Ocypode ceratophthalmus (Pallas, 1772)

(Fig. 2)

Cancer ceratophthalmus Pallas, 1772: 83, pl. 5, figs. 7, 8 (unknown locality); Fabricius, 1781: 499.

Ocypode ceratophthalma – Sakai & Türkay, 2013: 685 (Sumatra; Nias Island; We Island; Padang; Bengkulu; Lampung; Java Sea; Jakarta Bay, Java; Lesser Sunda Islands; Lombok Island; Flores Island; Sumba Island; Dobo Island; Ambon Island; Kalimantan; Cendrawasih Bay, Papua), figs. 1D–I, 10A–E, 32A–C.

Ocypoda ceratophthalma – Tesch, 1918: 36 (Labuan Bajo, Flores; Solor Island, East Nusa Tenggara; Makassar, Sulawesi; Kaniungan Island, east of Kalimantan; Sulu Archipelago; Talaut Islands, Karakelang; west coast of Seram Island; Kei Island); Wada, 2019: e147 (Lukupang, Sulawesi).

Ocypode ceratophthalmus – Shih et al., 2015: 159 (Southeast Asia).

Material examined. 9 males (13.7 × 11.4 mm – 26.1 × 22.8 mm), 3 females (16.8 × 13.7 – 21.9 × 18.7 mm) (MZB. Cru. 4913), Liki Village, Sarmi District, Sarmi Municipality, Liki Island, Papua Province, 01º37′27.46″S 138º44′29.96″E, 22 November 2018, DC Murniati, SNI Raharjo, Melati ; 10 males (14.1 × 12.0 mm – 38.7 × 34.1 mm) (MZB. Cru. 5017), Masyai Village, West Supiori District, Supiori Municipality, Bepondi Island, Papua Province, 00º24′37.30″S, 135º16′02.17″E, 22 November 2018, DC Murniati & SNI Raharjo ; 1 male (32.7 × 28.1 mm) (MZB. Cru. 532), Lampung, Sumatra Island, 08 November 1975, F Sabar ; 1 male (22.6 × 19.1 mm) (MZB. Cru. 1918), Seribu Islands, near Jakarta, 21 May 1972, Sidabutar ; 1 male (41.7 × 37.6 mm) (MZB. Cru. 1634), Adonara Timur, East Nusa Tenggara, 02 June 1982, D Wowor ; 1 male (31.7 × 28 mm) (MZB. Cru. 2683), Teluk Terima, Gerokgak, Buleleng, Bali, 18 July 2009, Dian & DC Murniati ; 1 male (40.2 × 35.7 mm) (MZB. Cru. 1996), Mumes Beach, Waigeo Island, Raja Ampat, Papua, 12 June 2007, CM Sidabalok .

Remarks. The morphology of the present specimens agrees well with the description and figures by Sakai & Türkay (2013). The inner surface of the major palm has a stridulating ridge which consists of 30–49 elements (tubercles and striae) (Fig. 2B), and the G1 is three sided proximally and has a small thumb-shaped projection subdistally (Fig. 2M–N). There are variations in the number of stridulatory elements on the inner surface of the palm of the major cheliped (35–51) and minor chelipeds (0–10). These variations are related to size of the carapaces. Larger crabs have a larger number of stridulatory elements. On the inner surface of the palm of the minor cheliped, only specimens with more than 40.0 mm cw have this element (Fadhillah et al., 2018).

This species inhabits high intertidal areas with sandy substrate and is typically nocturnal. They are widely distributed in the Indonesian Archipelago; i.e., Sumatra Island, Java Island, Sulawesi Island, the Lesser Sunda Islands, the Moluccas, the Aru Islands, and Papua (Rathbun, 1910; Tesch, 1918; Sakai & Türkay, 2013; Wada, 2019). The present study gives a new distribution record of the species in Indonesia.