Parasites of a marine benthic fish in the Southwester Atlantic: searching for recurrent geographical patterns of community structure.

VALES, D.G., N.A. GARCIA, E.A. CRESPO & J.T. TIMI.

Melbourne, Australia,

Congreso; THE XIITH INTERNATIONAL CONGRESS OF PARASITOLOGY (ICOPA); 2010

Parasite communities of Raneya brasiliensis are described and its parasites used as biological tags to discriminate populations in the southern boundary of its distribution. Fish were caught in two zones of the Argentinean Sea: one sample from the area of San Jorge Gulf (Patagonian Region) and three samples from off the coast of Buenos Aires (Bonaerense Region). A total of 183 specimens of R. brasiliensis were examined for parasites and 11 species were found. Host body size and its ecology are pointed out as drivers of the paucity of taxa found. Most parasites were unspecific larval stages, with the exception of a cucullanid nematode. Multivariate similarity analyses allowed the identification of three stocks: one in the San Jorge Gulf, and two other one off the coast of Buenos Aires Province. The parasite species that contributed most to the separation of the samples were generally those identified as biological markers in previous studies on other fish species. Patterns of distance decay in similarity among communities in R. brasiliensis were found; with dissimilarity values between distant localities (i.e. between Patagonian and Bonaerense regions) being higher than between close ones (i.e. localities of the Bonaerense region). Whereas the composition and structure of parasite assemblages in Bonaerense waters reflect those of other fish species in the areas, being mainly determined by the composition of the compound community, no repeatable patterns were found in the composition of parasites assemblages when R. brasiliensis was compared with other hosts species in Patagonia.