Spirostomum caudatum ( Müller, 1786 ) Delphy, 1939

Ghosh, Subhadeep, Ghosh, Arnab, Bharti, Daizy & Kumar, Santosh, 2022, Four New Records of Ciliated Protists from Lakshadweep, India, Records of the Zoological Survey of India 122 (3), pp. 291-298 : 294-297

4. Spirostomum caudatum ( Müller, 1786) Delphy, 1939 ( Figure 4 A-G)

Brief description of the Indian population (based on three specimens from live and six from protargol impregnation): Body size on average 95 × 20 μm in protargol preparations; shape is elongated cylindrical, slender, posterior end tail-like; anterior end slightly beak like, length to width ratio is about 5:1. A single macronuclear nodule positioned near the mid-body. Contractile vacuole at the posterior end of the body. Cortical granules are arranged in short rows between somatic kineties. On average, there are 16 somatic kineties. The adoral membranelles account for about 43% of body length, with 27 membranelles on average. Circumoral kinety arranged densely in a single row on the right side of adoral zone.

Material deposited: Three slides with protargolimpregnated specimens have been deposited at the National Zoological Collections of the Zoological Survey of India, Kolkata, India, with the following accession numbers: Pt. 5232, Pt 5233, and Pt 5246.

Occurrence and ecology: Found generally in brackish water and terrestrial habitats. It has been reported from Africa , China, Europe and Korea. The Indian population of S. caudatum was isolated from soil samples collected from Kavaratti Island (geographic position: 10°33’16.5”N 72°37’57”E) and Agatti Island (geographic position: 10°50’30.2”N 72°11’09.1”E), Lakshadweep. Usually feeds on bacteria .

Acknowledgement

The authors thank the Director, Zoological Survey of India, for providing the necessary facilities and support to carry out the research. Special thanks to Dr Anjum Nasreen Rizvi, Scientist-E, Zoological Survey of India,

Figures

Figure 4. Photomicrographs of live (A-E) and protargol impregnated (F, G) specimens of Spirostomum caudatum Indian population. A. Specimen showing the body shape. B. Posterior end of specimen showing contractile vacuole. C. Specimen showing cortical granules (arrowhead). D. Position and shape of macronuclear nodule with single globular micronucleus (arrow). E. Dorsal view of anterior end of specimen showing dorsal ridges, F.Specimen showing elliptical macronuclear nodule, G. Specimen showing adoral zone of membranelles and somatic kineties. AZM, adoral zone membranelles; CV, contractile vacuole; DR, dorsal ridge; Ma - Macronuclear nodule; SK - Somatic Kinety. Scale bars: 50 μm.