Estudos parasitológicos do tambaqui curumim Colossoma macropomum (Cuvier, 1818) (Osteichthyes: Characiformes) criado em tanques-rede sob altas densidades de estocagem no lago Paru, rio Solimões, Amazônia Central, Brasil

Abstract

The purpose of the present study is to monitor the parasite fauna of the tambaqui curumim (Colossoma macropomum), farmed in net cages on lake Paru, in the township of Manacapuru, Amazonas State. Ninety-three 93 tambaquis were examined from 22/09/2004 to 22/12/2004. At first 30 fish were analysed before being put into the net cages, which was carried out in order to get to know the health state of the animals before beginning the experiment. Then, 63 tambaquis which were conditioned in three different stock densities (50, 100 and 150 fish /m3) were examined in 9 net cages with a volumed equal to 6 m3 of flooded area. For reposition of the removed specimens 30 more fish were placed in every cage before starting the experiment. Seven fish were taken out from each stock density every month totalling 21 fish in each sampling. A drawing of lots was carried out before the sampling in order to determine which cages would be sampled each month, and there was no cage being repeated in any set. Fish were hauled alive to the laboratory where they underwent necropsies. The found parasites were collected, counted, fixed and identified. The following monogenoid species: Anacanthorus spathulatus, Notozothecium janauachensis, Linguadactyloides brinckmanni, New Genus 1 and New Genus 2 were found infesting the skin, gills, and nasal cavities of tambaqui. The statistical analysis showed no significant difference between stock densities and parasite intensity. Anacanthorus spathulatus was the species which presented the highest parasite indexes and the most abundant one with 84.7% of all collected parasites.