中国沿海拟相手蟹属（Parasesarma）一新记录种

A New Record Species of Parasesarma from The Coast of China

关键词:  敛拟相手蟹  拟相手蟹属  新记录种  红树林  中国沿海

Key words:  Parasesarma luomi  Parasesarma  new record species  mangrove  the coast of China

摘要:

通过对2012年-2020年在中国沿海红树林采集的拟相手蟹属Parasesarma De Man, 1895蟹类进行研究，发现了一新记录种，经形态鉴定和COI、16S rRNA基因片段分析，确定其为国内新记录种-敛拟相手蟹Parasesarma luomi Serène, 1981。敛拟相手蟹的主要形态特征为：头胸甲近方形，宽度约当长度的1.2-1.3倍，胃、心区分区明显，额后部具4叶，外眼窝角锐三角形，指向前方，侧缘无齿，眼柄长度大于宽度；雄性螯足粗壮等大，掌节背面具2列梳状栉，可动指背面约具16-18个纵行突起；步足扁平；雄性腹部三角形，第3节最宽，第6节长于第5节；雄性第一腹肢细长挺直，末端角质突起长而细锐，弯曲呈45°。本研究对敛拟相手蟹的形态特征、系统发育、分布区域等方面进行了详细描述，研究结果可为我国拟相手蟹属蟹类的分类和研究提供重要基础资料。

Abstract:

We studied the crabs of the genus Parasesarma De Man, 1895 which were collected in the mangroves along the coast of China from 2012 to 2020, and found a new record species. Through morphological identification and COI, 16S rRNA gene fragment analysis, they were identified as Parasesarma luomi Serène, 1981, a new record species of Parasesarma in China. The diagnostic characters of P. luomi are as following: Carapace rectangular, and 1.2 to 1.3 times broader than long; mesogastric, cardiac regions well defined; postfrontal margin with 4 distinct, similar lobes; external orbital tooth triangular, directed upward, lateral margins of carapace either without tooth, with shallow indentation. Eyestalk longer than wide, longer than corneal part in dorsal view. Male chelipeds robust, palm with two transverse pectinated crests on upper surface; dorsal surface of dactylus with 16-18 transversely broadened tubercles. Walking legs flattened. Pleon of male triangular; somite 3 widest; somite 6 slightly longer than somite 5. The male first gonopod is slender and straight, apical process long and thin, bent to form an angle of 45o. In this study, the morphological characteristics, phylogeny and distribution of P. luomi were described in detail, and the research results could provide basic data for the classification and research of the crabs of the genus Parasesarma in China.