Response to Mammalian ACTH of the Interrenal Tissue of Sockeye Salmon (Oncorhynchus nerka) at Various Stages of Sexual Maturation

1970 ◽  
Vol 27 (6) ◽  
pp. 1169-1172 ◽  
Author(s):  
U. H. M. Fagerlund
Keyword(s):  
Sexual Maturation ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Maximum Response ◽  
Significant Change

Cortisol concentrations in response to an intra-arterial dose of porcine ACTH were determined in plasma of sockeye salmon in which endogenous corticotrophin secretion had been suppressed with dexamethasone. Maximum concentrations were found 3 or 5 hr after the injection. Sexual maturation did not bring about a statistically significant change in maximum response. Cortisol maxima of males were 55–62% of those of females.

The Pituitary Gland of the Sockeye (Oncorhynchus nerka) During Sexual Maturation and Spawning

1967 ◽  
Vol 24 (8) ◽  
pp. 1791-1810 ◽  
Author(s):  
A. P. van Overbeeke ◽  
J. R. McBride
Keyword(s):  
Pituitary Gland ◽  
Sexual Maturation ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Gonad Development ◽  
Cell Types ◽  
Limited Extent ◽  
Degenerative Alterations ◽  
Different Cell Types

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.

Effects of Rhizopus extract administration on somatic growth and sexual maturation in lacustrine sockeye salmon Oncorhynchus nerka

2002 ◽  
Vol 68 (4) ◽  
pp. 776-782 ◽  
Author(s):  
RAMJI KUMAR BHANDARI ◽  
IKUO USHIKOSHI ◽  
HIDEO FUKUOKA ◽  
NOBUHISA KOIDE ◽  
KOHEI YAMAUCHI ◽  
...  
Keyword(s):  
Sexual Maturation ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Somatic Growth

Effect of Sexual Maturation and Gonadectomy at Sexual Maturity on Cortisol Secretion Rate in Sockeye Salmon (Oncorhynchus nerka)

1970 ◽  
Vol 27 (12) ◽  
pp. 2287-2296 ◽  
Author(s):  
Edward M. Donaldson ◽  
Ulf H. M. Fagerlund
Keyword(s):  
Sexual Maturation ◽  
Clearance Rate ◽  
Sexual Maturity ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Secretion Rate ◽  
Metabolic Clearance ◽  
Cortisol Secretion ◽  
Metabolic Clearance Rate ◽  
Male And Female

Changes in cortisol dynamics in male and female sockeye salmon (Oncorhynchus nerka) have been investigated at various stages during sexual maturation, after spawning, and after gonadectomy just prior to their reaching sexual maturity. The metabolic clearance rate of cortisol was determined by the single injection technique and calculated using the formula for a two-pool system. The volume of distribution of cortisol in the inner pool and the outer pool, metabolic clearance rate, and cortisol secretion rate increased in both male and female salmon during sexual maturation. These changes were reversed in fish that were gonadectomized just before reaching functional maturity and allowed to recuperate for 2 or 8 weeks.There was a decrease in the amount of red carotenoid pigment in the flesh of salmon held in the laboratory during sexual maturation. This loss of pigment was reversed in salmon that were gonadectomized and fed marine zooplankton for 8 weeks.

Behavioral thermoregulation by maturing adult sockeye salmon (Oncorhynchus nerka) in a stratified lake prior to spawning

2005 ◽  
Vol 83 (9) ◽  
pp. 1232-1239 ◽  
Author(s):  
Jennifer C Newell ◽  
Thomas P Quinn
Keyword(s):  
Sexual Maturation ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Behavioral Thermoregulation ◽  
Sudden Increase ◽  
Physiological Factors ◽  
Lake Washington ◽  
Temperature Preferences ◽  
Temperature Records ◽  
Recorded Temperature

Adult sockeye salmon, Oncorhynchus nerka (Walbaum in Artedi, 1792), return to Lake Washington several months prior to spawning, spending the warmest months of the year in the lake. We proposed that the fish selected a temperature range ideal for final sexual maturation and energy conservation prior to swimming upstream to spawn. The temperature preferences of the adult sockeye salmon in Lake Washington are attributable to physiological factors, as they are not avoiding predators or seeking prey and are not limited by dissolved oxygen. At the Hiram M. Chittenden Locks, 257 sockeye salmon were tagged with temperature loggers in the summer of 2003, and 38 tags with readable data were recovered. The fish spent an average of 6 days swimming through the ship canal's warm water (ca. 18 °C) and then experienced a drop to temperatures of 13 °C or lower when they entered the lake and descended below the thermocline. Fish remained in the lake for an average of 83 days before migrating upstream to spawn, as indicated by a sudden increase in recorded temperature. Approximately 92% of temperature records in the lake were 9–11 °C, corresponding to depths of 18–30 m. The salmon rarely occupied the cooler and warmer waters available to them. Finally, the apparent thermal preference decreased over the summer, perhaps as a function of sexual maturation.

Dynamics of Cortisone Secretion in Sockeye Salmon (Oncorhynchus nerka) during Sexual Maturation and after Gonadectomy

1970 ◽  
Vol 27 (12) ◽  
pp. 2323-2331 ◽  
Author(s):  
Ulf H. M. Fagerlund ◽  
Edward M. Donaldson
Keyword(s):  
Sexual Maturation ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Volume Of Distribution ◽  
Metabolic Clearance ◽  
In Captivity ◽  
Full Capacity ◽  
Mature Fish ◽  
Secretion Rates ◽  
Immature Fish

Indices of cortisone secretion in sockeye salmon (Oncorhynchus nerka) were determined by monitoring the disappearance of labelled cortisone in plasma after the injection of a single dose of 4-14C-cortisone. Cortisone concentrations were determined by a protein-binding method.The volume of distribution in the inner (V1) and outer (V2) pool, biological half-life [Formula: see text], metabolic clearance rate (MCR), plasma concentration, and secretion rate of cortisone increased with sexual maturation, except cortisone concentration in males during anaesthetic stress. Differences between sexually immature fish and fish matured in captivity were generally significant (P < 0.05). After gonadectomy of mature fish the return of many of these indices to the levels of immature fish was noted. With some exceptions the changes observed resembled qualitatively those of cortisol dynamics. In sexually mature and spawned fish, cortisone concentrations and secretion rates, did not increase during anaesthetic stress in contrast to those of cortisol, suggesting that the full capacity of the cortisone secretion mechanism had already been reached in the resting state.Cortisone secretion rates were similar in magnitude to those of cortisol in resting fish, but cortisol secretion rates were two to four times higher than those of cortisone during anaesthetic stress.

Resumption of anadromy or straying? Origins of Sockeye Salmon Oncorhynchus nerka in the Elwha River

2021 ◽  
Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Elwha River

Alternative Recruitment Models of Adams River Sockeye Salmon, Oncorhynchus nerka

1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Status Quo ◽  
Management Policy ◽  
Best Management ◽  
Interaction Terms ◽  
Ricker Model ◽  
The Status ◽  
Stock Recruitment ◽  
High Yields

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.

Reduced growth in wild juvenile sockeye salmon Oncorhynchus nerka infected with sea lice

2017 ◽  
Vol 91 (1) ◽  
pp. 41-57 ◽  
Author(s):  
S. C. Godwin ◽  
L. M. Dill ◽  
M. Krkošek ◽  
M. H. H. Price ◽  
J. D. Reynolds
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Sea Lice
Sign in / Sign up

Export Citation Format

Share Document