Plasma androgen levels in castrated adult male African catfish, Clarias gariepinus, in relation to pheromonal stimulation of ovarian growth in pubertal conspecifics

Pubertal female Clarias gariepinus (recipients) were exposed for 62 days to holding water from intact, completely castrated, seminal vesicles-extirpated or testes-extirpated adult male or from intact adult female conspecifics (donors). In operated male donor groups, levels of six androgens (measured by RIA) were lowest in testes-extirpaied and completely castrated males. However, even complete absence of the testes (GSI 0%) did not eliminate circulating androgens. Male holding water exerted primer pheromonal action in enhancing ovarian development of recipient females, irrespective of the male donor group. Holding water from female donors was ineffective, comparable to controls (fresh water). Thus, although the effect of holding water is linked to the male gender, the gonadal origin of ovarian growth-stimulating compounds in the holding water could not be demonstrated.