Effects of Feeding on the Thyroid, Kidney, and Pancreas in Sexually Ripening Adult Sockeye Salmon (Oncorhyncus nerka)

1967 ◽  
Vol 24 (1) ◽  
pp. 67-76 ◽  
Author(s):  
J. R. McBride

In unfed adult sockeye salmon, Oncorhynchus nerka, histological examination showed extensive degenerative changes in the thyroid, pancreas, and kidney during gonad development. The more pronounced changes were generally noted in starved fish spawned in the wild. Feeding either prevented (thyroid) or distinctly reduced (pancreas, kidney) these changes in the sexually ripe fish. In fed spent sockeye the thyroid showed little change, the kidney exhibited further deterioration although not as marked as in the corresponding unfed fish, but the pancreas showed marked degenerative changes comparable with those exhibited in the unfed.

1967 ◽  
Vol 24 (8) ◽  
pp. 1791-1810 ◽  
Author(s):  
A. P. van Overbeeke ◽  
J. R. McBride

This communication presents the results of a study of the pituitaries of 150 sockeye salmon in various stages of sexual maturation from the time they entered freshwater till after completion of spawning. In the homologue of the adenohypophysis, nine different cell types were distinguished. On the basis of changes in tinctorial and histochemical properties and relative proportions of each of these cells, it was concluded that the sockeye pituitary contains six different hormone-producing cell types. One of these probably possesses a gonadotrophic function. Degenerative phenomena in the pituitary were found in the sexually ripe and the spent salmon, but only to a limited extent. The implications of the changes in the occurrence of the six different cell types and the degenerative alterations are discussed in relation to gonad development and the death after spawning.


1963 ◽  
Vol 20 (1) ◽  
pp. 95-100 ◽  
Author(s):  
J. R. McBride ◽  
U. H. M. Fagerlund ◽  
M. Smith ◽  
N. Tomlinson

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.


1950 ◽  
Vol 28d (1) ◽  
pp. 35-43 ◽  
Author(s):  
G. Mary Bell ◽  
William S. Hoar

Ultraviolet radiation of wave lengths from 2800 Å to 3100 Å, generated by a General Electric RS sun lamp, was used to irradiate eggs and alevins of the sockeye salmon (Oncorhynchus nerka). Mortality curves are presented for a series of measured dosages. Irradiation of eggs in the later stages of development produced a stimulating effect on the rate of hatching. These premature alevins, which hatched a month before the controls, were abnormal in several respects. The vertebral column was curved downward over the region of the heart, growth was retarded, the yolk was not utilized as rapidly as in the controls and pigmentation was delayed. The mortality was particularly high at the time of hatching and the process was abnormal. Histological examination of irradiated alevins revealed changes in the epidermis and fibroelastic layers of the skin. These were localized to the irradiated regions. Heavy doses produced severe degeneration of the epidermal layer with the formation of granules in the nuclei, the breakdown of the goblet cells, and subsequent desquamation. The changes were less extreme with lower dosages and in these fish a recovery began about 13 days after irradiation. Internal organs and tissues beneath the fibroelastic layers of the skin were not visibly affected by the irradiation.


1998 ◽  
Vol 55 (6) ◽  
pp. 1387-1394 ◽  
Author(s):  
Andrew P Hendry ◽  
Jay E Hensleigh ◽  
Reg R Reisenbichler

Sockeye salmon (Oncorhynchus nerka) introduced into Lake Washington in the 1930s and 1940s now spawn at several different sites and over a period of more than 3 months. To test for evolutionary divergence within this derived lineage, embryos that would have incubated in different habitats (Cedar River or Pleasure Point Beach) or at different times (October, November, or December in the Cedar River) were reared in the laboratory at 5, 9, and 12.5°C. Some developmental variation mirrored predictions of adaptive divergence: (i) survival at 12.5°C was highest for embryos most likely to experience such temperatures in the wild (Early Cedar), (ii) development rate was fastest for progeny of late spawners (Late Cedar), and (iii) yolk conversion efficiency was matched to natural incubation temperatures. These patterns likely had a genetic basis because they were observed in a common environment and could not be attributed to differences in egg size. The absolute magnitude of divergence in development rates was moderate (Late Cedar embryos emerged only 6 days earlier at 9°C) and some predictions regarding development rates were not supported. Nonetheless our results provide evidence of adaptive divergence in only 9-14 generations.


1965 ◽  
Vol 22 (3) ◽  
pp. 775-782 ◽  
Author(s):  
J. R. McBride ◽  
U. H. M. Fagerlund ◽  
M. Smith ◽  
N. Tomlinson

It has been shown that sockeye salmon, Oncorhynchus nerka, will start to eat soon after capture during their freshwater spawning migration. Some will continue to eat up to, during, and after spawning, while others stop eating shortly before spawning. The effect of feeding has been investigated histologically in a number of tissues by comparison of feeding fish, unfed controls, and fish spawned in the wild. Atrophy, and often degeneration of the liver, stomach, and intestine in post-spawned unfed controls and fish spawned in the wild was equally marked, but was absent or much less pronounced in fed fish.


Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  

1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters

Despite evidence of depensatory interactions among year-classes of Adams River sockeye salmon (Oncorhynchus nerka), the best management policy is one of equal escapement for all year-classes. We fit alternative models (Ricker model and Larkin model) to 32 yr of stock–recruitment data and checked, using simulation tests, that the significant interaction terms in the Larkin model are not caused by biases in estimating the parameters. We identified a parameter set (Rationalizer model) for which the status quo cyclic escapement policy is optimal, but this set fits the observed data very poorly. Thus it is quite unlikely that the Rationalizer model is correct or that the status quo escapement policy is optimal. Using the fitted stock–recruitment parameters, we simulated the sockeye population under several management policies. The escapement policy optimal under the Ricker model is best overall because of the high yields if it should be correct. If the three stock–recruitment models are equally likely to be correct, the simulations predict that adopting a constant-escapement policy would increase long-term yield 30% over the current policy and that an additional 15% increase in yield could be obtained if the policy were actively adaptive.


2017 ◽  
Vol 91 (1) ◽  
pp. 41-57 ◽  
Author(s):  
S. C. Godwin ◽  
L. M. Dill ◽  
M. Krkošek ◽  
M. H. H. Price ◽  
J. D. Reynolds

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