Unprecedented Report of the Calanoid Copepod Acartiella faoensis Khalaf, 1991 from the Estuarine Waters of the Lower-Middle Stretch of River Hooghly, West Bengal, India

Acartiella faoensis, previously known as Acartia (Acartiella) faoensis, is a calanoid copepod which was observed during a biodiversity survey, during July-August of 2018, on the lower-middle stretch of the Hooghly River (upper reaches of Hooghly estuary). The species is reported for the first time from the aforementioned locality as well as anywhere from the eastern India and perhaps the entire country. Individuals belonging to both the sexes have been collected and studied. The observed species is native to Khour-Abdullah and Khor Al-Zubair waters of the Northwestern Gulf of Arabia as evidenced by earlier works and its appearance in the presently reported location is of great ecological significance. This account deals with the description of the species using compound microscopes and drawings made by using camera-Lucida, to be used as reference in future works.