Fish reproductive pheromones

Stacey, N.E., Kyle, A.L. Liley, N.R. 1986. Fish reproductive pheromones. In Chemical Signals in Vertebrates 4 (Ed. by D. Duvall, D. Muller-Schwarze R.M. Silverstein), pp 117—134. New York Plenum Press. 

SOURCES AND CHEMICAL NATURE OF FISH REPRODUCTIVE PHEROMONES... 

Despite the considerable observational and experimental evidence for the existence of reproductive pheromones in fish, less is known concerning the sites of pheromone production, while only in a few cases have the chemical identities of fish reproductive pheromones been proposed. This is unfortunate, for a better understanding of the origins and chemical natures of fish reproductive pheromones will not only allow a much greater sophistication in the experimental analysis of pheromone function, but can also be expected to provide insight into the evolutionary development of chemical communication systems in fish. 

In fish reproduction, the best-investigated pheromone system is that of the goldfish [Carassius auratus). Here, sex steroids and prostaglandins play important roles. The female produces two pheromones sequentially a preovulatory primer pheromone and a postovulatory prostaglandin pheromone that act on the male. 

Stacey NE, Sorensen PW (2006) Reproductive pheromones. Fish Physiol 24 359-412... 

Stacey NE, Sorensen P (2006) Reproductive pheromones. In Sloman KA, Balshine S, Wilson RI (eds) Behaviour and physiology of fish. Elsevier, Amsterdam, pp 359 112... 

Interestingly, although fish reproductive lifestyles are highly diverse, the steroids and F prostaglandins (PGFs) from which hormonal pheromones are derived appear highly conserved. For example, in all fish examined, estradiol-17p (E2) induces vitellogenesis... 

Generally, sexual activity in fish is restricted to a brief period in the adult lifespan. This restriction is most obvious in females, where sexual activity in oviparous species occurs for only a short period (hours or days) after ovulation. As the primary function of most reproductive pheromones in fish is evidently to attract and stimulate sexual arousal in potential conspecific partners, it is to be expected that pheromone production should be synchronized with transient episodes of sexual competence, and that these processes might share common regulatory mechanisms. 

Olfaction is thought to be the dominant chemosensory modality by which reproductive pheromones are detected in fish, although there is evidence that taste mechanisms are involved in some species (Liley,... 

Brett, B. L. H., and Grosse, D. J., 1982, A reproductive pheromone in the Mexican Poeciliid fish Poecilia chica, Copeia, 219 ... 

For fish, it is thought that pheromones derived from hormones. Hormones are pre-existing signals produced in temporal synchrony with discrete reproductive events (Sorensen and Stacey, 1990). These hormones are readily excreted into the water. The evolution of olfactory reception mechanisms for pheromones may have been facilitated by already existing internal endocrine receptors. Sorensen and Stacey (1990) argued that for pheromonal functions to arise mutations are initially required only in the recipient. Specificity of the signal... 

Scott, A. P., Liley, N. R., and Vermeirssen, E. L. M. (1994). Urine of reproductively female rainbow trout, Oncorhynchus mykiss (Walbuam), contains a priming pheromone which enhances plasma levels of sex steroids and gonadotropin II in malts. Journal of Fish Biology 44,131-148. 

Reproductive priming pheromones. Many species of fish are external fertilizers, and they spawn only a few times, which means that it is essential that male and female gamete outputs coincide. There is strong evidence that synchronization is mediated by sensory cues, including pheromones, most of which appear to be hormonally derived. 

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