Endoparasite diversity and liver alterations in Hoplerythrinus unitaeniatus and Cichlasoma bimaculatum in a quilombola area in Maranhão, Brazil

Diversidade endoparasitária e alterações hepáticas em Hoplerythrinus unitaeniatus e Cichlasoma bimaculatum de área quilombola maranhense, Brasil

Abstract

Our aim was to assess endoparasite diversity and liver alterations in Hoplerythrinus unitaeniatus (jeju) and Cichlasoma bimaculatum (acará preto) in a quilombola area in Maranhão, Brazil. For this, 21 H. unitaeniatus and 21 C. bimaculatum were caught in a natural environment and transported to a laboratory. After these had been euthanized, endoparasites were collected and identified. Liver alterations were evaluated histological analysis based on the severity of each lesion: stage I, organ functioning not compromised; stage II, more severe lesions that impair normal functioning of the organs; and stage III, very severe and irreversible lesions. Among the fish evaluated, 71.43% H. unitaeniatus and 61.90% C. bimaculatum were parasitized. Contracaecum sp. was found in both species; while acanthocephalans, only in H. unitaeniatus. The alterations were vacuolization, nucleus in the cell periphery, deformation of the cell outline, melanomacrophage center, hyperemia, cytoplasmic degeneration and nuclear vacuolization. Through calculating a histological alteration index, it was found that 26.19% of the specimens presented lesions in stage I; 38.09% lesions in stage II and 9.52% lesions in stage III. It was concluded that there is high prevalence of Contracaecum sp. and that the liver lesions may be adaptive responses by the fish to endoparasitic infection.

Keywords:
Native fish; traditional communities; Anisakidae; histology