A new species of the complex, (Annelida, Polychaeta, Serpulidae), from the rocky intertidal zone of Japan.

A new species of (Annelida: Serpulidae) is described based on specimens collected at the coastal Shonan area of Sagami Bay and the adjacent areas of Honshu, Japan. forms large aggregations in the intertidal rocky zone of warm-temperate Japanese shores. This species was referred to as (Baird, 1864) until the monotypic genus was synonymized with .

A new species of (Annelida, Sabellida, Sabellidae) from the Ariake Inland Sea, Kyushu, Japan.

A new species of the sabellid polychaete genus Fitzhugh, 2002, is described from Ariake Inland Sea, Kyushu, Japan. is a small genus, composed of three species worldwide. Its distinctive feature is the presence of foliaceous flanges at the distal ends of the radioles.

sp. n. (Annelida, Sabellidae) from Okinawa and Ogasawara, Japan, with notes on its ecology.

The polychaete (Sabellidae) is described from Okinawa and Ogasawara, south Japan, where it was found living embedded in a dead skeleton of the coral sp. The new species is characterized by the presence of a pigmented sub-distal swelling on the tips of the crown radioles, a unique feature among species of the genus. Besides, its collar chaetae have an L-shape orientation, and the dorsal basal flanges of the branchial lobes are long and have a dorsal joint.

Nomenclatural checklist for species (Annelida, Sabellidae), a replacement for the junior homonym Johansson, 1926.

, , is introduced as a replacement name for the polychaete genus Johansson, 1926 (Annelida, Sabellidae), preoccupied by Westwood, 1842 (Insecta, Coleoptera, Carabidae). The historical background of the homonymy and a full list with 36 new combinations in the new genus are included, while two species are considered as .

Sabellaria jeramae, a new species (Annelida: Polychaeta: Sabellariidae) from the shallow waters of Malaysia, with a note on the ecological traits of reefs.

A new species of the genus Sabellaria Lamarck, 1818 (Annelida: Polychaeta: Sabellariidae) is described from the intertidal zone of Jeram, Selangor, Malaysia. Sabellaria jeramae n. sp.

Corrigenda: Two new species of Mediomastus (Annelida, Capitellidae) from Tokyo Bay, Japan. ZooKeys 422: 115-126.

[This corrects the article DOI: 10.3897/zookeys.422.

Partial revision of Japanese Pectinariidae (Annelida: Polychaeta), including redescriptions of poorly known species.

Eight species of Pectinariidae de Quatrefages, 1866 were recorded from Japan and adjacent waters. We studied four species of the family and redescribe the poorly known species from the Seto Inland Sea and Ariake Sound, Kyushu based on recently collected material. The species covered in this study are Amphictene japonica (Nilsson, 1928), Lagis bocki (Hessle, 1917), Pectinaria okudai (Imajima & Hartman, 1964) and Pectinaria hiuchiensis Kitamori, 1965.

Two new species of Mediomastus (Annelida, Capitellidae) from Tokyo Bay, Japan.

Two undescribed species of polychaetes in Mediomastus (Annelida: Capitellidae) were collected from intertidal to shallow habitats in Tokyo Bay, Japan. These are M. duobalteus sp.

A new species of Pinnixa (Crustacea: Decapoda: Brachyura: Pinnotheridae) associated with a tube worm, Chaetopterus cautus (Annelida: Polychaeta), from Tokyo Bay, Japan.

A new species of the pea crab genus Pinnixa White, 1846 (Pinnotheridae), P. banzu n. sp.

Male dimorphism in the harem-forming gnathiid isopod Elaphognathia discolor (Crustacea: Isopoda).

Previously unreported males of a gnathiid isopod were found in reproductive aggregations of the harem-forming gnathiid Elaphognathia discolor. Although the male gnathiids were small in size and morphologically different from E. discolor males, the male sexual organ, appendix masculina, was similar to that of E.

Two new species of Spiochaetopterus (Annelida: Polychaeta) from Sagami Bay and Tokyo Bay, Central Japan with a comparative table of species from Japanese and adjacent waters.

Two new species of Spiochaetopterus (Chaetopteridae: Polychaeta), S. sanbanzensis, from Sanbanze, off Ichikawa and Funabashi Cities, Tokyo Bay, and S. izuensis from the shallow waters of Sagami Bay, were described.

Sabellaria tottoriensis n. sp. (Annelida: Polychaeta: Sabellariidae) from shallow water off Tottori, the Sea of Japan.

A new species of the genus Sabellaria Lamarck, 1812 (Annelida: Polychaeta: Sabellariidae), is described from shallow water off Tottori, the Sea of Japan. Sabellaria tottoriensis n. sp.

A new species of Alcyonosyllis Glasby and Watson, 2001 (Polychaeta: Syllidae: Syllinae) from Shimoda, Japan, commensal with the gorgonian Melithaea flabellifera.

A new species of Alcyonosyllis Glasby and Watson, 2001 (Polychaeta: Syllidae: Syllinae) is described from shallow water of Shimoda, Izu Peninsula, Japan. The worms were commensal with the gorgonian Melithae flabellifera (Kükenthal, 1909). Alcyonosyllis glasbyi n.