A steroid sex pheromone synchronizes male–female spawning readiness in goldfish

Understanding of pheromone function in teleost fish has been impeded by a lack of information on pheromone identities1. Our recent studies2,3 on goldfish Carassius auratus, however, provide strong evidence that 17α,20β-dihydroxy-4-pregnen-3-one (17,20P), the proposed oocyte maturation-inducing steroid hormone in goldfish4 and other teleosts5, could be a potent female sex pheromone. Milt (sperm and seminal fluid) volume in goldfish is increased …