Danielea noelensis ( Ward, 1934 ) Ng & Clark, 2003

Ng, Peter K. L. & Clark, Paul F., 2003, Three new genera of Indo-West Pacific Xanthidae (Crustacea, Decapoda, Brachyura, Xanthoidea), Zoosystema 25 (1), pp. 131-147 : 142-145

Danielea noelensis ( Ward, 1934) n. comb.

( Figs 1C ; 4 A-E)

Medaeus noelensis Ward, 1934: 17 , pl. 1 figs 1, 1a. — Forest & Guinot 1961: 56, fig. 42, 43, 44a, b, pl. 1 fig. 1. — Sakai 1965: 134, pl. 69 fig. 1. — Guinot 1967b: 266.

Lophozozymus (Lophoxanthus) bellus leucomanus – Miers 1886: 115, pl. 11 figs 1, 1a, 1b (non Xanthodes leucomanus Lockington, 1876 ).

Xantho distinguendus – Klunzinger 1913: 203 (107) (partim), pl. 1, fig. 7 (non Xantho distinguendus de Haan, 1835 ).

Medaeus granulosus – Balss 1934: 507 (partim) (non Medaeops granulosus ( Haswell, 1882)) .

Paramedaeus ? noelensis – Serène 1968: 76.

Paramedaeus noelensis – Sakai 1976: 426, fig. 224. — Ribes 1978: 127. — Takeda 1978: 39. — Thomassin 1978: annexe 3, p. 64. — Serène 1984: 90, fig. 51, pl. 12F. — Ho et al. 2000: 114.

Non Paramedaeus noelensis – Serène & Umali 1972: 68, pl. 7 figs 7-9 (= Cranaothus deforgesi Ng, 1993 ).

TYPE MATERIAL. — Christmas Island. Pres. Raffles Museum, cl 6.4 mm, cw 4 mm, holotype ( NHM 1935.5.21.9.).

OTHER MATERIAL EXAMINED. — Taiwan. Ma-Kang, Taipei County, 11. V.1990, coll. P.-H. Ho, 2

cl 7.9 and 8.5 mm, cw 12.2 and 12.6 mm ( NTOU 9005-02-34).

DISTRIBUTION. — Red Sea ( Klunzinger 1913); Madagascar ( Thomassin 1978; Serène 1984); Christmas Island ( Ward 1934); Tahiti ( Forest & Guinot 1961); Japan ( Sakai 1965, 1976; Takeda 1978); 34°38’0”N 135°1’0”E, Japanese Seas ( Miers 1886); Mauritius ( Balss 1934); Réunion ( Ribes 1978).

DESCRIPTION

Carapace quadrate, much wider than broad; dorsal surface gently convex, regions low, completely densely covered with small, evenly sized rounded to squamate granules, surface appearing squamiform. Front weakly produced, separated into two broad lobes by small, narrow fissure, lobes almost straight or slightly sinuous; margin folds downwards and inwards, appears folded. Inner supraorbital tooth very low, rounded; orbits subparallel with frontal margin. External orbital tooth very low, almost undiscernible, not confluent with rest of anterolateral margin. Anterolateral margin arcuate; first lobe very low, uneven, with two or three larger tubercles posterior to it; next three lobes low but more prominent, triangular, last lobe directed laterally; lobes separated from each other by narrow, short fissures which are discernible on sub-branchial region; region next to lobes with disinct punctae, appears somewhat eroded. Postero-lateral margin gently convex to almost straight. Posterior carapace margin almost straight, wider than frontal margin. Subhepatic, suborbital, pteryogostomial and sub-branchial regions densely covered with evenly sized small rounded granules; subhepatic region with distinct depression. Infraorbital margin granular, without obvious clefts, with one prominent submedian tubercle. Eyestalk granulated. Basal antennal segment stout, subrectangular, free but fills orbital hiatus, appears almost fused with suborbital region due to highly granulated inner margin of region, with short flagellum entering orbit. Antennules folding laterally; fossa relatively large. Endostomial ridges not discernible. Surface of third maxilliped densely covered with evenly sized small rounded granules; merus squarish, anteroexternal angle not auriculiform; ischium rectangular, with shallow but clearly discernible oblique median sulcus; exopod relatively broad, reaching anterior edge of merus, with well-developed flagellum.

Chelipeds elongate, relatively stout; all outer surfaces densely covered with evenly sized squamate granules. Dorsal margin of merus granular, without obvious tooth. Carpus rounded, inner angle with one prominent rounded tooth and several tubercles anterior to it, outer angle granular with uneven margin. Chela with inner surface granular; fingers slender, long, shorter than palm, tips sharp; palm with prominent uneven, almost subpetaloid crest on subdorsal inner surface; dorsal margin and outer subdorsal surface with two low, rounded carinae, forming shallow longitudinal depressions between them. Major (usually right) chela with two teeth and pronounced curved basal cutting tooth on cutting edge of dactylus; cutting edge of pollex with three or four teeth; dorsal margin of dactylus with a prominent carina on inner subdorsal margin. Minor (usually left) chela with fingers more slender, cutting edges blade-like, with two or three teeth and two or three denticles each. Ambulatory legs with all segments unarmed, almost glabrous; surfaces densely covered with evenly sized small rounded to squamate granules; merus not cristate, entire; carpus with distal part of dorsal margin subcristate, produced into rounded tooth, margin entire.

Thoracic sternum relatively broad, surface entirely covered with numerous small evenly sized granules except for sutures; suture between sternites 1 and 2 not discernible; suture between sternites 2 and 3 well-developed, complete; suture between sternites 3 and 4 prominent but becoming shallow medially; sutures between sternites 4 and 5, 5 and 6, and 6 and 7 incomplete; abdomen reaching to imaginary line joining posterior edges of the bases of chelipeds. Gonopore coxal, opening below abdominal segment 3.

Abdomen with segments 3-5 completely fused, sutures separating segments not discernible, lateral margins entire, without clefts; segments 1-3 trapezoidal, segment 6 rectangular, lateral margins gently concave, subparallel; telson semicircular, lateral margins distinctly convex, tip rounded; surfaces of all segments covered with numerous small evenly sized granules.

G1 relatively stout, gently curved, tip blunt; lateral margins lined with short spines and long plumose setae on dorsal margin. G2 short, slen- der, distal part with subpetaloid process.

REMARKS

Danielea noelensis n. comb. was described on the basis of only one male specimen from Christmas Island in the Indian Ocean. It has since been reported from many other areas. Ng (1993) clarified the record supposedly of this species by Serène & Umali (1972) and suggested that it should be referred to Cranaothus deforgesi , instead.

There is variation in the degree of erosion on the carapace and pereiopods of D. noelensis n. comb., although none of it is very significant. In no instance does the erosion form vermiculiform ridges or patterns on the carapace. In larg- er specimens, the front looks somewhat lamelliform when viewed from above, but the edge still folds downwards and inwards. The larval development has been reported by Suzuki (1978).

Danielea noelensis n. comb. has the special cutting (or peeling tooth) on the right chela present in calappids and some xanthids. It is probably used in the same manner as many species of Calappa Weber, 1795 , i.e. to open gastropods ( Ng & Tan 1984, 1985).

Figures

FIG. 1. — A, Marratha angusta (Rathbun, 1906) n. comb., cl 7.2 mm, cw 8.6 mm, Macclesfield Bank, c. 15°50’N, 114°20’E, South China Sea, HMS Penguin, det. D. Guinot 1967, pres. Lords of the Admiralty (NHM 1967.5.3.1.1); B, Jacforus cavatus (Rathbun, 1907) n. comb., cl 5.7 mm, cw 8.3 mm, NW Island, Capricorn Group, Queensland, Australia, coll. and det. M. Ward (NHM 1931.4.14.17); C, Danielea noelensis (Ward, 1934) n. comb., holotype cl 6.4 mm, cw 4 mm, Christmas Island, pres. Raffles Museum (NHM 1935.5.21.9).

FIG. 4. — Danielea noelensis (Ward, 1934) n. comb., holotype 6.4 mm, cw 4 mm, Christmas Island (NHM 1935.5.21.9); A, orbit and antennae; B, anterior thoracic sternites; C, right third maxilliped (setae not drawn); D, abdomen; E, G, distal part of left pleopod 1; F, pleopod 1. For all structures, minute granules not drawn. Figures F and G after Forest & Guinot, 1961. Scale bars: A, 0.5 mm; B-D, 1.0 mm; E, 0.01 mm.