Morphological and molecular study on Yininemertespratensis (Nemertea, Pilidiophora, Heteronemertea) from the Han River Estuary, South Korea, and its phylogenetic position within the family Lineidae

Ribbon worms (phylum Nemertea) from Bodega Bay, California: A largely undescribed diversity

The diversity of nemerteans along the Pacific coast of the United States is regarded as well characterized, but there remain many cryptic, undescribed, and "orphan" species (those known only in their larval form). Recent sampling of nemerteans in Oregon and Washington has begun to fill in these taxonomic gaps, but nemertean diversity in California has received relatively little attention over the past 60 years. During the summers of 2019 and 2020, nemertean specimens were collected from 20 locations in the Bodega Bay region of northern California, USA, including rocky intertidal shores, sandy beaches, mudflats, and other habitats. Based on morphological assessment and DNA sequence analysis (partial Cytochrome Oxidase I and 16S rRNA genes), our surveys identified 34 nemertean species. Only 13 of these (38%) can be confidently assigned to described species. Another 11 represent species that are new to science, including members of the genera Riserius, Nipponnemertes, Poseidonemertes, Zygonemertes, Nemertellina, Oerstedia, and three species of uncertain affiliation. The remaining ten species include undescribed or cryptic species of uncertain status that have been found previously along the Pacific Coast of North America. Our surveys also document extensions of known geographic ranges for multiple species, including the first records in California of Antarctonemertesphyllospadicola, Cephalothrixhermaphroditica, and Maculauraoregonensis. This is the first report of the genus Nemertellina in the northeast Pacific and Riserius in California. Overall, our findings highlight how much remains to be learned about the diversity and distribution of nemerteans in the northeast Pacific.

Lineid Heteronemerteans (Nemertea: Pilidiophora) from Sagami Bay, Japan, with Some Proposals for the Family-Level Classification System

We performed molecular phylogenetic analyses using nucleotide sequence data from five genes (16S rRNA, cytochrome c oxidase subunit I, 18S rRNA, 28S rRNA, histone H3) determined from 36 specimens representing 25 (10 named, 15 unnamed) species of lineid heteronemerteans collected in Sagami Bay, Japan, along with other sequences obtained from public databases. External features of the 25 species are briefly described and illustrated. Lineus fuscoviridis Takakura, 1898 is transferred to Notospermus Huschke, 1830. Our molecular analysis indicated that one of our Notospermus specimens from Sagami Bay and material previously collected from the Seto Inland Sea are conspecific with Notospermus geniculatus (Delle Chiaje, 1822) s. str. [the year of publication is not 1828 as previously regarded], originally described from Naples, Italy. The new species Siphonenteron nakanoi is established; our tree shows it as the sister taxon to Siphonenteron bilineatum Renier in Meneghini, 1847; it differs from the latter in having more diffuse, scattered yellow pigmentation at the anterolateral margin of the head on each side. Pros and cons of lumping and splitting Lineidae in future studies are discussed.

A new nemertean with a branched proboscis, Gorgonorhynchus citrinus sp. nov. (Nemertea: Pilidiophora), with molecular systematics of the genus

Among ~1300 species of world nemerteans, seven species in five genera of lineid heteronemerteans have been known to possess a branched proboscis. In this paper, we describe the eighth branched-proboscis species: Gorgonorhynchus citrinus sp. nov. from Okinawa, Japan. We also report Gorgonorhynchus cf. repens Dakin & Fordham, 1931 with uniformly orange body, as a new member for the Japanese nemertean fauna. We infer the phylogenetic relationships between these forms and other members of Lineidae McIntosh, 1874 for which partial sequences of the mitochondrial 16S rRNA and cytochrome c oxidase subunit I, and the nuclear 18S rRNA, 28S rRNA, and histone H3 genes are available in public databases, along with newly sequenced data of another branched-proboscis heteronemertean, Polydendrorhynchus zhanjiangensis (Yin & Zheng, 1984) from China. In the resulting tree, Gorgonorhychus Dakin & Fordham, 1931 was sister group to non-branched-proboscis Dushia Corrêa, 1963, whereas P. zhanjiangensis was sister group to likewise non-branched-proboscis Cerebratulus lacteus (Leidy, 1851). http://zoobank.org/urn:lsid:zoobank.org:pub:685992C5-F595-4C28-9178-256D945E595A