Jae-Ho Jung

A new soil urostylid ciliate, Birojimia soyaensis nov. spec. was discovered from Soya Island, Incheon, South Korea. The species is described based on live and stained specimen observations, and 18S ribosomal RNA gene sequence analysis. Birojimia soyaensis nov. spec. is characterized by the following features: body slender, elongate, and somewhat twisted; body size in vivo 170–200 μm × 40–50 μm; contractile vacuole located at middle of left cell margin; cortical granules present; 37–48 adoral membranelles; 3 frontal and 2 frontoterminal cirri present; III/2 and buccal cirrus present; midventral pairs only; pretransverse ventral and transverse cirri present; 1 left and 4 right marginal rows, including 3 compound rows; 5 long dorsal kineties with 3 additional shortened kineties in anteriorly compound rows; 8–11 caudal cirri; 53–69 macronuclear nodules; and 2 or 3 micronuclei. Birojimia soyaensis nov. spec. is distinguished from B. terricola by cortical granule size (0.4–1.2 μm in diameter vs. 2–3 μm × 1–2 μm), cortical granule shape (mostly spherical vs. broadly ellipsoid to lenticular, respectively); number of caudal cirri (8–11 vs. 2–7), and number of dorsal bristle rows (8 vs. 6–7). Phylogenetic analysis suggests this new species is most closely related to the genus Hemicycliostyla.

In this study, a new marine urostylid ciliate, Metaurostylopsis antarctica nov. spec. collected from the Antarctic Ocean was investigated using morphological, morphometrical, and molecular methods. Metaurostylopsis antarctica nov. spec. is characterized as follows: slender to ellipsoid form in body shape; two types of cortical granules, ellipsoid large one (type I, yellow-green, 1.5 × 1 μm) in rows along dorsal kineties and cirri, circular small one (type II, colourless, 0.3 μm in diameter) scattered throughout whole body; 19–24 adoral membranelles, 4 frontal cirri, 2–5 frontoterminal cirri, 1 buccal and 2 transverse cirri; 3–5 midventral pairs, 10–15 cirri of midventral row; 1 right and 2 left marginal rows; 3 dorsal kineties; about 43 macronuclear nodules. This new species mainly differs from the congeners by the number of marginal rows (1 vs. 3 or more on right side; 2 vs. 3 or more on left side). In addition, proter’s oral primordium  developed on the right side of the oral cavity (vs. in center of oral cavity), and the rightmost anlage splits into two parts, nam ely, the frontoterminal cirri and a transverse cirrus (vs. only frontoterminal cirri). Inter-specific dissimilarities of the SSU rRNA gene between the congeners range from 3.3 to 4.4%.

We collected an 18-cirri oxytrichid ciliate from the brackish lagoon Songjiho, South Korea, in March 2012. Based on analyses of morphological and molecular attributes, we conclude that it is new genus and species. Pseudocyrtohymenides lacunae nov. gen., nov. spec. has similar morphological attributes to the genus Pseudocyrtohymena, however, the former species lacks caudal cirri. The sequence similarity of the nuclear small subunit ribosomal RNA (SSU rRNA) gene was 99.4% (10 nt difference) between Pseudocyrtohymenides lacunae and Pseudocyrtohymena koreana (type species).

The soil ciliate Anteholosticha rectangula nov. spec. was discovered on King George Island in maritime Antarctica. Morphology and the nuclear SSU rDNA sequence were used to describe and infer the phylogenetic position of the new species. Anteholosticha rectangula is morphologically similar to A. bergeri and A. verrucosa, differing primarily by the morphology of the nuclear apparatus and dorsal kineties, respectively. The morphological features of related species are compared and discussed to confirm the validity of the new species. Molecular phylogenetic tree supports the previously reported polyphyly of the genus Anteholosticha.

A new soil ciliate, Pseudouroleptus jejuensis, was discovered from Jeju Island, South Korea and described based on live observation, protargol impregnation, and SSU rRNA gene sequence analyses. Pseudouroleptus jejuensis differs from other congeneric species mainly by number of dorsal kineties (5 vs. 4). Based on our observation of late dividers, we confirm that the dorsal kinety anlage 3 forms 3 kineties (i.e., dorsal kineties 3–5), and the dorsal kinety anlagen 1–3 form 3–5/1–2/0 caudal cirri, respectively. Our gene trees support the assignment of this new species in Pseudouroleptus to full supporting values.

Brackish water populations of Pinacocoleps pulcher were collected from a lagoon in Korea. This species has never been described using silver impregnation and nuclear small subunit ribosomal RNA (SSU rRNA) gene. In the present study, we investigated the morphological and molecular attributes of P. pulcher using standard methods. The morphology was studied based on observations of live materials, silver-impregnated preparations, and scanning electron microscopy. The morphological characteristics are as follows: body size 80–90 × 40–50 µm in vivo, shape broadly ellipsoidal, body cross-section ellipsoidal, about seven anterior spines and about seven posterior spines, approximately 21 somatic ciliary rows, one macronucleus and one micronucleus, and a single caudal cilium. The SSU rRNA gene tree supports a sister relationship of P. pulcher to the genus Apocoleps, not P. tesselatus.