摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f59-033

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Alterations in the blood levels of lactate, carbonate, hydrogen ion and hemoglobin following vigorous muscular exercise were studied in yearling Kamloops trout,Salmo gairdneri, over four years.Lactate increased during exercise and during the first 2 hours of rest, returning to the initial level after 6 to 8 hours. Carbonate increased to a maximum during the first 3 minutes of exercise, then dropped precipitously to a minimum far below the initial level afterhour of rest, later rose to near the initial level at the 4th hour of recovery, maintained this until the 12th hour, but it had decreased again at the 24th hour. Hydrogen ion concentration rose sharply during the first 3 minutes of activity, then fell off to a stable level a little above the initial figure until the end of exercise, after which it fell substantially below initial level and had not completely recovered after 24 hours of rest. A marked decrease in swimming rate occurred after 3 minutes exercise, following the initial rise of carbonate and hydrogen ion concentration.

ISSN:0706-652X    

DOI:10.1139/f59-034

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

A list is given of 180 stations where marine biological, oceanographic and fishing observations or collections were made by theCalanusand land-based investigations of the Arctic Unit between Labrador and the Yukon–Alaska boundary from 1955 to 1958.

ISSN:0706-652X    

DOI:10.1139/f59-035

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

The quantity of ribonucleic acid phosphorus (RNA-P) and deoxyribonucleic acid phosphorus (DNA-P) in various tissues of the sockeye salmon has been determined at three points in its spawning migration. During migration a net decrease in RNA-P and a net increase in DNA-P occurred in the whole fish of both sexes. Major losses in RNA-P occurred in the flesh, alimentary tract and milt, while major gains in DNA-P occurred in the milt and roe. In the combined head, skin, bones and tail large gains in both RNA-P and DNA-P took place.

ISSN:0706-652X    

DOI:10.1139/f59-036

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Capture by trolling subjects feeding coho and chinook salmon to hyperactivity which may lead to a distressed condition or death, and death cannot be predicted from examination of individual fish at time of capture. Mortality of coho was estimated to be in the 0.95 confidence interval of 34% and 52%. Time of maximum death rate of coho is shown to coincide with the period of maximum blood lactate response. Survival occurred either when blood lactate did not reach critical levels (above 125 mg%) or reached critical levels and subsequently subsided. Holding salmon in a live box for 8–14 hours before release did not improve tag recovery, suggesting additional indiscriminant stress was caused at release. Adult coho in fresh water did not appear capable of lethal hyperactivity. This led to the hypothesis that cessation of feeding during spawning migration has adaptive significance for survivial of Pacific salmon.

ISSN:0706-652X    

DOI:10.1139/f59-037

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Only rarely is Atlantic cod found with orange-red coloured skin and flesh. Astaxanthin and zeaxanthin, in the proportion of 2:1, were found to be responsible for the pigmentation of the flesh of such a specimen. Zeaxanthin was the only pigment detected in the flesh of a similarly pigmented haddock.

ISSN:0706-652X    

DOI:10.1139/f59-038

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Materials used were collected September 1955 to September 1956 near Igloolik, northwest Foxe Basin, in the Canadian arctic. A single station, about one mile from shore and 52 m deep, was occupied 27 times during the year. It is in a region of net flow of arctic water from Fury and Hecla Strait, whose strong current probably brings ever-changing hydrographic conditions and plankton populations to the station area. Sea ice formed in early November, and had thickened to about 152 cm by early May. Melting then began and continued until the station was free of fast ice soon after mid-July. Water temperatures varied only 3.55 °C at all depths during the year, and only 0.07° from November until May. The coldest record was −1.75° at 50 m in April and May, the warmest 1.80° at the surface in early September. Salinities varied from a maximum of 32.59‰ in early May to less than 1.68‰ at the surface in mid-July. A thin layer of brackish water, probably not exceeding 2 m in depth, was developed at the surface during the ice-melting period from late June until early August. Dissolved oxygen content varied from 9.52 ml/1 in early July to 4.08 ml/l in early September. The maximum saturation recorded was 110.3% at 10 m on July 15. Dissolved inorganic phosphate rose from near zero in February to a maximum of 1.5 μg-at/l in mid-June, then declined until autumn.Zooplankton volume (from the coarse net) was greatest in late September (4.85 ml per 50-m haul), least in mid-April (0.15 ml). Among identifiable material, copepods were volumetically the largest group. Twenty-eight species were identified, the most numerous forms being copepods (Pseudocalanus minutus,Calanus finmarchicus,C.hyperboreus,Oithona similis), chaetognaths (Sagitta elegans), cirriped larvae, medusae (Halitholus cirratus) and larvaceans (Fritillaria borealis). Several of the more abundant species provide life-history information. All the plankton species had previously been collected in the arctic, and all are circumpolar (one possible exception).Propagation times of primarily herbivorous plankters coincide with the abundance of their phytoplankton food, and the numerical cycle of these individuals during the year shows a restricted period of maximum numbers during the time of reproduction (summer) followed by gradual decline until late winter. In contrast, the primarily carnivorous plankters show relatively slight numerical variation throughout the year, and no concentrated period of reproduction. These species reproduce at various times of the year, many of them during winter. A rough estimate of the Igloolik yearly mean standing crop of zooplankton (without correction for straining efficiency of the No. 6xxx net) is 0.10 ml/m3or 5.2 ml/m2of surface area; the maximum observed was 0.50 ml/m3. Another arctic coastal locality, in Greenland, had similar figures; coastal boreal stations have mean crops 4 to 8 times as great (volume basis) or 2 to 9 times as great (surface area basis).

ISSN:0706-652X    

DOI:10.1139/f59-039

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

Records of fishes rare in Canada, and unusual occurrences of commoner ones, are presented for 65 species. First Canadian records are given for the short-nosed sturgeon (Acipenser brevirostrum), halfbeak (Hyporhamphus unifasciatus), four spot flounder (Paralichthys oblongus), weakflsh (Cynoscion regalis) and striped sea robin (Prionotus evolvans). Specimens of unusually large size include a cunner (Tautogolabrus adspersus) of 171/4 inches and 31/4 lb, and a redfish (Sebastes marinus) of 311/2 inches and 231/2 lb.

ISSN:0706-652X    

DOI:10.1139/f59-040

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f59-041

出版商:NRC Research Press    

年代:1959

数据来源: NRC

摘要:

There are considerable variations in the procedures used in the application of sodium nitrite as a preservative for fresh fish fillets. There is a corresponding lack of uniformity in the nitrite content of the treated fillets.The complexity of the problem has been pointed out by showing the number and relative importance of the factors affecting the uptake of nitrite from a solution by fillets.The suggestion is made either to abandon the use of nitrite as a preservative for fish or to standardize the procedures used in its application.

ISSN:0706-652X    

DOI:10.1139/f59-042

出版商:NRC Research Press    

年代:1959

数据来源: NRC