High level of residual heterozygosity in gynogenetic rainbow trout, Salmo gairdneri, Richardson

1984 ◽  
Vol 67 (4) ◽  
pp. 307-316 ◽  
Author(s):  
R. Guyomard
1986 ◽  
Vol 43 (6) ◽  
pp. 1149-1155 ◽  
Author(s):  
J. W. Hilton ◽  
S. J. Slinger

The digestibility study indicated that dry matter digestibility of canola meal (CM) was low (56.2–60.4%), probably due to the high fiber content of this product and its relatively high level of complex carbohydrates. Energy and protein digestibility of CM were 72.4 and 83.2%, respectively, and the essential amino acid digestibilities were similar to those of protein in the CM. CM cannot successfully replace either soybean meal or fish meal in practical-type diets for young rainbow trout (Salmo gairdneri) without sacrificing growth. Supplementation with additional arginine, lysine and zinc, or energy to CM-based diets did not overcome the growth depressing effects. CM supplementation to the trout diet affected the thyroid gland of the fish, producing a diffuse, microfollicular hyperplasia that increased in severity with increasing CM supplementation. Young rainbow trout appear to be more sensitive to dietary glucosinolates than chinook salmon (Oncorhynchus tshawytscha), and total glucosinolate levels of 158 μg/g or more are deleterious to these fish. We conclude that CM should not, at this time, be included as a feed ingredient in commercial trout diets for young rainbow trout.


1973 ◽  
Vol 30 (7) ◽  
pp. 1017-1020 ◽  
Author(s):  
D. J. Lee ◽  
J. H. Wales

Young rainbow trout (Salmo gairdneri) were fed semipurified diets containing varying levels of herring oil, casein–gelatin (70–30), and starch for 18 weeks. Fish fed diets containing 53% protein and fat levels of 8 and 16% developed livers with abnormal nuclei, bile duct proliferation, and some parenchymal cell injury. The same level of protein with 24% herring oil did not produce these liver changes. Increasing protein levels with concurrent lowering of starch content produced large livers that were high in glycogen. This effect was not as pronounced at the high level (24%) of fat. The liver abnormalities apparently did not impair growth since weight gains were unrelated to the condition of the liver histology.


1979 ◽  
Vol 21 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Craig A. Busack ◽  
Richard Halliburton ◽  
G. A. E. Gall

A total of 1462 rainbow trout (Salmo gairdneri Richardson) representing four California domestic strains, were examined electrophoretically at 24 gene loci to investigate the amount of genetic variability within strains and genetic differentiation between strains, relative to wild populations. Estimated heterozygosities of 0.071 to 0.134 were similar to those reported for wild populations and thus indicated that the domestic strains were at least as variable as wild populations. Genetic distances between strains ranged from 0.011 to 0.067, values typical of the level of differentiation observed between local conspecific populations in a variety of organisms. It was suggested that this high level of heterozygosity is due to mixing of populations in the strains' histories and perhaps also to balancing selection.


1971 ◽  
Vol 28 (11) ◽  
pp. 1801-1804 ◽  
Author(s):  
R. W. McCauley ◽  
W. L. Pond

Preferred temperatures of underyearling rainbow trout (Salmo gairdneri) were determined in both vertical and horizontal temperature gradients. No statistically significant difference was found between the preferred temperatures by the two different methods. This suggests that the nature of the gradient plays a lesser role than generally believed in laboratory investigations of temperature preference.


1979 ◽  
Vol 20 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Torill Bergsjø ◽  
Inger Nafstad ◽  
Kristian Ingebrigtsen

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