Ryphila bertrandi, Galil, Bella S. & Ng, Peter K. L., 2015

Galil, Bella S. & Ng, Peter K. L., 2015, Leucosiid crabs from Papua New Guinea, with descriptions of eight new species (Crustacea: Decapoda: Brachyura), Zootaxa 4027 (4), pp. 451-486 : 462

Ryphila bertrandi sp. nov.

( Figs. 4 E, 9, 10)

Material examined. Holotype: female (11.5 mm) (MNHN-IU-2013-12749), stn PD72, between Yabob & Bil Bil I., 05°16.2'S 145°46.5'E, 20–25 m, 6.12.2012. Paratypes: 1 ovigerous female (9.6 mm) ( ZRC 2015.270), same data as holotype; 1 ovigerous female (12.5 mm) (MNHN-IU-2013-12750), stn PD68, south Kesup Gun River mouth, 05°16'S 145°46.5'E, 2–3 m, Papua New Guinea, 4.12.2012.

Description. Carapace discoidal, with shallow branchio-cardiac grooves ( Fig. 9 A, B). Dorsal surface of carapace minutely granular anteriorly, with closely-spaced pearliform granules on branchial, cardial, intestinal regions. Frontal margin horizontal, setose ( Fig. 9 C). Margins of carapace closely beaded, granules smaller anteriorly ( Fig. 9 E). Hepatic facet distinct. Pterygostomian region prominently granular ( Fig. 9 F). Epimeral, posterior surfaces minutely granular. Antennular fossa sealed by basal antennular article. Antennae short, inserted between antennular fossa, orbit. Eyes retractable. Epistome continuous with expanded, beaded subhepatic margin, projecting beyond frontal margin, medially notched. Anterior margin of efferent branchial channel forms part of lower orbital margin, entire, fissure situated ventrally to orbit. Third maxilliped exopod semicircular ( Fig. 9 F), expanded, densely setose; endopod triangular, merus densely setose, shorter than ischium along inner margin, apex invisible in dorsal view.

Chelipeds subequal. Cheliped merus 0.6 as long as carapace in female; entirely covered with pearliform granules, decreasing in size distally ( Fig. 10 A–C). Carpus with row of minute granules on inner margin; patch of minute granules distally on dorsal margin. Dorsal margin of chela cristate, with 2 parallel rows of granules, ventral margin minutely granular. Fingers slightly longer than palm, cutting edges cristate, distally denticulate.

Ambulatory legs slender, short, meri subcylindrical, longer than carpi, propodi, ventral margin minutely granular; dorsal, ventral propodal margins carinate; dactyli longer than propodi, lanceolate, terminating in cornute tips.

Female abdomen with first 2 somites transversely narrow, yoke-like, granular; somites 3–6 fused, greatly enlarged, shield-like, proximally granular; telson laciniate ( Fig. 10 E). Thoracic sternites with closely spaced pearliform granules. Vulvae submedially near suture 6/5; small, rounded, opening interiorly, hooded by calcified pear-shaped dome ( Fig. 10 D).

Colour in life. Dorsal surface of carapace and chelipeds brown, granules bright orange-red, pale blotches on post orbital regions, and on both sides of cardiac region. Rounded knob distally on cheliped merus bright red, finger tips white. Ambulatory legs pale, spotted red on merus and carpus ( Fig. 4 E).

Remarks. Ryphila bertrandi sp. nov. shares with it congeners R. cancellus (Herbst, 1783) and R. verrucosa (Henderson, 1893) a projecting epistome and ventral margin of hepatic facet and reniform third maxilliped exopod. It is clearly distinguished from both, however, in having cheliped merus entirely covered with pearliform granules dorsally rather than with several rows of pearliform granules, and the carapace dorsally minutely granular anteriorly, with larger pearliform granules on the branchial, cardiac and intestinal regions.

Etymology. In honour of our good friend, Bertrand Richer de Forges, intrepid explorer and collector of crabs from all over the Indo-West Pacific.

Geographical distribution. This species is known only from type location, Papua New Guinea.

Figures

FIGURE 4. Colours in life. A, Nursilia dentata, male (7.2 mm) (ZRC 2014.0165), stn PD 75; B, Parilia major, immature male (35.1 mm) (MNHN-IU- 2013 - 1044), stn CP 3968; C, Raylilia coniculifera, ovigerous female (10.5 mm) (ZRC 2014.0169), stn PD 45; D, Raylilia uenoi, young female (10.4 mm) (MNHN-IU- 2013 - 117), stn PR 07; E, Ryphila bertrandi sp. nov., paratype ovigerous female (12.5 mm) (MNHN-IU- 2013 - 12750), stn PD 68; F, Tanaoa kuka sp. nov., holotype male (33.0 mm) (MNHN- IU- 2013 - 7963), stn CP 3984.

FIGURE 9. Ryphila bertrandi sp. nov. A, C – F, holotype female (11.5 mm) (MNHN-IU- 2013 - 12749), stn PD 72; B, paratype ovigerous female (9.6 mm) (ZRC 2015.270), stn PD 72. A, B, overall habitus; C, frontal margin and orbits; D, frontal view of cephalothorax and chelipeds; E, left lateral view of cephalothorax; F, third maxillipeds.

FIGURE 10. Ryphila bertrandi sp. nov., holotype female (11.5 mm) (MNHN-IU- 2013 - 12749), stn PD 72. A, inner view of right chela; B, dorsal view of right cheliped merus; C, anterior view of left cheliped merus; D, thoracic sternum and vulvae; E, ventral surfaces, thoracic sternum and abdomen.