Molecular evidence and differences in gonopod morphology lead to the recognition of a new species of the freshwater crab genus Candidiopotamon Bott, 1967 (Crustacea, Brachyura, Potamidae) from eastern Taiwan

Hsi-Te Shih; Tohru Naruse; Christoph D Schubart

doi:10.3897/zookeys.1179.106718

Molecular evidence and differences in gonopod morphology lead to the recognition of a new species of the freshwater crab genus Candidiopotamon Bott, 1967 (Crustacea, Brachyura, Potamidae) from eastern Taiwan

Zookeys. 2023 Sep 11:1179:169-196. doi: 10.3897/zookeys.1179.106718. eCollection 2023.

Authors

Hsi-Te Shih¹, Tohru Naruse², Christoph D Schubart³

Affiliations

¹ Department of Life Science and Global Change Biology Research Center, National Chung Hsing University, 250, Kuo Kuang Road, Taichung 402, Taiwan National Chung Hsing University Taichung Taiwan.
² Tropical Biosphere Research Center, Iriomote Station, University of the Ryukyus, 870 Uehara, Taketomi, Okinawa 907-1541, Japan University of the Ryukyus Okinawa Japan.
³ Zoology & Evolution, University of Regensburg, 93040 Regensburg, Germany University of Regensburg Regensburg Germany.

Abstract

A new freshwater crab of the potamid genus Candidiopotamon Bott, 1967, is described from eastern Taiwan. Candidiopotamonpenglai sp. nov. is morphologically similar to C.rathbuni (De Man, 1914) from western Taiwan, but can be distinguished by the morphology of the male first gonopod (G1), as well as by their mitochondrial DNA (16S rRNA and COI genes). In the G1 of C.rathbuni, the subterminal segment shows a cline from robust in northern populations to slender in southern populations. In the G1 of C.penglaisp. nov., a distinctly larger and more distally directed keel-like projection is found on the distal inner edge of the terminal segment, with northern populations having an inward-curving subterminal segment and southern populations a straight subterminal segment. The genetic differentiation of the two species of Candidiopotamon within Taiwan is discussed, and morphological differences are compared. A key to the species of Candidiopotamon is also provided.

Keywords: 16S rDNA; Candidiopotamonpenglai; Candidiopotamonrathbuni; Decapoda; cytochrome oxidase subunit I; morphology; new species; taxonomy.

Hsi-Te Shih, Tohru Naruse, Christoph D. Schubart.