobus cyprinellus (Valenciennes)
Authors: Johnson R. P.
Published: April 2011

The field study of the bigmouth buffalo (Ictiobus cyprinellus (Valenciennes)), conducted mainly in 1955 and 1956, was concentrated on two small eutrophic lakes in the Qu'Appelle River drainage of Saskatchewan. The bigmouth buffalo reaches its northern limit of range in the Qu'Appelle drainage. Migration into Saskatchewan was probably through postglacial connections at the headwaters of the Mississippi and Red River systems. In the lakes studied, the species prefers water shallower than 5 m.The relation of standard length to fork length and of fork length to weight is presented graphically, and the latter described by the equation: weight in pounds = (0.00097 fork length in inches)2.91. Length–frequency distributions and age determinations from scale reading show that the population studied was largely the very successful 1948 year-class, produced in a year of extensive flooding. Annulus formation occurred during the second or third week in June. Growth of the 1948 year-class in Pasqua Lake was extremely slow, probably influenced by the cool climate and population density here.Food of young buffaloes was mainly Cladocera and Copepoda. Larger buffaloes ate about 75% Entomostraca and 15% chironomids, the latter more important as the size of fish increased. Analysis of the living habits of the food eaten, and the feeding mechanism of the buffalo, shows that they occupy a food niche overlapping both bottom feeders and limnetic plankton feeders.Sexual maturation, especially of females, was extremely slow both in age and size as compared with southern populations. Examination of gonads suggests spawning occurs about May 18–25. Egg measurements indicate that females do not all spawn each year. The contention by other investigators that spawning is "triggered" by addition of fresh water analogous to normal spring floods of the Mississippi River is supported by the present study.The population in the Qu'Appelle drainage is probably dependent on the very sporadic production of strong year-classes. A more stable population would require association with regular spring floods of a nearby river or marsh. Commercial removal from the viewpoint of greatest productivity is most economical at the smallest marketable size, as yearly weight gains are probably more than offset by natural mortality.
A Modified Petersen Grab
Authors: Flury J.
Published: April 2011

not available
Laboratory Observations on Embryonic Development and Larvae of the Pacific Cod (Gadus macrocephalus Tilesius)
Authors: Forrester C. R.
Published: April 2011

The relationship between rate of development of eastern Pacific cod eggs and water temperature was found to be linear at temperatures of 5–11 °C. Time to 50% hatching ranged from 8.5 days at 11 °C to 17 days at 5 °C. Most successful hatching occurred at the lowest temperature. Newly hatched larvae from 5° water had an average length of 4.45 mm.
Lethal Concentrations of Copper and Zinc for Young Atlantic Salmon
Authors: Sprague J. B.
Published: April 2011

The toxicity of copper and zinc sulphates to immature Atlantic salmon (Salmo salar L.) was tested in soft water.The relation between concentration of metal and survival-time could be fitted by a straight line when logarithms were used. A sharp break in this relation marked the incipient lethal level, where survival became indefinitely long. Incipient lethal levels were 48 μg/l of copper and 600 μg/l of zinc.In solutions containing both copper and zinc, fish died twice as fast as would occur if the 2 metals were simply additive in their lethal action. Resistance-times in zinc solutions were increased at pH 7.9–9.3, and results fitted the hypothesis that dissolved zinc was toxic, but not suspended zinc. Survival in a given concentration of zinc was 4 times as long at 5° as at 15 °C, and the incipient lethal level was at least 1.5 times higher, with fish acclimated to each temperature.
Water-Thawing of Frozen Cod Blocks
Authors: MacCallum W. A. , Ellis D. G.
Published: April 2011

Thawing time for frozen blocks of dressed cod (Gadus morhua) was investigated. Observations were made on the effect of size of individual fish, water recirculation rates, water temperature, block height, thickness and orientation, separation of individuals from the block at some intermediate time, and the use of sodium alginate to promote quicker thawing. Over the range investigated, the first two variables did not affect thawing rate; the remainder were of importance. Blocks 4 and [Formula: see text] inches (102 and 115 mm) thick, weighing 75–80 lb (34–37 kg), were separated and thawed in 60°F (15.5 °C) water in about 3 and [Formula: see text], respectively. These times were equal to or better than the times for freezing between plates under best local commercial conditions. In comparison, similar blocks can be thawed in about [Formula: see text] in a commercially available dielectric thawer. Thawing blocks of dressed fish in recirculated water thus merits consideration with other methods.
The Cell Division Rates of Some Marine Phytoplankters as a Function of Light and Temperature
Authors: Jitts H. R. , McAllister C. D. , Stephens K. , Strickland J. D. H.
Published: April 2011

An apparatus is described for exposing phytoplankton cultures to 64 different combinations of light and temperature. The light was of a known spectral energy resembling sunlight after passage through a few metres of clear coastal sea water and was measured in the energy units of cals/cm2/min (langlies/min or ly/min). The temperature range used varied in each experiment, the range of illumination was from about 0.005 to 0.4 ly/min, the latter being equivalent to bright summer sunlight at a depth of only a few metres in the sea.The growth of five bacteria-free cultures, Dunaliella tertiolecta, Amphidinium carteri, Monochrysis lutheri, Skeletonema costatum and Thalassiosira nordenskiöldii was followed for a period of 3–5 days using a cycle of 16 hr illumination and 8 hr of darkness every 24 hr. Growth was measured by counting cell numbers and the rate constants for cell division were evaluated at standard times.The resulting growth-response curves are reported and discussed in relation to their ecological significance. Except for T. nordenskiöldii cell division was relatively insensitive to temperature over a range exceeding 10 °C. Cell division showed a "stress" response, the growth rate being more susceptible to extremes of illumination when the cells were near to the extremes of temperature for a given species and to extremes of both temperature and light if the chemical nature of the medium was unsatisfactory. At optimum temperatures there was no inhibition of cell division at intensities of 0.4 ly/min of photosynthetically active light.
Redescription of Lernaeopoda centroscyllii Hansen, 1923 (Copepoda: Lernaeopodidae)
Authors: Kabata Z.
Published: April 2011

Lernaeopoda centroscyllii, a lernaeopodid copepod parasitic on Centroscyllium fabricii, and briefly described by Hansen on the basis of one damaged female specimen in 1923, has not been recorded since that date. This paper gives a detailed account of both the male and the female of the species, recently taken in Newfoundland waters.
Serologically Differentiated Subpopulations of the Pacific Sardine, Sardinops caerulea
Authors: Vrooman Andrew M.
Published: April 2011

Three genetically distinct subpopulations of the Pacific sardine have been differentiated by the frequency of occurrence of a C-positive blood factor. Two of these subpopulations, a northern and a southern one, live off the coast of California and the outer coast of Baja California, Mexico. The third group inhabits the Gulf of California. The C-positive factor occurred in 13.6% of the northern subpopulation, 6.0% of the southern, and 16.8% of the Gulf subpopulation.
Effects of Food Supply on Fecundity in the Female Guppy, Lebistes reticulatus (Peters)
Authors: Hester Frank J.
Published: April 2011

Three distinguishable size groups of oocytes are contained in the ovary of the viviparous poeciliid, Lebistes reticulates — small, middle-sized, and large. At parturition some of the middle-sized oocytes develop into large oocytes and subsequently, upon fertilization, into embryos. The number of middle-sized oocytes is then replenished from a large store of small oocytes. The effect of changes in the amount of available food on these oocytes and hence on the number of offspring was explored by an experiment involving 27 female Lebistes. Rations varying from near starvation to normal were supplied over the course of three consecutive parturition periods. At the end of the third period each fish had received a different combination of the three rations. Variations in first-period rations affected the numbers of both first- and second-period offspring. Reduced numbers of offspring and reduced large and middle-sized oocyte counts were associated with reduced rations. No significant changes in the size of young or the length of the gestation period were observed.
Use of Gamma Radiation for the Preservation of Scallop Meat
Authors: Power H. E. , Fraser D. I. , Neal W. , Dyer W. J. , Castell C. H. , Freeman H. C. , Idler D. R.
Published: April 2011

Storage studies of iced irradiated scallops (Placopecten magellanicus Gmelin) have shown that treatment with a dose of 75,000 rads of gamma radiation increases the useful storage life at 0 °C with negligible changes in odour and texture. The raw scallops remained acceptable for 28 days, while the scallops assessed after cooking remained unchanged for 35 days and did not become unacceptable until 43 days storage. Doses of gamma radiation greater than 75,000 rads caused undesirable changes in texture and odour with a consequent loss of quality. Neither irradiated nor fresh iced scallops rated as high organoleptically as frozen control scallops which had been rapidly frozen in a pre-rigor condition and immediately stored at −26 °C.
A Morphometric description of Porbeagle (Lamna nasus) from Canadian Atlantic Waters
Authors: McKenzie R. A. , Tibbo S. N.
Published: April 2011

not available
Redescription of the Parasitic Isopod Holophryxus alaskensis Richardson, and a Note on Its Synonymy
Authors: Butler T. H.
Published: April 2011

Full descriptions of both sexes of Holophryxus alaskensis Richardson are given. The host is the decapod Pasiphaea pacifica Rathbun. Holophryxus californiensis Richardson and Hypodajus georgiensis Nierstrasz and Brender à Brandis are considered synonymous with Holophryxus alaskensis. The generic name Hypodajus Nierstrasz and Brender à Brandis is a synonym of Holophryxus Richardson. The type-species of Holophryxus remains as H. alaskensis.
Seasonal Variations in the Sterol, Fat and Unsaponifiable Components of Scallop Muscle
Authors: Idler D. R. , Tamura T. , Wainai T.
Published: April 2011

The total fats, unsaponifiable material, provitamins D, and sterols were determined on monthly samples of male and female sea scallop, Placopecten magellanicus (Gmelin). During the pre-spawning period (August), total fat, unsaponifiable, and sterol levels were low indicating an active transfer of these materials to the gonad tissue. During the retarded growth period (February, March), the fat content of the muscle decreased but there was a compensating increase in the unsaponifiable and sterol content of the total fat. The composition of the sterol fractions was determined by gas chromatography. The principal sterol components of the scallop muscle were found to be 22-dehydrocholesterol, cholesterol, brassicasterol, and 24-methylenecholesterol. Changes in the composition of the sterols were not as extreme as those reported in the literature for some other shellfish. However, variations in the cholesterol and 24-methylenecholesterol content of the scallop muscle suggested a relationship in the metabolism and biosynthesis of these sterols. There were no obvious differences in the composition of the muscle of male and female scallops.
Preliminary Results of Studies on Growth and Mortality of Pacific Cod (Gadus macrocephalus) in Hecate Strait, British Columbia
Authors: Ketchen K. S.
Published: April 2011

Preliminary results of tagging suggest that the Brody-Bertalanffy growth coefficient, K, of cod in northern Hecate Strait is 0.27 and the asymptotic length, L∞, is 94.0 cm. Life span is relatively short and the fishery appears to be dependent on fish which have completed 3 and 4 years of growth. Estimates of present day instantaneous total mortality rate, based on average length of fish in the catch, range from 1.05 to 1.53 (65–78% on an annual basis) depending on fishing area and length at full recruitment. Mortality rates of 0.83 and 0.99, computed from primitive length composition, may indicate the order of magnitude of the instantaneous natural mortality rate (56 and 63% expressed as an annual rate).
Ocean Migrations of Pacific Salmon
Authors: Neave Ferris
Published: April 2011

Sockeye salmon (Oncorhynchus nerka), pink salmon (O. gorbuscha), and chum salmon (O. keta) commonly return to their places of origin from distant high-seas areas. Maturing fish closely associated at high-seas localities travel in many different directions to their respective destinations. They also travel from many different high-seas localities to a common coastal area. Prior to their return to inshore waters, pink salmon perform ocean journeys which are associated with changes in temperature and which do not necessarily represent a direct approach to a spawning area. The ocean journeys of both juvenile and maturing salmon are largely independent of currents. Homing is not thought to be commonly accomplished by random or near-random ocean travel or by extensive searching of coastlines. It is suggested that ability to set a compass course, using a celestial feature, is insufficient to account for the indicated performance and that some form of bico-ordinate navigation may be required.
Fatty Acid Distribution in Lipids of Marine Plankton
Authors: Brockerhoff H. , Yurkowski M. , Hoyle R. J. , Ackman R. G.
Published: April 2011

In the diatom, Skeletonema costatum, as well as in a zooplankton sample, the polyunsaturated fatty acids of the triglycerides were found accumulated in the β-position of the glycerol. This fatty acid distribution pattern is typical for animal fats, in particular for fish oils. Together with the recent demonstration that fish and invertebrates retain in part the structure of ingested triglycerides, the findings of the present study show that the typical structure of marine triglycerides originates in phytoplankton and is to a large degree retained through the marine food chains.The fatty acid composition of several other lipid fractions of the plankton samples was also determined.
Dissolved Calcium Carbonate in the Labrador Sea
Authors: MacIntyre W. G. , Platford R. F.
Published: April 2011

Calcium and carbonate ion concentrations have been measured in the upper 100 m in an area southwest of Greenland. The values indicated that these waters were about 100% supersaturated with respect to calcite and about saturated with respect to aragonite. Because of the large influx of CO2 from the air in this region it was concluded that considerable CO2 must have been utilized or there would have been evidence for the transport of this gas to lower levels.
Ouest for the True Breeding Area of the American Eel (Anguilla rostrata LeSueur)
Authors: Vladykov Vadim D.
Published: April 2011

not available
The Application of Gas Chromatography to the Identification of the Sterols of Scallop
Authors: Wainai T. , Tamura T. , Truscott B. , Idler D. R.
Published: April 2011

not available
Effect of Polyphosphates and Other Salts on Drip Loss and Oxidative Rancidity of Frozen Fish
Authors: Boyd J. W. , Southcott B. A.
Published: April 2011

Pretreatment of fresh fillets of Dover sole (Microstomus pacificus), Pacific cod (Gadus macrocephalus), halibut (Hippoglossus stenolepis), and red snapper (Sebastodes ruberrimus) with sodium tripolyphosphate prior to freezing was found to be effective in reducing drip loss during thawing. Sodium chloride, in a few trials, was effective in reducing drip and cooking losses. Tripolyphosphate and sodium citrate dip solutions of corresponding ionic strengths were equally effective in reducing drip loss during thawing from fillets of red snapper. Pretreatment of chinook salmon (Oncorhynchus tshawytscha) fillets with sodium tripolyphosphate preceding freezer storage was found ineffective in retarding lipid oxidation during storage at −10 °C; however, unlike sodium chloride, sodium tripolyphosphate did not accelerate development of oxidative rancidity.
Larvae and Megalopa of Argis dentata (Crustacea: Decapoda) from Ungava Bay
Authors: Squires H. J.
Published: April 2011

Stage I and II larvae and the megalopa of Argis dentata Rathbun are described from plankton taken by the Calanus Expedition in Ungava Bay during July–August, 1947–1950.
Reproduction of King Crabs, Paralithodes camtschatica (Tilesius)
Authors: Powell Guy C. , Nickerson Richard B.
Published: April 2011

Sublegal, post-molt, male king crab graspers are capable of reproducing and may suffice as brood stock in the male-only king crab fishery. Observations in tanks revealed that the younger males bred successfully with an average of five females.
Lipids and Component Fatty Acids of the Newfoundland Squid, Illex illecebrosus (Le Sueur)
Authors: Jangaard Peter M. , Ackman R. G.
Published: April 2011

The component fatty acids of the muscle, liver, and viscera lipids from the squid, Illex illecebrosus (Le Sueur), caught in Newfoundland waters have been determined by gas–liquid chromatography (GLC). Silicic acid chromatography was used to segregate the main groups of lipids and the fatty acid composition of each fraction was determined on two organosilicone polyester columns.The lipids from the muscle consisted mainly of phospholipids with three fatty acids, palmitic (16:0), eicosapentaenoic (20:5), and docosahexaneoic (22:6) acids making up 80% of the total. The liver contained mainly triglycerides with a fatty acid composition similar to liver oils in other marine species.
Lampetra richardsoni, a New Nonparasitic Species of Lamprey (Petromyzonidae) from Western North America
Authors: Vladykov Vadim D. , Follett W. I.
Published: April 2011

A new nonparasitic species of Petromyzonidae, Lampetra richardsoni, the western brook lamprey, from streams of British Columbia, Washington, Oregon, and possibly Alaska, is described and illustrated. This species is distinguished from Lampetra planeri (Bloch), the European brook lamprey (with which it has long been regarded as identical), by dentition, body proportions, pigmentation of the head and tail, and geographical distribution. The description is based on an examination of 275 specimens (69 transformed individuals and 206 ammocoetes).
Application of Mass Transfer Theory to the Problem of Respiration of Fish Eggs
Authors: Daykin P. N.
Published: April 2011

The concentration of oxygen in the microenvironment of the developing fish egg is always less than the concentration in the supply water. Mass transfer theory is the theoretical tool for understanding the importance of the oxygen content and the velocity of the supply water as factors influencing oxygen uptake of fish eggs. The applicable literature on mass and heat transfer is reviewed and formulas for the calculation of oxygen depletion in the boundary layer surrounding the egg are suggested. Calculated dissolved oxygen requirements for eggs of two fish species at various water velocities are compared with experimentally determined dissolved oxygen requirements.
Respiratory Metabolism of Pumpkinseed (Lepomis gibbosus) in Relation to Swimming Speed
Authors: Brett J. R. , Sutherland D. B.
Published: April 2011

By use of a "tunnel" respirometer the relation between oxygen consumption (Y, mg O2/kg/hr) and swimming speed (X, body lengths/sec) for 45-g pumpkinseed at 20 °C was found to follow the equation log10Y = 1.65 4 + 0.31 X. Standard and active metabolic rates were 45 ± 6.6 and 408 ± 39 mg O2/kg/hr, respectively. Maximum 60-min sustained swimming speeds averaged 3.01 ± 0.27 lengths/sec.At low velocities, with more than one fish present, elevation of the metabolic rate occurred from aggressive behaviour, reaching one-half the active rate.
Studies on the Quality of Newfoundland Cod. 10. Effect of Some Commercial Freezing Rates on the Frozen and Stored Quality of Trap Cod
Authors: MacCallum W.A. , Chalker Dorothy A. , Laishley E.J. , Dyer W.J. , Idler D.R.
Published: April 2011

Time–temperature curves are reported for points at the centre, one-quarter depth, and at the surface of blocks of dressed cod, and blocks and packages of cod fillets, frozen in commercial plate freezers. Freezing rates at the centres varied by a factor of about 4 where thickness of the pack was the only variable. The same factor applied to the fastest- and slowest-frozen fish in [Formula: see text]-inch-thick blocks. Using a special arrangement, dressed trap-caught cod and cod fillets were then frozen, some at the fast rate and some at the slow rates normally encountered at the centre of [Formula: see text]- and [Formula: see text]-inch-thick commercial packs, respectively (0.7 and 2.7 hr through the temperature range of 32 to 5°F (0 to −15 °C)). The frozen and stored (at −10°F) samples were of similar quality for periods up to 22 weeks, based on taste panel assessment.
New Records and Descriptions of Plecoptera (Class Insecta)
Authors: Ricker W. E.
Published: April 2011

Descriptions are presented of the following new species: Brachyptera fosketti, B. selona, Capnia gregsoni, C. spenceri, C. sasquatchi, C. rogozera, C. bergi, C. cheama, C. beringi, C. sugluka, Nemoura wenatchee, Leuctra baddecka, Paraleuctra dasha, Paraperla wilsoni, and Chloroperla ovibovis; and of the new subgenus Bolshecapnia (type Capnia gregsoni). Supplementary descriptions, new synonymy, or new records are given concerning Capnia coloradensis Claassen, Isocapnia vedderensis (Ricker), Leuctra sibleyi Claassen, Isoperla nana (Walsh), Paraperla frontalis (Banks), and six species of the Ostrocerca subgenus of Nemoura.
Food and Growth of Fishes.: I. A Growth Curve Derived from Experimental Data
Authors: Paloheimo J. E. , Dickie L. M.
Published: April 2011

A general equation for growth of fishes is obtained through use of the relations among body weight, metabolic rate, and growth efficiency that have been found in laboratory experiments. The curves show an early inflection point and gradually decreasing growth rate thereafter, without a theoretical asymptote. When growth efficiency is constant this equation indicates that growth becomes nearly exponential and is fitted exactly by the Parker and Larkin (1959) equation. When growth efficiency decreases with increasing rations the curves become more complex, as described here.Growth curves having an asymptote, such as the von Bertalanffy curve, have often been fitted to growth data. When the estimated asymptote can be related to the inflection point of the early part of a growth phase, it is proportional to a physiological time scale suggested by the food–growth relations. Truly asymptotic growth would appear to result only from complex changes in metabolism, growth efficiency, or interactions with mortality of the sort suggested by Lee's phenomenon.Some consequences of these results of food–growth experiments are discussed in relation to studies of biological productivity, especially their bearing on objectives of fisheries management. They suggest that, in general, highest sustained yield from a particular growth phase or stanza is obtained from a type of cropping which results in a population of fish having an average size near that of the smallest fish in the stanza.
Zooplankton from the Arctic Ocean and Adjacent Canadian Waters
Authors: Grainger E. H.
Published: April 2011

Zooplankton collections from the Arctic Ocean, the Beaufort Sea, and northwestern Canadian coastal waters are described, along with physical characteristics of the waters sampled. About 50 species are included.The collections are compared with records from the central Arctic Ocean and other waters adjacent to the present region. The species are shown to fall into three groups. One is characteristic of the surface water of the Arctic Ocean, one of the Atlantic water and to a lesser extent the deep layer of the surface water of the Arctic Ocean, and one of the shallow peripheral seas of the Arctic Ocean.The surface water group includes eight species which account for more than 95% of the copepod individuals found in the surface layer, and which appear to be the only copepods which breed in the surface layer of the central Arctic Ocean. The same species are the major constituents of the zooplankton found in the waters of the Canadian arctic, from the Arctic Ocean to Davis Strait. The deeper Atlantic species of the Arctic Ocean, more numerous as species but far less numerous as individuals than those of the surface water, occur only very rarely in the surface layers, show no evidence of breeding there, and appear to be almost entirely absent from Canadian archipelago waters inside the shelf. Clear continuity of the Arctic Ocean surface fauna through the waters of the Canadian arctic is shown, along with the almost total exclusion from archipelago waters of the deeper Atlantic fauna. This intrusion of Atlantic species into the waters of arctic Canada appears to be almost entirely restricted to the southeast part of the region, especially Hudson Strait and adjacent waters.Development rates of two copepods in the Arctic Ocean, Microcalanus pygmaeus and Calanus glacialis, are discussed.
Seasonal Distribution of Monkfish Along the Canadian Atlantic Mainland
Authors: Jean Yves
Published: April 2011

not available
Canadian Atlantic Salmon Recaptured Near Greenland
Authors: Saunders R. L. , Kerswill C. J. , Elson P. F.
Published: April 2011

not available
Sex Ratios and Sexual Dimorphism Among Recently Transformed Sea Lampreys, Petromyzon marinus Linnaeus
Authors: Applegate Vernon C. , Thomas M. L. H.
Published: April 2011

The sex, length, and weight were determined of nearly all recently transformed sea lampreys migrating downstream in the Carp Lake River, Michigan, in the fall, winter, and spring of 1960–61. Similar data were collected from samples of an earlier run in the Carp Lake River and of runs in three other tributaries of Lakes Huron and Michigan. The sex ratio of the 1960–61 migrants in the Carp Lake River was 324 males:100 females. Sex ratios of migrants in the other runs varied from 77 to 86 males:100 females. The high proportion of males in the 1960–61 run in the Carp Lake River is attributed to the effective prevention of recruitment of sea lampreys in the river and transformation of the females at an earlier age than is characteristic of the males. A near equal sex ratio among recently transformed migrants is considered normal for the species. The sex composition of a run changed during the period of migration. The proportion of males among the migrants was greatest at the beginning of the run and declined steadily thereafter. The average size was smaller for males than for females. Differences in the mean lengths and weights of the sexes were statistically significant. The length–weight relation differed for the sexes and showed a slower rate of increase of weight with increase in length than is characteristic of other stages of the animals' life cycle. Seasonal changes in the length–weight relation had a trend toward lower weights among the migrants coming downstream in the later months of the run.