Vol. 47 No. 1, 2008

Taxonomy, Phylogeny, and Biogeography of the Endemic Mudflat Crab Helice/Chasmagnathus Complex (Crustacea: Brachyura: Varunidae) from East Asia

Hsi-Te Shih^1,* and Hiroshi Suzuki²

¹Department of Life Science, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan
²Laboratory of Aquatic Resource Science, Faculty of Fisheries, Kagoshima University, 4-50-20 Shimoarata, Kagoshima 890-0056, Japan

Hsi-Te Shih and Hiroshi Suzuki (2008) The taxonomy, phylogeny, and biogeography of the endemic genera Helice, Helicana, and Chasmagnathus from East Asia were studied using 2 mitochondrial genes: the large subunit (16S) ribosomal (r)RNA and cytochrome oxidase subunit I (COI).  Helice and Helicana were each shown to be monophyletic genera, while 3 species of the genus Helice, H. latimera, H. formosensis, and H. tientsinensis, formed an unresolved“H. latimera clade”, implying that they may represent the same species with an intraspecific variable number of suborbital tubercles.  Helice tridens is predominantly distributed Japan and might be adapted to a more-temperate (northern) climate with cooler temperatures.  The 3 species of Helicana can very clearly be genetically distinguished from one another.  The sympatric purple and olive forms of Chasmagnathus convexus appear to belong to the same species, and the color differences are probably caused by variable food sources or the substrate on which it lives.

Key words: Helicana, 16S rRNA, Cytochrome oxidase I, Morphology, Distribution.

*Correspondence: Tel and Fax: 886-4-22856496. E-mail:htshih@dragon.nchu.edu.tw