Relationship between pelagic larval duration and geographic distribution in Mediterranean littoral fishes.

Abstract

We examined the relationship between pelagic larval duration (PLD)—a predictor of a species’ dispersal potential—and the geographic distribution range of 62 Mediterranean littoral fishes. We found a significant, positive, weak relationship between PLD and distribution range. This relationship was observed in species with long PLDs that can cross the few dispersal barriers (Macaronesian Islands) present in the Mediterranean, and in endemic Mediterranean species with short PLDs. Species with inshore larvae exhibited a shorter PLD than species with offshore larvae. Species with larvae living in spring-summer had shorter PLDs than those developing in autumn-winter. Mean geographic range was clearly smaller for species with inshore larval distributions than for species with offshore larval distributions. However, the geographic range of species with benthic eggs was smaller than that of pelagic spawners. The size of the distribution range of fishes is probably not controlled only by the PLD. The inshore/offshore position and the season of planktonic life play an important role in ensuring the return of larvae to their settlement habitats. Consequently, these factors also affect the size of the species’ distribution range.