scholarly journals Hypophysectomy of coho salmon (Oncorhynchus kisutch) and survival in fresh water and seawater

Aquaculture ◽  
1987 ◽  
Vol 65 (3-4) ◽  
pp. 343-352 ◽  
Author(s):  
Richard S. Nishioka ◽  
N.Harold Richman ◽  
Graham Young ◽  
Patrick Prunet ◽  
Howard A. Bern
Keyword(s):  
Fresh Water ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch

scholarly journals Evidence for Freshwater Residualism in Coho Salmon, Oncorhynchus kisutch, From a Watershed on the North Coast of British Columbia

2017 ◽  
Vol 130 (4) ◽  
pp. 336 ◽  
Author(s):  
Eric A Parkinson ◽  
Chris J Perrin ◽  
Daniel Ramos-Espinoza ◽  
Eric B Taylor
Keyword(s):  
British Columbia ◽  
Fresh Water ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Water Levels ◽  
North Coast ◽  
The North ◽  
Seaward Migration ◽  
Mature Fish

The Coho Salmon, Oncorhynchus kisutch, is one of seven species of Pacific salmon and trout native to northeastern Pacific Ocean watersheds. The species is typically anadromous; adults reproduce in fresh water where juveniles reside for 1–2 years before seaward migration after which the majority of growth occurs in the ocean before maturation at 2–4 years old when adults return to fresh water to spawn. Here, we report maturation of Coho Salmon in two freshwater lakes on the north coast of British Columbia apparently without their being to sea. A total of 15 mature fish (11 males and four females) were collected in two lakes across two years. The mature fish were all at least 29 cm in total length and ranged in age from three to five years old. The occurrence of Coho Salmon that have matured in fresh water without first going to sea is exceedingly rare in their natural range, especially for females. Such mature Coho Salmon may represent residual and distinct breeding populations from those in adjacent streams. Alternatively, they may result from the ephemeral restriction in the opportunity to migrate seaward owing to low water levels in the spring when Coho Salmon typically migrate to sea after 1–2 years in fresh water. Regardless of their origin, the ability to mature in fresh water without seaward migration may represent important adaptive life history plasticity in response to variable environments.

Hormone-induced Ovulation of Coho Salmon (Oncorhynchus kisutch) Held in Seawater and Fresh Water

1982 ◽  
Vol 39 (4) ◽  
pp. 627-632 ◽  
Author(s):  
Stacia A. Sower ◽  
Carl B. Schreck ◽  
Edward M. Donaldson
Keyword(s):  
Luteinizing Hormone ◽  
Fresh Water ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Spawning Season ◽  
Pituitary Extract ◽  
Hormone Analogue ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone

Coho salmon (Oncorhynchus kisutch) mature and spawn naturally in fresh water. We investigated the feasibility of accelerating maturation and/or ovulation of coho salmon retained in seawater during the spawning season, and compared accelerated ovulation of coho salmon in seawater and in fresh water. Effective inducers of ovulation in salmon held in fresh water were partly purified or purified salmon gonadotropin followed 3 d later by luteinizing hormone releasing hormone analogue (LH-RHa); one injection of salmon pituitary extract (SPE); chum salmon pituitary (PIT) followed at 3 d by PIT; and one injection of 17α-hydroxy-20β-dihydroprogesterone. One injection of chinook SPE; coho SPE followed at 3 d by coho SPE; or partly purified or purified salmon gonadotropin followed at 3 d by LH-RHa were effective but to a much lesser extent in those salmon held in seawater. PIT followed at 3 d by PIT, or one injection of 17α-hydroxy-20β-dihydroprogesterane were ineffective in acceleration of maturation/ovulation of coho salmon retained in seawater. Cortisone or 20β-hydroxyprogesterone, which were only tested in salmon in seawater, also failed to elicit early ovulation compared with controls. We conclude that ovarian responses to the treatments of fish retained in seawater are reduced by osmoregulatory difficulties or high adult mortalities. Thus acceleration of ovulation of coho salmon held in seawater is not feasible at this time and requires further research.Key words: coho salmon, spawning, ovulation, induced breeding, gonadotropin, luteinizing hormone releasing hormone analogue

The potential for using the anabolic hormones 17α-methyltestosterone and (or) 3,5,3′-triiodo-L-thyronine in the fresh water rearing of coho salmon (Oncorhynchus kisutch) and the effects on subsequent seawater performance

1980 ◽  
Vol 58 (8) ◽  
pp. 1424-1432 ◽  
Author(s):  
U. H. M. Fagerlund ◽  
David A. Higgs ◽  
J. R. McBride ◽  
M. D. Plotnikoff ◽  
B. S. Dosanjh
Keyword(s):  
Fresh Water ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Food Utilization ◽  
Thyroid Activity ◽  
Cell Height ◽  
Thyroid Epithelial Cell ◽  
General Mortality ◽  
Hormonal Treatments ◽  
Better Than

Juvenile coho salmon (Oncorhynchus kisutch) held in 11 °C fresh water (FW) were fed Oregon moist pellets supplemented with 3,5,3′-triiodo-L-thyronine at 4 ppm (T34) or 20 ppm(T320) and (or) 17α-methyltestosterone at 0.2 ppm (MT0.2) or 1 ppm (MT1) until early or normal seawater (SW) transfer.During FW residency all hormonal treatments improved growth, appetite, and food utilization. In February, fish fed T320 singly or with MT had increased degranulation of somatotrop cytoplasm. Thyroid epithelial cell height of fish fed T34 or T320 was either suppressed or enhanced. MT1 singly or combined with T3 induced androgenic side effects in males. Proximate body composition was affected only by MT. T320 induced morphological anomalies and treatment was discontinued. In May, thyroid activity and number of putative gonadotrops of fish fed MT1 were increased. Androgenic effects of all groups given MT1 were greater in May than in February.After SW transfer in February growth, appetite, and food utilization were depressed but fish fed T34 performed better than controls. Performance of all groups improved after May but, in general, mortality increased slightly. After transfer in May, T3-fed fish had increased growth in length.It is concluded that MT and T3 effectively enhance growth in FW but only T3 facilitates SW transfer.

Osmoregulation and circulating growth hormone and prolactin levels in hypophysectomized coho salmon (Oncorhynchus kisutch) after transfer to fresh water and seawater

Aquaculture ◽  
1991 ◽  
Vol 92 ◽  
pp. 33-42 ◽  
Author(s):  
Kohei Yamauchi ◽  
Richard S. Nishioka ◽  
Graham Young ◽  
Tsuyoshi Ogasawara ◽  
Tetsuya Hirano ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Fresh Water ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch

Early warning: detection of exotic coho salmon (Oncorhynchus kisutch) by environmental DNA and evidence of establishment at the extreme south of Patagonia

2019 ◽  
Vol 76 (12) ◽  
pp. 2343-2349 ◽  
Author(s):  
Tomás Chalde ◽  
Cristina F. Nardi ◽  
Daniel A. Fernández
Keyword(s):  
Fresh Water ◽  
Propagule Pressure ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Environmental Dna ◽  
Tierra Del Fuego ◽  
Scale Analysis ◽  
Probable Occurrence ◽  
Three Rivers ◽  
Positive Results

The global expansion of aquaculture is a constant propagule pressure that enables the establishment of exotic species in freshwater and marine environments. Here, we provide the first report on the presence of exotic coho salmon (Oncorhynchus kisutch) at the extreme south of Patagonia, in the island of Tierra del Fuego (TDF). During the last 6 years, 43 juvenile coho salmon were captured along the Beagle Channel, while one adult was captured in fresh water. Scale analysis showed that migration from fresh water as smolt would occur during their first winter of life. Mitochondrial DNA analyses revealed two haplotypes previously reported in North America and a new haplotype not reported before. We developed an environmental DNA assay for detecting coho salmon DNA from fresh water, obtaining positive results in three rivers. Additionally, one of these rivers was monitored monthly for a year, and we detected coho salmon DNA over 7 months, revealing the probable occurrence of coho salmon juveniles in fresh water. These results suggest the potential establishment of self-sustaining populations of coho salmon in TDF.

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