Apolocystis perienteron sp. Nov..(Apicomplexa: Monocystinae) a new aseptate gregarine from Pheretima californica (Annelida: Oligochaeta) from Egypt

Abstract

An acephaline gregarine Apolocystis perienteron sp. nov. is described from the coelomic cavity and intestinal coelomic epithelium of earthworms Pheretima californica. Young trophozoites resided inside the coelomic epithelium cells of the intestine. Adult trophozoites (48-72.5 μm in diameter) were found extracellular within coelomic cavity, or attached to either somatic or splanchnic epithelium. Gametocysts were 76-150 μm in minor diameter. Navicular sporocysts (17×10 μm) demonstrated slightly projected flat plugs. The most conspicuous features differentiating the new species from the congeners are encapsulations by the host amoebocytes throughout the gregarine lifespan, and tight attachment of the parasite to the epithelial layer of the host intestine (enteron).