Ecological aspects of metazoan parasites of Astyanax altiparanae garutti & britski, 2000 (characidae) of the upper Paraná river floodplain, Brazil

Abstract

One hundred and ninety specimens of Astyanax altiparanae Garutti & Britski, 2000 were collected in the upper Paraná River floodplain, Brazil, between February 2000 and November 2001, with the aim to identify the parasite fauna and to observe the ecological aspects of metazoan parasites of A. altiparanae. A total of 3,908 parasite specimens of 23 species were collected. The metacercarian Ascocotyle (Ascocotyle) tenuicollis Price, 1935 was the most abundant and the acanthocephalan Quadrigyrus sp. was the most prevalent. According to degree of importance, all species were classified as satellites. The community of metazoan parasites of A. altiparanae showed a typical over-dispersion pattern. The diversity mean was H = 0.1492 ± 0.2406. Ascocotyle (A.) tenuicollis had a significant correlation between standard length and parasitism abundance and prevalence. The monogenean Amphitecium sp. had a significant correlation only between parasitism prevalence and host length classes. No significant differences in abundance and prevalence of parasitism, by sex, were observed.