ABSTRACT

A biodiversity survey of aseptate gregarines in earthworm hosts in the Calcutta district of West Bengal State revealed the existence of a new species of aseptate gregarine under the genus Monocystis Stein, 1848. The monocystid gregarines obtained from the earthworm host, Eutyphoeus quaripapillatus Michelsen, 1907 have been identified as a new species. The mucron was indistinct. The gamonts are elongated, ovoid, have a hood like structure at the anterior end and measure 150.1-212.4 (188.1± 2.1) μm x 66.1-112.1 (72.3 ± 1.1) μm. The gametocysts are ellipsoid and measure 92.3– 136.3μm (111.2 ± 2.1) × 78.3–114.4 μm (82.6 ± 3.6) μm. Prominent syzygy was apparent. Oocysts are navicular, measuring 14.1–22.3 (18.1 ± 3.2) μm × 9.1–15.2 (11.9 ± 1.1) μm.