Histologic sections of 120 mussels Perna perna (Linnaeus, 1758), from Itaipu Lagoon, Niterói, State of Rio de Janeiro, Brazil, were examined for the presence of parasites and lesions during a period of 12 months. Ninety mussels showed five different pathological processes: bucephalosis, protozoan Nematopsis sp., basophilic non-specific inclusions, parasitic encapsulations and ctenidia epithelial cysts. Fifty animals presented two or more pathological processes at the same time.
Mussel; Perna perna; bivalve; parasite; histopathology
