摘要:

The effects of storage on the fertility of salmonoid eggs and sperm have been studied. In these experiments mature eggs and sperm were stripped into dry sterile jars and stored for varying periods at low temperatures before testing their fertility with fresh genital products. The methods have been used and found to be feasible under field conditions. Eggs of the chum salmon,Oncorhynchus keta, were stored at temperatures of 2.5° to 5.8 °C. for 108 hours with an average infertility of less than 20%. The sperm of this species show a wide variation in their reaction to storage but may be retained for 36 hours in sterile jars with an average of less than 10% infertility. Data for the Kamloops (Salmo gairdnerii Kamloops) and cutthroat (Salmo clarkii lewisi) trout are confirmatory. Preliminary experiments indicate the feasibility of transporting eggs and sperm stored together in the absence of water.

ISSN:0706-652X    

DOI:10.1139/f50-008

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

The distribution of certain pelagic Amphipoda taken in the Belle Isle strait region during the summer of 1923 is correlated with ocean currents, light intensity and size of individuals.Hyperoche medusarum,Themisto libellulaandPseudalibrotus glacialisare index species of the cold Labrador current in the area.Hyperia galbaandH.medusarumare presumably also cold water indicators.Themisto abyssorumin sizeable numbers, andCalliopius laeviusculusare related to waters of the gulf of St. Lawrence.Themisto libellula,T.compressaformcompressaandT.compressaformbispinosaare more numerous, whileT.abyssorumis less numerous at the surface during daylight than during darkness. Part of the breeding season ofT.compressaandT.abyssorumoccurs in the area during August and September, when the young of both species are much more numerous than the adults, particularly at the surface. A new southern limit of distribution forP.glacialisis established. The known distribution of the tropical genusPhronimais extended into the gulf of St. Lawrence.

ISSN:0706-652X    

DOI:10.1139/f50-009

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

Changes in body chloride, density and water content of chum and coho salmon fry were measured when these fish were transferred from fresh water to sea water, and the reverse. Both species tolerated 50% sea water (8–9‰ Cl). Chum fry survived direct transfer from fresh water to sea water (15–17‰ Cl), but showed a marked increase in body chloride during the first 12 hours, followed by a return to the normal range between 12 and 24 hours. Coho, however, died within the first 36 hours, after a 60% increase in chloride. Coho fry lost more water than chum fry after introduction to sea water. The density of both species approximated that of the water within an hour of transfer to the new medium. When returned to fresh water after 12 hours in sea water the body chloride, density, and water content of both species regained normal levels within 10 hours. Chum salmon go to sea as fry, whereas cohos remain in fresh water a year or more. Although coho fry seem capable of some adjustment to sea water after a preliminary period in 50% sea water, permanent acclimatization could not be demonstrated under the experimental conditions.

ISSN:0706-652X    

DOI:10.1139/f50-010

出版商:NRC Research Press    

年代:1951

数据来源: NRC

摘要:

From an analysis of climatological conditions in the Skeena river watershed no climatic variations or cyclic trends which might account for a declining sockeye fishery have been detected.Most of the area in which sockeye spawn has an annual rainfall of less than 20 inches. A significant relation between sockeye production and rainfall in the spawning months of August and September was apparent for the years 1920 to 1934. While successful prediction cannot be anticipated, conservation through stream-level control is supported.

ISSN:0706-652X    

DOI:10.1139/f50-011

出版商:NRC Research Press    

年代:1951

数据来源: NRC