Pseudouroleptus jejuensis, Jung & Park & Min, 2014

Jung, Jae Ho, Park, Kyung Min & Min, Gi Sik, 2014, Morphology and Molecular Phylogeny of Pseudouroleptus jejuensis nov. spec., a New Soil Ciliate (Ciliophora, Spirotrichea) from South Korea, Acta Protozoologica 53 (2), pp. 195-206 : 196-201

Description of Pseudouroleptus jejuensis ( Figs 1–6 ;

Table 1)

Diagnosis: Size in vivo about 260 × 45 µm. Cylindrical to elliptical with tail-like posterior portion. Two macronuclear nodules and 3 micronuclei on average. Contractile vacuole slightly above mid-body. Cortical granules densely arranged in longitudinal stripes, colourless, spherical to globular, about 1.3 µm in diameter. On average 56 adoral membranelles, 59 cirri each in right and left marginal row, 52 cirri in right frontoventral row, 63 cirri in left frontoventral row, 1 buccal cirrus, 1 cirrus behind right frontal cirrus, 1 postperistomial cirrus, and 5 dorsal kineties. Dorsal kinety 3 multiple-fragmented without forming caudal cirri.

Type locality: Soil with the litter of tree, Celtis sp. , from Jeju Island, South Korea, N33°18′22″ E126°15′42″ .

Type material: One holotype slide (NIBRPR-0000104240) and seven paratype slides (NIBRPR-0000104241–NIBRPR0000104247) with protargol-impregnated specimens including some dividers have been deposited in the National Institute of Biological Resources ( NIBR), South Korea. Relevant specimens have been marked by circles on the bottom of the slides .

Etymology: Named after the island on which the specimens were discovered.

Description ( Figs 1–3 ): Size in vivo 220–300 × 35–55 µm in raw cultures, usually about 260 × 45 µm in vivo ( Table 1); posterior body portion usually slightly curved rightwards in protargol preparations. Length:width ratio in vivo moderately variable ([5.4– 6.3]:1); body length slightly shorter in protargol-impregnated specimens because of curved body shape (on average 4.8:1). Shape cylindrical to elliptical with tail-like posterior portion, i.e., left and right margin almost parallel, and posterior body part at three-quarters of cell distinctly narrower than mid-body part that forms a tail-like body shape ( Figs 1A, B, D , 2A, H); body shape straight in fast-moving behavior and slight-sigmoidal when gliding for feeding ( Fig. 2H). Invariably 2 macronuclear nodules on left of midline behind buccal vertex; ellipsoidal, on average 25 × 8 µm in protargol-impregnated specimens. Two to four micronuclei near to or overlapped with macronuclear nodules, ellipsoidal, on average 6 × 4 µm in silver preparations ( Figs 1A , 2D, 3I ). Contractile vacuole slightly above mid-body, without distinct collecting canals, on average 18 × 13 µm when fully extended ( Figs 1A , 2A). Cortex flex- ible; cortical granules densely arranged in narrow vertical stripes, colourless, about 1.3 µm in diameter ( Figs 1B, C , 2E, G, I, J). Cytoplasm colourless, with 8–16 µm-sized food vacuoles usually in posterior half of cell. Feeds on bacteria, testate amoebae, diatoms, and organic soil particles. Glides moderately fast on the bottom of Petri dish.

All cirri, except for frontal and buccal cirri, 15–20 µm long in vivo; frontal and buccal cirri 18–25 µm long in vivo, and composed of distinctly more basal bodies than other cirri ( Figs 1F , 3B ). Marginal and frontoventral cirri evenly spaced within the rows, and similarsized, but intervals and size becoming slightly wider and smaller, respectively, at posterior body portion ( Fig. 1F ). Right marginal and right frontoterminal row commence on dorsal side. Cirral pattern highly similar to that of type species P. caudatus (for morphometric data of these cirri, see Table 1).

Dorsal bristles 3–4 µm long in vivo, 5 dorsal kineties; dorsal kinety 3 multiple-fragmented and not associated with forming caudal cirri; dikinetids of dorsal kinety 4 sparsely arranged in a row and rarely appearing in 2 rows, because of the scattered distribution pattern, but considered here as a single row ( Figs 1E , 3D–F ). Four to seven caudal cirri developed from dorsal kineties 1 and 2 ( Figs 3G, H, J ). Late dividers observed and support the above features ( Figs 3E, F, J ; see ontogenesis section).

Oral apparatus oxytrichid pattern ( Berger 1999), i.e., undulating membranes Oxytricha pattern and adoral zone of membranelles 30% of body length on average ( Table 1); undulating membranes optical crossing at posterior half; buccal lip distinct ( Fig. 2C) and very likely angular (for review of oral apparatus, see Foissner and Al-Rasheid (2006)). Adoral zone of membranelles shaped like a question mark, largest membranelles about 10 µm width in vivo and in protargol impregnation; cilia about 15–20 µm long in vivo.

Figures

Figs 1A–F. Pseudouroleptus jejuensis from life (A–D) and after protargol impregnation (E, F). A – ventral view of a representative specimen, arrow indicates contractile vacuole; B, C – arrangement of cortical granules on dorsal side (B) and optical section (C); D – ventral view of a specimen gliding for feed, showing a slightly curved body shape;E, F – dorsal (E) and ventral views (F) of the holotype specimen. Arrow in F denotes postperistomial ventral cirrus.AZM – adoral zone of membranelles, BC – buccal cirrus, CC – caudal cirri, 1–5 – dorsal kineties 1–5, EM – endoral membrane, G – cortical granules, LFVR – left frontoventral row, LMR – left marginal row, PM – paroral membrane, RFVR – right frontoventral row, RMR – right marginal row. Scale bars: 100 μm.

Figs 3A–J. Pseudouroleptus jejuensis during interphase (A–D, G–I) and ontogenesis (E, F, J) after protargol impregnation. A–C – dorsal view (A) and ventral views (B, C), arrow indicates postperistomial cirrus; D – dorsal view showing basal bodies (asterisks) in dorsal kinety 4; E, F – dorsal views of late dividers, asterisks denote dorsal kinety 4 developed by multiple fragmentation of dorsal kinety anlage (DKA) 3; G, H, J – dorsal views showing caudal cirri developed from DKA 1, 2 while DKA 3 does not participate in the formation of these caudal cirri during ontogenesis; I – ventral view showing macronuclear nodules and micronuclei. CC – caudal cirri, MA – macronuclear nodules, MI – micronuclei. Scale bars: 100 μm.