Hymenicoides carteri Kemp, 1917

Naruse, Tohru & Ng, Peter K. L., 2007, On the taxonomy of the genus Hymenicoides Kemp, 1917 (Crustacea: Decapoda: Brachyura: Hymenosomatidae), with resurrection of Limnopilos Chuang & Ng, 1991, and descriptions of two new species, Zootaxa 1621, pp. 17-31 : 20

Hymenicoides carteri Kemp, 1917

( Fig. 2 )

Hymenicoides carteri— Kemp, 1917: 268; Lucas, 1980: 197; Ng & Chuang, 1996: 50; Guinot & Richer de Forges, 1997: 462.

Material examined. Lectotype (present designation): male, 4.0 × 4.8 mm, NHM 1919.11.1.121, R. Nughli, Sibpur, near Calcutta, India, coll. Annandale & S. Kemp, Jan. 1917.

Paralectotypes: 1 male, 4.0 × 4.8 mm, 1 female, 3.2 × 3.7 mm, 1 ovigerous female, 3.0 × 3.7 mm, NHM 1919.11.1.122–123, data same as lectotype.

Others. 1 male, 2.2 × 2.4 mm, 2 females, 2.6 × 2.9 mm, 2.7 × 2.9 mm, ZRC 2007.0107, Tangail District, North Central region, Ganges basin, Bangladesh, 4 Nov. 1992.

Remarks. Hymenicoides carteri has not been collected since Kemp (1917) described the species from near Calcutta, India and near Khulna, Bangladesh, on the basis of 22 specimens. In this study, we have located only four of the syntypes in NHM (Paul Clark, pers. comm.); the rest are presumably still in the Zoological Survey of India (ex Indian Museum). The G1 of H. carteri was first described by Lucas (1980: 197), although no figure was provided. The G1 of the lectotype ( Fig. 2 a, b, NHM, 4.0 × 4.8 mm) is very broad, bent outwards medially and with a line of long stiff median setae along the inner part of the ventral side. The distal part of the G1 is a complicated structure; composed of a bifurcated, U-shaped projection on the distal inner angle, a denticulate lip-like margin on the distal outer angle and a long bursiform projection on the dorsal side of the base of the distal outer angle. In situ, the G1 sits completely in the deep sterno-abdominal cavity ( Fig. 1 a).

Of the three recent specimens of H. carteri from Bangladesh, the only male specimen is small (ZRC 2007.0107, 2.2 × 2.4 mm) but it is basically similar to the type series of H. carteri (NHM 1919.11.1.121–123 3.0 × 3.7 - 4.0 × 4.8 mm) except for the G1 and the chela. The G1 is present but is still relatively undeveloped. The G1 of the lectotype specimen (NHM 1919.11.1.121, 4.0 × 4.8 mm) possesses a long bursiform projection on the dorsal side of the base of the distal outer angle ( Fig. 2 b), which is not observed in the small male Bangladesh specimen. The cheliped of the Bangladesh male specimen is proportionally small and the tubercle on the manus is very low. These differences, however, are possibly associated with size and growth. Larger series of the specimens from Bangladesh may help to better understand the degree of variation in this species.

Figures

FIGURE 1. Male abdominal cavity and pleotelson of Hymenicoides robertsi new species, and Limnopilos species. a, b, Hymenicoides robertsi new species (paratype, ZRC 2007.0109, 5.0 × 6.2 mm); c, d, L. naiyanetri Chuang & Ng, 1991 (ZRC 1991.6521 – 6555, 4.9 × 5.3 mm); e, f, L. sumatranus new species (paratype, ZRC 2007.0114, 5.0 × 5.9 mm). a, c, e, male abdominal cavity with sternal button (sb) and G 1; b, d, f, inner surface of male pleotelson.

FIGURE 2. Male first and second gonopods of Hymenicoides carteri Kemp, 1917. Lectotype, male (NHM 1919.11.1.121), 4.0 × 4.8 mm. a, left G 1, ventral view; b, left G 1, outer view; c, left G 2. Scale bar, 1 mm.