Myra fugax (Fabricius, 1798)

Shih, Yi-Jia, Ho, Ping-Ho & Chan, Tin-Yam, 2015, Leucosiid crabs (Crustacea: Decapoda: Brachyura) from Taiwan, with three new records, Zootaxa 4052 (1), pp. 127-134 : 131-133

Myra fugax (Fabricius, 1798)

( Figs. 1 D, 4A, B)

Material examined. YiLan County: Dasi. 1 female (ovig.), 26.8× 33.9 mm, NMNS (HPW00471), coll. J.-S. Wu, 26 Aug. 1994; 1 female, 31.6× 39.9 mm, NMNS –19940923, coll. unknown, 23 Sep. 1994; 1 female, 27.5× 34.1 mm, NMNS –L19981214, coll. K.-C. Lee & H.-T. Huang, 14 Dec. 1998; 1 female (ovig.), 25.4× 32.2 mm, NMNS – L19990414, coll. K.-C. Lee & H.-T. Huang, 14 Apr. 1999. Tainan City: Mashagou. 1 female, 17.8× 22.7 mm, NMNS (HPW00366), coll. S.-Y. Chen, 28 Jun. 1995. Kaohsiung City: 1 male, 31.3× 22.4mm, TMCD 002813, coll. K.-C. Hsia. Mituo. 2 females (1 ovig.), 18.8× 25.1 mm, 25.4× 32.6 mm, NTOU –L19930107, coll. J.-F. Huang, 7 Jan. 1993; 1 female (ovig.), 26.1×34.0 mm, NMNS (HPW00427), coll. T.-W. Lin, 13 Dec.1994; 1 female, 22.0× 28.8 mm, NMNS (HPW00609), coll. T.-W. Lin, 6 May 1995; 1 female, 25.0× 35.7 mm, NMNS (HPW19960304), coll. P.-W. Hsueh, 4 Mar. 1996. Jhongyun. 1 female, 17.7× 22.9 mm, NMNS (HPW00428), coll. M.-R. Wang, 12 Sep. 1994; 1 female, 27.2× 34.9 mm, 1 male, 19.4×25.0 mm, NMNS (HPW00652), coll. M.-R. Wang, 20 May 1995; 2 females, 24.4× 32.2 mm, 25.2× 34.1 mm, NMNS –L20000224, coll. M.-R. Wang, 24 Feb. 2000; 2 males, 25.0×33.0 mm, 29.9×39.0 mm, NMNS –L20000323, coll. M.-R. Wang, 23 Mar. 2000; 5 males, 26.4×36.0–28.3× 37.1 mm, 4 females (2 ovig.), 27.0×34.9–32.0× 42.7 mm, NMNS –L20000529, coll. M.-R. Wang, 29 May. 2000; 2 females (2 ovig.), 31.4× 39.2 mm, 38.3× 46.2 mm, NMNS –L20010426, 10– 40 m, coll. M.-R. Wang, 26 Apr. 2001; 4 males, 25.5×34.9–26.0× 34.9 mm, 2 females (ovig.), 26.1× 34.4 mm, 26.6× 36.3 mm, NMNS (CSM20010703), coll. M.-R. Wang, 3 Jul. 2001; 3 females (ovig.), 26.1×35.0–26.7× 36.3 mm, NMNS –L20010808, coll. M.-R. Wang, 8 Aug. 2001; 3 males, 30.1×39.4–32.9× 41.1 mm, 2 females (2 ovig.), 27.6× 35.9 mm, 33.4× 41.4 mm, NMNS –L20030724, coll. M.-R. Wang, 24 Jul. 2003; 1 male, 26.6× 35.9 mm, NMNS –L 20031030, coll. M.-R. Wang, 30 Oct. 2003. Keziliao. 1 male, 26.2× 35.7 mm, NTOU –L20140424, coll. Y.-J. Shih, 24 Apr. 2014.

Comparative material. Myra celeris . YiLan County: 1 male, 31.2× 40.1 mm, NTOU –L19850316, coll. J.-F. Huang, 16 Mar. 1985; 1 male, 26.2× 33.8 mm, NTOU –L19910305, coll. J.-F. Huang, 0 5 Mar. 1991. Dasi. 3 males (1 juvenile), 20.5×26.68–28.8× 32.2 mm, 1 female, 18.9× 20.9 mm, NTOU –L19921024, coll. J.-F. Huang, 24 Oct. 1992; 1 male, 26.7× 35.2 mm, NTOU –L19970821, coll. S.-H. Wu, 21 Aug. 1997; 1 male, 29.6× 38.7 mm, NTOU – L19971002, coll. S.-H. Wu, 2 Oct. 1997; 1 male, 28.3× 37.9 mm, NMNS –L19980316, coll. H.-T. Hung, 16 Mar. 1998; 2 males, 18.2×23.1–27.9× 36.2 mm, 1 female, 17.0× 21.5 mm, NTOU –L20090616, coll. W.-J. Huang, 16 Jun. 2009; 1 male, 20.3× 26.6 mm, NTOU –L20110831, coll. W.-J. Huang, 31 Aug. 2011. Kaohsiung City: Mituo. 1 female, 26.1× 34.2 mm, NTOU –L19880403, coll. J.-F. Huang, 0 3 Apr. 1988. Jhongyun. 1 male, 27.2× 35.5 mm, NMNS –L20010426, coll. M.-R. Wang, 26 Apr. 2001. Pingtung City: Tungkang. 1 male, 32.4×42.0 mm, TMCD 000415, coll. J.-Y. Wei, 14 Dec. 1967. Taitung City: 1 female, 26.4× 34.9 mm, NTOU –L19911011, coll. J.-F. Huang, 11 Oct. 1991.

Myra biconica . Tainan City: 1 male, 23.1×33.0mm, TMCD 000418, coll. J.-Y. Wei, 18 Dec. 1967; 1 female, 24.7× 31.4 mm, TMCD 000419, coll. J.-Y. Wei, 18 Dec. 1967. Kaohsiung City: 1 male, 37.7× 46.5 mm, TMCD 000416, coll. J.-Y. Wei, 15 Oct. 1974; 1 female, 37.9× 47.8 mm, TMCD 000417, coll. J.-Y. Wei, 15 Oct. 1974. Mituo. 1 female, 19.3× 25.5 mm, NTOU –L19920130, coll. J.-F. Huang, 30 Jan. 1992; 1 male, 25.5× 32.7 mm, 1 female, 18.9× 24.4 mm, NTOU –L19930107, coll. J.-F. Huang, 0 7 Jan. 1993. Jhongyun. 1 female, 23.3× 31.3 mm, NMNS –L20020718, coll. M.-R. Wang, 18 Jul. 2002. Keziliao. 2 females, 25.1× 32.1 mm, 25.5× 32.8 mm, NTOU – 20140611, coll. Y.-J. Shih, 11 Jun. 2014. Dalinpu. 1 female, 32.4× 40.4 mm, NMMBCDA196, coll. P.-H. Ho, 0 7 Sep. 2002. Pingtung City: Tungkang. 1 male, 17.2× 22.2 mm, 1 female, 25.9× 33.3 mm, NMMBCDA688, coll. S.- C. Chuang, 22 Sep. 2004; 2 males, 18.7×20.1–23.4× 32.2 mm, 1 female, 17.7× 23.3 mm, NMMBCDA697, coll. S.- C. Chuang, 23 Sep. 2004; 1 female, 12.5× 18.4 mm, NMMBCDA794, coll. S.-C. Chuang, 23 Sep. 2004.

Remarks. Crabs of the genus Myra are common in Taiwan and M. fugax has already been reported from Taiwan ( Lin 1949; Chang 1963; Wang & Chen 1981; Dai et al. 1986; Dai & Yang 1991; Huang 1994; Jeng et al. 1998; Ng et al. 2001). However, the only Taiwanese specimens available to Galil (2001) were M. celeris Galil, 2001 (NTOU–L19921024). We examined most of the available material and confirm that three species are present: M. celeris , M. biconica Ihle, 1918 , and M. fugax . Myra celeris is widely distributed in Taiwan except in the eastern part, whereas M. fugax and M. biconica are mainly found in southern Taiwan, but the former can sometimes be found in northeastern Taiwan, its distribution overlapping with M. celeris . Myra biconica is less common and found in southern Taiwan only (Ng et al. 2001). As M. biconica may be confused with M. digitata Galil, 2004 , we re-examined the specimens from Taiwan and confirm they are indeed M. biconica .

Galil (2001, 2004) utilized the form of G1 to differentiate species of Myra . Carapace and cheliped characters of the three species from Taiwan can nevertheless be used in most cases to identify adult specimens, regardless of sex, Myra celeris is easily distinguished from the other species in having fingers that are about half as long as the palm ( Fig. 4 C), whereas in M. fugax and M. biconica the fingers almost equal the length of the palm ( Figs. 4A, 4 E). The median posterior carapace spine in M. fugax is distinctly longer than in M. biconica ( Figs. 4B, 4 F), whereas in M. celeris , while it is long, is more acute ( Fig. 4 D). Juveniles of these three species are difficult to identify.

Figures

FIGURE 1. A, Ebalia nudipes Sakai, 1963 (male, 11.8 × 12.1 mm, ZRC 2015.277); B, Galilia petricola Komai & Tsuchida, 2014 (male, 25.4 × 28.2 mm, NTOU – DW 4095); C, Nursia rhomboidalis (Miers, 1879) (female, 18.8 × 13.9 mm, NMNS – L 19930529); D, Myra fugax (Fabricius, 1798) (male, 26.2 × 35.7 mm, NTOU – L 20140424).

FIGURE 4. A, B, Myra fugax (Fabricius, 1798) (female, 25.4 × 32.6 mm, NTOU – L 19930107); C, D, M. celeris Galil, 2001 (female, 17.0 × 21.5 mm, NTOU – L 20090616), E, F, M. biconica Ihle, 1918 (female, 25.1 × 32.1 mm, NTOU – L 20140611). A, C, E, cheliped; B, D, F, posteromedian spine of carapace. Scales = 5.0 mm.