Macrophthalmus (Macrophthalmus) milloti Crosnier, 1965

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 : 464-466

Macrophthalmus (Macrophthalmus) milloti Crosnier, 1965

( Figs. 9 , 10 )

? Macrophthalmus podophthalmus— Lanchester 1900: 760. (not M. podophthalmus Souleyet, 1841 )

Macrophthalmus telescopicus— Kemp 1919: 387 (part), pl. 24(11) [not pl. 24(10) = M. serenei Takeda & Komai, 1991 ]. (not M. telescopicus Owen, 1839 )

Macrophthalmus cf. telescopicus— Tweedie 1937: 164; 1950, 128 (part).

Macrophthalmus milloti Crosnier, 1965: 112 , figs. 217–220, 222, 223, 228, pl. 11(4) [type locality: Madagascar]; 1975: 737; Barnes 1977: 276 (key); Takeda & Komai 1991: 166, fig. 1.

Macrophthalmus (Macrophthalmus) milloti— Barnes 1967: 203 (list); Seréne 1973: 112, pl. 4(A–C); Barnes 1976: 135, fig. 3; Takeda & Nunomura 1976: 81; Morgan 1990: 60; Komai et al. 1995: 116, fig. 6; Davie 2002: 352, 353; Nagai et al. 2006: 13 (key), figs. 4g, h, 5e, f, i; Ng et al. 2008: 237 (list); Rahayu & Nugroho 2012: 24 , fig. 3C, D.

? Macrophthalmus (Macrophthalmus) telescopicus— Barnes 1967: 205 (part), pl. 1(a); 1970: 219.

Macrophthalmus verreauxi— Jeng 1997: 18, 22 (list). (not M. verreauxi H. Milne Edwards, 1848 )

Macrophthalmus serenei— Ng et al. 2001: 38 (list). (not M. serenei Takeda & Komai, 1991 )

Material examined. Taiwan: 1 ♀ (12.2 mm) ( ASIZ C684 J0177), Nanwan, Pingtung, coll. M.-S. Jeng, 14 Mar. 1987; 1 ♀ (11.5 mm) ( ASIZ 70999), Nanwan, Pingtung, coll. M.-S. Jeng, 8 Mar. 1997.

Comparative material. M. milloti: Ryukyu Islands , Japan: 2 ovig. ♀♀ (14.2, 17.0 mm) (RUMF-ZC-276), Iriomote Island, coll. T. Naruse, 24 Mar. 2005; 1 ♂ (9.4 mm), 2 ♀♀ (12.6, 14.4 mm, incl. 1 ovig.) (RUMF-ZC- 277), Ishigaki Island, coll. T. Naruse, 13 Apr. 2005; 1 ♂ (8.4 mm) (RUMF-ZC-278), Ishigaki Island, coll. H. Oka & T. Masumoto, 21 Aug. 2005; 1 ♂ (15.7 mm) (RUMF-ZC-279), Nakagusuku Bay, Okinawa Island, coll. H. Oka et al., 25 Aug. 2005. M. serenei : Thailand: 1 ♂ (7 mm) (NCHUZOOL 14770), Amphoe Mueang, Phuket, coll. H.- T. Shih, 29 May 2012. Indonesia: 2 ♂♂ (12.3, 13.5 mm) (NCHUZOOL 14771), Nusa Dua, Bali, coll. H.-T. Shih, 16 July 2014.

Diagnosis. Carapace ( Fig. 9 J) smooth, 1.6–1.7 times wider than long; posterolateral region with clumps of granules; 3 well separated anterolateral teeth. Largest carapace width across first lateral teeth. Eyestalks slender, cornea exceeding first anterolateral tooth about one fourth of eyestalk length. Middle portion of epistome protuberant. Outer surface of palm ( Fig. 9 L) with ridge near lower margin, extending to immovable finger. Cutting edges of fingers armed with small tuberculate teeth proximally; dactylus length almost equal to palm. Female gonopore with suboval operculum ( Fig. 9 K), directed mesially; deep depression on sternite of sixth thoracic somite mesial to gonopore.

Distribution. Red Sea, East Africa ( Zanzibar, Comoros, Madagascar), India (Gulf of Mannar, Andaman Islands), Thailand (Phuket), Singapore ( Pulau Senang), Indonesia, Japan (Ryukyu Islands), Taiwan (Pingtung), New Guinea, New Caledonia, Fiji, Hawaiian Island, and Australia (Torres Strait, Queensland, Lord Howe Island, Descartes Island, Shirley Island).

Habitat. Coral reefs, sandy mud ( Komai et al. 1995).

Remarks. The two female specimens from Taiwan agree well with the description of M. milloti ( Takeda & Komai 1991; Komai et al. 1995). The Taiwanese specimens form a clade with those from the Ryukyu Islands, sister to M. serenei , based on molecular evidence ( Fig. 11 ).

The diagnosis of males, based on the specimens from the Ryukyu Islands, is as follows. Palm ( Fig. 9 B) of cheliped stout, outer surface smooth, with a raw of indistinct ridge close to lower margin; inner surface covered with long setae to base of fingers. Immovable finger straight, near middle of cutting edge with triangular tooth; proximal region of cutting edge of dactylus with square tooth. Terminal process of G1 ( Fig. 9 D–I) elongated, directed outward, with short thumb-like projection dorsally.

This species is similar to M. serenei , and both species belong to the group of M. telescopicus Owen, 1839 ( Barnes 2010) . Macrophthalmus milloti , however, has shorter eyestalks and a shorter terminal G1 process than in M. serenei .

DNA results and discussion. A 567 bp segment of the 16S and 658 bp segment of COI from 17 species of macrophthalmids and four species of outgroups were amplified and aligned ( Table 1). The phylogenetic tree of the combined markers was reconstructed from Bayesian inference analysis, with the support value from the maximum likelihood analysis ( Fig. 11 ). Although the genus Macrophthalmus is monophyletic with high supports, further subdivision within the genus is not clear, which is similar to the result of Kitaura et al. (2006) based on 16S. The relationship of some groups agree with those of Kitaura et al. (2006) and Barnes (2010), including the M. brevis group, the M. convexus group and the M. telescopicus group within the subgenus Macrophthalmus . The M. brevis group is close to M. erato and M. quadratus of the subgenus Paramareotis ; and the close relationship between M. tomentosus and M. pacificus , as well as between M. banzai and M. japonicus . Macrophthalmus purpureocheir sp. nov. is highly supported, sister to M. crinitus , although their relationship is only supported weakly. The same applies to the sister relationship between M. serenei and M. milloti .

Figures

FIGURE 9. Macrophthalmus (Macrophthalmus) milloti Crosnier, 1965. A – I, ♂ (CW 14.4 mm), RUMF-ZC- 277 (3639), from Ryukyu Islands, Japan. A, carapace; B, palm of right chela; C, abdomen; D, ventral view; E, terminal segment of ventral view; F, outer view; G, terminal segment of outer view; H inner view,; I, terminal segment of inner view. J – M, ♀ (CW 12.5 mm), ASIZ C 684 (J 0177), from Pingtung, Taiwan, J, carapace; K, gonopore; L, palm of left chela; M, abdomen.

FIGURE 10. Macrophthalmus (Macrophthalmus) milloti Crosnier, 1965. A – C, ♂ (CW 14.4 mm), RUMF-ZC- 277 (3639), from Ryukyu Islands, Japan; D – F, ♀ (CW 12.5 mm), ASIZ C 684 (J 0177), from Pingtung, Taiwan. A, D, dorsal view; B, C, E, ventral view; F, frontal view.

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).