Uroleptus (Caudiholosticha) stueberi ( Foissner, 1987 ) Li et al., 2017

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

Uroleptus (Caudiholosticha) stueberi ( Foissner, 1987) Li et al., 2017 ( Figure 1 A-J, Table 1-2)

Diagnosis of Indian population: Pellicle flexible, wide-rounded anterior end, slightly narrowed posterior end (without tail). Movement is rapid. Average body size 160 × 60 μm, length-to-width ratio about 3:1. Flattened dorso-ventrally. Consistently two ellipsoidal macronuclear nodules slightly left of body midline in midbody; 1–4 globular micronuclei, roughly 4 μm in diameter, positioned near macronuclear nodules at varying locations. Contractile vacuole at left cellular margin near mid-body. Cortical granules absent. Cytoplasm is colourless and granular. Adoral zone occupies approximately 37% of body length in protargol preparations, composed of 47–56 membranelles. Buccal field deep, wide; Paroral and endoral strongly curved, optically intersecting. Ventral ciliature consists of three enlarged frontal cirri; one buccal cirrus; one parabuccal cirrus; two frontoterminal cirri, placed just behind distal end of adoral zone; 15-20 mid-ventral cirral pairs extending to the level of transverse cirri, right cirri slightly larger than left, invariably three large transverse cirri; one right and one left marginal row with about 24 and 22 cirri, respectively. Dorsal ciliature consists of 7 or 8 dorsal kineties, the first three kineties more or less bipolar and kineties 4–7/8 shortened posteriorly. Three caudal cirri (only one specimen found with caudal cirri stained), one each at rear ends of dorsal kineties 1–3.

Material deposited: Two slides with protargol-impregnated specimens have been deposited at the Protozoology Section (National Zoological Collections), Zoological Survey of India, Kolkata, India, with the accession numbers Pt. 5313 and Pt. 5342.

Occurrence and ecology: Thus far, reports from Austria ( Foissner, 1987), China ( Li et al., 2017) and India (present study). Usually feeds on bacteria and other small ciliates.

Remarks: The Indian population of Uroleptus (Caudiholosticha) stueberi ( Foissner, 1987) Li et al., 2017 has a smaller body size in comparison with other populations. However, other morphometric specifications are mostly overlapping (for detail, please see Table 2).

Figures

Figure 1. Photomicrographs ofUroleptus (Caudiholosticha) stueberi Indian population. (A-C) Live specimens (Ventral views). A. Ventral details with an arrow indicating twisted posterior end due to cover slip pressure. B. Position of contractile vacuole. C. Anterior portion depicting the oral apparatus. (D-H) Protargol impregnated specimens (Ventral views). D, E. Ventral ciliature in two different specimens. Arrows in (E) mark the right mid-ventral cirri at the rear end. F. Small section showing two frontoterminal cirri (arrows), cirrus III/2, and buccal cirrus. G. Nuclear apparatus. Arrows point to two globular micronuclei attached to the macronuclear nodules. H. Note the rounded posterior end (without tail). (I, J) Protargol impregnated specimens (Dorsal views). I. Dorsal kinety rows. J. Specimen showing the position of caudal cirri, each present at the rear ends of the first three dorsal kineties.