摘要:

The respiratory function of the blood of brook trout, acclimated to summer and winter conditions, was investigated at various temperatures and at various tensions of carbon dioxide. The marked sensitivity of hemoglobin to carbon dioxide served to offset the influence of lower temperature upon the equilibrium of oxygen and hemoglobin. There did not appear to be any adaptation of the Bohr effect to differences in acclimation temperatures.

ISSN:0706-652X    

DOI:10.1139/f66-001

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Total yearly growth of female yellow perch,Perca flavescens(Mitchill), in South Bay, Lake Huron, estimated by the distance along the lateral radius from last annulus to scale edge, showed a marked relationship to mean water temperature at a depth of 20 ft. When published data on growth of perch in Lower Red Lake, Minnesota, were compared with mean air temperatures for the period June through September at Redlake, no such relationship could be demonstrated. The reasons for the different results obtained in these and in other studies could not be determined.

ISSN:0706-652X    

DOI:10.1139/f66-002

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The seasonal variation in the oil content of cod livers is shown to affect the liberation of free fatty acids (FFA) when the "sun-rotted" method for producing cod-oil is used under laboratory conditions. Since lean livers produce an oil with a high FFA content, oil of this type would most likely be produced in April–June after the fish have spawned. An antibiotic, chlortetracycline, was found to have little effect on the liberation of FFA and cannot be used as a liver preservative without an enzyme inhibitor added. Isopropanol at suitable concentrations inhibits both the liberation of oil from the livers and the formation of FFA in the oil.

ISSN:0706-652X    

DOI:10.1139/f66-003

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

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

ISSN:0706-652X    

DOI:10.1139/f66-004

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

A hematological study was made on 119 mountain whitefish (Prosopium williamsoni) from the Yellowstone and Madison River drainages in Montana, 1961–62. Hemoglobin determinations had a range of 7.0–13.7 g/100 ml (mean 10.6 g) while hematocrits had a range of 28.5–62.2% (mean 43.5%). Erythrocyte counts ranged from 1.01 to 2.34 million/mm3(mean 1.57 million) and leucocyte numbers ranged from 360 to 25,500/mm3(mean 5400). Thrombocyte counts ranged from 870 to 47,200/mm3of blood (mean 17,600). Leucocyte differential counts had a mean of 33.9% lymphocytes and 66.1% neutrophilic granulocytes with the predominant granulocyte being the lobed mature form. Granulocyte means were higher in leucocyte counts over 8100/mm3. Few immature cells were seen in blood smears. Some polychromatic erythrocytes were found and myelocytes were the most immature granulocytes seen. Differences were observed in the various values between small and large fish, males and females, and for fish taken in summer and winter. The kidney was the active hemopoietic tissue, forming granulocytes, lymphocytes, and thrombocytes. The spleen produced most of the erythrocytes and occasionally other cell types. The liver was hemopoietic in some anemic fish.

ISSN:0706-652X    

DOI:10.1139/f66-005

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Physiological effects of physical conditioning to water current were studied on three groups of-year-old rainbow trout,Salmo gairdneri, acclimated to 4 C. Group one (control) was raised in still water. Groups two and three were conditioned to water velocities of 20 cm/sec and 40 cm/sec, respectively, for 16 days before sampling. Muscle and plasma samples were collected before exercise and four times during subjection to 15 min of forced swimming at 53.4 cm/sec and eight times during a 24-hr recovery period. Conditioning significantly delayed the point of fatigue during forced exercise: the unconditioned fish were fatigued after about 5 min swimming, group two after about 10 min swimming, and group three at about 15 min.Physically conditioned trout showed significantly higher muscle and plasma lactate levels when fatigued, and more rapid removal of lactate from muscle and plasma during recovery from fatigue, than unconditioned trout. Exercise resulted in parallel oscillating concentration fluctuations of tissue phosphate and significant increases in concentrations of plasma phosphate in both conditioned and unconditioned fish. Plasma glucose showed no significant change during exercise but rose slightly during the recovery of all groups.

ISSN:0706-652X    

DOI:10.1139/f66-006

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Stomachs of pink, chum, sockeye, and coho salmon and steelhead trout caught during the summer of 1958 in gillnets fished overnight in the northeastern Pacific Ocean contained mainly zooplankton (Limacina, amphipods, copepods, and euphausiids), squid, and fish. Except for sockeye, there were no differences in contents related to fish size or state of maturity. Differences were found between species in the kinds of stomach contents present. The predominant organisms were amphipods and fish in pink salmon, crustaceans in immature sockeye, euphausiids and squid in maturing sockeye, euphausiids, fish, and squid in coho, and fish and squid in steelhead stomachs. The stomach contents of chum salmon were notable in that most of their contents were too well digested to identify. Comparison with the findings of workers in the northwestern Pacific showed no significant differences in the kinds of stomach contents, however, a greater amount of material was present in the stomachs they examined. The contents of stomachs from fish taken in various ocean domains were compared. Greater differences were noted in the stomach contents of fish from different domains than from different species. It is suggested that feeding is associated more with availability rather than with preferences for specific organisms.

ISSN:0706-652X    

DOI:10.1139/f66-007

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The species specific muscle myogens ofSalmo gairdnerii,Oncorhynchus masou,O.masou ishikawae,O.kisutch,O.tshawytscha,O.keta,O.nerka, andO.gorbuschaare compared by starch gel electrophoresis. Plasma proteins of these same species are also examined by polyacrylamide disc electrophoresis. The range of usefulness of muscle myogens in species identification, and equally significantly, their value in establishing phylogenetic relationships of closely related groups, as the genusOncorhynchus, are discussed. The myogen patterns ofO.ketaandO.gorbuschafrom the Asiatic and North American coasts were found to be identical, further supporting the concept of absolute species specificity of these patterns.

ISSN:0706-652X    

DOI:10.1139/f66-008

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Observations on vertical patterns of migration were made on the Nova Scotian and Gulf of St. Lawrence fishing banks. The commercially important demersal species, cod, haddock, and redfish, were usually closely associated with bottom by day and moved off after dark. While this is the general pattern, variations occurred. Thus, on cloudy or dull days, redfish may remain in mid water. Cod did not always return to the seabed by day. Haddock, usually more closely associated with bottom than the other species, sometimes moved considerable distances from the seabed. Generally, concentrations of fish on bottom by day dispersed in mid water.In accord with vertical patterns of migration, bottom trawl catches were generally the lower by night. There was some suggestion of seasonal changes in the relation between day and night catches of cod and haddock. A suggestion of diurnal variation in size composition was found for haddock and yellowtail. More small haddock were taken by day than by night. Catches of large haddock tended to be the larger at night. Small yellowtail were the more abundant in night tows. No significant diurnal difference was found for large fish.

ISSN:0706-652X    

DOI:10.1139/f66-009

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The systematic status of ciscoes of theCoregonus autumnaliscomplex in Alaska and northwestern Canada is discussed. Two forms of "autumnalis" ciscoes occur in this area: a form with 26–30 gill rakers on the lower limb of the first gill arch is found in the Beaufort and Chuckchi Seas, and a form with 21–25 gill rakers on the lower limb of the first gill arch is found in the Gulf of Alaska, the eastern Bering, and the Chuckchi Seas. Both forms occur along the arctic coast of Alaska, apparently without intergrading, and therefore are considered valid species. The form with the high gill raker number isCoregonus autumnalis(Pallas) (sensu stricto), and that with the low gill raker number isCoregonus laurettaeBean.

ISSN:0706-652X    

DOI:10.1139/f66-010

出版商:NRC Research Press    

年代:1966

数据来源: NRC