On the occurrence of a gregarine parasite (Apicomplexa: Eugregarinorida) from the seminal vesicles of earthworms (Annelida: Oligochaeta) of Bangladesh.

In a survey of the endoparasitic acephaline gregarines in the Satkhira district of Bangladesh, seminal vesicles of earthworm, Metaphire posthuma were found to be infested with a new species of the genus Enterocystis Tsvetcov 1926, Enterocystis elongatum sp. nov. The new species is elongated and measures 55.3-87.8 (67.7 ± 10.3) μm in length and 33.2-37.8 (35.7 ± 1.6) μm in width. Nucleus ovoid and measures 4.4-8.8 (6.6 ± 2.2) μm in length and 4.4-6.6 (5.3 ± 1.1) μm in width. Gametocyst with two unequal sized gametocytes and measures 88.4-101.7 μm (97.9 ± 4.8) μm in length and 77.6-95.0 (86.9 ± 7.7) μm in width. Oocysts ellipsoidal and measure 13.7-19.9 (16.7 ± 2.6) μm in length and 6.6-8.8 (7.6 ± 1.1) μm in width. Prominent association or syzygy is present in life cycle.