Cyclorma lophopus ( Nobili, 1905 ) Nobili, 1905

Naruse, Tohru & Ng, Ngan Kee, 2012, Establishment of a new genus for Cyclograpsus lophopus Nobili, 1905, within Sesarmidae Dana, 1851 (Crustacea: Decapoda: Brachyura), Zootaxa 3572, pp. 63-68 : 67-68

Cyclorma lophopus ( Nobili, 1905) n. comb.

( Figs. 1–3 )

Cyclograpsus lophopus Nobili, 1905: 411 ; 1906: 321, pl. XI (4).—Ng et al. 2008: 223.

Material examined. Lectotype (by present designation): Female, 11.7 × 13.7 mm, MNHN-IU-2008-10673 (ex- MNHN-B12566), Djibouti, coll. H. Coutière.

Paralectotypes: 2 females, 10.5 × 12.8, 11.2 × 13.2 mm, 2 ovig. females, 10.1 × 11.7, 12.9 × 15.0 mm, MNHN- IU-2008-20697 (ex- MNHN-B32611), same data as lectotype.

Description. Carapace ( Fig. 1 ) subquadrate, CW 1.16–1.22 times (mean 1.18, n = 5) CL, dorsal surface slightly convex longitudinally, transversely; regions ill-defined; epigastric crista low but present, no other crista or groove present, branchial region with scattered small granules. Front moderately wide, 0.39–0.44 times (mean 0.42, n = 5) CW; frontal margin, anterior margin of eyestalk (when folded) and carapace proper forming smooth arc ( Figs. 1 , 2 ). Supraorbital margin laterally directed, J-shaped, entire; suborbital crista in same level with border between epistome, pro-epistome ( Fig. 2 c), lined with small granules. Inner orbital tooth ( Fig. 2 c) triangular, tip rounded, reaching midway to lateral angle of front, leaving wide gape for antenna; inner orbital tooth laterally connected to infraorbital margin, margin upcurved dorsally at lateral third of orbit, connected to inner angle of supraorbital margin. Anterolateral, posterolateral margins continuous, entire, cristate, slightly upcurved, lined with microscopic granules; anterior half of carapace laterally convex, posterior half slightly concave; suborbital, pterygostomial, subhepatic regions ( Fig. 2 c) covered with reticulated setal pattern, longitudinal groove on pterygostomial region along buccal cavern absent. Pro-epistome short, abruptly narrowed on anterior half, distally surrounded by ventral extension of front. Posterior margin of epistome with single median wide, low projection; submedian small projections. Endostome with 1 median, 2 submedian ridges.

Antennule ( Fig. 2 c) with elliptical basal article, transversely set in antennular fossa.

Antenna ( Fig. 2 c) not separated from antennule by septum, intruded into orbit, flagellum short.

Eye ( Fig. 2 a, c) short, with trigonal peduncle, cornea small, dorsal and anterior surfaces compressed, forming flat surface with dorsal, anterior surfaces of carapace.

Third maxillipeds ( Figs. 2 c, 3a) leaving rhomboidal gape when closed. Ischium trapezoidal, mid-length 1.5 times merus, median groove present. Merus subcircular, with oblique ridge, lined with setae from proximolateral to distomesial angles. Each segment of palp short. Exopod reaching proximal two-thirds of merus, flagellum longer than width of merus.

Chelipeds short ( Figs. 1 , 2 a, b), subequal. Merus short, high, highest at distal third, inner-lower margin convex at distal third, outer surface rough, sparsely granulated. Carpus with rough outer surface, scattered with small granules, setae, inner angle rounded, angle connected proximo-mesially by low ridge, followed downwards by short ridge. Chela with palm slightly longer than fingers, outer surface with small sparse granules, upper surface with short setae, upper inner part with thin line of small granules from hinge with carpus to upper part of proximal portion of movable finger; fingers tip pectinated, cutting edge lined with triangular teeth, upper margin of movable finger lined with ca. 8 small granules.

Ambulatory legs short, with unique flattened, wide meri to propodi. Meri widened distally, widest at distal third, widest on third ambulatory leg; subdistal angle of anterior margin present on second to fourth ambulatory legs, absent from first leg, distal angle also distinct on second to fourth legs; disto-posterior part foliaceous. Carpi only slightly shorter than respective propodi on first, third legs, almost same length in fourth leg, 3 ridges on outer half (upper, lower and outer ridges). Propodi gradually decreasing width distally, with 2 small, black spinules on upper, lower disto-mesial angles. Dactyli shorter than respective propodi, strongly tapered, tips pectinated.

Vulvae narrow ellipsoidal, transversely long, proximal margin slightly extended anteriorly, vulvae including proximal margin placed on distal quarter of sternite 6, just below inner ends of thoracic sternal suture 5/6.

Female abdomen, telson oval, telson with proximal third surrounded by distal margin of sixth somite.

Remarks. When Nobili (1905: 411) preliminarily diagnosed and named Cyclorma lophopus n. comb. (as Cyclograpsus lophopus ), he noted the size of only one female specimen (11.5 × 14.0 mm), but did not indicate the number of specimens examined nor designate any type specimens. Subsequently Nobili (1906: 321, pl. 11, fig. 4, as Cyclograpsus lophopus ) indicated that Coutière collected six female specimens of C. lophopus from Djibouti. In the introduction of Nobili (1906: 4, footnote) in complement to Nobili (1905), the author stated that the Red Sea material studied in these papers was, unless otherwise stated, deposited in the MNHN. We found 2 ovigerous and 3 non-ovigerous females that are indicated as “ types ” in the MNHN collection, but no other specimens were found. Following ICZN art. 73.2.1, we regard the abovementioned female specimens as syntypes, and designate the female specimen closest in size (11.7 × 13.7 mm, Fig. 1 a) with the measurements of Nobili (1905, 1906) as the lectotype (MNHN-IU-2008-10673, ex- MNHN-B12566).

Figures

FIGURE 1. Cyclorma lophopus (Nobili, 1905). a, lectotype (female, 11.7 × 13.7 mm, MNHN-IU- 2008 - 10673 ex- MNHN- B 12566); b, paralectotype (ovigerous female, 10.1 × 11.7 mm, MNHN-IU- 2008 - 20697 ex- MNHN-B 32611).

FIGURE 2. Cyclorma lophopus (Nobili, 1905). a, anterior view; b, ventral view; c, anterior part of right side of cephalothorax, ventral view. a, b, paralectotype (ovigerous female, 10.1 × 11.7 mm, MNHN-IU- 2008 - 20697 ex- MNHN-B 32611); c, paralectotype (ovigerous female, 12.9 × 15.0 mm, MNHN-IU- 2008 - 20697 ex- MNHN-B 32611).

FIGURE 3. Cyclorma lophopus (Nobili, 1905). a, right third maxilliped; b, right P 4, upper view; c, right P 4, lower view; d, left P 5, upper view. a, paralectotype (ovigerous female, 12.9 × 15.0 mm, MNHN-IU- 2008 - 20697 ex- MNHN-B 32611); b – d, paralectotype (female, 11.2 × 13.2 mm, MNHN-IU- 2008 - 20697 ex- MNHN-B 32611). Scales, 1 mm.