Crocydocinus saravananei, Padate & Lee & Cubelio, 2020

Padate, Vinay P., Lee, Bee Yan & Cubelio, Sherine Sonia, 2020, Description of a new species of deep-sea spider crab from the genus Crocydocinus Lee, Richer de Forges & Ng, 2019, from the south-eastern Arabian Sea (Crustacea Decapoda: Majoidea: Epialtidae), Zootaxa 4816 (2), pp. 229-234 : 230-233

publication ID	https://doi.org/ 10.11646/zootaxa.4816.2.8
publication LSID	lsid:zoobank.org:pub:304DA66D-292F-46DF-94AF-391E664EC65E
DOI	https://doi.org/10.5281/zenodo.4324127
persistent identifier	https://treatment.plazi.org/id/22089249-6844-FE26-FF56-E778274CFC9F
treatment provided by	Plazi
scientific name	Crocydocinus saravananei
status	sp. nov.

Treatment

Crocydocinus saravananei View in CoL n. sp.

( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 A–K, 3A–F)

Material examined. Holotype: male (30.8 × 26.7 mm) ( IO /SS/BRC/00180), FORVSS stn 36603, off Trivandrum, Arabian Sea, 8.41°N 76.16°E, 959 m, coll. Dr. Usha Parameswaran, 26 October 2017 GoogleMaps . Paratype: 1 male (23.5 × 18.6 mm) ( IO /SS/BRC/00293), FORVSS stn 26707, off Trivandrum, Arabian Sea, 8.46ºN 76.41ºE, 280 m, coll. 1 June 2009 GoogleMaps .

Diagnosis. Carapace pyriform, bearing thick tomentum, long setae tufts along edge of gastric and branchial regions, smooth when denuded. Pseudorostral spines straight, short, diverging in V. Carapace regions well-defined, gastric, cardiac and branchial regions highly elevated; gastric region with median row of 1 conical mesogastric granule, 1 low adjoining elongated granule, and 1 posterior elongated metagastric granule, 1 pair of lateral conical granules, (urogastric granule absent); cardiac region with 1 conical granule, flanked laterally by 1 pair of small granules at base; intestinal region with 1 compressed granule; branchial region with 3 short conical granules; lateral branchial margins of carapace with 2 granules. Pterygostomian region with 3 granules ( Fig. 2C, E View FIGURE 2 ). G1 relatively straight, laterally flattened, distal tip constricted ( Fig. 3 View FIGURE 3 A–D).

Description. Carapace pyriform, bearing thick tomentum, long setal tufts along edge of gastric and branchial regions, smooth when denuded ( Figs.1 View FIGURE 1 , 2A, B View FIGURE 2 ). Pseudorostral spines straight, short (0.21 times of maximum carapace length), diverging, V-shaped ( Fig. 2 View FIGURE 2 A–E). Supraorbital eave fused to carapace; pre-orbital lobe directed forwards; distinct U-shaped hiatus separating pre-orbital and post-orbital lobes ( Fig. 2A, D View FIGURE 2 ). Post-orbital lobe cup-like ( Fig. 2A, D View FIGURE 2 ).

Carapace regions well-defined, with granules; gastric, hepatic, branchial and cardiac regions swollen; hepatic lobe with 1 conical granule; gastric with 1 mesogastric granule anteriorly, 1 low adjoining elongated granule, 1 elongated metagastric granule, 2 granules along median row; urogastric region depressed, granule absent; swollen cardiac region with 1 granule medianly, 2 small granules at base of cardiac region; swollen intestinal region with 1 compressed granule; swollen branchial region with 3 granules; 2–4 granules along lateral margin of carapace at branchial region ( Fig. 2A View FIGURE 2 ).

Antennal flagellum nearly equal in length to pseudorostral spines. Antennules completely retractable in deep fossae. Basal antennal article longer than broad, slightly rounded outer margin. Presence of large granule at base of article ( Fig. 2C, E View FIGURE 2 ). Buccal frame covered by third maxilliped, distal angle of frame slightly protruded; third maxilliped covered with setae, smooth and slightly granulated when denuded; ischium sub-rectangular with sub-median longitudinal depression; merus subquadrate, 0.58 times as long as ischium, antero-external angle slightly rounded ( Fig. 2E View FIGURE 2 ). Pterygostomian region with 3 granules ( Fig. 2B, C, E View FIGURE 2 ).

Chelipeds subequal; male cheliped with margins of ischium, merus, carpus, and palm of chela carinate; merus triangular in cross-section, with carinate anterior margin; palm of chela inflated; fingers slightly curved, slightly shorter than length of upper margin of palm, tapering distally, distal tips acuminate ( Figs. 1 View FIGURE 1 , 2F, G View FIGURE 2 ). Ambulatory legs covered with setae, with tufts of longer setae on anterior and posterior margins, smooth when denuded; posterior margin of dactylus with single row of 1–8 flattened granules, distal tips corneous, sharp ( Figs. 1 View FIGURE 1 , 2H, I, J View FIGURE 2 ).

Male thoracic sternum wide, depressed anteriorly; sternites 3–4 fused, lateral margins slightly constricted, sternite 4 elevated posteriorly, sterno-pleonal cavity extends anteriorly to middle thoracic sternite 4 ( Fig. 2C View FIGURE 2 ). Male pleon with 6 free somites and telson, widest at somite 3, somite 5 with lateral margins constricted, somite 6 with lateral margins diverging, telson triangular with round distal margin ( Fig. 2K View FIGURE 2 ). G1 relatively straight, flattened laterally ( Fig. 3A, C View FIGURE 3 ), distal tip blunt, constricted, slightly bifid ( Fig. 3B, D View FIGURE 3 ). G2 shorter than G1, distal tip rounded ( Fig. 3E, F View FIGURE 3 ).

Etymology. The species name is dedicated to the Principal Investigator of the research project titled “Resource Exploration and Inventorization System” and scientist at CMLRE, Shri N. Saravanane, who is a distinguished marine scientist in India.

Remarks. Crocydocinus saravananei n. sp. was collected from the continental slope that is located off the southwest coast of Thiruvananthapuram (Trivandrum), India. Two male specimens were obtained using a High Speed Demersal Trawl (Crustacean Version) net (HSDT (CV)) on-board the FORVSS cruise number 366 and 267.

Crocydocinus saravananei n. sp. ( Figs. 1 View FIGURE 1 , 2A View FIGURE 2 ) resembles C. brevirostris in the general shape of carapace, relative length of the pseudorostral spines and shape of orbit (see Lee et al. 2019: fig. 13B). The new species, however, is morphologically distinct from the other species of Crocydocinus in the absence of urogastric granule on carapace ( Figs. 1 View FIGURE 1 , 2A View FIGURE 2 ) (versus having urogastric granule on C. ewok , C. brevirostris and C. porg ; see Lee et al. 2019: figs. 13A, B, 14B); the presence of two granules along lateral margin of carapace at branchial region ( Figs. 1 View FIGURE 1 , 2A, B, C View FIGURE 2 ) (versus a lack of granule on C. brevirostris , C. crosnieri and C. decipiata ; one granule on C. ewok and C. panglao ; and three granules on C. porg and C. vanuatu ; see Lee et al. 2019: fig. 17A–G); the presence of granules on P2–P4 dactyli ( Fig. 3H, I, J View FIGURE 3 ) (versus lack of granules on the dactyli of the ambulatory legs in the other species of Crocydocinus ); and the slightly bifid, blunt and constricted distal tip of the G1 ( Fig. 3B, D View FIGURE 3 ) (versus G1 with sharp distal tip in C. ewok (see Lee et al. 2019: fig. 18A–D), sharp distal tip with slight constriction in C. crosnieri (see Lee et al. 2019: fig. 18G–J), bilobed distal tip in C. decipiata (see Lee et al. 2019: fig. 19A–D), and sharp distal tip in C. vanuatu ; see Lee et al. 2019: fig. 19A–D).