Eurycarcinus orientalis A. Milne-Edwards, 1867

Trivedi, Jigneshkumar, Mitra, Santanu, Patel, Pooja, Maheta, Niketa, Patel, Krupal & Ng, Peter K. L., 2021, On the Indian species of Eurycarcinus A. Milne-Edwards, 1867, Heteropanope Stimpson, 1858, and Pilumnopeus A. Milne-Edwards, 1867 (Decapoda: Brachyura: Pilumnidae), Nauplius (e 2021004) 29, pp. 1-18 : 3

Eurycarcinus orientalis A. Milne-Edwards, 1867

( Figs. 1 , 9A–C )

Eurycarcinus orientalis A. Milne-Edwards, 1867: 277 ; Jones, 1986: 162, pl. 47; Vousden, 1987: 36, tabs. 4, 7; Apel and Türkay, 1992: 194, 204, 205; Ismail and Ahmed, 1993: 158; Apel 1994a: 43, 44; Apel, 2001: 97, 98; Al-Khayat and Jones, 1996: 806, fig. 5; Al-Khayat and Jones, 1999: 58, 61; Tirmizi and Ghani, 1996: 30–32, fig 10; Cooper, 1997: 168– 170, figs. 4, 5, 15; Hornby, 1997: 16 (? part); Ng et al., 2008: 140 (list); Naderloo and Türkay, 2012: 37 ; Al-Khafaji et al., 2017: 363, fig. 3; Naderloo, 2017: 304, figs.26.10c, 26.11, 26.13; Ng et al.,2018: 484, figs. 1C, 3B, 4B, 5B, 6B, E, 7B, E, H, 8B, F, G; Trivedi et al., 2018: 59 (list).

Eurycarcinus grandidieri — Alcock, 1898: 211, 212 [not Eurycarcinus grandidierii A. Milne-Edwards, 1867 = E. natalensis (Krauss, 1843) ].

Eurycarcinus sp. — Basson et al., 1977: 58, 228 (in list), fig. 38; Titgen, 1982: 131.

Type locality. Mumbai, India.

Material examined. 5 males (CW 27.6–41.5 mm, CL 17.5–26.9 mm), 4 females (CW 28.5– 6.4 mm, CL 17.5–23.0 mm), LFSc.ZRC-64, Kamboi (22°12’59”N 72°36’59”E), Gujarat State, India, 11 April 2014, coll. J. Trivedi.

Remarks. The specimens examined in the present study agree with the description and figures of the species provided by Ng et al. (2018). Eurycarcinus orientalis resembles E. natalensis in carapace shape and dentition of the anterolateral border but can be separated from the latter in the following characters: the carapace is high ( Fig. 1A ) (not prominently raised in E. natalensis ; cf. Ng et al., 2018: figs. 1A; 6A, D); suborbital and pterygostomial regions are prominently granulated ( Fig. 1B ) (less granulated in E. natalensis ; cf. Ng et al., 2018: fig.6D); G1 distal part gently recurved, tip gently curved ( Fig. 9A, B ) (distal part prominently recurved, tip hook shaped in E. natalensis ; cf. Ng et al., 2018: fig. 8A, D, E).

Eurycarcinus orientalis is so far reported from the Gulf of Aden, Persian Gulf, Gulf of Oman, Pakistan, India, and Thailand ( Naderloo, 2017; Ng et al., 2018). In India, the species is recorded from Gujarat, Maharashtra, Karnataka ( Chhapgar, 1957) and Kerala ( Dev Roy, 2013). Trivedi et al. (2018) commented that all the records of this species from the east coast including Andhra Pradesh ( Dev Roy and Nandi, 2007), Orissa ( Dev Roy and Rath, 2017), West Bengal ( Dev Roy and Nandi, 2012), and Andaman and Nicobar Islands ( Dev Roy and Nandi, 2012) require re-examination.

Trivedi et al. (2018) commented that the records of E. natalensis from India: Andhra Pradesh ( Dev Roy and Nandi, 2007), Tamil Nadu ( Thomas, 1969), West Bengal ( Dev Roy and Nandi, 2012), and Andaman and Nicobar Islands ( Thomas, 1969) are doubtful. Some of these may have been based on earlier incorrect identifications of Indian material by Alcock (1898) as Eurycarcinus grandidieri , the latter species being a junior synonym of E. natalensis . On the basis of the available specimens examined here, these records are probably a species of Heteropanope or Eurycarcinus and require re-examination, but, based on biogeography, they are likely to be E. bengalensis or E. integrifrons (see discussion for these species).

Figures

Figure 1. Eurycarcinus orientalis A. Milne-Edwards, 1867, male (CW 41.5 mm, CL 26.9 mm) (LFSc.ZRC-64), Kamboi, India. A, habitus, dorsal view; B, frontal view; C, anterior thoracic sternum (sternites 1–4) and pleon; D, chelae, outer view; E, posterior thoracic sternum and pleon.

Figure 9. A– C, Eurycarcinus orientalis A.Milne-Edwards,1867, male (CW41.5 mm, CL 26.9 mm) (LFSc.ZRC-64), Kamboi, India; D–F, Eurycarcinus integrifrons De Man, 1879, male (CW 28.2 mm,CL 19.9 mm) (LFSc.ZRC-63), Lakhpat,India; G–I, Eurycarcinus bengalensis Deb, 1999, holotype male (CW 25.1 mm, CL 16.9 mm) (ZSI-C3349/2), Chamta Block, India. A, D, G, ventral view of left G1; B, E, H, ventral view of distal part of left G1; C, F, I, left G2.