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The influence of parasitism on the relative condition factor (Kn) of Metynnis lippincottianus (Characidae) from two aquatic environments: the upper Parana river floodplain and Corvo and Guairacá rivers, Brazil

2009; Editora da Universidade Estadual de Maringá (Eduem); Volume: 32; Issue: 1 Linguagem: Inglês

10.4025/actascibiolsci.v32i1.3668

1807-863X

Luís Henrique de Aquino Moreira, Fábio Hideki Yamada, Tiago Lopes Ceschini, Ricardo Massato Takemoto, Gilberto Cezar Pavanelli,

Fish Biology and Ecology Studies

The study analyzed 84 specimens of Metynnis lippincottianus (Cope, 1870) (Characidae) from two environments with different degrees of impact due to a hydroeletric plant; 44 hosts from the upper Parana river floodplain (low degree of impact) and 40 from Paranapanema tributaries (Corvo and Guairacá rivers, high degree of impact).The prevalence found, among the total collected fishes, was 77.4%.One digenetic species, Dadayus pacupeva, and four nematodes, Spinoxyuris oxydoras, Contracaecum sp.(larval stage), Procamallanus (Spirocamallanus) inopinatus and Raphidascaris (Sprentascaris) mahnerti were identified.In the floodplain, the fishes parasitized by D. pacupeva and S. oxydoras presented better relative condition factor (Kn) than non-parasitized species.Positive correlation between Kn and abundance of these parasites was found in the same area.In the tributaries, the Kn did not differ significantly between parasitized an non-parasitized fishes, not even correlation with abundance of any parasite found.