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.

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.

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

Comparative indexes of thyroid function in sheep

1961 ◽  
Vol 201 (5) ◽  
pp. 819-822 ◽  
Author(s):  
T. M. Hoersch ◽  
H. E. Henderson ◽  
E. P. Reineke ◽  
H. A. Henneman
Keyword(s):  
Thyroid Function ◽  
Hormone Secretion ◽  
Secretion Rate ◽  
Half Time ◽  
Thyroid Activity ◽  
Height Measurement ◽  
Cell Height ◽  
Thyroid Epithelial Cell ◽  
Thyroid Secretion ◽  
Zero Time

The effects of light and temperature on thyroid activity of sheep were assessed by four methods: thyroid secretion rate, zero time per cent uptake of I131, I131 output half-time, and measurement of the thyroid epithelial cell height. Increased ambient temperature inhibited thyroid activity as evaluated by all methods. Reduced temperatures consistently resulted in a depressed uptake of I131. I131 output half-time had no relationship with actual hormone secretion. Light alterations imposed the same trend on thyroid function when activity was assessed by secretion rate and cell height measurement. As evaluated by these two methods the lowest thyroid activity was observed at 12 hr of illumination per day and increased with both increasing and decreasing light beyond this 1:1 light-to-dark ratio. When the three isotopic measures of thyroid activity were correlated with the histological method the highest correlation was found between cell height and thyroid secretion.

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

Seasonal changes in thyroid activity in the lesser snow goose (Anser caerulescens caerulescens) including reference to embryonic thyroid activity

1980 ◽  
Vol 58 (6) ◽  
pp. 1144-1150 ◽  
Author(s):  
R. R. Campbell ◽  
J. F. Leatherland
Keyword(s):  
Thyroid Activity ◽  
Cell Height ◽  
Lesser Snow Geese ◽  
Anser Caerulescens Caerulescens ◽  
Thyroid Epithelial Cell ◽  
Lesser Snow Goose ◽  
Apparent Correlation ◽  
Anser Caerulescens ◽  
Gonadal Recrudescence ◽  
Plasma Triiodothyronine

Plasma thyroxine (T4) levels in adult lesser snow geese (Anser caerulescens caerulescens) increased concomitantly with gonadal recrudescence and remained elevated until shortly before moult. This pattern of declining plasma T4 concentrations preceding moult was evident in gosling, yearling, and adult birds. Plasma triiodothyronine (T3) concentrations did not change significantly throughout the year. There was no apparent correlation between plasma thyroid hormone levels and thyroid weight or thyroid epithelial cell height. Plasma levels of both T3 and T4 increased in goslings shortly before hatch and on day 20 of incubation reached levels (0.58 ± 0.36 and 19.5 ± 2.5 ng∙mL−1, respectively) similar to those found in the plasma of newly hatched birds (0.76 ± 0.24 and 36.0 ± 6.5, respectively).

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