摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f56-009

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Bacto-oxgall has shown a differential effect on the red halophilic bacteria commonly found in solar salt and in contaminated salted fish.Pseudomonas salinariawas inhibited by low oxgall concentrations whileSarcina littoralistolerated high ones. When this differentiating test is applied to a larger number of strains it will be possible to determine if Bacto-oxgall can be used as the basis of a selective medium to distinguish one genus from the other. The clearing of bacterial suspensions and microscopical examination have shown that the inhibition ofPs.salinariawas produced by the lysis of the cells. The inhibition ofPs.salinariawas effective and rapid. It was not affected by pH variations but was reduced by the presence of proteins. When compared similarly to other bile products, Bacto-oxgall was found to have the same inhibitory power as sodium taurocholate. Bacto-oxgall, diluted to the equivalent of fresh bile, was also found to be three times more effective than fresh cod bile. From the evidence gathered it was concluded that the inhibition ofPs.salinariaby Bacto-oxgall is due to a mechanical disruption of the bacterial cytoplasm.

ISSN:0706-652X    

DOI:10.1139/f56-010

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

A simple method, based on oxgall tolerance, is proposed for differentiating red halophilic bacteria commonly found in solar salt and discoloured salted codfish. Tests carried out on 18 strains isolated from various sources have shown that the rod forms are inhibited by low concentrations of Bacto-oxgall and that the coccus forms tolerate relatively high ones. Bacto-oxgall can thus be used as the basis of a simple selective medium. This test has been found useful for the isolation, purification and partial identification of unidentified strains and also for determining the relative proportions of the two main types of red halophilic bacteria present in solar salt and salted fish samples.

ISSN:0706-652X    

DOI:10.1139/f56-011

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Small amounts of nitrite slowly accumulated in cod fillets that had been dipped in a solution of hydroxylamine. Cultures ofPseudomonasisolated from fish, as well as two species ofProteusand one species ofMicrobacterium, were able to convert hydroxylamine to nitrite when grown in a nutrient broth.

ISSN:0706-652X    

DOI:10.1139/f56-012

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Sodium nitrite, used as a 1% dip, or as a 0.1% solution made into flake ice, has been used with gutted cod and haddock in trawlers under normal fishing conditions. The dipping was more effective in preserving the fish than storing them in the ice containing nitrite. Dipping added about 4 days to the keeping time of the fish in the boats at sea.There appears to be little or no advantage in using nitrite either as a dip or in ice with fish that are properly iced and not stored longer than 6 days.

ISSN:0706-652X    

DOI:10.1139/f56-013

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

In 1940, from June 8 to June 28, 68 salmon and 386 grilse were tagged at Bonavista on the east coast of Newfoundland. The fish used were caught by commercial fishermen in salmon traps set along the coast within 3¼ miles of the lighthouse at Bonavista.The proportion of tagged salmon recaptured during the year of tagging was 41.2%, and 1.5% in the following year. The 28 tagged salmon recaptured in 1940 were distributed as follows: Newfoundland 57.1%, mainland of Canada 39.3%, and Labrador 3.6%. The greatest distance travelled was 785 miles, and the fastest apparent rate of travel was 26.2 miles per day.The tagged grilse returns were 36.3% in 1940 (year of tagging), 2.6% in 1941, and 0.3% in 1942. The 140 tagged grilse recaptured in 1940 were distributed as follows: Newfoundland 92.9%, and mainland 7.1%. The greatest distance travelled by recaptured grilse was 792 miles, and the fastest apparent rate of travel was 32.5 miles per day, both exceeding the highest values for salmon. The average interval between tagging and recapture (during the same year) for the grilse taken commercially on the east coast of Newfoundland was 14.3 days, on the south coast 20.2 days, and on the mainland 28.8 days.

ISSN:0706-652X    

DOI:10.1139/f56-014

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Thirty-seven species of Polychaeta from the western Canadian arctic and northwest Alaska, 27 of which are new to these regions, are enumerated and discussed. Comparison is made with their records in the American arctic to the east of these regions, in the European arctic, and on the east and west coasts of North America. Six species new to the east coast of Canada are also recorded.

ISSN:0706-652X    

DOI:10.1139/f56-015

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Thermal acclimation for lobsters transferred from 14.5 °C. to 23.0 °C. is complete in 22 days. Substantial acclimation to low salinity and to low oxygen occurs within one week. Lethal levels of these three factors are not altered by differences in size within the range 16–34 cm., by difference in the areas where lobsters were caught, or by starvation for up to 57 days. Moulting lobsters are less resistant to high temperature, low salinity and low oxygen conditions than hard-shelled lobsters.Upper lethal temperature levels and lower lethal salinity and oxygen levels were investigated for hard-shelled lobsters acclimated to each of the 27 combinations of three levels of temperature (5, 15 and 25 °C.), salinity (20, 25 and 30‰), and oxygen (2.9, 4.3 and 6.4 mg./l.). The upper lethal temperature is raised by an increase in thermal acclimation, and is lowered by a decrease in the salinity and oxygen acclimation levels. The lower lethal salinity is raised by an increase in the level of thermal acclimation and a decrease in the level of oxygen acclimation. It is lowered by acclimation to reduced salinity. The effect of salinity acclimation is not always the same, but depends on the temperature acclimation. The lower lethal oxygen is raised by either an increase in the temperature acclimation level of a decrease in the salinity acclimation.The lower lethal temperature is 1.8 °C. for 17° acclimated lobsters, and 5.0° for 27.5° acclimated lobsters.Ultimate and maximum or minimum lethal levels of temperature, salinity and oxygen—the highest and lowest lethal levels that can be attained by acclimation—were interpolated from the results. These measures were used to integrate the lethal levels of the three factors into a single three-dimensional graph which describes the boundary of lethal conditions for lobsters exposed to the three factors operating together (Fig. 7).

ISSN:0706-652X    

DOI:10.1139/f56-016

出版商:NRC Research Press    

年代:1956

数据来源: NRC