Eobathynella gwangjuensis sp. nov., a new species of Parabathynellidae (Crustacea, Bathynellacea) from South Korea.

A new species of Parabathynellidae (Crustacea, Bathynellacea) was found in the interstitial groundwater of the Yeongsangang River in South Korea. The new species belongs to the genus Eobathynella Birstein and Ljovuschkin, 1964, which previously comprised six species, including two from South Korea. Eobathynella gwangjuensis sp. nov. can be distinguished from its congeners by the absence of setae on the last segment of the thoracopod endopods and by the presence of three finger-like setae on the exopod of male thoracopod VIII. In addition, we present gene sequences of the nuclear 18S rDNA and the mitochondrial cytochrome c oxidase subunit 1 of the new species, which was used to infer phylogenetic relationships with closely related species.

A new species of Hangangbathynella (Crustacea, Bathynellacea, Parabathynellidae) from South Korea.

A new parabathynellid bathynellacean species, Hangangbathynella mihoensis sp. nov., was found in the groundwater of the Geumgang River in South Korea. This is the first report of Hangangbathynella from a tributary of the Geumgang River. All previously-reported species were found in the Hangang River and the origins of the two rivers are distinct from each other. The new species can be distinguished from its congeners by the two-segmented mandibular palp and the absence of epipods on thoracopod II. In this study, we provide a description of the new species and an identification table for the genus Hangangbathynella. In addition, we obtained partial sequences of the mitochondrial cytochrome c oxidase subunit I gene for DNA barcoding.

Antarctic population of Anteholosticha sigmoidea (Foissner, 1982) Berger, 2003 (Ciliophora: Urostylidae) with notes on its phylogenetic position.

Anteholosticha sigmoidea (Foissner, 1982) Berger, 2003 was isolated from a wet soil sample collected on King George Island, Antarctica. Morphological observations and molecular phylogenetic analyses based on the gene sequences of small subunit ribosomal RNA (18S rRNA) were used to identify the species. Anteholosticha sigmoidea can be divided into two groups: group I (three populations described by Foissner 1982) and group II (described by Foissner 1984) based on the morphological differences. Group I differs from group II by the length of the midventral complex (65.1% vs. 52.5% of the cell length), the number of adoral membranelles (25-28 vs. 16-24), and the number of dorsal bristles in kinety 1 (16 bristles vs. nine bristles). Group I differs from the Antarctica population by the absence/presence of the collecting canals of the contractile vacuole and the number of macronuclear nodules (6-12 vs. 13-19). Group II differs from the Antarctica population by the number of macronuclear nodules (five to nine vs. 13-19); the arrangement of cortical granules (forming longitudinal rows vs. irregularly distributed); the length of the midventral complex (64.7% vs. 53.8% of cell length). In the phylogenetic analyses, A. sigmoidea was not nested with any species, and the gene tree indicated polyphyly of the genus Anteholosticha.

The complete mitochondrial genome of the Antarctic marine triclad, Obrimoposthia Wandeli (Platyhelminthes, Tricladida, Maricola).

For the first time, we report the complete mitochondrial genome (mitogenome) sequence of the marine triclad species, Obrimoposthia wandeli. The complete mitogenome of O. wandeli was 15,185 bp in length, contains 12 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), and 2 ribosomal RNAs (rRNAs). Compared to previously reported gene orders from the order Tricladida, O. wandeli had unique gene order. We constructed a phylogenetic tree based on the mitogenomes belonging to Rhabdocoela, Polycladida, and Tricladida and confirmed that O. wandeli is located in the basal position in the Tricladida.

The complete mitochondrial genome of the South American freshwater crayfish, Parastacus nicoleti (Crustacea, Decapoda, Parastacidae).

We determined the complete mitochondrial genome (mitogenome) sequence of a Chilean freshwater crayfish, Parastacus nicoleti (Philippi, 1882). This is the first complete mitogenome sequence of a non-Australian crayfish belonging to the family Parastacidae. The complete mitogenome of P. nicoleti is 20,894 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs) and a putative control region (CR). In the phylogenetic analysis, freshwater crayfishes were clearly divided into two monophyly groups, Northern and Southern Hemisphere groups. The P. nicoleti exhibited a sister-group relationship with all other Australian parastacid crayfishes.