Parasites of the Brazilian sandperch Pinguipes brasilianus Cuvier: a tool for stock discrimination in the Argentine Sea

TIMI, JUAN T.; LANFRANCHI, ANA L.; ETCHEGOIN, JORGE A.; CREMONTE, FLORENCIA

Viterbo, Italia

Simposio; 7th International Symposium on Fish Parasites; 2007

Universidad de Roma

The use of parasites as biological tags allowed the identification of three stocks of Brazilian sandperch in the Argentine Sea. A total of 156 specimens caught during spring 2006, in the coasts of Buenos Aires Province (38°27’S-57°90’S n=54), Puerto Lobos, San Matías Gulf (42°S, 65°10’W, n=52) and Bahía Craker, Nuevo Gulf (42°09’S, 64°05’W, n=56), were examined for parasites and parasites belonging to 21 species were found, including monogeneans, digeneans, cestodes, nematodes, acanthocephalans and crustaceans. Diet analyses showed that fish feed mainly on benthic macroinvertebrates, with differences in the relative importance of main items between zones. Univariate analysis on parasite population descriptors, as well as a discriminant analysis, allowed the identification of discrete stocks in each zone, although a higher degree of similarity was observed between both Patagonian Gulfs. Northern samples were characterized by higher values of prevalence and abundance of Grillotia sp., Corynosoma australe and Scolex polymorphus. On the other hand, Trifur sp. and Qpecoelidae gen. sp., were important in determining the position of Patagonian samples and specially related to those from Nuevo gulf, whereas none of the species was clearly related to fish from San Matías Gulf. The size of the hosts is likely to influence the similarity among zones, with larger fish as better tools to discriminate stocks, probably because they harbor “mature” infracommunities shaped by differential environmental conditions and diet in each zone. Parasite species characteristic of sandperch from Buenos Aires Province, which display very low specificity among fish species in this area, have been previously used as biological tags for other host species in these region, confirming therefore their value as tags for stock delineation.