Observations sur la structure et l’utrastructure du cilié Myxophthirus anomalocardiae gen.nov., sp.nov. (Scuticociliatida, Thigmophryidae), parasite du bivalve Anomalocardia brasiliana Gmelin, 1791

Abstract

We describe a new genus of Thigmophryidae which is characterized by the cytoskeleton of the thigmotactic area, the median position of the buccal cavity with paroral and adorai organelles. On the locomotive cortex, the kinetosomes are in pairs and ciliated with a median parasomal sac. With the posterior kinetosome are associated: a) a kinetodesmal fibre, b) a ribbon of postciliary fibres, c) a ribbon of transverse microtubules, d) a transverse tractus, e) a microfibrillar tractus. Two or three microtubules run along each kinety. On the thigmotactic cortex, each posterior kinetosome is associated with a kinetodesmal fibre, a postciliary ribbon, a ribbon of transverse fibres and a transverse tractus. Moreover, a skeletal fibre with periodic structure, at the proximal end of the kinetosomes, runs along the left of each kinety. The endoplasm is full of host cells or organisms of the palleal cavity. The ultrastructure of the ciliate is typical of Scuticociliates, just as the buccal organization, with presence of a scuticus. The paroral membrane is a row of dyads with a development of a microfibrillar network as at the level of the single adoral organelle the kinetosomes of which have postciliary fibres.