Zoological Studies

Vol. 56, 2017

(update: 2017.9.26)

A New Species of Land-locked Freshwater Shrimp of the Genus Neocaridina (Decapoda: Caridea: Atyidae) from Iki Island, Kyushu, Japan

Hsi-Te Shih1,*, Yixiong Cai2, Nobuaki Niwa3, and Yasuhiko Nakahara4

1Department of Life Science and Research Center for Global Change Biology, National Chung Hsing University, 250, Kuo Kuang Road, Taichung 402, Taiwan
2National Biodiversity Centre, National Parks Board, 1 Cluny Road, Singapore 259569, Republic of Singapore
3Faculty of Science, Kyoto University, Kitashirakawa, Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
4SEIBU Environmental Research Co., LTD, Mikawachishin-machi, Sasebo-City, Nagasaki, 859-3153, Japan

(Received 17 August 2017; Accepted 23 September 2017; Communicated by Benny K.K. Chan)

Hsi-Te Shih, Yixiong Cai, Nobuaki Niwa, and Yasuhiko Nakahara (2017) A new species of land-locked freshwater shrimp, Neocaridina ikiensis (Decapoda: Caridea: Atyidae), is described from Iki Island, Kyushu, Japan, based on morphological and molecular (mitochondrial cytochrome oxidase I gene) evidence. This new species can be distinguished from its congeners by a suite of characters, including rostrum structure, number of post-orbital rostral teeth, male first and second pleopods and telson structure. The molecular evidence of mitochondrial cytochrome oxidase subunit I (COI) shows this species has sufficient interspecific divergence, and its high intraspecific variation suggests that it evolved on this island over a long period of time. Based on the molecular clock estimation, the speciation of N. ikiensis n. sp. is supposed to be related with the quiescent periods of volcanoes on this island. This is the second endemic species of Neocaridina known, after N. denticulata (De Haan, 1844), from the main islands of Japan.

Key words: Neocaridina ikiensis, Mitochondrial cytochrome oxidase subunit I, New species, Morphology, Molecular clock.

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