Hasegawa Naohiro, Kajihara Hiroshi
Department of Natural History Sciences, Graduate School of Science, Hokkaido University, Kita 10 Nishi 8 Kitaku, Sapporo, Hokkaido 060-0810, Japan Hokkaido University Sapporo Japan.
Faculty of Science, Hokkaido University, Kita 10 Nishi 8 Kitaku, Sapporo, Hokkaido 060-0810, Japan Hokkaido University Sapporo Japan.
Zookeys. 2019 Jun 24;857:1-15. doi: 10.3897/zookeys.857.32654. eCollection 2019.
Two species of styelid colonial ascidians in the genus Redikorzev, 1913 are known from the northwest Pacific. The valid status of the lesser known species, (Tokioka, 1951) (type locality: Akkeshi, Japan), is assessed here. To assess the taxonomic identity of , we compared one of the syntypes and freshly collected topotypes of with a syntype of Redikorzev, 1913 (type locality: Ul'banskij Bay, Russia). Specimens of consistently differed from the syntype of in the number of oral tentacles, the number of size-classes of transverse vessels, and the number of anal lobes. In this paper, is redescribed as distinct from , and its phylogenetic position inferred within Styelidae based on the 18S rRNA and cytochrome oxidase subunit I gene sequences. In our phylogenetic tree, formed a well-supported clade together with MacLeay, 1824. In and , a single gonad is situated on the right side of the body, which is unique among Styelidae, and thus can be a synapomorphy for this clade.
1913年，在西北太平洋发现了Redikorzev属的两种Styelid群体海鞘。本文评估了鲜为人知的物种（Tokioka，1951年）（模式产地：日本厚岸）的有效地位。为了评估该物种的分类身份，我们将该物种的一个同模标本和新采集的地模标本与1913年Redikorzev的一个同模标本（模式产地：俄罗斯乌尔班斯基湾）进行了比较。该物种的标本在口触手数量、横向血管的大小类别数量和肛叶数量上与的同模标本始终存在差异。在本文中，该物种被重新描述为与不同，并根据18S rRNA和细胞色素氧化酶亚基I基因序列推断其在Styelidae科中的系统发育位置。在我们的系统发育树中，该物种与1824年的MacLeay形成了一个得到充分支持的分支。在该物种和中，单个性腺位于身体右侧，这在Styelidae科中是独一无二的，因此可能是该分支的一个共衍征。
