Uca (Gelasimus) borealis Crane, 1975

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, Zootaxa 4083 (1), pp. 57-82 : 63-64

Uca (Gelasimus) borealis Crane, 1975

( Fig. 3A–D )

Uca marionis — Maki & Tsuchiya 1923: 107, pls. 23(6), 24(8).

Uca marionis nitidus — Sakai 1935: 213, pl. 58(3).

Gelasimus marionis nitidus — Sakai 1934: 319; Horikawa 1940: 28 [list]; Sakai 1940: 32 [list]; Lin 1949: 27 [list]

Uca (Thalassuca) vocans borealis Crane, 1975: 90 , figs. 64A, 99 [type locality: Hong Kong]; Su & Lue 1984: 63: Dai et al. 1986: 424, pl. 58(8); Dai & Yang 1991: 464, pl. 58(8); Shih 1994: 86, figs. 60–62; Ho & Hung 1997: 59, 4 unnumbered figs.

Uca (Thalassuca) vocans vocans — Sakai 1976a: 605 (part); Su & Lue 1984: 64, fig. 6 (not Cancer vocans Linnaeus, 1758 ).

Uca vocans borealis — Fukui et al. 1989: 227; Chen 2001: 203, 2 unnumbered figs. (part).

Uca borealis — Huang et al. 1989: 198, fig. 7, pl. 4A–C; Wang & Liu 1996a: 52, 7 unnumbered figs.; Hung 2000: 140 -1, 2 unnumbered figs. (part); Lee 2001: 102 (part); Ng et al. 2001: 37 [list]; Wang & Liu 2003: 75, figs. 71–73; Shen & Jeng 2005: 158, 2 unnumbered figs. (part); Liu & Wang 2010: 32, 3 unnumbered figs.

Uca (Gelasimus) borealis —Ng et al. 2008: 240 [list]; Toyota & Seki 2014: 231, 1 unnumbered fig.

Material examined. Taiwan: 1 ♂ (18.1 mm) (NCHUZOOL 13169), Yilan, coll. S. Huang, 31 May 1996 ; 1 ♂ (26.6 mm) (NCHUZOOL 13170), Yilan, coll. S. Huang, 31 May 1996 ; 1 ♂ (22.0 mm) (NCHUZOOL 13208), Wazaiwei, New Taipei City, coll. H.- T. Shih, 17 Nov. 1995 ; 3 ♂♂ (15.4–22.3 mm), 1 ♀ (18.4 mm), 2 ovig. ♀♀ (14.8, 17.9 mm) (NCHUZOOL 13209), Wazaiwei, New Taipei City, coll. H.- T. Shih, 18 June 1996 ; 1 ♂ (18.4 mm), 1 ♀ (14.2 mm) ( TMCD CHCD 227 ), Haishangu, Hsinchu, 16 Mar. 1991; 1 ovig . ♀ (19.9 mm) ( TMCD CHCD 29 ), Haishangu, Hsinchu, 22 Mar. 1991 ; 1 ♂ (16.1 mm) (NCHUZOOL 14743), 1 ♂ (23.6 mm) (NCHUZOOL 14744), Haishangu, Hsinchu, coll. H.- T. Shih, 11 July 1998 ; 2 ♂♂ (19.4, 23.7 mm) (NCHUZOOL 14740), Houlong R. estuary, Miaoli, 30 May, 2014 ; 1 ♂ (26.2 mm) (NCHUZOOL 14742), Gaomei, Taichung, 22 Sep. 2006 ; 3 ♂♂ (18.3–29.5 mm), 1 ovig. ♀ (16.9 mm) ( TMCD CHCD 1237 ), Shengang, Changhua, coll. H.- C. Liu, 4 June 1996 ; 4 ♂♂ (14.1–20.9 mm) ( TMCD CHCD 391 ), Santiaolun, Yunlin, coll. H.- C. Liu, 24 May 1994 ; 1 ♂ (25.1 mm), 1 ovig. ♀ (22.2 mm) ( TMCD), Haomeiliao, Budai, Chiayi, coll. C.- H. Wang, 13 July 1996 ; 4 ♂♂ (18.4–22.7 mm) (NCHUZOOL 14741), Yanshuei R. estuary, Tainan, 4 Aug. 2009 ; 1 ♂ (24.5 mm) (NCHUZOOL 14737), Yanshuei R. estuary, Tainan, 26 Apr. 2014 ; 1 ♂ (26.5 mm) (NCHUZOOL 13220), Cigu, Tainan, coll. H.- T. Shih, 31 May 1996 ; 2 ♂♂ (12.5, 13.1 mm), 1 ♀ (16.1 mm), 1 ovig. ♀ (13.7 mm) (NCHUZOOL 14739), Dingtouer Shoal, Cigu, Tainan, coll. J.- H. Lee, 14 Aug. 2009 ; 1 ♂ (22.6 mm) (NCHUZOOL 13173), 1 ♂ (17.9 mm) (NCHUZOOL 13174), Gaoping R. estuary, Kaohsiung, coll. H.- T. Shih, 29 Apr. 1998 . Penghu Islands: 1 ♂ (27.1 mm) (NCHUZOOL 13178), Cingluo, coll. H.- T. Shih, 15 Aug. 1996 ; 1 ♀ (18.6 mm) (NCHUZOOL 14725), Citou, coll. H.-T. Shih et al., 11 Aug. 2010; 1 ♀ (15.4 mm) (NCHUZOOL 14722), Chihsi, Siyu, coll. H.-T. Shih et al., 12 Aug. 2010. Kinmen Islands: 6 ♂♂ (17.0–27.0 mm) , 2 ♀♀ (18.5, 20.3 mm) (TMCD CHCD 853), Wujiang R. estuary, coll. H.-C. Liu & C.-H. Wang, 9–12 Oct. 1995; 2 ♂♂ (21.4, 27.7 mm), 2 ♀♀ (16.8, 17.8 mm) (NCHUZOOL 13991), Wujiang R. estuary, coll. J.-H. Lee, 30 May 2004; 1 ♂ (29.8 mm), 1 ovig. ♀ (23.1 mm) (NCHUZOOL 14601), Wujiang R. estuary, coll. Y.-H. Wang, 16 Aug, 2011; 4 ♂♂ (18.8–26.6 mm) (NCHUZOOL 14000), Mashan, Jinsha, coll. Y.-H. Wang, 17 Aug. 2011; 2 ♂♂ (22.3, 28.1 mm), 2 ♀♀ (18.9, 20.0 mm), 1 ovig. ♀ (19.4 mm) (TMCD CHCD 874), Yangcuo, Lieyu, coll. H.-C. Liu & C.-H. Wang, 10 Oct. 1995; 3 ♂♂ (9.3–19.5 mm), 2 ♀♀ (10.8, 17.3 mm) (NCHUZOOL 14751), Coastal Avenue, Lieyu, coll. P.-Y. Hsu, 23 June 2013. Matsu Islands: 2 ♂♂ (12.9, 26.9 mm) , 1 ♀ (20.1 mm), 1 ovig. ♀ (20.1 mm) (NCHUZOOL 13165), Cingshuei, coll. J.-H. Li, 9 July 2005; 2 ♂♂ (10.8, 18.2 mm) (NCHUZOOL 14750), Jhuluo Harbor, Nangan, 29 Aug. 2011. Main Japan islands : 2 ♂♂ (23.5, 24.1 mm) , 2 ♀♀ (15.4, 20.6 mm) (NCHUZOOL 13297), Hitotsuba Inlet, Miyazaki, coll. H. Suzuki, 11 Oct. 2008.

Distribution. Main Japanese islands, Taiwan (including Penghu, Kinmen, Matsu), China (including Hainan), and Vietnam.

Remarks. We confirm herein that there are three species of U. vocans species complex, viz. U. borealis , U. jocelynae and U. vocans , in Taiwan. Two or three species are sympatric in some localities, e.g. U. borealis and U. jocelynae (Yilan and Tainan); U. jocelynae and U. vocans (Pingtung [Hengchun Peninsula] and Taitung); and three species (Pingtung [Dapengwan] and Penghu).

The most reliable characters used to separate the three species are the shape of the dactylus and pollex of the major cheliped ( Fig. 3A, C, E, G ). Major cheliped of Uca borealis with pollex having a deep proximal depression and a shallow or without distal depression in gape, distal tooth small, dactylus slightly deeper than pollex only in young; U. jocelynae with pollex having a shallow proximal and a deep distal depressions in gape, distal tooth triangular, moderately large, dactylus deeper than pollex, especially basal half; U. vocans with pollex having both deep proximal and distal depressions in gape, distal tooth triangular, large, dactylus not deeper than pollex.

While the G1 of male is also a useful character to separate the three species (see Crane 1975: table 3, fig. 64A, B, F), it is difficult to identify the females by the external morphologies, although the morphologies of their vulvae (gonopores) are different ( Crane 1975: table 3, fig. 64AA, BB, FF).

With regard to U. borealis from the main islands of Japan ( Fig. 3C–D ; Shih et al. 2010a), the morphologies of major chela and G1 ( Fig. 3C, D ) agree well with the characters of this species ( Fig. 3A ; Crane 1975; Shih et al. 2010a). Yamashita & Yamanishi (1999: fig. 9) reported U. vocans from Osaka Bay, but the chela of the young male specimens is more similar to U. borealis . It is noteworthy that there are no records of U. borealis from the Ryukyus. Such discontinued distribution is similar to U. lactea (see Remarks under U. lactea ). The northern limit of distribution of Uca borealis in continental Asia is Fujian, China, but it is absent in other northern locations, including Korea ( Shih et al. 2010b; this study). It is worthy studying the factors affecting the larval dispersal of the two species in this northern region of the East China Sea.

Figures

FIGURE 3. Species of the subgenus Uca (Gelasimus). A, B, Uca borealis Crane, 1975, male from Yanshuei River estuary, Tainan, Taiwan; C, U. borealis, male from Miyazaki, Japan, with G 1 (D); E, F, U. jocelynae Shih, Naruse & Ng, 2010, males from Siyu, Penghu, Taiwan; G, H, U. vocans (Linnaeus, 1758), males from Cingluo, Penghu, Taiwan.