Macrophthalmus serenei Takeda & Komai, 1991

Naderloo, Reza, Türkay, Michael & Apel, Michael, 2011, Brachyuran crabs of the family Macrophthalmidae Dana, 1851 (Decapoda: Brachyura: Macrophthalmidae) of the Persian Gulf, Zootaxa 2911, pp. 1-42 : 27-29

Macrophthalmus serenei Takeda & Komai, 1991

( Figs. 15 a–e, 16a–e, 17c, d)

Macrophthalmus verreauxi — Nobili 1906b: 317. — Sakai 1976: 610, 378.

Macrophthalmus (Macrophthalmus) verreauxi — Serène 1973: 107, figs. 2a–b, pl. 3, figs. C–D. — Barnes 1976: 135, fig. 1; 1977: 276 (in key). [not Macrophthalmus verreauxi H. Milne-Edwards, 1848: 358 = Macrophthalmus telescopicus (Owen, 1839) ]

Macrophthalmus telescopicus — Basson et al. 1977: 231, 256. — Titgen 1982: 253 (in list). — Vousden 1987: 35.

Macrophthalmus (Macrophthalmus) kempi Serène 1982: 1140 .

Macrophthalmus serenei Takeda & Komai 1991: 168 , figs. 3a–e.

Macrophthalmus (Macrophthalmus) serenei — Komai et al. 1995: 122, fig. 9a–p. — Apel 2001: 109, 110. — Barnes 2010: 34 (in key), 40.

Type locality. Macrophthalmus serenei : Red Sea and Gulf of Aden.

Material examined. Holotype: 1 male ( MNHN B12617), Red Sea, Perim and Obock, Jousseaume, 1879; Paratypes: 4 males, 1 female, 7 juv. ( MNHN B12618), type locality same as holotype.

Persian Gulf: 1 male ( SMF 36098) (CL = 17.8, CB = 11.7 mm), Saudi Arabia, N. Jubail, Abu Ali, 27º 18.833'N, 49º 57'E, 0 8.04.1993, M. Richmond; 1 male ( SMF 36099), Saudi Arabia, N. Jubail, southern entrance of Dauhat al Musallamiya, 27º 24.09'N, 49º 13.53'E, rocky shore, 23.07.1992, M. Apel.

Redescription. Carapace ( Figs. 17 c, d) wider than long (CB/CL = 1.5), relatively convex, small granules set sparsely on lateral region of carapace, some relatively large ones in groups of 2–5; transverse row of low tubercles extending curvedly from middle of third lateral tooth toward central region. Regions well defined, epibranchial furrow relatively deep. Frontal region smooth; front narrow, about 0.19 times as wide as carapace, anterior edge bilobed.

Lateral margin ( Fig. 15 a) with three distinct teeth including exorbital angle; exorbital angle oblongly triangular, directed laterally, larger than second, maximum carapace width between first teeth; second broadly triangular, directed laterally; third smallest, but well discernible.

Eyestalk narrow ( Figs. 15 a, 17c, d), remarkably long, about 3/4 as long as carapace width, extending beyond exorbital angle.

Chelipeds ( Figs. 15 c, d) equal. Merus ( Fig. 15 b) with upper surface smooth, bearing some round tubercles near inner margin; outer margin fully covered with denticles, larger distally, distal portion smooth; upper inner margin sparsely set with small granules, denticles on distal portion; lower margin with small granules; inner surface smooth, with patch of setae. Palm about 1.3 times as long as high in proximal portion, outer surface ( Fig. 15 c) with small granules on most of it, granular ridge on lower portion, extending from subproximal part almost to end of immovable finger; lower, upper margins with small granules; inner surface ( Fig. 15 d) smooth, with small granules on proximal portion, small patch of setae covering distal portion of palm, base of both fingers. Movable finger long; upper margin with small granules along whole length; cutting edge with large subproximal tooth, being low, subquadrate. Immovable finger short, with large median tooth, extending proximally. Walking legs stout in comparison to cheliped. Merus with anterior margin being serrated, with sparsely set long setae and large subdistal tooth, merus of fourth legs without this subdistal tooth, posterior margin of merus minutely denticulate, with some large denticles distally, merus of second walking leg about 2.8 times as long as wide, with patch of plumose setae along one fourth of inner margin.

Male abdomen ( Fig. 15 e) moderately narrow; segments 3, 4 of same length; segment 5 about as long as segment 6; lateral margins of segment 6 remarkably swollen proximally, gently converging distally; telson semicircular, shorter than segment 6, about 2 times as long as wide, with margins curved, distally rounded.

Male G1 relatively narrow ( Figs. 16 a, b, c), curved outward medially; apical process remarkably long, narrow, directed ventrolaterally at about 45°; subdistal palp prominent on dorsal surface; distal opening small, located distally on apical process; long setae around apical part, not completely concealing apical process.

Female gonopore ( Fig. 16 e) on outer wall of depression, directed mesially, without operculum; upper margin rounded.

Remarks. Serène (1973) distinguished three species within the M. telescopicus complex: M. telescopicus (Owen, 1839) , M. verreauxi H. Milne-Edwards, 1848 und M. milloti Crosnier, 1965 . A re-examination of the type material of M. verreauxi by the same author, however, revealed that this material was identical with M. telescopicus and that the species that is distinct from M. telescpopicus needs to be renamed. He thus described it as M. kempi ( Serène 1982) . This name, however, was a homonym of M. convexus kempi Gravely, 1927 , and therefore could not be used for another species of the genus ( Takeda & Komai 1991; Komai et al. 1995). Takeda & Komai (1991) thus renamed the species M. serenei .

Macrophthalmus serenei is easily recognisable amongst the Persian Gulf species of the genus by having very long eyestalks, which extend far beyond the exorbital angle. It thus belongs, based on this and other characters, to the Macrophthalmus telescopicus -group ( Barnes 2010).

Komai et al. (1995) mentioned spinules occurring along the lateral face of the terminal process of the G1. In the specimens from the Persian Gulf, such spinules were not seen on the terminal process, instead there are some short setae along lateral surface of the terminal process. Komai et al. (1995) most probably considered these short setae as spinules.

Macrophthalmus serenei has been recorded from the Saudi coast of the Persian Gulf by Basson et al. (1977) (as M. telescopicus ) and by Apel (2001).

Biology. Macrophthalmus serenei is a medium-size species. Nobili (1906b) has given the measurement for the largest male and female of the type series (largest male CL = 10.5, CB = 18 mm, largest female CL =9, CB = 15 mm), the male measurement being almost identical to that of the largest male specimen (CL = 17.8, CB = 11.7 mm) from the Saudi Arabian coast in the Persian Gulf (SMF 36098). Macrophthalmus serenei is an intertidal crab that has been collected on sandy flats ( Basson et al. 1977) and rocky shores ( Apel 2001) of the Saudi Arabian coast of the Persian Gulf.

Geographical distribution. Wide Indo-West Pacific distribution: Madagascar, Red Sea, Persian Gulf, Japan, Eastern Australia.

Figures

FIGURE 15. Macrophthalmus serenei Takeda & Komai, 1991, male (SMF 36098): a, posterior surface of carapace, left side; b, merus of male cheliped, inner surface; c, cheliped of male, outer surface; d, cheliped of male, inner surface; e, male abdomen.

FIGURE 16. Macrophthalmus serenei Takeda & Komai, 1991: a – c, male (SMF 36098); d, e, female (MNHN B 12618). a, G 1 of male, ventral surface (right); b, apical part of G 1, lateral surface; c, apical part of G 1, dorsal surface; d, female abdomen, penultimate segment and telson; e, female gonopore.

FIGURE 17. a, b: Macrophthalmus graeffei A. Milne-Edwards 1873, male (UZM 1782), a, posterior surface; b, ventral surface; c, d: Macrophthalmus serenei Takeda & Komai, 1991, male (SMF 36097), a, posterior surface; b, anterior surface; e, f: Macrophthalmus sinuspersici Naderloo & Türkay, 2010, holotype, male (SMF 3690), e, posterior surface; f, ventral surface.