Community structure of digenean parasites of sparid and labrid fishes of the Mediterranean sea: a new approach

The aim of this work was to study the structure of the parasite communities of Digeneans of 2 families of Teleost fishes (Sparidae and Labridae) of th e Mediterranean sea. We tried to quantify the importance of both the microh abitat requirements of the parasite species and the effect of host biologic al factors on the parasite communities. We applied, for the first time in p arasite community studies, the Canonical Correspondence Analysis (CCA) to a nalyse ii) the spatial distribution of parasite species within the digestiv e tract of the hosts; (ii) the host's biological factors (such as diet, hos t length, gregariousness and abundance) that may influence this spatial dis tribution of parasite species. Our results showed that potential microhabit ats were vacant in the 2 host families studied revealing a lack of niche sa turation because either there was little inter- and/or intraspecific compet ition or there were enough available space and resources within the host. O ur results also indicated that the position of the parasite in the digestiv e tract is much more important than host biological factors for the structu re of parasite community. Finally, we highlight the potential use of the CC A method for controlling for phylogenetic constraints in multi-species anal yses.