Polyonyx obesulus Miers, 1884

Naderloo, Reza & Türkay, Michael, 2012, Decapod crustaceans of the littoral and shallow sublittoral Iranian coast of the Persian Gulf: Faunistics, Biodiversity and Zoogeography 3374, Zootaxa 3374 (1), pp. 1-67 : 22

Polyonyx obesulus Miers, 1884

Persian Gulf. Iran ( Haig 1966; present study).

Iran. Hormozgan Province: Qeshm I. (Dustku, Basaeedu).

General distribution. Indo-West Pacific: Persian Gulf, Indo-Malayan Archipelago, Philippines, Australia (Western Australia, Northern Territory, Queensland) .

Habitat. Rocky/cobble intertidal, sponge associated species.

Remarks. Johnson (1958) mentioned that the records of P. parvidens and P. paucidens by Nobili (1905a, 1906a) from the Persian Gulf were based on juvenile specimens of P. obesulus . Haig (1966) supported Johnson’s idea in synonymising Nobili’s species P. parvidens and P. paucidens with P. obesulus . Haig (1966) noted that juvenile specimens of P. obesulus resemble more closely the description of P. parvidens by Nobili (1905a), in particular, regarding the presence of spines on the anterior margin of the merus and carpus of the cheliped. Titgen (1982) recorded this species from the Persian Gulf, Dubai. We examined his small specimen (CL/CB = 5.93/4.82), which looks slightly different in regard to a CL/CB ratio which is about 1.2, but in the present specimens from the Qeshm I. the carapace is clearly wider than long with CL/CB ratio average of 1.35. However, differences in the carapace-ratio can more likely be dependent on growth. Furthermore, Johnson (1958) stated that some small specimens from eastern India and the western Pacific examined by him have a ventral spine on the merus of cheliped; this was also noted by Haig (1964, 1966). But in the present specimen, as usual, no spine is seen on this part of cheliped.