Observations on the recruitment of Musculista senhousia (Mollusca, Bivalvia) in the Taranto seas (Eastern-Central Mediterranean Sea)

Abstract

Biogeographia vol. XXV — 2004 (Printed December, 30 ”’ 2004) Marine Biogeography of the Mediterranean Sea: patterns and dynamics of biodiversity Observations on the recruitment of Musculistrz sen/vousirz (Mollusca, Bivalvia) in the Taranto seas (Eastern—Central Mediterranean Sea) FRANCESCO MASTROTOTARO, ALFONSO MATARRESE, GIANFRANCO D’ONGHl.A Dzjmrtimenra dz‘ Zoologia, Universitiz dz’ Bari, Via Ombomz, 4, 70125 Bari (Italy) e— mail: mzzstrototzzro @bz'o[0gz'zz. zmibrz. it Key words: Mumilistrz ten/yazzrizz, Taranto seas, Mediterranean Sea, non indigenous species, recruitment. S UMMARY Juveniles and adults of 11/Ium¢lz'.rtzt sen/Jamirz were collected during four monthly benthic surveys carried out from September to December 2002 in the Mar Piccolo ofTaranto (Southern Italy). Two recruitment pulses were observed in September and December and a growth rate of about 2 mm/month was observed for the juveniles. In September and October rwo cohorts were shown in the sampled population. The present study confirms the settlement of M. mz/zaurizz in the Mar Piccolo ofTaranto. Considering the ephemeral nature ofthe mussel mats and the seasonal changes in some environmental factors in the study area, Further studies are required in order to define the dynamics of such a settlement. INTRODUCTION The presence of non indigenous species in the Mediterranean basin has increased in the recent years. The spreading of these species is often due to adult or larval transport by fouling on the hulls of ships and in ballast waters, respectively (Occhipinti Ambrogi, 2001). Furthermore, the transfer of exotic species into the Mediterranean for aquaculture purposes often causes the entrance of other non indigenous species (Rossi, 1992). \When a non indigenous species reaches a new habitat it may die immediately because it cannot withstand the new climatic conditions or it may survive