The gregarine Cephaloidophora communis
was observed for the first time in Brazil in the barnacles Euraphia rhyzophorae
collected in Angra dos Reis, Rio de Janeiro, Brazil, between 1990 and 1996. Histological
studies showed growth phases of the parasite in specific parts of the digestive
system. The intracellular forms occurred in the vacuoles of the intestinal cells.
Syzygy was frequent, and the most common form following syzygy was cylindrical,
with a single membrane. The cytoplasm of the gregarines was always irregular,
dense, and occasionally presenting a dark stoch area.