ISSN:0002-8487    

DOI:10.1577/00028487.1955.10492674

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1955.10492686

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1955.10492687

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/00028487.1955.10492688

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

摘要:

Explanation of the recent decrease in production of the soft-shell clam in New England is the objective of the Fish and Wildlife Service Clam Investigations. Experimental clam farms failed unless protected from green crabs, Carcinides maenas. Laboratory experiments proved that Carcinides is a serious predator.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1954)84[13:TEOTAP]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

摘要:

Nearly 800 scale samples submitted by anglers were used to investigate features of the life history of steelhead trout (Salmo gairdneri gairdneri) from the Chilliwack River, a tributary of the Fraser River near Vancouver, British Columbia. After criteria for scale reading were established, data on age, fork length, sex, month and year of capture, previous spawning history and lengths at previous ages were treated statistically. Age groups are so designated as to indicate the amount of time spent in the river and in the ocean; thus 2/3 refers to fish that were 2 years in the stream and 3 in the ocean. Age composition of adult runs of steelhead trout tended to be uniform from year to year. The four major types of life history were: fish spending 2 or 3 years in fresh water and 2 or 3 years in salt water. No correlation existed between the numbers of years spent in fresh water and in salt water. Length at maturity was determined by the number of years in salt water. There was no tendency for fish of any particular age, length, or sex to return to fresh water at any particular time of year. Sixty percent of young steelhead trout migrate to salt water in the spring months as age 2 at an average length of 16.49 centimeters. Thirty-five percent go seaward as age 3 at an average length of 19.95 centimeters. A few smolts remain in fresh water until late summer. These and other findings are related to management of steelhead trout for sport fishing.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1954)84[27:LHOTST]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

摘要:

The reservoir construction program during the last few years in Oklahoma has effected a tremendous increase in fishing opportunities. The answers to many fishery management problems arising out of the reservoir construction have been answered through cooperative endeavor of Federal agencies, state agencies, and schools of higher learning. Artificial reservoirs are so prolific in fish production that overpopulation is the main problem. Much more efficient commercial fish and sport fish harvest programs are needed, however, public resistance is at present the principal impediment to better management.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1954)84[39:PORM]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

摘要:

The principal spawning grounds of lake trout (Salvelinus namaycush namaycush) in United States waters of southern Lake Superior are on rocky shoals at depths of less than 20 fathoms. Most spawning occurs in October and early November. Of the mature fish collected on or near the spawning grounds, 60 to 69 percent were males. Among mature fish the average length of females was greater than that of males; few males less than 24 inches or females less than 26 inches in total length were caught. Recoveries of lake trout tagged on the spawning grounds showed that some males remained in the immediate area for a period of several weeks during the spawning season. Marked fish showed a tendency to return during later years to spawning grounds on which they had been tagged, even though many of them ranged long distances between spawning seasons.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1954)84[47:TROLTI]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

摘要:

The effect of beaver, Castor canadensis (Kuhl), on an eastern brook trout, Salvelinus fontinalis (Mitchill), population was studied in the vicinity of five beaver dams in the headwaters of Sunkhaze Stream. The beaver dams were found to present a serious obstacle to trout movements but they were not a complete barrier. Estimated unit-area production of bottom organisms was poor in the beaver ponds but the beaver had so increased the bottom area that total production of the stream section was probably more than doubled. Forage fishes appeared to be somewhat more abundant in the beaver ponds than in the open stream and constituted an unexpectedly high percentage of the food of 6- to 10-inch brook trout taken in the ponds. Measurable but not serious water-quality reduction was found in and below the beaver ponds.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1954)84[75:BRITHO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor

摘要:

Sulfonamides such as sulfisoxazole (GantrisinR), sulfamerazine, and a mixture of sulfamerazine with sulfaguanidine were fed to apparently normal fingerlings of brook trout (Salvelinus fontinalis), brown trout (Salmo trutta), and rainbow trout (Salmo gairdneri). None of these drugs had any growth-affecting influence on rainbow trout. Growth of brook trout was somewhat retarded by sulfamerazine. The retardation of the growth of brown trout was greater with sulfamerazine than with the mixture of two sulfonamides. Sulfisoxazole did not retard growth of any of the three species. As soon as the medicated food was replaced with normal, brown trout resumed growth. Observations are also furnished on the tissue levels of sulfonamides and hemoglobin in the experimental trout.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1954)84[86:TEOSSO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1955

数据来源: Taylor