Macrophthalmus (Mareotis) definitus Adams & White, 1848

Teng, Shao-Jyun & Shih, Hsi-Te, 2015, A new species of Macrophthalmus Desmarest, 1823 (Crustacea: Decapoda: Brachyura: Macrophthalmidae) from Taiwan, with notes on four new records, Zootaxa 4058 (4), pp. 451-470 : 462-464

Macrophthalmus (Mareotis) definitus Adams & White, 1848

( Figs. 7 , 8 )

Macrophthalmus definitus Adams & White, 1848: 51 [type locality: Philippines]; Ortmann 1897: 342; Rathbun 1910b: 307, pl. 2(1); Tesch 1915: 198; 1918: 59; Shen 1940: 234; Barnes 1966: 46; 1977: 278 (key).

Macrophthalmus depressum— Ortmann 1894: 745. (not M. depressus Rüppell, 1830 )

Macrophthalmus teschi— Gordon 1931: 549. (not M. teschi Kemp, 1919 )

Macrophthalmus (Mareotis) definitus— Barnes 1967: 214, fig. 4, pl. ld; 1970: 232; 1971: 17; Lundoer 1974: 8 (list); Takeda 1981: 73, fig. 2; Tai & Song 1984: 82 (key); Dai et al. 1986: 436, pl. 60(7), fig. 243(2); Dai & Yang 1991: 478, pl. 60(7), fig. 243(2); Komai et al. 1995: 126, fig. 10; Rahayu & Setyadi 2009: 118, 1 unnumbered fig.

Macrophthalmus convexus— Hung 2000: 136, fig. 413. (not M. convexus Stimpson, 1858 )

Macrophthalmus erato— Shen & Jeng 2005: 171, 1 unnumbered fig. (not M. erato De Man, 1888 )

Material examined. Taiwan: 1 ♂ (20.8 mm) (NCHUZOOL 14761), Yuanjhonggang, Kaohsiung, coll. J.-H. Lee, 29 Apr. 2011; 1 ♀ (18.2 mm) (NCHUZOOL 14762), Yuanjhonggang, Kaohsiung, coll. Y.-H. Wang, 26 Apr. 2014; 1 ♂ (16.1 mm) (NCHUZOOL 14769), Houwan, Pingtung, 19 Sep. 2013; 1 ♂ (18.6 mm) ( NMNS 003153–00032), Wanlitong, Pingtung, coll. H.-T. Hung, 19 Oct. 1998; 3 ♂♂ (8.5–22.0 mm), 1 ♀ (13.1 mm) (NCHUZOOL 14763), Citou, Penghu, coll. Y.-H. Wang et al., 2 Sep. 2014; 1 ♂ (21.5 mm) (NCHUZOOL 14764), Chihdong, Siyu, Penghu, coll. H.-T. Shih, 18 Oct. 2008; 1 ♀ (19.9 mm) (NCHUZOOL 14765), Shihcyuan, Penghu, coll. H.-T. Shih, 18 Oct. 2008; 2 ♂♂ (14.2, 19.3 mm), 1 ovig. ♀ (21.9 mm) (NCHUZOOL 14766), Tiesian Village, Penghu, coll. Y. - H. Wang et al., 1 Sep. 2014. Comparative material. Ryukyu Islands, Japan: 1 ♂ (2.9 mm) (CEL-Ishigaki-045), Miyara River, Ishigaki Island, coll. P.-C. Tsai & H.-C. Lin, 18 Sep. 2011; 2 ♂♂ (14.0, 16.8 mm), 2 ♀♀ (15.9, 16.3 mm) (CEL-Ishigaki-011), Miyara River, Ishigaki Island, coll. P.-C. Tsai & H.-C. Lin, 18 Sep. 2011.

Diagnosis. Carapace ( Fig. 7 A) 1.3–1.4 times wider than long, 3 anterolateral teeth well separated. First tooth square, blunt; second tooth wider than preceding tooth, more protruding than other two teeth, separated from first tooth by narrow U-shaped incision; third tooth well-defined. Eyestalks slender, cornea not exceeding first anterolateral angle. Middle region of epistome concave. Palm ( Fig. 7 B) of male cheliped stout, outer surface smooth, inner surface of palm, fingers heavily setose, inner surface of palm with large granules close to lower margin; immovable finger deflexed, with cutting edge with large, long, crenulated tooth; cutting edge of dactylus proximally with small, distinct tooth, crenulated distally. G1 ( Fig. 7 G, H) with long apical chitinous process directed laterally at nearly 60°. Female gonopore with semiellipsoidal operculum ( Fig. 7 D), directed mesially, projecting; shallow depression on sternite anteromesial to operculum.

Coloration. Carapace ( Fig. 8 E, F) is grayish brown, with dark brown dots, and the margin of carapace is reddish brown. The pterygostomian region and the male abdomen are dark brown. Thoracic sternites is orangebrown.

Distribution. Thailand (Phuket), Malaysian Peninsula, Japan (Iriomote Island), Taiwan (including Penghu), Philippines, China (Guangdong, Fujian, Hong Kong, Hainan, South China Sea, southern East China Sea), Indonesia (Sulawesi, Sumbawa, Soela Islands), and Solomon Islands.

Habitat. Flat muddy bottoms.

Remarks. See remarks of M. crinitus for differences between the two species. The specimens from Taiwan form a clade with specimen from Phuket, Thailand, based on molecular evidence ( Fig. 11 ), which further supports the identity of the Taiwanese specimens. Two records of macrophthalmids from Penghu, Taiwan previously identified as M. erato ( Shen & Jeng 2005: 171, 1 unnumbered fig.) and M. convexus ( Hung 2000: 136, fig. 413), actually based on the same photograph, agree well with the characters of M. definitus , including the lower orbital margin, first anterolateral tooth, and coloration.

Figures

FIGURE 7. Macrophthalmus (Mareotis) definitus Adams & White, 1849. A – B, E – H: ♂ (CW 21.5 mm), NCHUZOOL 14764, from Penghu, Taiwan; C – D: ♀ (CW 21.9 mm), NCHUZOOL 14766, from Penghu, Taiwan. A, male carapace; B, palm of male left chela; C, palm of female left chela; D, gonopore; E, male abdomen; F, female abdomen; G, H, terminal segment of right G 1, G, ventral view; H, dorsal view.

FIGURE 8. Macrophthalmus (Mareotis) definitus Adams & White, 1849. A – D, ♂ (CW 22.0 mm), NCHUZOOL 14763, from Penghu, Taiwan. A, dorsal view; B, C, ventral view; D, frontal view. E, F, ♂, color in life.

FIGURE 11. A Bayesian inference (BI) tree of the macrophthalmid species and outgroups used in this study, based on the combined 16 S rRNA and cytochrome oxidase subunit I (COI) genes. See Table 1 for details of the specimens. Probability values at the nodes represent support values for BI and maximum likelihood (ML).