Ectoparasites in hibrid tambatinga from net cage fish farm in the Amapá State (Brazil)

Abstract

This study evaluated the parasitic infestations in hybrid tambatinga (Colossoma macropomum and Piaractus brachypomus) farmed in net-cage in the State of Amapá, Northern Brazil. The mouth, operculum, gills and gastrointestinal tract of 50 fish were examined to collection of protozoans and metazoans. Among the examined fish, 60% had the gills infected by Ichthyophthirius multifiliis (Ciliophora), Piscinoodinium pillulare (Dinoflagellida) and by Mymarothecium boegeri (Monogenoidea). The low parasitic community consisted of high parasitism by protozoans and low parasitism by monogenoideas, which occurred in 10% of the hosts. Thus, there was dominance of I. multifiliis and P. pillulare, both parasites with aggregated dispersion in the hosts. The parasitism found have not effect in the body condition of hosts, because the relative condition factor (Kn) of parasitized (Kn = 0.999 ± 0.008) and non-parasitized (Kn = 1.000 ± 0.018) was similar, probably due to moderate infestation levels. This first study on parasitic infestation levels in hybrids tambatinga from Brazil showed a low species richness of parasites.