Sex pheromones in amphibians: a review

Abstract

Amphibians are interesting animals, very often kept by aquarists and vivarists. Their ability of intraspecific chemical signalization belongs to very interesting biological features. The skin glands of anurans secrete various biologically active compounds. The pheromones are peptides consisting of various numbers of amino acid residues and their synthesis is regulated by hormones (e.g. prolactin and androgens). Similarly, the responsiveness of the vomeronasal epithelium to some of these compounds is enhanced by some hormonal substances (prolactin and oestrogen). Hypophyseal hormones, arginine vasotocin and gonadotropin-releasing hormone are involved in the humoral regulation of pheromone discharge. The storage of some compounds with pheromonal activity in a biologically inactive form was also proved. The pheromones have an important role in sexual relationships. These chemosignals increase female receptivity and are probably involved in the mate choice. The courtship pheromone signals may be conserved across related species. Chemosignals play an important role in female attraction and/or territorial announcement. In addition to sex pheromones, various neuropeptides, antimicrobial and other biologically active peptides were found in skin glands of these amphibians. The infochemical system can be disturbed by a chemical influence in the environment.