摘要:

A reported, but as yet unconfirmed, ill effect on fishes of wastes from a munition plant led to a study of the toxicity of these wastes to fishes. The red liquor from the manufacture of tri-nitro-toluene (T.N.T.) was suspected. The constituents of this waste include dissolved T.N.T. and toluene, both of which are very toxic. Many other compounds which may be very toxic are also present.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[45:SOTTOA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

Partial creel-census records of Fish Lake, Utah, for the seasons of 1941–1943, were analyzed for evidence of a relationship between moonlight and fishing success. For both trolling and fly-fishing, the difference in the catch at times of new and full moons was not significant. The fly-fishing catch at times of first quarter moons (1.69 fish per man-trip) was significantly less than the mean catch at times of adjacent new and full moons (3.87 fish per man-trip); mean difference, 2.19 ± 0.675; value of t, 3.244. It is probable that light is the essential factor in producing the observed effect on fly-fishing at times of first quarter moon. This type of fishing is done almost exclusively after dark. A high ridge on the east shore of the lake protects the fishing area from the light of the full moon during effective fishing time, but the area is exposed to the light of the first quarter moon. Suggested explanations for the mode of operation of moonlight in reducing the catch are discussed.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[52:TEOMOF]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

A condition of algal nuisance in small ponds involving the water net, Hydrodictyon reticulatum, is described. A serial treatment with copper sulphate, in which daily applications of 0.33 p.p.m. of the chemical are made, resulted in the complete removal of the algae in five days. Sixteen ponds are kept free of algae by serial treatments with copper sulphate at regular intervals. The advantages of serial treatment over one-dose-treatment are discussed.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[59:COHRIS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

The addition of salmon flesh and salmon viscera to a diet for chinook salmon fingerlings produced growth equal to that resulting from all-meat diets. The cost of production was reduced considerably. Salmon flesh did not prevent the appearance of an anemic condition and therefore is considered deficient in the anti-anemia factor. Some evidence obtained indicated that salmon flesh might have a destructive influence upon the anti-anemia factor present in other foods. This effect may be similar to that exhibited by other frozen fish upon vitamin B1. Salmon viscera in the diet prevented anemia in some instances and is presumed, therefore, to contain some anti-anemia factor. However, it cannot be fed as a sole diet over long periods at the Leavenworth, Washington, Station.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[63:EOSFAS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

Descriptions and reasons for the installation and operation of the most important types of two-way fish weirs used in Michigan are presented, with a summary of the results obtained and the conclusions reached as a result of the operations.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[70:EOTUOT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

The scale method of growth analysis is applicable to the pike-perch of Lake of the Woods, but the body-scale relationship is that of a third-degree polynomial rather than a straight line. Length calculations were made using the corrected body-scale relationship. Female pike-perch grow more rapidly than the males, but the differences in growth rate are small. Lee's phenomenon is pronounced and is apparently due to the selective removal of the faster growing fishes by the commercial fisheries. The growth rate is more rapid during years with high mean summer temperatures, July temperatures being most significant. The weight increases approximately as the standard length raised to the 3.1 power. Male pike-perch mature when 4 years old, but females usually do not mature until 5 or 6 years of age.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[90:AGSMAP]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

Jaw-tagged 7- to 10-inch brook trout and brown trout were placed in two Minnesota streams to determine their survival. A creel census conducted on Duschee Creek showed that trout were returned at the rate of 1.49 and 1.55 fish per hour in succeeding seasons. Brown trout planted in this stream in the fall and spring yielded returns of 21.7 per cent and 28.0 per cent respectively, but no brook trout and only 2.0 per cent of the brown trout planted in summer were caught the following year. Planted trout contributed 8.8 per cent and 22.7 per cent of the total catch in successive seasons.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[108:SOSTTP]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

The results of experimental plantings of rainbow trout in Convict Creek (California) are presented as related principally to changes in growth, mortality, and condition from month to mouth over two summer seasons. Survivals are discussed in relation to a food-requirement ratio that has been shown to correlate positively with survival rates obtained.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[117:SCIGMA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

The tullibee, Leucichthys artedi tullibee (Richardson), is one of the most important commercial fishes in the Lake of the Woods. The relationship between standard length and the anterior scale radii of the tullibee can be described by a third degree parabola. Growth calculations were made using the corrected body-scale relationship. The greatest growth in length occurs during the first year of life, and the annual increment decreases each succeeding year. Males and females grow at approximately the same rate. The appearance of Lee's phenomenon is pronounced and probably is due to the differential mortality between slow-growing and fast-growing fish. No correlation could be demonstrated between annual fluctuations in growth rate and fluctuations in temperature or rainfall.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[125:GLRAPF]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor

摘要:

Increased prices and the scarcity of meat have created a much greater demand for fishery products. Meeting this demand will require the fullest utilization of our fresh-water fishery resources because our marine fishery is partly inoperative due to war conditions. It is believed that the fishes produced in the TVA impoundments can make a significant contribution to the food-for-victory program. Investigations conducted on these impoundments during the past 5 years indicate that they are rich in fish life and are capable of supporting an extensive fishery. Although all forms of netting are prohibited, there was an average take of 25 pounds of fish per acre by sport and setline fishermen during 1940 in the four lower reservoirs: Guntersville, Wheeler, Wilson, and Pickwick. This rate of production greatly exceeds the average yield of 1.8 pounds per acre from the Great Lakes.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1943)73[137:TPOACF]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1945

数据来源: Taylor