Caracterização morfológica e molecular de helmintos de piau coletados na bacia do Rio Tocantins .

Abstract

Parasitic diseases represent one of the most important problems in fish production due to the decline of infected carcasses and public health problems due to the risk of zoonoses, being scarce studies on fish parasites. This study identified the parasites, using morphological and molecular techniques, and determined infection indicators, of the collared Laemolyta garmani, Leporinus tigrinus, Argonectes robertsi and Hemiodus unimaculatus the Tocantins River. Fifty four fish were adquired between August and October 2015, anesthetized, euthanized and submitted to necropsy, according to the Brazilian Good Practice Guide for Animal Euthanasy of the Federal Board of Veterinary Medicine. The body surface, gills, abdominal cavity, heart, liver, gallbladder, spleen, stomach, intestines, gonads and swimming bladder were analyzed for the presence of parasites. A total of 461 specimens of parasites were identified in 59.26% (32/54) of the fish collected. L. tigrinus presented infection by two species of helminths, Goezia leporini, found in 16% of the animals and Rondotrema microvitellarum in 8%. L. garmani presented infection by Spinitectus rodolphiheringi (4%), Brasilnema sp. (28%), R. microvitellarum (16%) and Culuwiya sp. (8%). The study reported for the first time the occurrence of the nematode Spinitectus rodolphiheringi in the intestine of A. robertsi, with a prevalence of 7%, as well the confirmation of the taxonomic classification by mitochondrial cytochrome C subunit I phylogenetic analysis. Procamallanus inopitanus and Neochinorhychus sp. were found in the intestine of H. unimaculatus. The identification of the parasites and determination of their infection indicators allow to establishing appropriate management methods, reducing infections in the animals, avoiding a decrease in the commercial value and negative impact on the productive chain.