Uca (Austruca) perplexa (H. Milne Edwards, 1837) (Fig. 2C–E) Gelasimus perplexus H. Milne Edwards 1852: 150, pl. 4(18) [type locality: Java]. Uca (Celuca) lactea perplexa — Crane 1975: 300. figs. 18D–F, 19B–H, 20A–C, 26D, 31E, 54K, 69C, pl. 39E–F; Miyake 1983: 163, pl. 55(1); Nagai & Nomura 1988: 55, 1 unnumbered fig.; Shih 1994: 103, figs. 69. Uca (Celuca) lactea lactea — Sakai 1976a: 608 (part); Wang, 1984: 42 (not Ocypode (Gelasimus) lactea De Haan, 1835). Uca lactea perplexa — Fukui et al. 1989: 227; Chen 2001: 208, 1 unnumbered fig.; Nakasone & Irei 2003: 269, fig. 31F. Uca lactea — Ho et al. 1993: 20 (part?). Uca perplexa — Ho et al. 1993: 20; Okutani 1994a: 214, fig. 1; Yamaguchi 1994: 165; Wang & Liu 1996a: 61, 2 unnumbered figs.; Hung 2000: 140 -1, figs. 438–439; Lee 2001: 103, 3 unnumbered figs.; Ng et al. 2001: 37 [list]; Yoshigou 2001: 4, fig. 2, pl. 1N; Wang & Liu 2003: 82, figs. 84–86; Shen & Jeng 2005: 166, 1 unnumbered fig.; Katsu 2007: 92, 5 unnumbered figs.; Liu & Wang 2010: 41, 3 unnumbered figs.; Shih 2012b: 66, figs. 94–96; Fujita & Uyeno 2015: 95, fig. 2A, B. Uca (Paraleptuca) perplexa —Ng et al. 2008: 241 [list]; Toyota & Seki 2014: 226, 4 unnumbered figs. Uca (Austruca) perplexa — Naderloo et al. 2010: 24, figs. 16a–g, 17a, b, 18c–f. Material examined. Taiwan: 1 ♂ (13.5 mm) (NCHUZOOL 14647), Lanyang R. estuary, Yilan, 25 July 2004; 4 ♂♂ (16.6–17.6 mm) (NCHUZOOL 14677), 1 ♀ (13.7 mm) (NCHUZOOL 14643), Yanshuei R. estuary, Tainan, coll. J.- H. Lee et al., 4 Aug. 2009; 2 ♂♂ (14.4, 15.6 mm), 1 ♀ (14.5 mm) (NCHUZOOL 14637), Dingtouer Shoal, Cigu, Tainan, coll. J.- H. Lee, 14 Aug. 2009; 2 ♂♂ (14.3, 17.2 mm), 1 ♀ (15.7 mm) (NCHUZOOL 14645), Gaoping R. estuary, Kaohsiung, coll. H.- T. Shih, 29 Apr. 1998; 1 ♂ (14.5 mm), 1 ♀ (12.0 mm) (NCHUZOOL 14640), Dapengwan, Pingtung, 20 July 2007; 2 ♂♂ (9.3, 11.8 mm), 1 ♀ (12.9 mm) (NCHUZOOL 13252), 1 ♂ (10.6 mm) (NCHUZOOL 13253), Baoli R. estuary, Pingtung, coll. H.- T. Shih, 7 July 2001; 1 ♂ (14.0 mm), 1 ♀ (12.1 mm) (NCHUZOOL 14641), Fengcueisha, Kenting, Pingtung, 18 May 2001; 3 ♂♂ (14.2–17.2 mm) (NTOU), Dulanwan, Taitung, coll. P.- H. Ho, 7 Apr. 2001. Penghu Islands: 1 ♂ (20.7 mm) (NCHUZOOL 14662), Citou, coll. H.- T. Shih, 17 Aug. 1996; 1 ♂ (15.1 mm) (NCHUZOOL 14675), Shihcyuan, 21 June 2006; 2 ♂♂ (13.3, 16.5 mm) (NCHUZOOL 14639), Chihsi, Siyu, 18 May 2007; 3 ♂♂ (15.8–16.4 mm) (NCHUZOOL 14649), Chihsi, Siyu, 19 May 2007. Dongsha Island: 3 ♂♂ (12.2–17.5 mm), 2 ♀♀ (10.4, 15.1 mm), coll. C.-Y. Chung & Y.-H. Huang, 7 June 2011; 1 ♂ (16.6 mm) (NCHUZOOL 14651), 19 Nov. 2011; 1 ♂ (17.6 mm) (NCHUZOOL 14644), 26 May 2012. Ryukyus: 1 ♂ (15.8 mm) (NCHUZOOL 14652), Oura Bay, Okinawa, 13 Nov. 1975; 3 ♂♂ (9.6– 15.1 mm), 1 ♀ (7.9 mm) (NCHUZOOL 14654), Yuhi R., Okinawa, 19 Mar. 1992; 1 ♂ (7.1 mm), 2 ♀♀ (6.5, 10.6 mm) (NCHUZOOL 14650), Okinawa, 9 July 2009; 4 ♂♂ (11.0– 14.2 mm) (NCHUZOOL 14642), Sashiki, Okinawa, 28 Dec. 2011; 2 ♂♂ (13.4, 16.2 mm) (NCHUZOOL 14752), Nagura, Ishigaki, coll. T. Naruse, 23 June 2004. Distribution. Widely distributed in the western Pacific (Ryukyus, Taiwan [including Penghu and Dongsha], Philippines, New Guinea, Australia, New Caledonia, Indonesia, Borneo, Peninsular Malaysia, Thailand, Cambodia), eastern Indian Ocean (Nicobar Islands), western and central Pacific Ocean. Remarks. See Remarks under U. lactea for the morphological comparison between U. lactea and U. perplexa, and Discussion for the distribution of U. perplexa in Japan.

Published as part of Shih, Hsi-Te, Lee, Jung-Hsiang, Ho, Ping-Ho, Liu, Hung-Chang, Wang, Chia-Hsiang, Suzuki, Hiroshi & Teng, Shao-Jyun, 2016, Species diversity of fiddler crabs, genus Uca Leach, 1814 (Crustacea: Ocypodidae), from Taiwan and adjacent islands, with notes on the Japanese species, pp. 57-82 in Zootaxa 4083 (1) on page 62, DOI: 10.11646/zootaxa.4083.1.3, http://zenodo.org/record/1050889