摘要:

The proximate analysis of the cod parasite,Porrocaecum decipiens, has been carried out. During the determination of the amino acid composition of a hydrolysate of the parasite the presence of an unusual complex was detected as an unknown peak in the amino acid ion-exchange chromatogram. The unknown complex was also found to be present in a protein-free nucleic acid fraction prepared from the parasite. The substance proved to be highly resistant to conventional methods of hydrolysis. Glutamic acid was found to be an end product when the complex was degraded and it is thought that the complex consists of a thymine nucleoside associated with a peptide consisting of three to five glutamic acid residues. It is not known whether the complex is naturally occurring or is an artifact formed during the acid hydrolysis.

ISSN:0706-652X    

DOI:10.1139/f63-002

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The sampling procedure commonly used on board research vessels in which catches are sorted by species and picked up into baskets was examined in catches containing several species, principally haddock. The procedure does not appear to permit withdrawal of random samples for lengths or counts of fish. Mixing these basket lots results in sample units which are effectively homogeneous for length composition and reduces the amount of sampling necessary to estimate numbers of fish caught. However, mixing does not appear to be effective if the species sort is omitted, especially in large catches.

ISSN:0706-652X    

DOI:10.1139/f63-003

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Ventral spine length and the number of lateral plates, dorsal spines, and gill rakers inPungitius pungitiusfrom 132 North American localities were compared. The number of lateral plates is consistently high in populations from tidal waters, and low in inland populations. Geographic variation in the number of dorsal spines and gill rakers suggest two allopatric forms ofP.pungitiusin North America. A Bering form ranges from Alaska along the arctic coasts of Canada, and a Mississippi form ranges from the Great Lakes to the Mackenzie River. Two glacial refugia are hypothesised to explain the origin and present distribution of these forms.

ISSN:0706-652X    

DOI:10.1139/f63-004

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The superficial red muscle of lingcod (Ophiodon elongatus) was shown to exhibit unique properties of post-mortem contraction and tension development. In comparison with white muscle, rigor contraction and isometric rigor tension in red muscle were about three times as great. The rate of contraction of the red muscle was dependent on temperature and also on the oxygen concentration in the surrounding atmosphere. The elastic modulus of the red muscle of trout and lingcod increased with increasing post-mortem time. Following the onset of rigor mortis a gradual increase in elasticity was observed. The maximum effects of contraction, tension and elasticity coincided with the onset of rigor mortis and each could therefore be used as a measure of this phenomenon. It was concluded from these experiments that stiffening of a fish with the onset of rigor mortis is not due to contraction or tension development of the muscles, but rather to their changing mechanical properties. A convenient measure of the changing mechanical properties in the muscle was the elastic modulus.Morphological differences between the very active, myoglobin rich, red muscle and the white muscle of lingcod were demonstrated by means of electron micrographs. The high glycogen content in the area of sarcoplasm of the red muscle, as indicated in electron micrographs, was confirmed by chemical analysis. Red muscle in rested fish was shown to contain from 1 to 3 times more glycogen than white muscle.

ISSN:0706-652X    

DOI:10.1139/f63-005

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Techniques of estimating population size, level of fishing, and the degree of dependence of fishing success on environmental factors are examined on the basis of tagging, catch and effort data. A new method is developed to estimate population size from catch, effort, and temperature data when the catchability varies with temperature.The methods of estimation discussed are applied to data collected from a number of lobster fisheries on Canada's Atlantic coast. Analysis confirms a relationship between the catchability of lobsters and bottom temperature. Differences in this relationship are found between areas and between tagged and untagged lobsters within areas. It is suggested that these differences are attributable to the differences in densities as well as to aggregations of lobsters and fishing. The effect of these aggregations on population size estimates is considered.Calculated average catchabilities at comparable temperatures are different for different areas. These differences are correlated with the numbers of trap hauls per day per square miles fished. It is suggested that the differences in the catchabilities might be due to interactions between units of gear not predicted by the customary relationship between catch and effort.

ISSN:0706-652X    

DOI:10.1139/f63-006

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The effect of air blowing at two temperatures, 80 and 130 °C, on the major component fatty acids of cod liver oil has been determined. As expected, the proportions of the highly unsaturated fatty acids drop rapidly, especially at the higher temperature investigated. The saturated acids are virtually unchanged under the conditions employed, while the proportion of monounsaturated acids shows only a slight drop.

ISSN:0706-652X    

DOI:10.1139/f63-007

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Adult, migrating, fasting sockeye salmon (Oncorhynchus nerka) were held in captivity in fresh water without spawning well beyond the time when they would normally have done so and died. A few of the fish were then gonadectomized and force feeding was begun. A few unoperated fish were fed similarly while the remainder served as unoperated, unfed controls. The gonads of the operated fish were well developed. After a period of feeding of about four months some fish in each group had survived. The fed fish had regained their green color and much of their weight and vigor, while the surviving unfed fish were extremely emaciated and listless. At this time voluntary feeding by the force-fed fish was observed for the first time, and it was then found that the five surviving unfed controls would also take food voluntarily. While two of these fish died without apparent improvement in their condition, the other three gradually regained green color, weight and vigor.

ISSN:0706-652X    

DOI:10.1139/f63-008

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The muscle myogen patterns obtained by starch gel electrophoresis of the Dolly Varden and eastern brook trout (Salvelinus), the rainbow and steelhead trouts and the Atlantic salmon (Salmo), and the coho, spring, chum, sockeye and pink salmon (Oncorhynchus) are compared. The myogen protein patterns are clearly distinct for each species of fishes studied, except for the rainbow and steelhead trouts, and constitute a remarkably constant property which can be employed to differentiate between species and for other useful purposes. The specific and generic inter-relationships have been analyzed by these patterns and developed as further criteria for classification purposes and are discussed in conjunction with currently accepted beliefs.

ISSN:0706-652X    

DOI:10.1139/f63-009

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Age, growth and food habits of leopard dace (Rhinichthys falcatus) in the lower Fraser River are described. Although recently emerged leopard dace and longnose dace (Rhinichthys cataractae) occur together in regions of slow or no current along the river margin, older longnose dace soon begin to occupy regions of higher water velocity. Yearling and older leopard dace remain predominantly in areas of little current. Laboratory experiments in a stream tank demonstrate a strong current preference in longnose dace fry, yearlings and adults. Leopard dace of comparable size show no preference for water current. The swimbladder volume of yearling and adult longnose dace is much lower than that of leopard dace, possibly an adaptation of the former species to occupation of riffle habitat. Temporary coexistence of the two closely related species in the same niche is discussed briefly.

ISSN:0706-652X    

DOI:10.1139/f63-010

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

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.

ISSN:0706-652X    

DOI:10.1139/f63-011

出版商:NRC Research Press    

年代:1963

数据来源: NRC