Toshino Sho, Yamamoto Gaku, Saito Shinsuke
Kuroshio Biological Research Foundation, 560 Nishidomari, Otsuki, Hata 788-0333, Japan.
Enoshima Aquarium, Katasekaigan, Fujisawa 251-0035, Japan.
Animals (Basel). 2022 Jun 21;12(13):1600. doi: 10.3390/ani12131600.
Approximately 300 species of cnidarian jellyfish have been reported in Japanese waters. However, many specimens remain unidentified. In this study, taxonomic investigations, including morphological observations and molecular 16S phylogenetic analyses, were conducted on unknown specimens collected off Oarai, Sagami Bay, and Tosa Bay, Japan. The specimens have the following morphological characteristics: distinct peaks in jelly above the base of the manubrium, a red band on the manubrium, and cylindrical marginal bulbs, each with an abaxial ocellus that is common to the family Halimedusidae. However, the specimens can be distinguished from other Halimedusidae species by their eight radial canals, eight tentacles with numerous stalked nematocyst knobs, and eight nematocyst tracks on the exumbrella. Moreover, molecular phylogenetic analyses revealed that the Kimura two-parameter distance between the specimens and other species was 0.066-0.099, which is considered to represent intergeneric variability. Based on this result, we described it as a new species and established a new genus for taxonomic stabilization. We also emended the diagnostic characters of the family Halimedusidae owing to the establishment of the new genus. Halimedusidae comprises five species in four genera. This paper provides taxonomic keys for the identification of species in the family Halimedusidae.
据报道，日本海域有大约300种刺胞动物水母。然而，许多标本仍未被鉴定。在本研究中，对从日本相模湾的大洗、土佐湾采集的未知标本进行了分类学调查，包括形态学观察和分子16S系统发育分析。这些标本具有以下形态特征：在口柄基部上方的伞部有明显的峰，口柄上有一条红色带，以及圆柱形的边缘球，每个边缘球都有一个背侧单眼，这是海月水母科共有的特征。然而，这些标本可通过其八条辐射管、八条带有许多柄状刺细胞瘤的触手以及伞面上的八条刺细胞轨迹与其他海月水母科物种区分开来。此外，分子系统发育分析表明，这些标本与其他物种之间的Kimura双参数距离为0.066 - 0.099，这被认为代表属间变异性。基于这一结果，我们将其描述为一个新物种，并为分类学的稳定性建立了一个新属。由于新属的建立，我们还修订了海月水母科的诊断特征。海月水母科包括四个属的五个物种。本文提供了海月水母科物种鉴定的分类检索表。
