This is the report of the occurrence of Lernaea cyprinacea (Linnaeus, 1758) parasitizing the native fish species Steindachnerina insculpta (Fernández-Yépez, 1948). Sixty host specimens were captured in Taquari River, municipality of Taquarituba, São Paulo State, Brazil. Three hosts were infested with L. cyprinacea. The infestation rate was low, with one parasite per host. Proper management should be applied in fish farms to prevent the escape of this parasite, and its consequent spread.

A study on the nematode parasites of nine species of freshwater fishes from Peixe River São Paulo, State, Brazil. was conducted. Fish were ollected between February 2010 and March 2011 and the following species were found: Procamallanus (Spirocamallanus)inopinatus and Contracaecum sp. (larvae) in Astyanax altiparanae; Contracaecum sp. (larvae), Dioctophyma renale (larvae), Philometroides caudata, P. (Spirocamallanus) inopinatus, P. (Spirocamallanus) neocaballeroi (larvae) and P. (Spirocamallanus) saofranciscensis in Acestrorhynchus lacustris; Contracaecum sp. (larvae), Guyanema sp., Hysterothylacium sp. (larvae) and Icthyouris sp. in Cyphocharax modestus; Contracaecum sp. (larvae), Cosmoxynemoides aguirrei and Pharyngodonidae gen. sp. in C. nagelii; Dioctophyma renale (larvae), Hysterothylacium sp. (larvae) and Rhabdochona sp. in Gymnotus sylvius; Capillariidae gen. sp. in Hoplosternum ...