Several squat lobster specimens of the genus Munidopsis were collected from an artificially placed carcass fall (cow bones) on Weijia Guyot in the western Pacific Ocean. Based on morphological comparisons and molecular analysis, three specimens were confirmed as juveniles of M. albatrossae Pequegnat & Pequegnat, 1973, which represents the first record of this species in the western Pacific. The other specimens collected are newly described as Munidopsis spinifrons sp. nov., which is distinguished from the closely related species in having a spinose rostrum and basal lateral eyespine on the eyestalk. The M. albatrossae from Weijia Guyot exhibited very low genetic distances when compared with a conspecific sample from Monterey Bay, USA, and the closely related species M. aries (A. Milne Edwards, 1880) from the northeastern Atlantic. A phylogenetic tree based on the mtCOI gene shows M. spinifrons sp. nov. as sister to M. vrijenhoeki Jones & Macpherson, 2007 and M. nitida (A. Milne Edwards, 1880), although M. vrijenhoeki presents a complex relationship with other species in the clade. The systematic status of the new species and the closely related species are discussed.

KARUBENTHOS 2

Eiconaxius Bate, 1888 is a genus of axiid shrimps exclusively associated with deepsea hexactinellid sponges. Due to its special morphology and habitat, Eiconaxius is taxonomically and ecologically controversial. Based on material recently collected from seamounts in the northwestern Pacific, a new species of Eiconaxius is described. Intraspecific morphological and genetic variation and host specificity were evaluated. The complete mitochondrial genome of the new species was sequenced to explore the systematic status of Eiconaxius and some other axiidean taxa. Our analyses showed that differentiation of the new species occurs both allopatrically and sympatrically, probably resulting from the interaction of geographical isolation and deep water current movement, rather than from adaptation to different hosts. In addition, species of Eiconaxius are suggested to have wider ranges of distribution and host than expected. The reconstructed mitogenomic phylogeny supported merging Eiconaxius into Axiidae, and recognized most axiidean families, except that Strahlaxiidae was suggested to be paraphyletic. However, more comprehensive taxon sampling is still needed to resolve the explicit internal relationships among Axiidea.

BATHUS 3, KARUBAR, KARUBENTHOS 2, KAVIENG 2014

MAINBAZA

Trachinocephalus gauguini Polanco, Acero & Betancur, 2016 was described based on eighteen specimens collected from off the Marquesas Islands, the only location where this species has been recorded until now. Through morphological and molecular examination of Trachinocephalus specimens collected from an exploratory cruise conducted in June 2014 under the Tropical Deep-Sea Benthos program along the northern coast of the New Ireland Province, Papua New Guinea, we demonstrate the presence of this species in Papua New Guinea waters. This new record suggests a wide distribution for this rarely collected species in the western Pacific Ocean.

KAVIENG 2014, MADEEP, PAPUA NIUGINI

MUSORSTOM 8, TAIWAN 2000, TAIWAN 2001

BATHUS 3

Restricted, ANT-XXIX_3, ATIMO VATAE, BATHUS 2, BATHUS 4, Restricted, Restricted, Restricted, BENTHAUS, Restricted, BIOCAL, Restricted, Restricted, Restricted, BIOGEOCAL, BIOMAGLO, BIOPAPUA, Restricted, CEAMARC-AA, CHALCAL 2, CONCALIS, CORINDON 2, Restricted, Restricted, Restricted, Restricted, EBISCO, EXBODI, HALIPRO 2, Restricted, KANACONO, KANADEEP, KANADEEP 2, KARUBENTHOS 2, KAVIENG 2014, MADEEP, MD42 (SIBEX), MUSORSTOM 1, MUSORSTOM 10, MUSORSTOM 2, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, MUSORSTOM 7, Restricted, NORFOLK 2, NanHai 2014, Restricted, SALOMON 1, SALOMON 2, SALOMONBOA 3, SPANBIOS, TAIWAN 2000, Restricted, TARASOC, Restricted, Walters Shoal, ZhongSha 2015