Some observations on the fine structure of trophozoites of the haemogregarine Cyrilia lignieresi (Adeleina: Haemogregarinidae) in erythrocytes of the fish Synbranchus marmoratus (Synbranchidae)

Abstract.

This communication describes the fine structure of trophozoites of the haemogregarine Cyrilia lignieresi (Laveran, 1906) found in erythrocytes of the fresh-water fish Synbranchus marmoratus from Belém, Pará, North Brazil. The parasite possesses the usual structures, such as conoid, rhoptries and micronemes, seen in members of the phylum Apicomplexa. Three structures, however, appear to be characteristic features of this parasite. The parasitophorous vacuole is unusual in containing a large number of spherical bodies. Secondly, some of the dense bodies, which are usually spherical organelles, may appear as elongated structures. Thirdly, peculiar invaginations of the inner membrane appear to divide the parasite into compartments.