The genus Reductodrilus Pic, 1943 has hitherto been considered monotypic, comprising a single described species from Borneo. Here, Reductodrilus from the Philippines is revised and three endemic species recognized. Reductodrilus longelytratus Packova & Kundrata, sp. nov . and Reductodrilus maculatus Packova, Vorst & Kundrata, sp. nov . are described. Furthermore, Dodecatoma testaceiceps Pic, 1924 (formerly placed in Rhagophthalmidae) is transferred to Lampyridae as Reductodrilus testaceiceps (Pic, 1924), comb. nov ., and Ototretadrilus philippinus Wittmer, 1941 established as its new junior synonym. In addition, a lectotype is designated for Dodecatoma testaceiceps . This revision improves our understanding of the poorly known Southeast Asian Ototretinae and demonstrates that the diversity of Philippine Ototretinae has been substantially underestimated.
Ophelia limacina (Rathke, 1843), originally described from Norway, is the only species of Ophelia Savigny, 1822 recorded from Chinese waters, but these records have never been verified. To clarify the identity of the Chinese Ophelia , specimens from the Chinese coast, from Shandong to Fujian, were examined. They differ from O. limacina and from all other congeners and are described here as Ophelia yangi sp. nov .; the earlier Yellow Sea record of O. cf. limacina is also tentatively referred to the new species. The new species has 32 chaetigers with the body formula 10a + 16b + 6a, i.e., ten anterior abranchiate, 16 branchiate, and six posterior abranchiate chaetigers, and simple cirriform branchiae; branchial fenestrations are present. The body formula was constant in all specimens examined, except on one side of one of 20 specimens. In the mitochondrial cytochrome c oxidase subunit I (COI) and 16S rRNA genes, the new species differs from all other sequenced taxa of Ophelia by uncorrected p-distances of 15.6–16.5% (COI) and 6.4–7.8% (16S), whereas the maximum intraspecific COI distance is 0.5%. The variation observed in the examined specimens was used to evaluate the characters that have been used to distinguish species of Ophelia . The body formula was stable in these specimens, whereas the length of the branchiae, the posterior dorsal longitudinal ridges, the origin of the ventral groove, and the nephridiopores varied among specimens or were difficult to observe in preserved material; these characters should therefore be used with caution.
Genus Elmomorphus Sharp, 1888 is distributed across East and Southeast Asia representing one of the most species-rich lineages of Asian Dryopidae. Here, five new species from Vietnam are described ( E. bachma sp. nov ., E. calvoides sp. nov ., E. cucphuong sp. nov ., E. parastriatellus sp. nov ., and E. vestitus sp. nov .) and E. sarawakensis Chûjô & Satô, 1964 is redescribed, based on the specimens from Sarawak (Malaysia). DNA sequences were generated for four loci (COI, 28S rDNA, ITS2, and CAD) for 15 species collected in Vietnam, two Japanese species ( E. brevicornis Sharp, 1888 and E. amamiensis Nomura, 1959), and the Malaysian E. sarawakensis . Phylogenetic relationships were inferred using maximum likelihood and Bayesian inference on concatenated datasets and compared with species-tree estimates obtained under the multispecies coalescent framework. To assess gene-tree discordance, phylogenetic networks using PhyloNet and NANUQ were reconstructed. Our analyses provide new molecular insights into the phylogeny of Elmomorphus , revealing that majority of the species form distinct lineages, but several clades appear to be affected by incomplete lineage sorting and exhibit conflicting phylogenetic signal across loci. The new molecular data clarify relationships within the analysed species and provide a foundation for future phylogenetic and biogeographic studies of Oriental Dryopidae.
A new species of the galatheid squat lobster genus Lauriea Baba, 1971, Lauriea aurea sp. nov ., is described from Korea based on a male specimen collected from an unidentified sponge at a depth of 35 m. The new species can be distinguished from its congeners by the carpi of the third pereopods bearing six or seven spines along the extensor margin, the dactyli of pereopods 2–4 with a weak but distinct blunt protuberance on the flexor margin, and a live colour pattern characterised by yellow or green spots on the carapace and medial yellow spots on pleonal tergites 1–3. Pairwise uncorrected p -distances between the new species and its seven congeners ranged from 1.61–8.10% for 16S rRNA and 6.95–17.31% for cytochrome c oxidase subunit I, supporting the recognition of L. aurea sp. nov . as a distinct species.
Esolus fodingshanus sp. nov . is described from the Fodingshan National Nature Reserve and the Fanjingshan Nature Reserve in Guizhou, southwestern China. The genus Esolus Mulsant & Rey, 1872 hitherto comprised 11 described species, which are distributed almost exclusively in the western Palearctic region, with one species, E. nepalensis Jäch, 1982, occurring in the Himalaya. The new discovery represents the first record of this genus from China and East Asia. Esolus nepalensis is here recorded from India (Uttarakhand) and Bhutan for the first time.
