Helminth parasites of Cichla ocellaris Bloch & Schneider, 1801 collected in the Jacaré-Pepira River, São Paulo state, Brazil.

Cichla ocellaris is native to the Amazon region. It is popularly known as tucunaré and is widely used for human consumption. It is difficult to breed in captivity due to its highly predatory habits, it is considered symbolic of sport fishing in Brazil. This study aimed to make a qualitative and quantitative survey of helminth parasites of C. ocellaris. Thirty specimens from the Jacaré-Pepira River, located in the municipality of Ibitinga, in the interior of the state of São Paulo, were studied. The river is located 13 km from the urban area and at an altitude of approximately 600 m. A total of four taxa of metazoan parasites were collected and identified in Cestoda, Digenea, Monogenea and Nematoda. The cestoid Proteocephalus macrophallus presented the highest prevalence (63.3%) and had the greatest abundance and intensity, being found only in the intestine and stomach. The parasites found showed a significant positive correlation between the total body length of the hosts and the prevalence, as did the weight. This is the first study of helminth parasites of this host conducted in the Jacaré-Pepira River and the first record of a new location for P. macrophallus.