The biogeography of Mediterranean cephalopods

Abstract

SUMMARY This paper presents an updated picture of the Mediterranean teuthobiogeography. Sixty-five cephalopod species have been recorded in the Mediterranean, i.e. about 9% of the world teuthofauna, belonging to the following orders: Spirulida (1 species), Sepiida (4), Sepiolida (15), Teuthida (30), and Octopoda (15). Only 53 of them are represented by well established populations in this basin; all the others either have been very rarely collected or are recent occurrences, including cephalopods recently entered from the Atlantic Ocean and from the Red Sea through the Suez Canal. The width of the cephalopod horizontal distribution is discussed in relation to their modes of life and reproduction. In particular the in situ speciation of a flock of endemic or quasi-endemic sepioline species is attributed to certain body features (small size, "lock-and-key" copulatory organs), reproductive strategies, short life span, and habitat. A concise history of the knowledge of the Mediterranean teuthofauna is also illustrated. A list of the Mediterranean cephalopods is reported in Appendix I.