Petrolisthes tuerkayi, Naderloo, Reza & Apel, Michael, 2014

Naderloo, Reza & Apel, Michael, 2014, A new species of porcelain crab, Petrolisthes tuerkayi n. sp. (Crustacea: Anomura: Porcellanidae), from the Persian Gulf, Zootaxa 3881 (2), pp. 190-194 : 191-193

Petrolisthes tuerkayi n. sp.

( Figs. 1 A–G).

Material examined. Holotype: 1 male, CL 7.61 mm, CB 7.29 mm, ( SNMNH 182), N. of Al-Jubayl, Jubail Marine Wildlife Sanctuary, Saudi Arabia, Persian Gulf, 27°25.41'N, 49°13.53'E – 27°25.41'N, 49°13.53'E, rocky intertidal, under stones, 0 7.02.1993, coll. M. Apel.

Paratypes: 1 male, 1 female ( SMF 38755), UAE, M. Apel; 1 male, 1 female (ovig.) ( SMF 38756), UAE, 18.11,1999, M. Apel; 3 males, 1 female ( SMF 38757), UAE, 18.11.1999, M. Apel; 1 female ( SMF 38758), UAE, 23.11.1999, M. Apel; 1 male, 1 juv. ( SMF 38759), UAE, 18.11.1999, M. Apel; 1 male, 1 female ( SMF 38760), UAE, M. Apel; 2 males, 3 females (ZMUC-CRU-20507), Manama, Bahrain Island, tidal zone, clay, sand. 28.03.1937, G. Thorson, “Danish Expedition” St. 40.

Comparative material. Petrolisthes rufescens (Heller, 1861) : Type material, lectotype, 1 male ( NHMW 24220), Red Sea, coll. Frauenfeld.

Persian Gulf, Iran: 17 males, 12 females ( ZUMC CRU-20502), Bushehr, intertidal zone, rocky, 8– 28.02.1937, G. Thorson, “Danish Expedition“; 4 males, 1 female ( ZUMC CRU-20503), 6 km S of Bushehr, intertidal zone, coral reef, 27.02.1937, Loppenthin, “Danish Expedition”; 1 male ( ZUMC CRU-20504), Kharg I., intertidal zone, rocky, 0 6.03.1937, G. Thorson, “Danish Expedition”; 4 males, 2 females ( ZUMC CRU-20505), Tula, Qeshm I., intertidal zone, G. Thorson, “Danish Expedition”; 1 male ( ZUMC CRU-20506), Nabiyu I., 0 7.04.1938, Loppenthin, “Danish Expedition”; 50 specimens ( NHMW 18817), Karak, Kotschy; 12 males, 9 females ( ZUTC Anom 1080), Bushehr, Bandare Deylam, 30°02′N, 50°08′E, jetty stones, H. Saleih, A. Kazemi, 30.09.2007; 4 males, 4 females ( ZUTC Brach. 1074), Qeshm I., Namakdan, 26°35′N, 55°29′E, rocky, boulder and shingle shore, 16.12.2007, R. Naderloo; 3 males, 4 females ( ZUTC Brach. 1072), Laft Desalination Center, Qeshm I., 26°57′N, 55°45′E, muddy/rocky, 15.12.2007; 2 males, 3 females ( ZUTC Anom 1077), Hormuzgan, Bandar-Pol, 26°58′N, 55°44′E, fishery jetty, under the large stone covered with Saccustrea sp., 26.01.2007, H. Salehi; 1 male, 3 females ( ZUTC Anom 1070), Qeshm I., city shore, 26°56′N, 56°16′E, sandy-rocky/boulder, H. Salehi, 14.12.2007; 15 males, 8 females ( ZUTC Anom1075), Qeshm I., Simin plage, 26°53′N, 56°18′E, rocky and coral bed, 15.12.2007, H. Salehi; 4 males, 4 females ( ZUTC Anom1071), Qeshm I., Kani, 26°34′N, 55°23′E, rocky/sandy with corals, 16.12.2007, H. Salehi; 2 males, 2 females ( ZUTC Anom1078), Qeshm I., northwest of Qeshm City to Dargahan, stony/muddy, 26.1.2008, H. Salehi.

UAE: 1 female (NHM 1966:10:4:37), Abu Dhabi, Khor al Bazam, Trucial coast.

Bahrain: 1 male (NHM 1971:257), Jufair beach, 0 2.07.1971, M.D. Gallagher; 1 male (NHM 1971:14), 0 2.07.1971, M.D. Gallagher.

Kuwait: 1 male, 2 females (NHM), Ras al Jlayah, 12.10.1979, D. Clayton.

Qatar: 3 females (NHM), Alwusail, 28.03.1983, G. Bradley; 1 female (ovig.) (NHM 1974:393), Khor Fakkan, M.J. Bearman.

Description. Carapace ( Fig. 1 B) very slightly longer than broad (CL/CB 1.04), widest in epibranchial region. Front broad, in distal region about one third of carapace breadth, noticeably trilobate, median lobe largest, widely triangular, distally rounded, distinctly extended beyond lateral lobes; laterals making nearly right angle with inner orbital margin. Outer orbital angle forming wide triangular angle with lateral margin; outer infraorbital angle spinelike tooth. Epibranchial margin distinctly swollen, finely dentate, no epibranchial spine; lateral margin arched, smooth. Posterior region of carapace with transverse granulated ridges, ridges getting larger on metabranchial regions; frontal region with relatively deep median furrow, 2 shallow furrows extending posteriorly between lateral lobes and inner orbital margin; 2 distinct transverse ridges on posterior part of frontal region; gastric region distinctly swollen; cardiac region faintly distinct, relatively depressed.

First movable antennal segment with a quadrate process on distal margin, small anteriorly-directed spine on distal part of process.

Basal antennular segment, with a distinct spine on inner margin; anterior margin smooth, lateral margin finely dentate distally.

Third maxilliped with long transverse ridges on outer surfaces of all segments.

Chelipeds ( Fig. 1 A) relatively large, robust, with short transverse ridges over segments. Cheliped merus with spine distally on lower surface, not visible from posterior view, inner margin distally produced, making an apically rounded process. Carpus with 4 serrated long teeth on anterior margin, proximal tooth largest, distal tooth faintly distinct; posterior margin serrated on proximal half, 3 or 4 distinct distally-directed spines on distal half, most distal spine largest; distal margin of carpus with 2 median produced lobes, anterior lobe rounded, smooth, posterior lobe serrated, more triangular. Manus nearly equal; lower margins serrated, dorsal margin distinct with fringe of longitudinal ridge of scales, extending to dorsal margin of dactylus; outer surface of manus with longitudinal furrow running parallel to lower margin over lower portion. Fingers without gape when closed; cutting edges with small granules; movable finger larger than immovable finger, with distinct round tooth on proximal part of cutting edge, not visible when closed; immovable finger curved inward apically; fingers apically twisted.

Walking legs ( Figs. 1 C–F) robust, second leg largest; ischium with feather-like setae on antero-distal margin; merus with anterior margin serrated, posterior surface with irregular long transverse ridges, extending to posterior margin; dorsodistal margin of first leg with few denticles, that of second leg nearly right angle, without denticles, that of third leg curved. Carpus irregularly serrated along anterior margin; posterior margin smooth; distinct longitudinal ridge along posterior surface of that of first and second legs, ridge faint on last leg carpus. Propodus cylindrical, slightly longer than carpus, relatively slender, with scattered long setae; 3 movable spines along posterior margin, spines getting larger distally; 2 or 3 spines on postero-distal margin. Dactylus becoming spinelike apically, with 3 movable spines along posterior margin.

Remarks. Petrolisthes tuerkayi n. sp. closely resembles P. rufescens (Heller, 1861) , but is most easily distinguishable from the latter species by the armature of the posterior margin of the cheliped carpus. In P. tuerkayi n. sp. there are three or four large spines along the posterior margin of cheliped carpus, whereas it is completely smooth without any spine in P. rufescens . Regarding the presence of spines along posterior margin of cheliped carpus, the new species resembles P. lamarckii (Leach, 1820) and P. boscii (Audouin, 1826) , but these two species are characterized by having a distinct epibranchial spine. The epibranchial spine is characteristic of the P. boscii - group ( P. boscii , P. carinipes (Heller, 1861) , P. donanensis Osawa, 1997 , P. lamarckii , and P. moluccensis (De Man, 1888)) , while the P. rufescens -group ( P. rufescens , P. leptocheles and P. tuerkayi n. sp.) is distinguishable from congeners by lacking epibranchial spines. Haig (1966) examined specimens of P. rufescens collected by the Danish Expedition 1937/38 from the Persian Gulf and found five specimens different from typical P. rufescens by having two or three teeth along posterior margin of carpus of the chelipeds. We examined Haig’s (1966) material and identify those with teeth along posterior margin of cheliped carpus as the new species. Haig (1966) indicated the similarity of the new species with P. lamarckii in having teeth on the posterior margin of cheliped carpus, but as discussed above, P. lamarckii is included in the P. boscii -group by having a distinct epibranchial spine. Nobili (1906) also noticed the presence of such teeth in some specimens reported as P. rufescens collected from the Persian Gulf. The specimens of Nobili (1906) are most likely referable to P. tuerkayi n. sp.

Petrolisthes rufescens is a western Indian Ocean species, which is common in the intertidal zone of the Persian Gulf ( Naderloo & Türkay 2012) and the Gulf of Oman (R.N. pers. obs.). A large number of specimens of P. rufescens from the Persian Gulf and outside the Gulf from the Pakistan and Red Sea have been examined and the consistency of the character (smooth posterior margin of cheliped merus) was observed in all specimens.

Etymology. The species is named after Prof. Dr. Michael Türkay, curator of the crustacean department of the Senckenberg Museum, who dedicated 45 years of his life to the taxonomy of decapod crustaceans, in particular in the northern Indian Ocean. Michael Türkay was supervisor of the Ph.D projects of the both authors dealing with the decapod crustacean fauna of the Persian Gulf.

Geographical distribution. So far only known from the southern coast of the Persian Gulf ( Saudi Arabia, Bahrain, and UAE).

Figures

FIGURE 1. Petrolisthes tuerkayi n. sp., holotype. A, right cheliped, outer surface; B, carapace, posterior surface; C, first walking leg, posterior view; D, second walking leg, posterior view; E, third walking leg, posterior view; F, thoracic sternum; G, side wall of carapace.