Publication Abstract

Female rainbow trout urine contains a pheromone which causes a rapid rise in plasma 17,20beta-dihydroxy-4-pregnen-3-one levels and milt amounts in males

Female rainbow trout urine contains apheromone which causes a rapid rise in plasma 17,20beta-dihydroxy-4-pregnen-3-one levelsand milt amounts in males

E.L.M. Vermeirssen A.P. Scott and N.R. Liley

Previousstudies have shown that spermiating male rainbow trout respond to the presence of femaleurine in the water with significant increases in plasma levels of gonadotrophin 11, 17,20β-dihydroxy-4-pregnen-3-one(17,20β-P) andtestosterone. The present results show that males only need a single brief exposure tofemale urine in order to respond; levels of 17,20β-P rise significantly within I h of exposure, and peak between 3 and4 h. Also, milt amounts increase significantly following exposure of males to femaleurine. Levels of 17,20β-P are also related positively to the amount of female urine to which the malesare exposed. Furthermore, when live females are placed, out of physical and visualcontact, in the same tank as males, levels of 17,20β-P rise in the same way as in males which are exposed to femaleurine. However, if females are fitted with urinary catheters (which drain the urineoutside the tank), males respond more slowly. These results indicate that urine is themain source of the male' priming' pheromone.

Reference:

E.L.M. Vermeirssen A.P. Scott and N.R. Liley, 1997. Female rainbow trout urine contains apheromone which causes a rapid rise in plasma 17,20beta-dihydroxy-4-pregnen-3-one levelsand milt amounts in males. Journal of Fish Biology, 50, 107-119.

E.L.M. Vermeirssen *, A.P. Scott* and N.R. Liley

Journal of Fish Biology, 50, 107-119