Karstarma ardea, Wowor, Daisy & Ng, Peter K. L., 2009

Wowor, Daisy & Ng, Peter K. L., 2009, Two new species of sesarmid crabs (Crustacea: Decapoda: Brachyura) associated with limestone formations in West Papua, Indonesia, Zootaxa 2025, pp. 21-31 : 22-23

Karstarma ardea n. sp.

( Figs. 1 , 6 C, 7A, B)

Material examined. Holotype: female (34.9 x 28.0 mm) ( MZB Cru 2156), Gua Kalepale, Kp. Lopintol, Waigeo , Teluk Manyailibit District, Raja Ampat Regency, West Papua Province, coll. C. Rahmadi & S. Wiantoro, 31 May 2007. Paratypes: 1 female (23.4 x 19.5 mm) ( MZB Cru 2157), 1 female (35.0 x 29.3 mm) ( ZRC), same data as holotype.

Type locality. Waigeo , West Papua Province, Indonesia.

Comparative material. Karstarma ultrapes (Ng, Guinot & Iliffe, 1994) : 1 paratype female (20.5 x 16.2 mm) ( ZRC 1993.7200), Kwakwaru Cave (station 88–087), Basakana Island, off northern Malaita island, Solomon Islands, coll. T. M. Iliffe & S. Sarbu, 27 August 1988. Karstarma n. sp. from Philippines: 1 paratype female (28.2 x 34.7 mm) (National Science Museum, Tokyo, Cr 2007.0103).

Diagnosis. Carapace distinctly trapezoidal in shape, widest between bases of second and third ambulatory legs; anterior regions well defined; dorsal surfaces distinctly rugose, especially on lateral regions, covered with scattered short stiff black setae; deep longitudinal medial groove, lined with inward-curving setae, begins at frontal margin, diverging at meso- and metagastric regions, continuing along lateral margins of cardiac region to form distinct inverted Y-shape; epigastric, postorbital crests swollen, rugose; epigastric crests separated by very deep narrow groove; frontal margin strongly deflexed downwards; supraorbital margin entire, sinuous; infraorbital margin cristate, not meeting supraorbital angle; antero- and distal half of posterolateral margins not demarcated; lateral margin strongly diverging backwards, with 3 distinct teeth including external orbital angle, first, second teeth separated by deep V-shaped cleft, third tooth separated from second tooth by shallow notch, third tooth very low, indistinct. Chelipeds slender, similar in form, equal in size, merus triangular in cross-section, fingers as long as palm, pollex with 2 median longitudinal ridges, cutting edges with numerous teeth, denticles. Ambulatory legs very long, slender; third pair longest; length to width ratios of meri of second, third legs ca. 4.6, 5.5, respectively; outer surfaces of meri, dactyli rugose, margins of dactyli, propodi lined with very stiff long black setae; third ambulatory leg 4.4 times CL, merus 5.4 times CW, 1.5 times CL. Female abdomen very wide; telson distinctly sunken into posterior margin of segment 6; lateral margins of somites 4–6 convex. Vulva complex, with operculum; gonopore surrounded by broad posterior U-shaped elevated projection and a narrow anterior projection, both projections partially cover rounded operculum. Male characters not known.

Etymology. The species name is derived from the Latin genus name for herons ( Ardea ), alluding to its very long legs. The name is used as a noun in apposition.

Colour. Dorsal surface of carapace, meri and propodi of ambulatory legs bright orange. The carpi and dactyli of the ambulatory legs are white ( Fig. 7 A, B).

Remarks. In the general form of its carapace and very long ambulatory legs, Karstarma ardea n. sp. closely resembles K. ultrapes and a new Karstarma species now being described from the northern Philippines (Husana et al. in press). Their ambulatory leg proportions, however, differ markedly. Although males are not known for K. ardea n. sp., male and female specimens are known for K. ultrapes and the new Philippines species, and the leg proportions do not differ significantly between the sexes of these taxa (Ng et al. 1994; Husana et al. in press). Karstarma ardea n. sp. has the third ambulatory leg relatively shorter than that of K. ultrapes ( Fig. 1 A) (4.4 times CL vs. 4.9 times CL) but still longer than that of the new Philippines Karstarma (4.4 times CL vs. 4.2.times CL). The frontal margin of K. ardea n. sp. is also relatively narrower than that of K. ultrapes ( Fig. 1 C vs. Fig. 6A ). The structures of the vulvae of these three Karstarma species are also different. Although the general structures of the vulvae of all three species are similar, they differ significantly in the details ( Fig. 6 B-D).

Distribution. So far only known from the type locality.

Figures

FIGURE 1. Karstarma ardea n. sp., holotype female (34.3 x 28.0 mm) (MZB Cru 2156). A, overall view; B, dorsal view of carapace; C, frontal view.

FIGURE 7. Colours in life. A, B, Karstarma ardea n. sp.; C, D, Karstarma waigeo n. sp. A, Triton Bay, West Papua Province, Indonesia, by A. Tay, 2006 (specimen not collected); B – D, Gua Kalepale, Waigeo, Raja Ampat Regency, West Papua Province, Indonesia, by C. Rahmadi (specimens not collected).

FIGURE 6. A, B, Karstarma ultrapes, paratype female (20.5 x 16.2 mm) (ZRC 1993.7200); C, Karstarma ardea n. sp., holotype female (34.3 x 28.0 mm) (MZB Cru 2156); D, Karstarma n. sp., paratype female (28.2 x 34.7 mm) (National Science Museum, Tokyo, Cr 2007.0103); E, Karstarma waigeo n. sp., paratype female (23.4 x 19.6 mm) (MZB Cru 2159); F, Sesarmoides borneensis, paratype female (18.1 x 15.4 mm) (ZRC 1964.9.8.5 – 6).