Effects of Diet or Liming on Steroid Hormone Metabolism and Reproduction in Atlantic Salmon (Salmo salar) Held in an Acidic River

Autor:	H. C. Freeman, L. S. Sperry, G. B. Sangalang, J. F. Uthe
Rok vydání:	1990
Předmět:	biology Ecology media_common.quotation_subject Aquatic animal Aquatic Science Reproduction Salmo biology.organism_classification Ecology Evolution Behavior and Systematics Steroid hormone metabolism media_common Aquatic organisms
Zdroj:	Canadian Journal of Fisheries and Aquatic Sciences. 47:2422-2430
ISSN:	1205-7533 0706-652X
DOI:	10.1139/f90-270
Popis:	Attempts to avert the impacts of an acidic river environment on Atlantic salmon (Salmo salar) were carried out in 1985 and 1986. Salmon were held in the Westfield River (pH 4.7–5.2) and the nearby Medway River (pH 5.3–5.6) during their sexual maturation. A diet containing 3% NaCl was fed to the Westfield salmon in 1985. Marble chips were used to elevate the pH of Westfield River water in 1986. Fish fed the salt diet had higher peak levels of plasma sex hormones, higher fecundity, greater incidence of spawners, lower egg mortality, and less weight loss than fish fed a commercial trout diet. The reproductive performance of fish held in limed water (pH 5.1–5.9) almost attained the level observed in the Medway (control) fish. Limestone treatment stimulated early peaking of blood androgen levels, testosterone, and 11-ketotestosterone in Westfield males, and 17α, 20β-dihydroxy-4-pregnen-3-one, a follicular mediator of gonadotropin, in a few Westfield females. The head kidneys produced more cortisol and corticosterone in all Westfield fish in both years compared to Medway fish. The results suggest that neither dietary salt nor liming completely prevented the decline of reproductive performance and the alteration of steroid hormone metabolism in salmon.
Databáze:	OpenAIRE
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