Macrophthalmus (Paramareotis) quadratus A. Milne-Edwards, 1873

Rahayu, Dwi Listyo & Nugroho, Dharma Arif, 2012, The Indonesian species of Macrophthalmus Desmarest, 1823, with the description of a new species (Crustacea: Decapoda: Brachyura: Macrophthalmidae), Zootaxa 3158, pp. 20-36 : 33

Macrophthalmus (Paramareotis) quadratus A. Milne-Edwards, 1873

( Figures 8B , C)

Macrophthalmus quadratus A. Milne-Edwards, 1873: 280 , pl. 12, fig. 6.

Macrophthalmus (Mareotis) quadratus — Barnes 1971: 17, fig. 4.

Macrophthalmus (Paramareotis) quadratus — Komai et al. 1995: 141, fig. 15. — Barnes 2010: 42.

Material examined. 1 male (6.36 x 8.01 mm) (RCLA-C.B.0276), 1 female (4.72 x 5.45 mm) ( MZB Cru 3279), Teluk Kombal, Lombok, 0 9.06.2009.

Remarks. Macrophtalmus quadratus is characterized by a large and strongly pointed exorbital angle that overreaches the second anterolateral tooth, the presence of 3−5 large lobules or protuberances followed by about seven bluntly pointed granules on the lower orbital margin, a short horny ridge on the inner margin of the meri of the male chelipeds, a row of granules along the middle of the surface of the fixed finger of the male chelipeds, and the thick setae on the upper margin of the pereopods meri and on the upper margin of the propodus of the third pereopod ( Barnes, 1971, Komai et al., 1995).

The two specimens in the present study agree well with the description of the species by Barnes (1971) and Komai et al. (1995). Several differences were noted, however. The lobules or protuberances on the lower orbital margin in the male specimen are replaced by a row of large pointed granules, the pereopods are glabrous except for very sparse hair on the upper and lower margin of the meri and carpi of pereopods 3−5, and on the propodi and dactyli of pereopods 4 and 5. It is impossible to tell whether these differences represent only variations within the species or if they represent a distinctive species because only one male and a juvenile female were examined.

Habitat. Muddy sand flat of mid intertidal area near seagrass beds.

Geographical distribution. New Caledonia, Andaman Sea coast of Thailand (Phuket), Indonesia ( Maluku; Barnes 1971), and now Lombok.

Figures

FIGURE 8. A, B, Macrophthalmus (Paramareotis) erato De Man, 1888, male (7.97 x 11.27 mm) (RCLA-C. B. 0274); C, D, Macrophthalmus (Paramareotis) quadratus A. Milne-Edwards, 1873, male (6.36 x 8.01 mm) (RCLA-C. B. 0276); E, F, Macrophthalmus (Venitus) latreille Desmarest, 1877, male (20.79 x 28.84 mm) (RCLA-C. B. 0277).