As comunidades de metazoários parasitos das Abróteas, Urophycis brasiliensis e U. mystacea (Gadiformes: Phycidae): composição, estrutura e uso como ferramentas para a discriminação de estoques populacionais

Abstract

The general objective of this work was to study the composition and structure of parasite communities of codlings (Urophycis brasiliensis and U. mystacea ) and verify its use as a tool for discrimination of population stocks. During the period July 2012 to December 2012, a total of 222 specimens of U. brasiliensis from three localities along the Brazilian coast (Rio de Janeiro, Santa Catarina and Rio Grande do Sul) and one locality from Argentina (Mar Del Plata) were collected and 75 specimens of U. mystacea from two localities off Brazil (Rio de Janeiro and Santa Catarina) . In the first chapter, a species of nematode Cucullanus sp. is described based on specimens collected from U. brasiliensis from Brazil. In the second chapter samples of the two species of Urophycis off Rio de Janeiro and Santa Catarina were analyzed to comparison the structure and composition of their parasite communities. Significant differences were found in relation to mean total abundance and diversity index values in the samples compared in the State of Rio de Janeiro. In samples of U. brasiliensis and U. mystacea from Santa Catarina there are differences in some quantitative characteristics: mean parasite richness, mean total abundance, diversity index values Brillouin and dominance index of Berger-Parker. Similarity analysis made between the parasite communities of U. brasiliensis and U. mystacea of Rio de Janeiro and Santa Catarina, showed a pattern of higher similarity between the parasitic infracommunities of Santa Catarina. The discriminant analysis showed more significant difference between the hosts and between samples of the two states. In the third chapter, four population stocks of U. brasiliensis in the southwest Atlantic Ocean from South America were identified using parasites as biological tags. The discriminant multivariate analysis of parasite infracommunities showed notable differences between the Brazilian and Argentine samples. The similarity between the parasitic infracommunities U. brasiliensis declines with increasing of geographic distance. Different oceanographic conditions and their influence on the distribution of parasites as well as biological aspects such as feeding and reproduction as well as scarce vagility and migration of codlings could be key factors to explain the observed differences.