Ilyograpsus rhizophorae Barnard, 1955

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: 3-5

publication ID 10.5281/zenodo.203098

persistent identifier

treatment provided by


scientific name

Ilyograpsus rhizophorae Barnard, 1955


Ilyograpsus rhizophorae Barnard, 1955 

( Figs. 1View FIGURE 1, 2View FIGURE 2 a –j, 3 a, b)

Ilyograpsus rhizophorae Barnard 1955: 26  , fig. 8. — Kensley 1981: 46 (in list). — Sawada et al. 2005: 862. — Komai & Wada 2008: 361, figs. 2–5.

Ilyograpsus paludicola  — Crosnier 1965: 31–33, figs. 36 –37, 38 a –b, 39, 59. — Fishelson 1971: 128. — Basson et al. 1977: 228, 234. — Titgen 1982: 254 (in list). — Jones 1986: 160, pl. 46. — Vousden 1987: tab. 4. — Ismail & Ahmed 1993: 158. — Hywel-Davies 1994: 37, 48. — Apel 1996: 331 (in list). — Al-Ghais & Cooper 1996: 415. — Tirmizi & Ghani 1996: 143, fig. 55. — Hornby 1997: 14. — Apel & Türkay 1999: 132. — Apel 2001: 117 [not Ilyograpsus paludicola Rathbun, 1909  ].

Ilyograpsus vanninii  — Sawada et al. 2005: 853 (part), fig. 5 b, d, f.

Type locality. Inhambane, Mozambique (East Africa).

Examined material. Persian Gulf ( Iran): 2 females (1 ovig.), 2 juv. ( ZUTC brach 1265) Qeshm I., S. coast, 26 º 43 'N, 55 º 49 'E, sandy flat with patch of dead corals, 0 9.01. 2008, R. Naderloo & M. Türkay; 2 males ( ZUTC brach 1262), Qeshm I., N coast, 3 km W. of Kuweii, 26 º 57 'N, 56 º 00'E, muddy flat, 13.01. 2008, R. Naderloo & M. Türkay; 3 males, 9 females (6 ovig.) ( ZUTC brach 1261), Qeshm I., 2 km E. of desalination centre, 26 º 56 'N, 55 º 47 'E, muddy sand with shells, 15.12. 2008, R. Naderloo & M. Türkay; 1 female (ovig.) ( ZUTC brach 1263), 15 km E. of Bandar-Deylam, behind Boyrat police station, 29 º 56 'N, 50 º 08'E, muddy flat, 23.05. 2008, R. Naderloo, A. Kazemi & H. Salehi; 3 females ( ZUTC brach 1264), Qeshm I., Dargahan, 26 º 58 'N, 56 º 04'E, sandy mud-flat, with planted mangroves, 13.01. 2008, R. Naderloo & M. Türkay; 1 female ( SMF 36856View Materials), Qeshm I., Zeyton (olive) park beach, 27 º 11 'N, 56 º 24 'E, rocky with dead corals, 0 8.01. 2008, R. Naderloo & M. Türkay; 1 male ( SMF 36857View Materials), Bandar-Khamir, E. fishery Jetty, 26 º 56 'N, 55 º 36 'E, muddy flat, water channel, 24.04. 2008, R. Naderloo, A. Kazemi, & A. Keykhosravi; 2 females (ovig.) ( SMF 36858View Materials), Bandar-Emam, Park Saheli, 30 º 28 'N, 49 º 04'E, muddy flat with artificial rocky structure covered with Saccostrea  sp., 20.05. 2008, R. Naderloo, A. Kazemi & H. Salehi; 2 males, 3 females ( SMF 36859View Materials), Khalij-Nayband, mangroves, 27 º 23 'N, 52 º 39 'E, muddy substrate, 0 5.01. 2005, R. Naderloo & A. Kazemi; 2 males, 1 female ( SMF 36860View Materials), Bandar-Khamir, E. fishery Jetty, 26 º 56 'N, 55 º 36 'E, sandy mud-flat, 0 7.06. 2006, R. Naderloo & A. Kazemi; 1 male ( SMF 36861View Materials), Bandar-Khamir, E. of City, behind mangroves, 26 º 28 'N, 55 º 35 'E, muddy substrate, 31.12. 2005, R. Naderloo, A. Kazemi.

Gulf of Oman: ( Iran): 3 females ( SMF 36862View Materials), Khor-Khalasi, 25 º 35 'N, 58 º 02'E, mangroves, muddy substrate among trees, 20.11. 2005, R. Naderloo & A. Kazemi.

Comparative material. Ilyograpsus rhizophorae Barnard 1955: 1  male, 2 female (NHM 1984: 416), Pakistan, Manora I. mangroves, Karachi, 0 4.03. 1982, N.M. Tirmizi & N. Ghani. Ilyograpsus paludicola Rathbun, 1909: 1  male, 2 females ( ZRC 1998.1030), Indonesia, Pulau Bintan, P.K.L. Ng & C.G.S. Tan, June. 1995, det. T. Komai.

Redescription. Carapace nearly subquadrate ( Figs. 1View FIGURE 1, 3View FIGURE 3 a), slightly wider than long (CL/CB = 1.18), maximum width between third lateral teeth; posterior surface uneven, relatively convex, regions poorly defined; 2 transverse ridges on frontal region, smooth, straight; without epigastric ridges; several transverse ridges on posterolateral region, short, oblique. Front relatively broad, about 0.4 times as wide as carapace, broadly bi-lobed, lobes slightly extending beyond inner orbital angle. Anterolateral margin with 4 distinct teeth, first (exorbital angle) largest, acute, wide triangular, directed forwards; second blunt, as long as first, slightly higher than latter; insetting between first, third teeth; third acute, triangular, highest among all teeth; fourth very small, acute; posterolateral margin nearly subparallel, converging posteriorly ( Fig. 1View FIGURE 1).

Eyestalks moderately long, orbit slightly more than one fourth of maximum carapace width, upper orbital margin slightly sinuous; lower orbital margin of males ( Fig. 2View FIGURE 2 a) with 3, 4 long tubercles; lower orbital margin of females ( Fig. 2View FIGURE 2 b) with numerous denticles, irregular, variously-sized, larger laterally.

Third maxilliped ( Fig. 2View FIGURE 2 f) with moderately large gap; ischium about 1.5 times as long as merus, with wide elevation near inner margin, short setae scarce along inner margin; merus short, much shorter than wide, with relatively narrow elevation near inner margin, short setae scarce on inner margin; exopod proximally wide, narrowing distally.

Chelipeds relatively small; upper margin of merus minutely serrated, with small subdistal spine; lower inner margin finely serrated proximally, distally denticulated, slightly expanded; lower outer margin denticulate; plectrum ( Fig. 2View FIGURE 2 e) on inner surface near lower margin, distinct, short. Manus ( Fig. 2View FIGURE 2 c) about 2.4 times as long as high, slightly longer than movable finger; outer surface smooth, very small, sparse granules on upper portion; lower margin concave in middle part; inner surface smooth, patch of dense setae on distal portion, extending to proximal part of fingers. Fingers relatively narrow, long, smooth, narrow gap between fingers, wider distally; long setae along inner, outer margins of cutting edge; movable finger with cutting edge slightly elevated proximally, with small, variously-size denticles; immovable finger with small denticles on cutting edge, large ones on middle portion; tip of fingers spoon-shaped. Cheliped of females ( Fig. 2View FIGURE 2 d) narrow, long, about 3.2 times as long as high; merus with small subdistal spine on upper margin, stridulating ridge on inner surface; palm without patch of setae on inner surface; cutting edge of fingers scarcely with small denticles; gap between fingers becoming slightly wider distally.

Walking legs ( Fig. 1View FIGURE 1) relatively long, moderately slender, flattened; second, third largest; merus with large subdistal spine, anterior margin sinuous, faintly serrate, posterior margin nearly straight, merus of fourth leg about 2.6–2.9 times as long as wide (around 2.0 in females); propodus with distal spine on posterior margin, fourth walking legs with short setae along anterior, posterior margins; dactylus narrow, long, unarmed.

Male abdomen ( Fig. 2View FIGURE 2 g) moderately narrow, segments 4, 5 longest, of equal length; segment 6 about 1.75 as wide as long, lateral margin nearly straight on anterior half, converging posteriorly; telson longer than wide, slightly longer than segment 6, posteriorly rounded.

Male G 1 ( Figs. 2View FIGURE 2 i, j) narrow, straight, slightly curved mesially, apical process long, slightly bent laterally, with depression on lateral surface, distal opening distally on lateral surface; long setae along apical process, short setae scarce along lateral, ventral surface.

Female gonopore ( Fig. 2View FIGURE 2 h) with elevated lateral lobe; operculum small, hinging on inner margin, directed outwards.

Remarks. Ilyograpsus paludicola (Rathbun, 1909)  has been frequently recorded from the Persian Gulf ( Basson et al. 1977; Titgen 1982; Jones 1986; Vousden 1987; Ismail & Ahmed 1993; Hywel-Davies 1994; Apel 1996; Al-Ghais & Cooper 1996; Tirmizi & Ghani 1996; Hornby 1997; Apel & Türkay 1999; Apel 2001). We collected a large number of specimens from the different sections of the Iranian coast of the Persian Gulf. Precise examination revealed that the Persian Gulf species clearly belongs to I. rhizophorae Barnard, 1955  . Morphological differences between these two species as listed by Komai & Wada (2008) are all seen between the Persian Gulf specimens and specimens of I. paludicola  (one male and one female, ZRC 1998.1030). In particular, the G 1 of the present specimens has a terminal process that is narrow and long, curved laterally, resembling to that of I. rhizophorae  . Persian Gulf specimens, however, are slightly different from I. rhizophorae  from other regions regarding the length/width ratio of the merus of the fourth walking leg. In our specimens, this proportion in males is smaller than 3.00 (about 2.6–2.9) in males and about 2.00 in females, whereas the length/width merus ratio of the fourth leg of I. rhizophorae  is about 3.48–3.84 in male and 2.52 in females ( Komai & Wada 2008).

Komai & Wada (2008), in their revision of Ilyograpsus  , did not record any specimens of I. rhizophorae  from the Persian Gulf and did not refer to the numerous published records from the region (see above). Nevertheless, they mentioned that the species recorded from Pakistan ( Tirmizi & Ghani 1996) is likely to be identical with I. paludicola  . We examined material from Pakistan (one male and one female, NHM 1984: 416) which is clearly I. rhizophorae  . Ilyograpsus rhizophorae  is thus widely distributed in the western Indian Ocean ( Komai & Wada 2008) including the Red Sea, Gulf of Oman and the Persian Gulf, whereas I. paludicola  occurs in eastern India and the western Pacific, including Thailand (type locality), Indonesia, Malaysia to Vietnam, Australia and New Caledonia, but does not extend into the western Indian Ocean.

Biology. Ilyograpsus rhizophorae  is a small-size species (largest male CL = 4.92, CB = 5.60 mm, largest female CL = 9.65, CB = 11.64) usually found in the lower intertidal zone of muddy substrates. They are among the most common crabs in mangroves, occurring among trees and pneumatophores. In one case a male was found underneath the bark of a decaying trunk of the mangrove Avicennia marina  . The carapace of I. rhizophorae  is dirty white to whitish brown, with the appendages being slightly lighter than the carapace. There are irregular light brown bands on the legs, being more distinct on the distal part of carpus and propodus. The ventral surface of the carapace is lighter than the dorsal surface. Flores et al. (2003) described the first zoeal stage of I. paludicola  from East Africa, but based on the present study and Komai & Wada (2008), their larvae can be attributed to I. rhizophorae  .

Geographical distribution. Western Indian Ocean: Madagascar, Mozambique, East Africa, Gulf of Aden, Red Sea, Persian Gulf, Pakistan.


Forschungsinstitut und Natur-Museum Senckenberg


Zoological Reference Collection, National University of Singapore














Ilyograpsus rhizophorae Barnard, 1955

Naderloo, Reza, Türkay, Michael & Apel, Michael 2011

Ilyograpsus rhizophorae

Komai 2008: 361
Sawada 2005: 862
Barnard 1955: 26

Ilyograpsus vanninii

Sawada 2005: 853

Ilyograpsus paludicola

Apel 2001: 117
Apel 1999: 132
Hornby 1997: 14
Apel 1996: 331
Al-Ghais 1996: 415
Tirmizi 1996: 143
Hywel-Davies 1994: 37
Ismail 1993: 158
Jones 1986: 160
Titgen 1982: 254
Basson 1977: 228