Climacostomum virens (Ehrenberg, 1838) Stein, 1859

Ghosh, Arnab, Krishnan, Sreerag, Bharti, Daizy, Pathania, Prakash Chand & Kumar, Santosh, 2023, Morphological characterization of two newly recorded ciliates Uroleptus (Caudiholosticha) stueberi (Foissner, 1987) Li et al., 2017 and Climacostomum virens (Ehrenberg, 1838) Stein, 1859 from India, Records of the Zoological Survey of India 123 (2), pp. 143-150 : 144-148

Climacostomum virens (Ehrenberg, 1838) Stein, 1859 ( Figure 2 A-J, Table 3)

Diagnosis of Indian population: Body shape oval, slightly tilted to the left, posterior end broadly rounded. Movement Abbreviations: AZM, adoral zone membranelles, BC, buccal cirrus, CC, caudal cirri, CV, contractile vacuole, E, endoral, FC, frontal cirri, LM, left marginal cirral row, Ma, macronuclear nodules, Mi, micronuclei, MVP, mid-ventral cirral pair, P, paroral, PK, peristomial kinety, RM, right marginal row, TC, transverse cirrus, III/2, cirrus III/2 (= Parabuccal cirrus), 1-3, dorsal kineties, 4-7, dorsomarginal kineties. Scale bars: 40 μm (A-E, G, H), 30 μm (I), 10 μm (J).

Abbreviations: AZM, adoral zone membranelles, CG, cortical granules, CT, cytopharyngeal tube, FV, food vacuole, Ma, macronucleus, SK, somatic kinety. Scale bars: 75 μm (A, B, G, H), 50 μm (E, F), 20 μm (I, J).

is relatively slow, mainly crawling on the bottom of the Petri dish. Body size 156–349 × 92–185 μm in protargol preparations, length-to-width ratio about 1.7:1. Usually single (some specimens have two) long ribbon-like coiled macronucleus. On average 13 micronuclei scattered mainly near the macronucleus. Single contractile vacuole at the posterior body end. Cortical granules are spherical, colourless, densely packed in the cortex, arranged in between somatic kineties. Cytoplasm colourless, and contains food vacuoles and granules. About 46 somatic kineties are arranged in oblique rows. Adoral zone of membranelles with 42–87membranelles, curved rightward forming a hook-shaped structure, begins right of the oral field and extends to the cytopharynx. About 42 cilia in peristomial kineties run into the cytopharyngeal tube.

Material deposited: One slide with protargol-impregnated specimens has been deposited at the Protozoology Section (National Zoological Collections), Zoological Survey of India, Kolkata, India, with the accession number Pt. 5263.

Occurrence and ecology: A cosmopolitan species present in brackish and freshwater habitats. It has been reported

Figures

Figure 2. Photomicrographs of live (A-F) and protargol-impregnated (G-J) specimens of Climacostomum virens Indian population. A. Specimen showing the body shape. B. Specimen showing the position of the contractile vacuole (arrow). C. Food vacuole. D. Cortical granules, densely placed in between somatic kineties. E. Oral apparatus of the specimen. The arrowhead in (E) denotes the peristomial field. F. Close view of somatic kineties. G. Ventral view of specimens, showing nuclear apparatus and somatic kinety rows. H. Dorsal view of the specimen showing somatic kineties. I. Oral apparatus of the specimen showing peristomial kineties. J. Enlarged view of the coiled macronucleus, arrows point to the small micronuclei.