Male traits associated with alternative reproductive tactics in Gobius niger

摘要: Male black goby Gobius niger, adopting parental or sneaking tactics, differed in secondary sex traits (elongation of the 4th ray first dorsal fin and nuptial colouration) thus allowing classification wild-caught males. Parental males were larger older than sneaker males, suggesting that mating tactic is an expression ontogenetic gradient. Males alternative tactics also primary traits, including their testes two pairs accessory structures: seminal vesicles mesorchial glands. Sneaker had a higher investment testes, while showed more developed Histological analyses from presented some functional differences those sneakers. In former these organs devoted solely to mucin secretion, latter they stored sperm lower activity secretion. Seminal vesicle features influenced ejaculate (sperm trail) characteristics performance. male trails richer mucins, but poorer deposited by As consequence, sneakers produced released large amount immediately active sperm, laid less constantly over long time.