Publication Abstract

Electrophysiological and endocrinological evidence that F-series prostaglandins function as priming pheromones in mature male Atlantic salmon parr

Electrophysiological andendocrinological evidence that F-series prostaglandins function as priming pheromones inmature male Atlantic salmon parr

A. Moore and C.P. Waring

Previouswork has demonstrated that the urine from mature female salmonids contains a primingpheromone that significantly enhances the reproductive physiology of receiving males. Thechemical identity of the pheromone(s) has not yet been identified. The present studyinvestigated the possibility that F-type prostaglandins (PGFs) may have a pheromonal rolein Atlantic salmon by measuring the olfactory sensitivity of male salmon to PGFs, theeffect of waterborne PGFs on male reproductive physiology and the PGF content of maturefemale urine. Electrophysiological studies demonstrated that the olfactory epithelium ofmature male salmon parr was acutely sensitive to PGF_1α and PGF_2α, with detectionthreshold concentrations of 10^-11 mol l^-1. The olfactory epitheliumwas also sensitive to the PGF metabolite 15-ketoPGF_2α (threshold 10^-8 mol l^-1),but did not detect a further metabolite, 13,14-dihydro-15ketoPGF_2α. Sensitivity to bothPGFIa and PGF2a increased as the reproductive season progressed. Exposure of mature maleparr to waterborne PGF_1α and PGF_2α (10^-8 mol l^-1) resulted in significantincreases in levels of expressible milt and in the plasma concentrations of 17,20β-dihydroxy-4pregnen-3-one,testosterone and 11-ketotestosterone. Urine from ovulated female salmon also containedlarge quantities (18 ng ml^-1) of immunoreactive PGFs, whereas urine from maturemales and non-ovulated mature females contained significantly smaller amounts (<1 ng ml^-1).The results support the theory that PGFs function as priming pheromones in Atlantic salmonand are released in the urine of ovulated female salmon. The involvement of thesepheromones in synchronising male-female salmon spawning is discussed.

Reference:

A. Moore and C.P. Waring, 1996. Electrophysiological and endocrinological evidence thatF-series prostaglandins function as priming pheromones in mature male Atlantic salmonparr. Journal of Experimental Biology, 199: 2307-2316.

A. Moore* and C.P. Waring*

Journal of Experimental Biology, 199: 2307-2316