On First Record of a Trematode Parasite of Genus Pleorchis Railliet, 1896 (Digenea: Pleorchiidae Poche, 1926) From Intestine of a Fish, Psettodes erumei (Pleuronectiformes: Psettodidae) From Indian Ocean

The genus Pleorchis Railliet, 1896 is designated to rare digenetic distomes living as parasite in the intestine of marine fishes, having numerous testes arranged in four longitudinal rows in hindbody. A total of 14 species have been attributed to the genus, while another 4 species are no longer considered the member of Pleorchis. In this study a new form is described and we critically overviewed the genus. Collection of two ovigerous specimens was recovered live at Deegha, West Bengal, India (Indian Ocean) from the intestine of a marine fish, Psettodes erumei (Bloch & Schneider) out of 40 examined. The present form differs from all nominal species of the Pleorchis in having 48 testes, unequal anterior intestinal caeca, vitellaria extending from a little anterior of ovary up to hind end of body and an entire unlobed ovary. In view of unique morphoanatomical characters it seems that the present form deserves the status of a new species with a specific name Pleorchis srivastavai n. sp. All known species of genus seems to be rare digeneans as evident by their respective studies and these are important link of marine ecosystem.