Doclea unidentata, Chen & Ng, 2004

Chen, H. - L. & Ng, Peter K. L., 2004, On Two Species Of Spider Crabs Of The Genus Doclea (Crustacea: Decapoda: Brachyura: Majidae: Pisinae) From China, One Of Which Is New, Raffles Bulletin of Zoology 52 (1), pp. 201-208 : 202

Doclea unidentata , new species

( Figs. 1 , 2 )

Material examined. – Holotype – male (cw 12.7 mm, cws 18.5 mm, cl 14.7 mm, cls 18.4 mm) ( IOCAS Q133B34 ), station 6183, Beibu Bay , 16 m, sandy-mud, China, coll. 13 Feb.1960.

Description. – Carapace rounded, dorsal surface covered with short, dense pile; rostrum entire, very short, not extending beyond orbits, broadly triangular, not bifid; margins slightly rimmed. Orbital margin separated from the postorbital spine by deep V-shaped slit. Postorbital spine strongly produced anteriorly, extending to just beyond tip of rostrum, inner margin concave, outer margin strongly convex, distal part of spine curved inwards. Epigastric region with 3 median low, rounded granules arranged close to each other. Medial line of carapace with 7 rounded granules or spines, last 2 most pronounced, produced as spines. Each protogastric region with 1 small granule along inner edge adjacent to mesogastric region, 2 large granules on posterior outer edge adjacent to branchial region. Mesogastric region with 3 longitidudinally arranged rounded granules. Metagastric region with a large median tubercle. Urogastric region with 1 low granule. Cardiac region with 1 obliquely posteriorly directed spine. Intestinal region with 1 large posteriorly directed spine. Subhepatic region with 1 rounded granule dorsally, 1 large subventral tubercle and 1 smaller granule just anterior to this. Branchial region with 6 rounded granules, 1 anterior, 1 posterior, 4 arranged in an oblique median row with inner 3 positioned close to each other. Anterolateral margin with 3 progressively larger tubercles, culminating in very large obliquely posteriorly directed epibranchial spine. Basal antennal article with 1 inner spine. Anterolateral angle of buccal frame produced into a low spine. Pterygostomial canal not discernible. Chelipeds short, slender; merus ca. 3 times as long as broad; chelae slender; palm about twice as long as broad; fingers slightly shorter than palm; cutting margins with small teeth. Ambulatory legs long, slender, covered with pile; first ambulatory leg not substantially longer than second pair.

Remarks. – The present new species is represented by only one relatively young male, but its features are so distinctive that we do not hesitate in naming it. With regards to its rounded carapace and very short rostrum, it is closest to D. brachyrhynchos Bleeker, 1856 , and D. macracanthus Bleeker, 1856 , both from Indonesia. Doclea unidentata , however, can easily be distinguished from these two species in that the rostrum is composed of just one triangular lobe, without any distal cleft or fissure to even suggest it may be bifid. There are no indications that the rostrum is due to regrowth or had been damaged, and all indications that it is normal. The simple rostrum allies the new species to Neodoclea boneti Buitendijk, 1950 , from Mexico, but the latter species has an unarmed buccal cavity, a differently proportioned third maxilliped and the tip of the G1 is bifid (see Wagner, 1986: 895).

Figures

Fig. 1. Doclea unidentata, new species. Holotype male (cws 18.5 mm, cls 18.4 mm) (IOCAS Q133B34), China. A, overall view; B, carapace; C, front.

Fig. 2. Doclea unidentata, new species. Holotype male (cws 18.5 mm, cls 18.4 mm) (IOCAS Q133B34), China. A, male abdomen; B, anterior part of thoracic sternum; C, right third maxilliped; D, ventral surface of right G1; E, dorsal surface of right G1. Scales: A-C = 1.0 mm, D, E = 0.5 mm.