摘要:

Depths at which largemouth bass (Huro salmoides), walleye (Stizostedion vitreum), and sauger (S. canadense) were most abundant in Norris, Douglas, and Cherokee Reservoirs were predicted on a weekly or bi-weekly basis during summer of 1946. Information was released through local newspapers. Predictions were based on relation of temperature and dissolved oxygen to distribution of fish taken in gill nets in 1943, 1944, and 1945. On June 2 the prediction was the same for all three reservoirs. Because of changes in thermal stratification and in supply of dissolved oxygen, fish distribution could not be expected to remain similar in any two reservoirs. Field analyses and a method of presenting predictions are described. Managers and guides at five out of the six fishing docks felt this service improved the fishing success, especially of individuals unaccustomed to storage reservoirs. With refinements and evaluations for specific applications such a program might pay good dividends on private or public waters.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[65:PDDOFI]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

A comparison is made of the fecundities of herring from Seal Rock, Washington, British Columbia, Hokkaido, Japan, and Peter the Great Bay, Siberia. Among herring of the same size, the Seal Rock fish produce more eggs than the British Columbia herring; and the British Columbia specimens bear more eggs than the Siberian herring. Among herring of the same age, the Siberian herring is far more fecund than either the herring of Seal Rock or Hokkaido. Fecundity is suggested as an additional criterion to aid in the differentiation of herring races.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[72:TFOHFV]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

During the winter of 1941–42, measurements and scale samples were collected from sport and commercial catches of steelhead trout (Salmo gairdnerii Richardson) caught in Tillamook County, Oregon. The commercial fish were taken in gill nets. It was found that the angler took both smaller (11.25–34.5 inches, fork length) and younger fish (2–5 years old) on the average, than did the nets (21.5–36 inches, fork length; 3–9 years old). The angler also took a higher proportion of females (1.56 females to 1 male) than did the nets (1.35 females to 1 male).

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[77:AAGOST]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

Hybrid sunfish from male bluegill and female redear parents have been used to stock new ponds. Using densities of the order of 2,000 fingerlings per acre, excellent growth has been obtained. In the absence of competition from other species, the hybrids have increased by 3–4 ounces in their first growing season, and have achieved a pound in weight three summers after stocking—without the use of fertilizers. The F1hybrids included only 2 percent females. They have spawned successfully, however, and in two ponds produced F2broods in what seem to be fairly good numbers per female involved. The F2brood has been exclusively male, but only 13 have been examined so far. The hybrids seem to be excellent for stocking in small ponds, provided contamination by other fish can be avoided. That is, their rate of reproduction is so slow that overcrowding does not occur, and growth is rapid throughout life. However, other fishes have appeared in all but one of the ponds stocked to date, the usual adventitious arrivals having been green sunfish and black bullheads. These fish very quickly crowd the pond and restrict first-year hybrid growth to as little as a third of an ounce.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[84:HSFSSP]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

A means of obtaining young sockeye salmon, Oncorhynchus nerka, during their seaward migration by use of a netting fence and a central trap has been found successful in the Lakelse River, British Columbia. By operating at the point of maximum width and minimum rate of flow, the problems of current force and accumulation of debris were overcome. Increased rate of flow into the trap, which served to attract the fish, was obtained by use of a funnel entrance. It was discovered that the size of the openings of the trap must be such as to allow the entrance of schools of sockeye rather than individuals. These schools were found to converge and enter the trap more readily through slits in a horizontal plane than through those in a vertical position.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[97:TDAOOA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

Heavy losses of largemouth bass fingerlings at the Jonkershoek Inland Fish Hatchery, Stellenbosch, South Africa, were attributed to heavy infestation of the ureters with a gyrodactyloid parasite closely related to Acolpenteron ureterocoetes. The parasite has no intermediate host, and in heavily infested fish may complete its entire life cycle in the ureters. Infected fish display inflammation of the kidneys, ureters, and urinary openings and, in acute cases, great abdominal distension anterior to the cloaca. Some diseased fish die gradually, others in convulsive spasms. This disease occurs only in fish reared on artificial food in concrete rearing tanks. The spread of the disease can be checked by transferring fish from such small tanks to fertilized open ponds, where natural food and absence of crowding usually alleviate the condition. It is recommended that largemouth bass be reared to the fingerling stage in fertilized earthen ponds 0.1 acre or more in size, stocked at the rate of 12,000 advanced fry per acre and drained after about two months, when a survival of 80 percent or more may be expected.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[105:AGPFTU]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

The stomach contents of 912 channel catfish (769 containing food) taken in a short section of the Des Moines River from September, 1940, to October, 1941, are analyzed. The physical and biotic characteristics of the study area are described; a partial list of the fishes present together with comments on their importance and relative abundance is included.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[110:FHOTSC]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

During the period 1934–1942, 32 lakes in Michigan were treated with rotenone to remove or reduce unwanted fish populations, and an attempt to recover the entire fish population was made on 18 of them. The majority of these lakes were not supporting a desirable or normally growing fish population at the time they were treated. They were mostly small, all less than 22 acres, and included lakes whose waters ranged from very soft to very hard, from acid to alkaline, and from shallow to very deep.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[139:ASOEIM]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

Data obtained on Crystal Creek, New York, relative to the effectiveness of planting brown trout in slow and in fast water are presented. Of three plantings of fingerlings made throughout the length of tile stream, annual electrical inventories showed a significantly greater number of fish present in fast-water sections than in slow-water sections. Of the June 1940 planting, 20.2 trout per fast-water section and 10.1 per slow-water section were found after 3 months; of the September 1941 planting, 6.8 per fast-water section and 2.6 per slow-water section were recovered after one year; of the October 1940 planting, 1.00 per fast-water section and 0.62 per slow-water section were taken after one year.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[147:SAGOFB]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor

摘要:

Fishery workers in the United States and Canada are unable to think readily in terms of the metric system of weights and measurements. Even long experience does not make it possible to form a clear idea as to the actual size of fish for which lengths and weights are given in metric units, without first converting to the English system. A more general adoption of the English system of weights and measurements in fishery work is recommended. The use of English units exclusively is suggested for articles of a popular or semi-popular nature, but in more formal publications the key information, at least, should be recorded in both systems. In highly technical papers metric units alone may prove satisfactory.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1945)75[157:SOMOEL]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1948

数据来源: Taylor