Guinotinia cordis, Forges, Bertrand Richer De & Ng, Peter K. L., 2009

Forges, Bertrand Richer De & Ng, Peter K. L., 2009, New genera, new species and new records of Indo-West Pacific spider crabs (Crustacea: Brachyura: Epialtidae: Majoidea), Zootaxa 2025, pp. 1-20 : 10-13

Guinotinia cordis n. sp.

Figs. 6A, B , 7 , 11 C

Material examined. New Caledonia. NORFOLK 1: Stn. DW 1701, 24°40.23’S 168°39.30’E, 564–586 m, 24 June 2001: 1 male holotype (23.0 x 16.3 mm) ( MNHN B31857), 1 ovigerous female paratype (25.1 x 17.6 mm) ( MNHN B31858).

Diagnosis. Relatively small-size species (largest specimen: ovigerous female 25.1 mm carapace length carapace length). Carapace pyriform with several raised plates. Carapace covered with club-shaped setae denser on surface of plates. Bifid rostrum with short flattened sharp, rostral spines; rostral spines very close to each other, outer border straight, giving triangular aspect to anterior part; ventral side of rostral spines depressed. Eyes small, with round cornea. Orbit formed by reduced supraocular eave, forming sharp tooth anteriorly, postocular plate cupped; narrow fissure present between 2 plates. Carapace plates arranged as follows: gastric area with 3 fused plates, 1 mesogastric, 2 lateral; round plate under mesogastric plate; cardiac region with large, rounded plate indented anteriorly, nearly heart-shaped, on each side of medial plate with 2 small oblique plates; branchial region with 4 plates on each side, small oblong plate directed laterally, large oblique ovoid plate with anterior indentation; hepatic plate rounded, fused with flatter postocular plate. Pterygostomian region with row of rounded tubercles on external border. Epistome narrow. Antennae shorter than short rostral spines. Buccal frame quadrangular; third maxillipeds operculiform. Chelipeds longer than P2, inflated, smooth; merus triangular in cross section, with 2 blunt teeth on distal border; carpus short, with 2 external carinae; propodus enlarged, flattened, with carinate borders, lower proximal angle expanded to form right-angled corner; fingers curved, touching each other only distally, with serrulated inner border. Ambulatory legs short, with short curved articles; dactylus as long as propodus, sharp, claw-shaped; proximal inferior border of propodus of P3-P5 with unusual swelling covered with dense setae. Anterior part of male thoracic sternum depressed; sternal sutures well defined, interrupted medially. Male abdomen with 7 free somites including telson. G1 relatively straight, slender, distally flattened, enlarged on distal part ( Fig. 7 D, E).

Etymology. From the cordis, Latin for “heart,” alluding to the shape of the cardiac plate.

Remarks. Guinotinia cordis n. sp. is so different from the other species of Pisinae that it is rather difficult to compare it with allied species. The closest species appears to be Laubierinia carinata ( Griffin & Tranter, 1986) . The two species have a similar size and a carapace with prominently swelled regions. However, they are easily separated by the following characters: the presence of laminated plates on the lateral branchial border of the carapace in L. carinata (absent in G. c o rd i s n. sp.); the carapace swellings are circular and flattened in L. carinata (elongated with a rounded surface in G. c o rd i s n. sp.); in L. carinata , the short rostral spines are divergent, forming a V-shape (spines parallel and adjoined to each other in G. c o rd i s n. sp.); the ambulatory legs have a carinated merus in L. carinata (uniformly cylindrical in G. c o rd i s n. sp.); and the propodi and dactyli of P3-P5 are not highly modified in L. carinata (adapted as pseudochelae in G. c o rd i s n. sp.).

Although the general pattern of the plates is similar in the two species, there is only one gastric plate vaguely resembling a cross in G. lehouarnoi n. sp. while the same plate is more elongated and rounded in G. cordis n. sp., and the epibranchial plate touches the hepatic plate in G. lehouarnoi n. sp. but these two plates are clearly separated in G. c o rd i s n. sp. .

Guinotinia cordis n. sp. apparently lives on gorgonians on hard substrates on the summit of seamounts. Its colour in life is rose brown, very similar to the gorgonians on which they were found ( Fig. 11 C). It was obtained in the same trawl as Oxypleurodon orbiculatum Guinot & Richer de Forges, 1986.

Figures

FIGURE 7. Guinotinia cordis n. sp., holotype male (23.0 x 16.3 mm) (MNHN-B 31857). A, dorsal view of carapace; B, face, showing antennae, antennules and third maxillipeds; C, lateral view of carapace; D, E, G 1 s. Scales: A, C = 10.0 mm; B = 5.0 mm; D, E = 1.0 mm.

FIGURE 11. Colours in life. A, Oxypleurodon sanctaeclausi n. sp., paratype ovigerous female (18.7 x 16.8 mm) (ZRC 2009.0018); B, Garthinia disica n. sp., paratype male (22.7 x 13.3 mm) (MNHN-B 31856); C, Guinotinia cordis n. sp., holotype male (23.0 x 16.3 mm) (MNHN-B 31857); D, Laubierinia carinata (Griffin & Tranter, 1986), male (26.7 x 22.5 mm) (MNHN-B 31864).

FIGURE 6. A, B, Guinotinia cordis n. sp., holotype male (23.0 x 16.3 mm) (MNHN-B B 31857); C, D, Guinotinia lehouarnoi n. sp., holotype male (16.2 x 10.8 mm) (MNHN- B 31859); E, F, Laubierinia carinata (Griffin & Tranter, 1986), male (19.1 x 14.8 mm) (MNHN-B 31863). A, C, E, overall dorsal views; B, D, F, thoracic sternum and abdomen.