Studio su basi chimiche dei comportamenti biologici dei molluschi Opistobranchi

Gastropods are generally protected against predators by their shells. However, in the gastropod subclass Opisthobranchia there is an evolutionary decrease of the shell which in nudibranchs is completely lost. In spite of this apparently unprotected opisthobranchs suffer a very low level of predation. This is due to the fact that these animals have elaborated a series of defensive strategies which include some chemicals used as allomones or pheromones. Recent studies on opisthobranchs have characterized many of the defense allomones. We will present the results obtained studying some Mediterranean opisthobranchs with particular emphasis for origin and role of the compounds present in defensive secretions. Some considerations will be made about the structure-activity relationship of some molecules, with particular attention for those characterized by 1, 4-dialdehydic function, which have allowed an intriguing connection between defensive chemistry of the nudibranchs and the human hot taste.