Hirsutodynomene vespertilio, Mclay & Ng, 2005

Mclay, Colin L. & Ng, Peter K. L., 2005, On a collection of Dromiidae and Dynomenidae from the Philippines, with description of a new species of Hirsutodynomene McLay, 1999 (Crustacea: Decapoda: Brachyura), Zootaxa 1029 (1), pp. 1-30 : 21-24

Hirsutodynomene vespertilio n. sp. ( Figs. 6 , 7 )

Material. Holotype: male, 22.8 x 19.9 mm, Balicasag Island , Panglao, Bohol, Visayas, Philippines, in tangle nets, 200–300 m, coll. local shell fishermen, 28 Nov 2001, ZRC 2001.523 . Paratypes: 1 male, 17.4 x 14.6 mm, ZRC 2001.685 , 1 male, 20.3 x 16.3 mm, MNHN , 28 Nov 2001; 1 male, 16.9 x 13.4 mm, USNM , 1 male, 20.2 x 16.9 mm, 25–30 Jul 2003, ZRC 2003.676 ; 1 male, 24.9 x 19.8 mm, ZRC , 1 male, 24.2 x 19.6 mm, 1 male, AM , 20.5 x 16.6 mm, NMCR, Mar 2004; 1 male, 22.3 x 18.0 mm, Nov 2003 – Apr 2004, ZRC . All paratype locations in Balicasag Island , Panglao, Bohol, Visayas, Philippines; purchased from local shell fishermen, obtained by tangle nets, 200–300m depth .

Comparative material of H. spinosa : 1 female, 36.1 x 26.9 mm, near Turtle Island , off Tashi port, Ilan Province, northeastern Taiwan, coll. K.­X. Li, Apr 2002, ZRC ; 1 male, 17.5 x 14.0 mm, Gorong Island , stn. GO 3, no depth, Seram, Indonesia, coll. T . Monod & R . Serène , RUMPHIUS 2 Expedition, 27 Jan 1975, MNHN­B 9906 ; 1 female, 11.3 x 8.9 mm, Tulear , stn 14­11­2, pente externe, 5 m, Madagascar, coll. M. Peyrot­Clausade, 1968, MNHN­B 22077 ; 1 male, 16.4 x 14.3 mm, Grande Glorieuse , intertidal zone, Glorieuses Islands, coll. A. Crosnier, 30 Jan 1971, MNHN­B 6899 .

Description. Carapace wider than long, ratio of carapace width to carapace length 1.15, oval in outline; surface convex, smooth except for 2 prominent protuberances behind rostral area; these separated by a frontal groove extending backwards to define gastric and cardiac regions of carapace. Urogastric area strongly marked by deep grooves. Anterolateral margin armed with 4 well­developed, similarly­sized, acute teeth, followed by a single posterolateral tooth smaller than preceding teeth. Frontal margin without teeth, suborbital margin minutely granulate, with prominent tooth visible dorsally. Orbits obliquely arranged, clearly exposed dorsally. Body evenly tomentose, setae not arranged in tufts, with longer coarse setae fringing pereopods. Long setae filiform, short setae bent at right­angles.

Cheliped stout, dorsal margin of propodus with row of 4 small teeth along outer margin and 5 smaller teeth along inner margin. Fingers strongly curved, gaping, fixed finger with 7 well developed teeth, moveable finger with 4 teeth, fingers only touching at tips. Carpus with blunt lobe restricting folding of remainder of limb.

First 3 pairs of walking legs decreasing in size posteriorly, faces of merus of third leg smooth, superior margin with 5 small spines, inferior margin with 3 small spines, superior margin of carpus with 2 small spines. Dactylus curved, inferior margin armed with 5 small spines. Last pair of legs reduced lying alongside carapace margins above bases of third legs.

No effective abdominal locking mechanism: abdomen only loosely held against sternum. Crista dentata consists of 6 or 7 well developed, broad, distally placed teeth Female characters unknown.

Remarks: Hirsutodynomene vespertilio n. sp. differs from the other two species of the genus in several characters. The carapace surface of H. vespertilio is smooth while the other species have small spines and granules, which are the most dense in H. spinosa . The carapace width is also closer to the length in H. vespertilio than in H. spinosa and H. ursula (CW/CL = 1.15 versus 1.25–1.30). In H. vespertilio , the short setae on the carapace are bent at right angles, as in H. spinosa , whereas in H. ursula , they are almost straight. The inner carpal margin of the cheliped of H. vespertilio has a blunt lobe, as in H. ursula , but H. spinosa has an acute lobe instead. The outer surface of the cheliped propodus is granulate in H. ursula and H. spinosa , but is smooth in H. vespertilio .The margins of the first three pairs of walking legs have only weakly developed spines in H. vespertilio , but these are well developed in H. spinosa and to a lesser degree in H. ursula .

The maximum size of male H. vespertilio is 24.9 x 19.8 mm but for females, this is not known as none were collected. The maximum size of H. vespertilio is similar to that of the other two species. It should be noted that the female H. spinosa , 36.1 x 26.9 mm, collected near Turtle Island, off Tashi port, Ilan Province, northeastern Taiwan, is the largest individual reported for this species and the genus as a whole (see Comparative Material above).

Figures

FIGURE 6. Hirsutodynomene vespertilio n. sp. Holotype male, 22.8 x 19.9 mm, ZRC 2001.523, Philippines. A, overall dorsal view; B, detail of carapace surface; C, frontal view.

FIGURE 7. Hirsutodynomene vespertilio n. sp. Holotype male, 22.8 x 19.9 mm, ZRC 2001.523, Philippines. A, overall dorsal view; B, external view of left chela; C, dorsal view of left chela; D, posterior view of right fourth pereopod. Scale bars = 2.0 mm.