Entosiphon sulcatum (Dujardin, 1841) Stein, 1878

Bharti, Daizy & Kumar, Santosh, 2019, Two freshwater flagellates from the Mahananda Wildlife Sanctuary, West Bengal, Records of the Zoological Survey of India 119 (4), pp. 451-455 : 452

2. Entosiphon sulcatum (Dujardin, 1841) Stein, 1878 (Figure

2A-F)

Diagnosis of the Indian population (Data based on 5 specimens): Size about 30 × 15 μm in stained preparations; shape ovoid, flattened dorsoventrally, slightly narrowed at the posterior body end, body with deep grooves. Nucleus near body midline, about 10-13 μm from anterior body end with diameter about 5-7 μm, nucleolus visible in stained preparation with irregular shape and length about 4-6 μm. Crystals and granules were observed on the surface in live observations.Cytoplasm with food vacuoles and lipid droplets. A vacuole present in the anterior 2/3 of the cell. Feeding organelles conspicuous extending from anterior to nearly posterior body end, conical in shape with capability of protruding and withdrawing. Two flagella emerging out from a prominent small groove at the anterior body end, one flagellum slightly shorter than the other. Some specimens observed with very short flagella.

Material deposited: A slide including protargolimpregnated specimens have been deposited at the National Zoological Collections of the Zoological Survey of India, Kolkata, India with the following accession numbers Pt. 4506/1 (specimens marked with black ink circles on the slide).

Occurrence and ecology: The species Entosiphon sulcatum is rather common in freshwater ecosystems and has a cosmopolitan distribution. The present study reports its presence from water sample collected from a small pond near Helay Khola watch tower, Lower Ghoramara Block, Sevok Beat, North Range , Mahananda Wildlife Sanctuary, West Bengal (26°50'671"N 88°26'293"E). It feed on bacteria and detritus .