Publication Abstract

Milt, plasma endocrine status, biliary accumulation of steroids and F-series prostaglandins by male Atlantic salmon exposed to female and male urine

Milt, plasma endocrine status, biliaryaccumulation of steroids and F-series prostaglandins by male Atlantic salmon exposed tofemale and male urine

C.P. Waring, A. Moore and A.P. Scott

Mature maleAtlantic salmon (Salmo salar L.) parr responded to the urine from ovulated females withsignificant increases in plasma gonadotropin II, 17,20β-dihydroxy-4-pregnen-3-one, testosterone, and 11-ketotestosteroneconcentrations and volumes of expressible milt. There were also significant increases inbiliary free steroid and steroid conjugate concentrations. Urine from mature adult malesalmon also affected male parr, which responded with increased plasma gonadotropin IIconcentrations and expressible milt. However, male urine did not elevate the plasma andbile concentrations of any of the steroids. When two of the three known steroids which aredetected by the mature male salmon parr olfactory epithelium were tested for primingactivity, results showed that these compounds had little or no activity when added to thewater. Only plasma gonadotropin II concentrations increased in mature male parr exposed to17,20β-dihydroxy-4-pregnen-3-one20-sulfate. Female and mature adult male urines contain at least one priming pheromone andthere was no conclusive evidence for this priming pheromone being one of the testedsteroids. However, the fact that water-borne 17,20β-dihydroxy-4-pregnen-3-one 20-sulfate can have a physiologicaleffect in male parr suggests that it may have a role as one of a mixture of compounds infemale urine that males detect and respond to. The lack of a priming-like effect oftestosterone supports a previous hypothesis that the major pheromonal role of this steroidis as an attractant for mature male salmon parr.

Reference:

C.P. Waring, A. Moore and A.P. Scott, 1996. Milt, plasma endocrine status, biliaryaccumulation of steroids and F-series prostaglandins by male Atlantic salmon exposed tofemale and male urine. General and Comparative Endocrinology, 103: 142-149.

C.P. Waring*, A. Moore* and A.P. Scott*

General and Comparative Endocrinology, 103: 142-149