Raphidopus indicus Henderson, 1893

Osawa, Masayuki & Ng, Peter K. L., 2018, A new species of the genus Raphidopus Stimpson, 1858 (Crustacea: Decapoda: Anomura: Porcellanidae) from Peninsular Malaysia, with additional records of R. johnsoni Ng & Nakasone, 1994 from Southeast Asia, and a key to species in the genus, Zootaxa 4433 (1), pp. 111-126 : 112-114

Raphidopus indicus Henderson, 1893

( Figs. 1 , 2 , 9A )

Raphidopus indicus Henderson, 1893: 427 , pl. 39, figs. 19–22 (type locality: Madras, India).— OsaWa & McLaUghlin 2010: 115 (list).

Not Raphidopus indicus .— Haig 1966: 62, fig. 6 (= R. persicus Ng, Safaie & Naser, 2012 ).— Haig 1981: 275 (= R. Johnsoni Ng & Nakasone, 1994 ).—Ng & Nakasone 1994: 7, fig. 3 (= R. brevipes n. sp.).

Type material. Holotype: NHM 1892.7 .15.246, male (cl 6.5 mm), Madras , India.

Description. Carapace ( Fig. 1A ) 1.4 times as broad as long; gastric and cardiac regions with scattered, Very short, weak striae; branchial regions with interrupted, short ridges of small, low tubercles anteriorly and long, tuberculate ridges posteriorly; branchial margins narrowly laminar, each with row of small, rounded tubercles (those on median margin larger). Rostrum ( Fig. 1B ) trilobate, with median lobe distinctly exceeding leVel of apices of lateral lobes.

Third thoracic sternite ( Fig. 1C ) 4.6 times broader than long measured along midline.

Telson ( Fig.1D ) distinctly broader than long, with each posterior plate broader than long.

Eyes ( Fig. 1A, F ) small, not exceeding lateral limits of orbits.

Basal article of antennular peduncle ( Fig. 1E ) approximately as long as broad.

Antennal peduncle ( Fig. 1F ) slender. First article approximately equal in length to combined second to fourth articles. Third article elongate rectangular, about 1.5 times longer than second.

Third maxilliped ( Fig. 1G ) moderately stout, nearly smooth on lateral surface. Merus with rounded lobe proximal to median part of Ventral margin. Propodus moderately slender. Exopod about 0.8 width of ischium.

Chelipeds ( Fig. 2A–G ) somewhat unequal in size. Merus with strong slender spine (larger) or unarmed (smaller) on Ventro-anterior margin. Carpus 1.9 (larger cheliped) –2.0 (smaller cheliped) times as long as broad; dorsal surface with short rows of small tubercles entirely and with single, flattened tubercles distally, no blunt ridge on longitudinal midline; posterior margin unarmed, rounded entirely. Chela about 2.9 times longer than broad; dorsal surface with coarse, small tubercles; cutting edge of fixed finger with row of small rounded teeth and large blunt teeth on proximal and distal parts (larger) and with row of small, low teeth (smaller). Dactylus 0.5 length of chela; cutting edge with row of small, low, rounded teeth and large proximal tooth, median margin slightly eleVated (larger) and with row of small, low teeth (smaller).

Ambulatory legs ( Fig. 1H–J ) comparatiVely slender, lateral surface nearly smooth. Meri 3.6, 3.7, 2.9 times longer than high on respectiVe second to fourth pereopods. Carpi relatiVely slender. Propodi 3.4, 3.0, 2.7 times longer than high on respectiVe second to fourth pereopods. Dactyli 0.8 length of propodi.

Coloration. Not recorded.

Distribution. Known only from Madras (= present day Chennai), southeastern India ( Henderson 1893).

Habitat. Not recorded.

Remarks. The holotype of R. indicus currently ( Fig. 9A ) lacks the left second and third pereopods, although they were originally illustrated by Henderson (1893: fig. 19); it does not haVe many setae on the carapace and appendages. It appears that most setae on the holotype were either lost or decreased with time and preserVation as congeners are typically more setose (cf. Osawa & Chan 2010; Ng et al. 2012; present study, Fig. 9B–F ).

In addition to Henderson’s (1893) record from Madras (= present day Chennai), India, R. indicus has been recorded from Iran ( Haig 1966), “Indo-Chinese Sea” (= probably South China Sea) and Indonesia ( Haig 1981), and Peninsular Malaysia (Ng & Nakasone 1994). HoweVer, Ng et al. (2012) showed that Haig’s (1966) material from the Persian Gulf belonged to a new species, R. persicus . The present comparison of the holotype of R. indicus with Haig’s (1981) and Ng & Nakasone’s (1994) specimens also shows that the latter specimens are not R. indicus but actually R. johnsoni or R. brevipes n. sp. Raphidopus indicus is known only by the holotype at present, and it more closely resembles R. johnsoni rather than R. brevipes n. sp., as discussed below in the Remarks of the new species.

Figures

FIGURE 1. Raphidopus indicus Henderson, 1893, holotype, male (cl 6.5 mm), NHM 1892.7.15.246, Madras. A, carapace and ocUlar and antennal pedUncles, dorsal vieW (transverse striae and ridges on right side not draWn); B, rostrUm, dorso-anterior vieW; C, third and foUrth thoracic sternites, ventral vieW; D, telson, external vieW; E, basal article of left antennUlar pedUncle, ventral vieW; F, left ocUlar and antennal pedUncles, dorsolateral vieW; G, left third maxilliped, lateral vieW; H–J, right second to foUrth pereopods, lateral vieW. Setae are not draWn on all figUres. Scale bars = 1.0 mm.

FIGURE 2. Raphidopus indicus Henderson, 1893, holotype, male (cl 6.5 mm), NHM 1892.7.15.246, Madras. A, larger cheliped, dorsal vieW; B, larger cheliped, merUs and carpUs, ventral vieW; C, larger cheliped, carpUs, dorsal perpendicUlar vieW (sUrface strUctUre not draWn); D, larger cheliped, chela, dorsal perpendicUlar vieW (sUrface strUctUre not draWn); E, smaller cheliped, merUs, ventral vieW (sUrface strUctUre not draWn); F, smaller cheliped, carpUs, dorsal perpendicUlar vieW (sUrface strUctUre not draWn); G, smaller cheliped, chela, dorsal perpendicUlar vieW (sUrface strUctUre not draWn). Setae are not draWn on all figUres. Scale bars = 1.0 mm.

FIGURE 9. Preserved specimens of three Raphidopus species. Entire animal, dorsal vieW (A–D); carapace, dorsal vieW (E); larger and smaller chelipeds, dorsal vieW (F). A, Raphidopus indicus Henderson, 1893, holotype, male (cl 6.5 mm), NHM 1892.7.15.246; B, Raphidopus Johnsoni Ng & Nakasone, 1994, holotype, male (cl 3.8 mm), ZRC 1992.10669; C, Raphidopus Johnsoni Ng & Nakasone, 1994, female (cl 5.9 mm), CBM-ZC 12485; D, Raphidopus brevipes n. sp., female (cl 5.1 mm), ZRC 2016.528; E, Raphidopus brevipes n. sp., male, holotype, male (cl 5.8 mm), ZRC 1992.10521; F, Raphidopus brevipes n. sp., paratypes, ZRC 1992.10522–10526.