Ocorrência de ectoparasitas em Ancistrus sp. em riachos neotropicais no Estado do Paraná

Abstract

In catchment areas, the streams are fundamental elements for the ecosystem, are rich in peculiar yet little known faunas of the high degree of endemism and threatened by uses and urban and rural occupations. One way to assess the environmental quality of a body of water is the parasitic fauna of fish. The small fish act as intermediate hosts for parasites, usually feature a parasitic fauna of different compositions, and the presence of these parasites in an ecosystem is of extreme importance in the population dynamics and community structure. Thus, the objective of this study was to conduct a survey of the fauna of flies present in Ancistrus sp. of two Neotropical streams of Paraná, one located in an environment with features preserved and another located in an urban area. Specifically, it was evaluated the possibility of the occupation of urban environment increase the density of parasites present in Ancistrus sp. Was conducted in both environments the Rapid Assessment Protocol (PAIR), where he showed that the Creek located in the urban area was polluted and the environment was preserved in natural conditions. The specimens were collected by electric fishing, in three collections between June 2014 and March 2015, analyzed the fins and the integument of 22 specimens collected, being 10 fish collected in the Creek and 12 in urban Creek preserved. Of these, 36.36% (8 subjects) presented, being parasites parasited by monogênias 7 on the fins and integument and hirudíneos infected 3 only on the fins. Only the urban stream to submit infected hosts. The Z test carried out showed that the proportion of parasited in urban stream fish (8/12) was significantly higher than the proportion observed in the Creek preserved (0/10). The parasites found are used as indicators of environments, and point out that the quality of the environment where they were is impacted (polluted).