Palapedia persica, Naderloo, Reza, 2015

Naderloo, Reza, 2015, Two new species of Palapedia Ng, 1993 (Crustacea, Decapoda, Brachyura, Xanthidae) from the Persian Gulf, Zootaxa 3994 (2), pp. 265-274 : 266-270

Palapedia persica n. sp.

( Figs. 1 a–b, 3a–f, 5a–c)

Palapedia sp. nov. Apel 2001: 88 (part of the material from Saudi Arabia).

Material examined. Holotype: 1 female (CL = 15.56, CB = 17.05 mm) ( ZUTC 5484), Park-Ghadir, Abu-Musa Island, Persian Gulf, 25° 53' N 55° 01' E, sandy substrate between corals, shallow subtidal, 13 April 2015, coll. R. Naderloo & A. Sari.

Paratypes: 1 male (CL = 13.41, CB = 15.14 mm) ( SMF pending), Karan Island, Saudi Arabia, Persian Gulf, 27° 43'N, 49° 49'E, between corals, 10–12 m, 16 Jul. 1992, coll. M. Apel; 1 male (CL = 12.07, CB = 13.52 mm) ( SMF pending), Karan Island, Saudi Arabia, Persian Gulf, 27° 43'N, 49° 49'E, under dead corals, 10–12 m, 27 May1995, coll. M. Apel.

Description. Carapace round ( Fig. 1 a, 3a), slightly broader than long (CB/CL about 1.10–1.13); posterior surface of carapace gently convex, finely tuberculate, small tubercles in irregular transverse rows, tubercles becoming denser on lateral, frontal portions; carapace regions weakly defined, gastric region relatively smooth, with fewer tubercles, weakly defined by posterior depression. Frontal breadth about 0.3 times carapace breadth, slightly shorter than posterior margin of carapace, with two distinct lobes, lobes anteriorly straight, anterior margin denticulate, separated from each other by V-shaped notch, shallow furrow extending backward on frontal region, frontal lobes not distinctly separated from inner orbital angle. Orbits with upper margin medially concave, medial fissure relatively deep, lateral margin with larger denticles exorbital angle with spine-shaped tooth curving slightly inward; infraorbital margin relatively straight, with nearly similar denticles; inner angle slightly extending beyond distal margin of first antennal segment; outer angle separated from exorbital angle by narrow fissure, exorbital angle supplemented with small tooth on lower margin. Lateral margins of carapace irregularly denticulate, serrated with long setae; anterolateral margins distinctly arched, very longer than posterolateral margins, epibranchial region markedly distinct with larger denticle; posterolateral margins concave, with small granules. Eyestalks short, granulate on anterior margin, three large teeth on distal part, more distinct from ventral view. Antennules folded obliquely, with large basal segment, finely granulate on outer surface. Antenna with basal antennal segment very slightly longer than broad, not distinctly separated from inner orbital angel, longer than second segment, second segment as long as third one. Third maxillipeds ( Fig. 3 b) with ischium distinctly longer than two times as long as merus, granulate on inner distal region, inner margin with blunt triangular teeth; merus subquadrate, distinctly wider than long, outer surface with dense granules. Thoracic sternum 3–4 fused, without any suture, distally bulged.

Male chelipeds subequal. Merus about 1.3 times as long as breadth, outer surface granulate in upper part; inner, lower surfaces smooth; margins minutely granulate, with long setae; upper margin with large subdistal denticle, smaller distal one. Carpus nearly as long as merus, granulate on distal inner surface, large spine-like teeth on distal inner margin ( Fig. 3 e). Manus robust ( Figs. 3 d, e), its height around 0.6 times as along as whole manus length; outer surface with transverse lows of granules on upper, distal parts, longitudinal row of granules distally on lower part, running to outer surface of immovable finger, transvers row of large denticles distally on manus, near to base of movable finger; inner surface smooth ( Fig. 3 e); upper margin with relatively large granules; lower margin smooth. Movable finger ( Fig. 3 d) with two longitudinal rows of large denticles along upper margin, denticles smaller distally; outer surface with two tubercles, proximal one larger, patch of long setae on lower portion; outer surface with supplementary row of smaller granules, inner to larger granules, with subdistal patch of long setae; cutting edge with blunt tooth on medial part. Immovable finger smooth on both surfaces, medial patch of long setae on inner, outer surface; cutting edge with median blunt tooth. Smaller chelipeds with elongate manus, fingers, denticles longer, narrower; movable finger with small median tooth.

Ambulatory legs relatively medium-sized, margins with long setae. Merus about two times as long as broad, lower, upper surfaces smooth; anterior margin with proximal spine-shaped tooth; posterior margin with about three spine-shaped teeth along half proximal. Carpus slightly shorter than merus, outer surface with longitudinal ridge on middle part, last leg without median ridge, anterior margin with denticles along half distal, denticles becoming larger distally, last leg with very small denticles on half proximal; propodus slightly shorter than carpus, propodus of last leg subquadrate, with two or three rows of larger denticles along anterior margin, outer surface with patch of setae; dactylus sickle-shaped, dactylus of first leg with small denticles along proximal half of anterior margin, dactylus of last three legs with larger denticles along whole anterior margin, dactylus of last legs ( Fig. 3 c) less sickle-like, with two rows of denticles, anterior margin nearly straight, slightly concave.

Male abdomen long, with three first somites visible from dorsal view of carapace; somites 3–5 tightly fused; somite 6 medially concave, about 1.6 times as long as breadth, telson with apical margin nearly straight.

Male G1 ( Figs. 5 a–c) narrow, long, apically curving outside; apical part tapering, sparse denticle-shaped spines subdistally on dorsal surface, long setae subapically along lateral margin. G2 short, distal process small, basal segment narrow ( Fig 5 g).

Distribution. Persian Gulf (Abu Musa Island, Karan Island).

Etymology. The species is named after the type locality of the species, the Persian Gulf.

Remarks. Apel (2001) collected the material of Palapedia persica n. sp. from the Persian Gulf and noticed that the species is different from the known species of Palapedia . He placed the material together with “ Kraussia ( nitida Stimpson ?)” recorded by Stephensen (1946) in a same undescribed taxon as Palapedia n. sp. Palapedia persica n. sp. is very similar to P. s ere n e i Ng, 1993, according to the overall feature of the G1, particularly using the apical part of the G1, but still small differences are seen in the curving in the subapical process, which is stronger in P. serenei (figs. 5a–c; Ng et al. 1993: fig. 7a, b). The new species is different from its congeners using a number of morphological characteris. The new species has the frontal lobes nearly continuous with the inner orbital angle, leaving no distinct fissure or furrow in the junction, similar to that of P. roycei Serene, 1972 , whereas in P. serenei , and in P. apeli n. sp. the inner orbital angle is separated from the frontal lobes. The chelipeds of P. persica n. sp. is particularly similar to those of P. rastripes Serène, 1972 , and P. marquesa (Müller, 1887) , by having distinctly large denticles along the upper margins of the palm and fingers, whereas in other species, e.g. P. serenei and P. apeli n. sp., there is small granules or denticles on the upper margin of the fingers. Furthermore, the dactylus of the ambulatory legs, particularly those of the first three legs are strongly sickle-shaped, arching dorsally and markedly armed with large, spine-like denticles along the anterior margin.

Figures

FIGURE 1. Palapedia persica n. sp. female holotype (ZUTC 5484). a, dorsal view; b, ventral view.

FIGURE 3. Palapedia persica n. sp. Male paratype (SMF pending), CL = 13.41, CB = 15.14 mm: (a) posterior surface of carapace; (b) third maxilliped, outer surface; (c) last ambulatory leg, left; (d) large cheliped, outer surface; (f) large cheliped, inner surface.

FIGURE 5. Palapedia persica n. sp. Male paratype (SMF pending): (a) G 1, abdominal surface; (b) apical part of G 1, abdominal surface; (c) apical part of G 1, dorsal surface; (g) G 1, lateral view. Palapedia apeli n. sp. Male holotype (SMF pending): (d) G 1, abdominal surface; (E apical part of G 1, abdominal surface; (f) apical part of G 1, dorsal surface; (h) G 1, lateral view.