A new genus and species of Sphyrapodidae (Crustacea, Peracarida, Tanaidacea) from the southern coast of the South Korea.

Wandogarida canaliculagen. n et sp. n. (Tanaidacea, Sphyrapodidae) is described from the southern coast of Korea (NW Pacific). The genus is included in the subfamily Sphyrapodinae Gutu, 1980 by having a mandible lacking a palp. It has a close affinity with the genus Poligarida Bamber & Marshall, 2013 in the third pereonite having lateral pointed apophyses, the antennule of males with fringes of aesthetascs on articles 1 and 2 of the outer flagellum and the antenna with an elongate article 2. However, it is distinguished from Poligarida by having a maxillular palp. Wandogaridagen. n. can be differentiated from other genera within the subfamily Sphyrapodinae by the unique shape characterised by the male's antennule article 1 with its rough denticles and a deep groove, pleonites each with a ventral hyposphenium, the maxillule with uniarticulate palp and the presence of prominent sexual dimorphism in the mouthparts. An identification key to the five genera of the subfamily Sphyrapodinae is presented.

A new species of the genus Hexapleomera Dudich, 1931 from the South Korea, with molecular evidence (Crustacea, Tanaidacea, Tanaididae).

Two populations of new species are described for Hexapleomera Dudich, 1931 from the southeastern coast and Jeju island of South Korea (north west Pacific). The specimens were collected using a light trap set overnight at the entrance near a pier or harbour. Hexapleomera ulsanasp. n. is clearly differentiated from other species in the genus by the uropod with five articles, a maxillule palp with four distal setae, the maxilliped coxa with three proximal setae, the epignath with short and blunt spiniform seta, the propodus of pereopods 2-3 with three ventral setae, and the maxilla with a rugged shape of the distal margin. Differences of mitochondrial cytochrome c oxidase subunit I (mtCOI) gene observed between two populations of H. ulsana from different regions (Ulsan and Jeju Island) and between H. ulsana and H. urashima (Japan) were 1.1 % and 32.4 %, respectively. Two genetically-close populations differed in the setae on pleopod 3, the proximal setae on the maxilliped coxa, and the ventral setae on pereopods 2-3, which showed that geographical distance affected the morphological divergence. In addition, a comprehensive comparison with previous records of Hexapleomera was conducted and close examinations on the appendages, known to have morphological variations between the individuals of one species and/or between different genders, were carried out based on new species and discussed herein.

A new Notomastus (Annelida, Capitellidae) species from Korean waters, with genetic comparison based on three gene markers.

Notomastus koreanussp. n., collected from the sublittoral muddy bottom of Korean waters, is described as a new species. The Korean new species closely resembles N. torquatus Hutchings & Rainer, 1979 in the chaetal arrangement and the details of abdominal segments, but differs in the position of genital pores and the absence of eyes. DNA sequences (mtCOI, 16S rRNA, and histone H3) of the new species were compared with all the available sequences of Notomastus species in the GenBank database. Three genes showed significant genetic differences between the new species and its congeners (COI: 51.2%, 16S: 38.1-47.3%, H3: 3.7-9.3%). This study also includes a comprehensive comparison of the new Korean Notomastus species with its most closely similar species, based on the morphological and genetic results.

Two new species in the genus Phoxokalliapseudes Drumm & Heard, 2011 (Crustacea: Tanaidacea: Kalliapseudidae) from the southwestern and southern coasts of Korea.

Two new species of Phoxokalliapseudes from the southwestern and southern coasts of Korea are described. Phoxokalliapseudes aculeatus n. sp. is distinguished by the two robust spiniform setae on the ventral margin of the cheliped basis, pereonites 2-6 each with a hyposphaenium and small spinules, and the setiferous lobe on the mandibles with different numbers of serrated spiniform setae in the female and male (five and six, respectively). Phoxokalliapseudes cinctus n. sp. can be distinguished by the propodus of the male cheliped with the largest length to width ratio (2.5: 1) of the genus, and the fixed finger with small denticles on the cutting edge and near the insertion of the dactylus. The female has the largest dactylus to propodus length ratio of pereopod 6 in the genus. Only four species of Phoxokalliapseudes have been described or redescribed previously, of which some exhibit morphological differences with the type specimens, possibly indicating additional new species. To minimize identification difficulties caused by morphometric variations in developmental stages, the morphological characteristics of the new species are described in detail for a fixed size range and compared to different-sized individuals. Additionally, a comprehensive comparison of the new Phoxokalliapseudes species with the other known species is provided and discussed.

A new species of Leiochrides from the Korean subtidal waters with notes on the taxonomic status of the genus Pseudomastus (Annelida, Capitellidae).

Leiochrides yokjidoensissp. n., collected from the sublittoral muddy bottom in southern Korea, is described as a new species. The taxonomic status of the monospecific genus Pseudomastus has been a subject of controversy for many years, as its characteristics overlap those given in recent generic definitions of Leiochrides. The results of a comprehensive review and comparison regarding the two genera, based on previous records showed minor differences. In this study, a detailed description of L. yokjidoensissp. n. is given and a comparison with closely related species is tabulated and discussed.The taxonomic status of Pseudomastus is discussed and the genus placed in synonymy with Leiochrides.

Two new species of the deep-sea genus Parameiropsis (Copepoda: Harpacticoida) from the eastern central Pacific.

Two new species of Parameiropsis are herein described that were identified from the Korean Deep Ocean Study (KODOS) in the Clarion-Clipperton Fracture Zone, located in the eastern central Pacific. Parameiropsis kodosensis n. sp. is similar to P. magnus Itô, 1983 in two key respects: the presence of a distal seta on the syncoxa of the maxilliped, and the general features of its swimming legs. However, P. kodosensis can be differentiated from P. magnus by a higher length-to-width ratio of the caudal ramus (2.5:1 and 1:1 respectively), the setal number on the exp-3 of P1, and the exp and benp of P5 are separated in P. kodosensis, while they are fused in P. magnus. Parameiropsis tetraspinosa n. sp. resembles P. peruanus Becker, 1974 in the absence of a fused seta in the outermost spine on the endopod of antenna and the general features of the swimming legs. However, P. tetraspinosa can be distinguished from P. peruanus by a higher length-to-width ratio of the caudal ramus (3.9:1 and 2.3:1 respectively), the presence of a distal seta on the syncoxa of the maxilliped, and by its medially fused P5. In this study full descriptions and a comparison with previously described species are provided. Additionally, a key to females of Parameiropsis species is given.

Description of two new species of Neotanais Beddard, 1886 (Crustacea, Tanaidacea) from KODOS area.

Two new species of Neotanais Beddard, 1886 are described from the Korea Deep Ocean Study (KODOS) area in the Clarion-Clipperton Fracture Zone, based on the collections performed on board R/V Onnuri from a depth of 5180 m. Neotanais triqueturus n. sp. is similar to the 'pfaffi group' characterized by pereonites with a swollen distolateral margin, pleonites with mid-ventral spurs and tapered lateral margins but can be differentiated by a longer cephalothorax (length: width 1.6: 1), a cheliped with a large protrusion on the mid-dorsal margin of the fixed finger, and the presence of a ventral process on the cheliped carpus. Neotanais brevis n. sp. has the characteristics of the 'micromopher' group, with pleonites narrower than pereon, a cheliped carpus without a ventral process, and a uropod endopod with nine articles but can be differentiated by a combination of the pleonites without mid-ventral spurs, a relatively longer pleotelson (length: width 1: 1.5 vs. 1: 2), a uropod basis with one seta on each of the ventral and dorsal margins, and the cheliped fixed finger with proximal denticles. In this study, in order to prove N. triqueturus and N. brevis were new species, full descriptions and a comparison with the closely related species are given. In addition, comprehensive comparisons with the species of Neotanais from the east-central Pacific are tabulated and discussed.