Hiruta Shimpei F, Kakui Keiichi
Center for Molecular Biodiversity Research, National Museum of Nature and Science, Tsukuba 305-0005, Japan.; Email:
Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.; Email:
Zootaxa. 2016 Sep 21;4169(3):515-539. doi: 10.11646/zootaxa.4169.3.6.
We describe three new species of brackish-water ostracods representing two genera in the ostracod tribe Thalassocypridini from mangrove forests in the Ryukyu Islands, subtropical southwestern Japan, and provide their barcoding sequences for the mitochondrial cytochrome c oxidase subunit I (COI) gene. Mangalocypria ryukyuensis sp. nov. was found on Okinawa Island. We also found a Mangalocypria population on Ishigaki Island that was morphologically identical to M. ryukyuensis on Okinawa, but an individual differed by 4.7% in COI sequence (K2P distance) from an individual from Okinawa. This is the first record for Japan of a species in Mangalocypria. Paracypria longiseta sp. nov., obtained from Okinawa Island, is similar to Pontoparta hartmanni. Paracypria plumosa sp. nov. from Ishigaki Island is similar to Pa. adnata described from Yakushima Island, Japan. The COI genetic distance between individuals of Pa. longiseta and Pa. plumosa was roughly as large as that between either of these species and individuals in the Mangalocypria populations. Our study underscores that genera in Thalassocypridini may not represent natural groups, and that this tribe needs taxonomic revision.
我们描述了来自日本西南部亚热带琉球群岛红树林的咸淡水介形虫的三个新物种，它们分属于介形虫部落海生圆介虫族中的两个属，并提供了它们线粒体细胞色素c氧化酶亚基I（COI）基因的条形码序列。新种琉球海生圆介虫（Mangalocypria ryukyuensis sp. nov.）发现于冲绳岛。我们还在石垣岛发现了一个海生圆介虫种群，其形态与冲绳岛上的琉球海生圆介虫相同，但一个个体与来自冲绳的个体在COI序列上有4.7%的差异（K2P距离）。这是日本首次记录海生圆介虫属的一个物种。新种长刚毛副圆介虫（Paracypria longiseta sp. nov.）采自冲绳岛，与哈特曼庞托帕塔介虫（Pontoparta hartmanni）相似。来自石垣岛的新种羽状副圆介虫（Paracypria plumosa sp. nov.）与日本屋久岛描述的贴生副圆介虫（Pa. adnata）相似。长刚毛副圆介虫和羽状副圆介虫个体之间的COI遗传距离大致与这两个物种中的任何一个与海生圆介虫种群中的个体之间的遗传距离一样大。我们的研究强调，海生圆介虫族中的属可能并不代表自然类群，这个族需要进行分类修订。
