Gelasimus jocelynae ( Shih, Naruse and Ng, 2010 )

Murniati, Dewi Citra, Asakura, Akira, Nugroho, Dharma Arif, Hernawan, Udhi Eko & Dharmawan, Wayan Eka, 2022, On a collection of thoracotreme crabs (Crustacea: Brachyura: Ocypodidae, Macrophthalmidae, Dotillidae) from two offshore islands of Papua, eastern Indonesia, with descriptions of two new species, Raffles Bulletin of Zoology 70, pp. 461-491 : 466-469

Gelasimus jocelynae ( Shih, Naruse and Ng, 2010) .

( Fig. 4 )

Mesuca (Latuca) neocultrimana Bott, 1973: 317 (in part: Halmahera, Sulawesi). Not Mesuca (Latuca) neocultrimana Bott, 1973 (= Gelasimus excisus ( Nobili, 1906)) .

Uca (Thalassuca) vocans pacificensis Crane, 1975: 90 (in part: Ambon). Not Uca (Thalassuca) vocans pacificensis Crane, 1975 (= Gelasimus excisus ( Nobili, 1906)) .

Uca jocelynae Shih et al., 2010: 51 , fig. 2, fig. 3, fig. 4 (Sulawesi) Gelasimus jocelynae – Shih et al., 2016: 151, fig. 7D (Bunaken, North Sulawesi).

Material examined. 17 males (14.0 × 9.4 mm – 18.4 × 12.8 mm) ( MZB.Cru.4912), Liki Village, Sarmi District, Sarmi Municipality , Liki Island , Papua Province, 01º37′25.29″S, 138º44′26.54″E, 23 November 2018, DC Murniati ; 2 males (14.3 × 9.6 mm – 18.2 × 11.8 mm) ( MZB.Cru.3723), Kaimana , West Papua Province, 26 June 2001, DL Rahayu ; 1 male (24.5 × 15.4 mm) ( MZB.Cru.3911) Kamora Village , Mimika, Papua Province, DL Rahayu .

Comparative material examined. Gelasimus vocans ( Linnaeus, 1758) , 4 males (17.4 × 12.0 mm – 20.0 × 13.2 mm) ( MZB.Cru.3728), Gilimanuk Bay, Malaya District, Jembrana Municipality , West Bali National Park , Bali Province, 14 July 2009, DC Murniati; (18.3 × 12.4 mm – 23.1 × 14.8 mm) ( MZB.Cru.4179), Jebak River , Blonsong, Kidang Village , East Praya District , Central Lombok Municipality , 25 April 2015, DC Murniati, Mariana .

Remarks. This species belongs to the Gelasimus vocans complex, and was described as new based on morphological and molecular data by Shih et al (2010). Close similarities are present between G. vocans and G. jocelynae in the live colouration of the body and morphology of the major chela of the male. In both species, the carapace is generally white to greyish-white and the cheliped is deep yellow to orange in the lower part of the palm and fixed finger ( Fig. 4A ); the major chela has two distinct teeth with a wide gap on the cutting margin of the fixed finger ( Fig. 4C ). Our careful examination has shown that the specimens agree well with the description by Shih et al. (2010) for Uca jocelynae .

Based on our observation of comparative materials, Gelasimus jocelynae differs from G. vocans in the shape of the major chela. In G. jocelynae , the proximal portion of the dactylus is slightly wider than that of the fixed finger, and the distal tooth of the fixed finger is small and positioned subdistally ( Fig. 4C ). Meanwhile, in G. vocans , the proximal portion of the dactylus is narrower than that of the fixed finger, and the distal tooth of the fixed finger is large and positioned distally.

We found some morphological variations in the male chela within the population of G. jocelynae from Liki Island. In some specimens, the width of the proximal portion of the dactylus and fixed finger are similar, while others have a slightly wider proximal portion of the fixed finger compared to the dactylus. Nonetheless, the morphology of the G1 of all our specimens ( Fig. 4H–I ) is well in agreement with the illustration given by Shih et al. (2010).

According to Shih et al. (2010), the geographical distribution of this species is confined to the Western Pacific islands including Papua New Guinea. The present record extends the distribution of this species further eastward in the Indonesian Archipelago. This species inhabits sandy-muddy substrates on the intertidal zone of the coast.

Figures

Fig. 4. Gelasimus jocelynae (Shih et al., 2010). MZB.Cru.4912, male, 18.4 × 12.9 mm; Papua: Liki Island. A, in-situ with live colouration (photograph by Sumaryanto Bronto); B, dorsal habitus, preserved colouration. C, outer surface of major chela. P2–P5: D–G. Right G1: H, dorsal and ventral view; I, apical portion. Scale bars: B–G, 5 mm; H, 3 mm; I, 1 mm.