Uyeno Daisuke, Watanabe Hiromi K, Shimanaga Motohiro
Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan.
Zootaxa. 2018 Apr 30;4415(2):381-389. doi: 10.11646/zootaxa.4415.2.8.
A new species of dirivultid copepod (Siphonostomatoida) is described from hydrothermal vents in a volcanic seamount in Izu-Bonin Arc, western part of North Pacific Ocean. The copepod was collected during the research cruise NT13-09 using the R/V Natsushima with the ROV Hyper-Dolphin in April 2013. The type series of the new species was collected from the populations of Paralvinella spp. (Annelida: Alvinellidae) on an active vent chimney at the depth of 795 m. Stygiopontius senokuchiae n. sp. is most closely related to S. teres Humes, 1996 but clearly distinguished from the latter species by the possession of the following characters: the basis of leg 1 with an attenuated inner process; the genital double somite with a conical process lateral to the genital opening; and caudal rami without distal process. The findings of the copepod in the present study represents the first record of nominal species of the Dirivultidae from Japanese waters and a record of the shallowest depth of the genus. A key to species of the genus Stygiopontius from Western Pacific is provided.
在北太平洋西部伊豆-小笠原弧的一座火山海山的热液喷口中发现了一种新的双刺猛水蚤目桡足类动物（管口水蚤目）。该桡足类动物是在2013年4月使用“那津岛”号科考船和“超级海豚”号遥控潜水器进行的NT13-09科考航次中采集到的。新物种的模式标本系列采自深度为795米的一个活跃喷口烟囱上的拟阿尔文虾属（环节动物门：阿尔文虾科）种群。濑户内海双刺猛水蚤新种与1996年描述的细长双刺猛水蚤最为相似，但通过具有以下特征与后者明显区分开来：第一触角基部有一个变细的内突；生殖双节在生殖孔外侧有一个锥形突起；尾叉无远端突起。本研究中该桡足类动物的发现代表了双刺猛水蚤科在日本海域的首个定名物种记录以及该属在最浅深度的记录。提供了西太平洋双刺猛水蚤属物种检索表。
