首页|Taxonomic revision of the free-living marine nematode genus Deontostoma (Enoplida: Leptosomatidae) and inclusion of a new species from the Southern Ocean

Taxonomic revision of the free-living marine nematode genus Deontostoma (Enoplida: Leptosomatidae) and inclusion of a new species from the Southern Ocean

扫码查看
A new species of free-living marine nematode, Deontostoma quadridentatum sp. nov., is described from a deep-sea sediment sample collected off the South Orkney Islands, the Southern Ocean, during a cruise (KH-19-6-Leg 4) conducted on the R/V Hakuho-Maru. Deontostoma quadridentatum sp. nov. differs from its congeners by the possession of: i) a cephalic capsule with a smooth posterior edge and without intralobar lacunae; ii) interlobar fenestrae with two posterior incisions; iii) four odontia on each mandible; iv) three onchia; v) spicules with velum and lateral process; vi) gubemacula with a hollow triangular crus, vii) one ventromedian supplement; viii) two precloacal subventral rows consisting of 8-10 setae and 12-20 papillae; and ix) by the lack ofocelli. Partial 18S rRNA and cytochrome c oxidase subunit I gene sequences were determined for D. quadridentatum sp. nov., and the diagnosis of Deontostoma and the dichotomous keys to the subfamilies of Leptosomatidae, genera of Deontostomatinae, and species of Deontostoma were revised. Two known species, Triceratonema montredonense comb. nov. and Triceratonema papillosum comb, nov., were transferred from Deontostoma. Our molecular phylogenetic analysis did not clarify the position of Deontostoma quadridentatum sp. nov., but we placed this species into Deontostoma based on morphological observations. We also tried to find a relationship between distribution and morphological characteristic because it seems that there are two phylogenetic lineages thatexist in Deontostoma based on the distribution of all species. However, no such relationships could be found from our literature survey.

Antarcticameiobenthosmeiofaunamolecular phylogenysystematicstaxonomy.

Daisuke Shimada、Naoto JlMI

展开 >

Department of Biological Sciences, Faculty of Science, Hokkaido University, N10 W8, Sapporo,Hokkaido 060-0810, Japan

Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Toba, Mie 517-0004, Japan

2022

Nematology

Nematology

SCI
ISSN:1388-5545
年,卷(期):2022.24(Pt.9)