Prevalence, intensity and seasonality of Ichthyouris voltagrandensis (Nematoda: Pharyngodonidae) in Myleus tiete (Osteichthyes: Characidae) from Volta Grande Reservoir, Minas Gerais State, Brazil

Abstract

The prevalence, intensity and seasonality of Ichthyouris voltagrandensis (Nematoda), as a parasite of Myleus tiete (Osteichthyes) from Volta Grande Reservoir, Minas Gerais, Brazil, were studied. A total of 91 fishes were captured between April 2000 and April 2001. The highest parasite prevalence (100%) was observed in fish captured in April and August 2000. A prevalence of 86.7%; 86.7% and 93.3% and a mean intensity of 317.4; 112.6 and 123.7 parasites were recorded respectively in December 2000 and February and April 2001. Parasite prevalence was not related to host sex. However, infection was noted in 100% of the female specimens in August and December 2000 and April 2001. The highest mean parasite intensity was found in April and December 2000 and February 2001, pertaining, these last two months, to the rainy season. Moreover, a great number of larvae of the nematode were collected in December 2000. The relation between parasite/host/environment is also discussed.