Análise comparativa das comunidades de metazoários endoparasitas de Metynnis lippincottianus (Cope, 1870) (Characidae) em dois diferentes ecossistemas aquáticos influenciados pela Usina Hidrelétrica de Rosana.

Abstract

Brazil has a rich hydrografy, resulting in great diversity of fishes. Among these fishes species was developed an ichthyoparasitological study with Metynnis lippincottianus (Cope, 1870) (Characidae) in two places, showing different degrees of impact due to Hydro electric plant; The upper Parana River floodplain (low degree of impact) and Paranapanema tributaries (Corvo and Guairacá rivers, high degree of impact). Among 84 hosts collected, 44 in the floodplain (from March of 2006 to December 2007 ) and 40 in the tributaries (from April to August ), the prevalence was 77.4% (72.7% in the floodplain and 82.5% in the tributaries). One digenetic species, Dadayus pacupeva, and four nematoda, Spinoxyuris oxydoras, Contracaecum sp. (larval stage), Procamallanus (Spirocamallanus) inopinatus e Raphidascaris (Sprentascaris) mahnerti were identified (new records in M. lippincottianus). The parasites showed clumped distribution. Several central and secondary species were found, suggesting stability in the parasite community. There was no correlation between parasitism and sex host. The stages of sexual maturation, relative conditional factor, locality, standard length of host showed correlation with prevalence and abundance of some parasites species. There was no correlation between parasitic diversity with sex host in both places, however, was correlated with standard length.