Pleisticanthoides cameroni Ng & Forges, 2012, n. sp.

Pleisticanthoides cameroni n. sp.

(Figs. 1 C, 5, 6, 8A, 9A, B, D, 10A, 11B, D)

Material examined. Holotype: male (18.7 × 13.9 mm) (NMCR), Bohol Sea, Philippines, station CP 2358, 8°51.3’N 123°37.8’E – 8°52.1’N 123°37.1’E, 569–583 m, sandy substrate, coll. PANGLAO 2005, 26 May 2005. Paratypes: 1 male (15.5 × 11.6 mm) (ZRC 2012.0903) (photographed), station CP 2396, 9°36.7’N 123°42.9’E – 9°36.2’N 123°42’E, 609–673 m, sandy substrate, coll. PANGLAO 2005, 31 May 2005.— 1 male (13.1 × 9.9 mm) (ZRC 2012.0904), station CP 2399, 9°31.8’N 123°41.7’E – 9°31.7’N 123°41.9’E, 342– 309 m, rock, sand and coral substrates, coll. PANGLAO 2005, 31 May 2005.—AURORA 2007 (Philippines): 1 male (15.3 × 11.4 mm) (ZRC 2012.0905) (photographed), east coast of Luzon, station CP 2660, 15°52.06’N 121°49.6’E, 500–542 m, coll. 20 May 2007.— 1 female (12.8 × 9.2 mm) (ZRC 2012.0906), station CP 2708, 15°07.61’N 121°36.95’E, 309– 307 m, 28 May 2007.— 1 female (13.0 × 9.6 mm) (MNHN-IU-2012-765), station CP 2730, 15°21’N 121°34’E, 358–378 m, 31 May 2007.— 1 male (16.1 × 11.9 mm) (MNHN-IU-2012-766), station CP 2727, 15°20’N 121°34’E, 300–318 m, 31 May 2007. — 1 male (18.1 × 13.0 mm), 1 juvenile (8.7 × 6.8 mm) (NMCR), station CP 2735, 15°59’N 121°50’E, 431–442 m, 1 June 2007.—1 ovigerous female (21.6 × 16.4 mm) (ZRC 2012.0907), station CP 2710, 15°15’N 121°33’E, 206–216 m, 28 May 2007.— 1 male (16.3 × 12.5 mm), 1 female (13.8 × 10.6 mm) (MNHN-IU- 2012–767), station CP 2734, 15°56’N 121°49’E, 453–460 m, 1 June 2007.—1 ovigerous female (18.1 × 14.5 mm) (ZRC 2012.0908), station CP 2749, 15°56’N 121°49’E, 473 m, 2 June 2007.—1 ovigerous female (21.2 × 16.0 mm) (ZRC 2012.0979), station CC 2744 15°58.75’N 121° 50.36E – 15°58.14’N 121°49.22’E, 456– 418 m, coll. AURORA 2007, 2 June 2007.— 1 male (21.0 × 16.2 mm) (ZRC 2012.0980), Maribojoc Bay, Panglao, Bohol, in tangle nets, coll. J. Arbasto, 2011.— 1 female (24.3 × 18.6 mm) (ZRC 2012.0981), Balicasag Is, Panglao, Bohol, in tangle net, coll. J. Arbasto, July 2006. All localities in Philippines.

Description. Carapace pyriform, dorsal surface covered by long hooked setae, surface smooth, without trace of spines, spinules or granules; regions well-defined: gastric region slightly inflated; branchial region inflated, separated from cardiac, gastric regions by deep groove. Front with 2 sharp, short, diverging pseudorostral spines; base of pseudorostral spine with sharp accessory spine directed anteriorly; supraocular eave with sharp anterior spine, strong supraocular tooth posteriorly; subhepatic region slightly inflated, with strong tooth longer than supraocular tooth; short tooth present between subhepatic, supraocular teeth. Ocular peduncle relatively long, slender; cornea rounded, diameter slightly greater than that of peduncle. Interantennular spine (= true rostrum), pointed downwards, medially divided to form 2 teeth. Antennae ca. 2 times length of pseudorostral spines; antennal basal article slender, fused with carapace; urinary article with large green gland opening, surrounded by raised rounded margin, outer border with strong flattened triangular tooth. Epistome smooth; buccal frame quadrangular. Third maxilliped with segments flattened, covered by long setae; outer border of carpus crenulated. Cheliped not inflated; lower margin of pollex weakly serrulated, dorsal margin of dactylar finger smooth. Ambulatory legs conspicuously long; P2 longest; segments with several rows of very long, relatively rigid setae, looking like thin spines. Male abdomen with 6 free somites, telson; somites covered with long, stiff setae; sixth somite with distolateral margins expanded, overlapping telson. G1 strongly curved, C-shaped, G1 curved, distinctly C-shaped, distal third dorsolaterally flattened.

Etymology. The species is named after director and deep-sea explorer James Francis Cameron, to honour his landmark dive into the Mariana Trench on 24 March 2012 onboard the Deepsea Challenger, the third man ever to dive to such depths. His films on deep-sea and extra-terrestrial worlds have also been an inspiration to explorers everywhere.

Remarks. There are several differences between Pleisticanthoides cameroni n. sp. and P. nipponensis Yokoya, 1933. Most significantly, the carapace of P. nipponensis is covered with spinules (Figs. 2 B–D, 3A, B) but is almost completely smooth and unarmed in P. cameroni n. sp. (Figs. 1 C, 5, 8A). The basal antennal article has only two small distal spines in P cameroni n. sp. (Figs. 9A, 10 A) (three spines in P. nipponensis, Fig. 3 C), the cheliped merus and carpus are not armed with spines, having only low granules or tubercles (Figs. 5, 6, 8 A, 9A) (five distinct spines on the merus and four spines on the carpus of P. nipponensis, Figs. 2 A, 3A), and the G1 is relatively longer and prominently C-shaped (Fig. 11 A–C) (G1 relatively shorter and gently curved in P. nipponensis, Fig. 4).

The specimens, collected in the upper bathyal zone (207–673 m) of the Bohol Sea and on the Pacific coast of Luzon, Philippines, were covered with debris and mud trapped by the long, hooked setae of the carapace and pereiopods.