Environmentally Induced Precocious Sexual Development in the Male Pink Salmon (Oncorhynchus gorbuscha)

1976 ◽  
Vol 33 (11) ◽  
pp. 2602-2605 ◽  
Author(s):  
Colin N. MacKinnon ◽  
Edward M. Donaldson
Keyword(s):  
Sexual Development ◽  
Sea Water ◽  
Average Length ◽  
Pink Salmon ◽  
First Record ◽  
Oncorhynchus Gorbuscha ◽  
Average Weight ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Sexually Mature ◽  
Precocious Development

Nine males within a group of approximately 200 pink salmon (Oncorhynchus gorbuscha) reared in heated sea water became sexually mature in October of the year of hatching. These mature males (average weight = 119.44 g; average length = 19.8 cm) were larger than the immature males (average weight = 92.22 g; average length = 18.9 cm but not significantly so. This is the first record of precocious development in pink salmon other than as a result of the use of exogenous gonadotropin.

Comparison of the effect of salmon gonadotropin administered by pellet implantation or injection on sexual development of juvenile male pink salmon (Oncorhynchus gorbuscha)

1978 ◽  
Vol 56 (1) ◽  
pp. 86-89 ◽  
Author(s):  
Colin N. MacKinnon ◽  
Edward M. Donaldson
Keyword(s):  
Body Weight ◽  
Chinook Salmon ◽  
Sexual Development ◽  
Oncorhynchus Tshawytscha ◽  
Pink Salmon ◽  
Mitotic Division ◽  
Oncorhynchus Gorbuscha ◽  
Juvenile Male ◽  
Time Intervals ◽  
Pink Salmon Oncorhynchus Gorbuscha

In juvenile male pink salmon complete maturity was induced by September in the year of hatching by both pellet implantation (once per 3 weeks) and injection (thrice weekly) of 1.0μg of chinook salmon (Oncorhynchus tshawytscha) gonadotropin per gram body weight. Time of onset of mitotic division of spermatogonia and rate of spermatogenesis were accelerated in the precociously mature testes. Similar doses of salmon gonadotropin injected at longer time intervals (once per week and once per 2 weeks) resulted in slower maturation.

Induction of precocious sexual development in female pink salmon (Oncorhynchus gorbuscha)

1973 ◽  
Vol 51 (5) ◽  
pp. 493-500 ◽  
Author(s):  
James D. Funk ◽  
Edward M. Donaldson ◽  
Helen M. Dye
Keyword(s):  
Body Weight ◽  
Chinook Salmon ◽  
Sexual Development ◽  
Oncorhynchus Tshawytscha ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Ovarian Maturation ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Large Numbers ◽  
Estradiol 17Β

Acceleration of ovarian maturation was achieved in immature pink salmon (Oncorhynchus gorbuscha) with injections of chinook (spring) salmon (Oncorhynchus tshawytscha) gonadotropin alone, and in combination with estradiol 17β. Oocytes containing yolk globules were evident in fish treated three times per week with 1.0 μg/g body weight salmon gonadotropin in combination with 1.5 μg/g body weight estradiol 17β for 126 days. After 168 days they were also seen in salmon treated with the same dosage of salmon gonadotropin alone. Estradiol 17β alone, at a dosage of 15 μg/g body weight, or in combination with salmon gonadotropin, inhibited vitellogenesis. Formation of oocytes 2 mm in diameter required [Formula: see text] months of treatment with 1.0 μg/g body weight salmon gonadotropin in combination with 1.5 μg/g body weight estradiol 17β, and 9 months of injections with 1.0 μg/g body weight gonadotropin alone. Few large yolky oocytes were developed by any of the treatments. Large numbers of preovulatory corpora atretica were observed in all treated fish.Only a small amount of histochemically demonstrable Δ5-3β hydroxysteroid dehydrogenase activity was present in ovaries from pink or chinook salmon juveniles treated for 3 months with various dosages of salmon gonadotropin.

Two Epidemics of Apparent Kidney Disease in Cultured Pink Salmon (Oncorhynchus gorbuscha)

1961 ◽  
Vol 18 (4) ◽  
pp. 559-562 ◽  
Author(s):  
Gordon R. Bell
Keyword(s):  
Kidney Disease ◽  
Severe Disease ◽  
Pink Salmon ◽  
First Record ◽  
Oncorhynchus Gorbuscha ◽  
Presumptive Diagnosis ◽  
Pink Salmon Oncorhynchus Gorbuscha

Two epidemics of a severe disease in cultured, juvenile pink salmon (O. gorbuscha) are described. The symptomatology of the disease and the morphology of the stained bacteria found in tissue lesions suggest that the fish were affected by "kidney disease". If the presumptive diagnosis is correct, this report is the first record of kidney disease occurring in pink salmon.

A Technique for Prolonged Blood Sampling in Free-Swimming Salmon

1964 ◽  
Vol 21 (4) ◽  
pp. 711-717 ◽  
Author(s):  
Lynwood S. Smith ◽  
Gordon R. Bell
Keyword(s):  
Sockeye Salmon ◽  
Sea Water ◽  
Pink Salmon ◽  
Blood Sampling ◽  
Dorsal Aorta ◽  
Oncorhynchus Gorbuscha ◽  
Free Swimming ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Cannulation Technique

A technique is described for insertion of a cannula in the dorsal aorta of salmon for long-term blood sampling or vascular injection while the fish is confined, but free-swimming. Previous methods for single injections into the dorsal aorta are improved by a modified cannulation technique. The practicality of the technique was tested by introducing Evans Blue (T-1824) into the dorsal aorta of immature pink salmon (Oncorhynchus gorbuscha) in sea water and mature sockeye salmon (O. nerka) in fresh water to make preliminary estimates of blood volumes. It was shown that the technique can also be applied to angiography of salmon.

Variation in the Time of Run, Sex Proportions, Size and Egg Content of Adult Pink Salmon (Oncorhynchus gorbuscha) at McClinton Creek, Masset Inlet, B.C.

1937 ◽  
Vol 3 (5) ◽  
pp. 403-416 ◽  
Author(s):  
A. L. Pritchard
Keyword(s):  
Average Length ◽  
Pink Salmon ◽  
Spawning Migration ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
The Third ◽  
Main Portion

The spawning runs of pink salmon to McClinton creek, Masset inlet, B.C., in 1930, 1932, 1934, and 1936, differed little in time of appearance of the first migrant and disappearance of the last. The period occupied for the main portion of each run to reach the spawning beds depended chiefly upon rainfall and freshet conditions. Males occurred in greater numbers at the beginning of every run but a subsequent increased influx of females eventually brought about equality of the sexes in two seasons. In the third the males predominated slightly, and in the fourth the females. The average length and weight of males are consistently greater than those for females in the same year. Usually a significant increase in length occurred in both sexes from the commencement to the end of the run. In some cases a similar gain in weight was demonstrated but in others it was apparently masked by loss in weight consequent upon fasting during the spawning migration. The number of eggs per female in a given year increases with increase in length and weight.

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