Endocrinology of teleost reproduction: A testicular steroid pheromone in the black goby, gobius jozo l

Abstract

The male black goby, Gobius jozo, is known to possess a large mesorchial gland which synthesizes large amounts of 5β-reduced androgens conjugates, especially etiocholanolone glucuronide. When gravid females releasing eggs on stripping were exposed singly to this steroid in a tank monitored through a closed television circuit, most of them manifested appetitive behaviour with negative kinesis towards the steroid source and were stimulated to lay their eggs. The steroid stimulus was effective in low concentration (below 2μM), in still water, and in the absence of sensorial reinforcements by a male partner. Females were little or not responsive outside in the interval between ovulation and oviposition. The pheromonal system of the black goby resembles that of the pig where the smell of the testicular 16-androstenes in the boar’s breath induces the mating stance in the estrous sow. Both.species are characterized by overdevelopment of the Leydighian compartment, chemical divergence between hormonal and pheromonal androgens and environmental diffusibility of the testicular pheromones. © 1980 Taylor & Francis Group, LLC.