A new species of (Annelida, Opheliidae) from the Yellow Sea of South Korea.

Background: Ehlers, 1897 is a genus of Opheliidae characterised by the body divided into three distinct regions, modified parapodia in chaetiger 10 and a ventral groove restricted to the posterior half of the body. To date, 18 species have been described in the genus. Amongst them, six species have been recorded in northeast Asia.

A new species of the genus (Rotifera, Monogononta) from Korea, with reports of four additional cephalodellid species.

A new monogonont rotifer, , was described from a soil sample collected in Korea. The new species is morphologically similar to but is distinguished by having two frontal eyespots, a vitellarium with eight nuclei, and the shape of its fulcrum. We also described four other cephalodellid species collected in Korea; , , , and .

A new species of (Crustacea, Amphipoda, Gammaridae) from South Korea.

A new species of freshwater gammarid, , was collected from Somaemuldo Island, South Korea. This new species is morphologically characterised by the absence of calceoli in antenna 2, absence of anteroproximal setae on bases in pereopods 6 and 7, outer ramus in uropod 3 with plumose setae on both margins, and a small terminal article of the outer ramus, which is shorter than adjacent spines. A description of the new species and morphological differences from related species are provided in the text.

 sp. nov., a new spionid species (Annelida, Spionidae) from the Korea Strait.

A new spionid polychaete, , was discovered in the fine sandy sediments of an intertidal habitat from Korean waters. The new species is considered a simultaneous hermaphrodite, but no brooding embryos were found in any of the specimens collected in this study. This species is unique in the absence of ciliation in the anteriormost chaetigers.

Two new species of feather mites (Acariformes, Astigmata) from the black-tailed godwit, (Charadriiformes, Scolopacidae), in Korea.

Two new species of feather mites are described from two individuals of the black-tailed godwit, (Linnaeus, 1758), in Korea: Alloptes (Conuralloptes) neolimosae (Analgoidea, Alloptidae) and (Pterolichoidea, Syringobiidae). Males of A. (C.

New species of the genus (Annelida, Spionidae) from the southern and western coasts of Korea.

A new spionid polychaete, , is described from the southern and western coasts of Korea. This new species differs from its congeners by the combination of the following morphological characteristics: the presence of orange-brown pigmentation on the anterior part of the prostomium, black pigmentation on the peristomium and along the body, U-shaped nuchal organs, a comparatively long extension of metameric dorsal ciliated organs, three pairs of white dots per chaetiger, two to three posterior abranchiate chaetigers, and the presence of tridentate neuropodial hooded hooks. The partial 16S ribosomal DNA (rDNA) and nuclear 18S rDNA sequences of the new species and sp.

Feather mites (Acariformes, Astigmata) from marine birds of the Barton Peninsula (King George Island, Antarctica), with descriptions of two new species.

We report on the first investigation of feather mites associated with birds living on the Barton Peninsula (King George Island, Antarctica). We found seven feather mite species of the superfamily Analgoidea from four host species. Two new species are described from two charadriiform hosts: Alloptes (Sternalloptes) antarcticus (Alloptidae) from Saunders (Stercorariidae), and (Xolalgidae) from (Gmelin) (Chionidae).

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

A new parabathynellid bathynellacean species, , was found in the groundwater of the Geumgang River in South Korea. This is the first report of 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.