Samadinia longispina, Ng, Peter K. L. & Forges, Bertrand Richer De, 2013

Ng, Peter K. L. & Forges, Bertrand Richer De, 2013, Samadinia longispina, a new genus and species of deep-sea spider crab from the western Pacific, and a new species of Rochinia A. Milne-Edwards, 1875, from Papua New Guinea (Crustacea: Brachyura: Majoidea: Epialtidae), Zootaxa 3718 (4), pp. 357-366 : 358-361

publication ID

https://doi.org/ 10.11646/zootaxa.3718.4.5

publication LSID

lsid:zoobank.org:pub:50BBC8C0-C684-4738-8E0D-795805CC0BEF

DOI

https://doi.org/10.5281/zenodo.6148796

persistent identifier

https://treatment.plazi.org/id/038A87DF-2B66-3221-FF05-FD06FE20F500

treatment provided by

Plazi

scientific name

Samadinia longispina
status

sp. nov.

Samadinia longispina View in CoL n. sp.

( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 , 3A, E View FIGURE 3. A, E , 4 View FIGURE 4 A–D)

Material examined. Holotype: male (25.3 × 17.9 mm) (MNHN-IU-2011-4190), stn CP 3381, 15°41’S 146°56’W, French Polynesia, south of Society Islands, Tarava Seamounts, 830–988 m, coll. TARASOC, RV Alis, 5 October 2009. Other material: EXBODI: 1 ovigerous female (12.9 × 8.9 mm) (MNHN-IU-2013-1678), stn CP 3911, Astrolabe reefs, northern New Caledonia, 19°50’S 165°33’E, 680–802 m, coll. RV Alis, 23 September 2011. — 1 female (13.8 × 9.6 mm) (ZRC ex MNHN-IU-2013-1688), stn CP 3911, Astrolabe reefs, northern New Caledonia, 19°50’S 165°33’E, 680–802 m, RV Alis, 23 September 2011.

Diagnosis. Dorsal surface of carapace with numerous small rounded granules ( Figs. 1 View FIGURE 1 A, 3A). Pseudorostral spines long, curved, diverging ( Figs. 1 View FIGURE 1 A, 3A). Supraocular eave narrow forming acute sharp tooth, directed anteriorly; postocular tooth acutely triangular ( Figs. 1 View FIGURE 1 A, B, 3A). Hepatic spine long, sharp, subequal in length to branchial spine, directed sublaterally ( Figs. 1 View FIGURE 1 A, 3A). Lateral margin with numerous small rounded granules, with long branchial spine directed laterally ( Figs. 1 View FIGURE 1 A, B, 3A). Basal antennal article broad, with 2 low distal teeth ( Figs. 1 View FIGURE 1 C, 2A). Ambulatory legs, especially meri, relatively long ( Figs. 1 View FIGURE 1 A, 3A). Surface of female abdomen with raised median ridge of tubercles. G1 gently sinuous with 3 folds ( Fig. 4 View FIGURE 4 A?C).

Description. Carapace pyriform; dorsal surface with regions poorly defined, uniformly covered by rounded granules, without tubercles or spines; cardiac region elevated ( Figs. 1 View FIGURE 1 A, B, 3A). Pseudorostral spines long, slender, straight, cylindrical in cross-section, prominently diverging outwards ( Figs. 1 View FIGURE 1 A, 3A). Supraocular eave short, forming acute sharp tooth, directed anteriorly; postocular tooth relatively short, acutely triangular, tip rounded. Hepatic spine long, straight to slightly curved, directed laterally to sublaterally ( Figs. 1 View FIGURE 1 A, 3A). One long lateral spine, directed laterally, subequal in length, subparallel to hepatic spine ( Figs. 1 View FIGURE 1 A, 3A). Intestinal region with a large rounded tubercle just before posterior carapace margin ( Figs. 1 View FIGURE 1 A, 3A).

Ocular peduncle short, with granular tooth on upper border; cornea round, fully pigmented ( Figs. 1 View FIGURE 1 , 3A View FIGURE 3. A, E ). Suborbital margin confluent with lateral margin of basal antennal article ( Fig. 2 View FIGURE 2 A, B). Basal antennal article longer than broad, with 2 low distal teeth; third, fourth articles cylindrical, flagellum relatively short, slender, positioned just outside orbit ( Figs. 1 View FIGURE 1 C, 2B, C). Antennules folding vertically ( Fig. 2 View FIGURE 2 B). Epistome longitudinally narrow; posterior margin crenulated ( Fig. 2 View FIGURE 2 B). Pterygostomial area smooth, separated from sub-branchial region by row of 4 large, rounded granules ( Fig. 2 View FIGURE 2 A). Third maxillipeds completely covering buccal cavity when closed; surfaces smooth, covered by short pubescence; ischium wider distally than proximally, with distinct, broad median sulcus; merus quadrate, anterolateral margin auriculiform; exopod relatively stout, reaching to just before distal edge of merus, with long flagellum ( Fig. 2 View FIGURE 2 A, C).

Chelipeds subequal, chelae not inflated; merus trigonal in cross-section, with distal tooth on dorsal margin; carpus short, with dorsal surface somewhat flattened; surface of palm slightly rugose; fingers subequal in length to palm, distal portion of cutting margin with distinct teeth, proximal portion uneven to serrulate ( Figs. 1 View FIGURE 1 A, 2D, 3A). Ambulatory legs relatively long, slender; first leg longest, fourth leg shortest; surfaces with scattered short setae; meri unarmed; carpus short with lateral sulcus; dactylus tapering, surface with dense short setae except for corneous tip ( Figs. 1 View FIGURE 1 A, 3A).

Surface of thoracic sternum covered with short pubescence. Sternites 1, 2 completely fused, forming small triangular plate, separated from sternite 3 by distinct suture; sternite 3, 4 completely fused except for lateral clefts; sternite 3 discernible as small triangular plate, medially depressed; sternite 4 strongly constricted, anterior part much narrower than posterior part, with anterolateral margins almost parallel, median part of lateral margins strongly convex ( Figs. 2 View FIGURE 2 A).

Abdomen broadly triangular, with 6 free somites, telson; somites 3, 4 trapezoidal; somites 5, 6 subrectangular, somite 6 longer; telson broadly triangular, subequal in length to somite 6, with almost straight lateral margins ( Figs. 2 View FIGURE 2 A).

G1 relatively straight, flattened laterally along distal third; distal part forming 3 folds ( Fig. 4 View FIGURE 4 A?C). G2 short, about a quarter length of G1; tip with cup-like structure, no distal segment ( Fig. 4 View FIGURE 4 D).

Female abdomen rounded, dome-shaped, covering entire thoracic sternum; all somites, telson free; outer surface of somites with raised median ridge of tubercles. Sterno-abdominal cavity deep; vulva large, raised, opening large, subcircular ( Fig. 3E View FIGURE 3. A, E ).

Etymology. The new species is named for the long hepatic and lateral branchial spines.

Remarks. The two female specimens from New Caledonia agree well with the holotype male in most nonsexual characters. The smaller female (12.9 × 8.9 mm, MNHN-IU-2013-1678) ( Fig. 3A View FIGURE 3. A, E ) is already fully mature, with the abdomen forming a dome-like structure covering the entire thoracic sternum and is ovigerous. The larger female (13.8 × 96.1 mm, ZRC ex MNHN-IU-2013-1688) is not fully mature with the abdomen not swollen and covering only about half the thoracic sternum. In both females, the hepatic spines are directed more laterally than in the male ( Fig. 1 View FIGURE 1 A) but are shorter than the lateral branchial carapace spines ( Fig. 3A View FIGURE 3. A, E ).

Other than the generic differences between Rochinia and Samadinia n. gen. (see remarks for Rochinia ), Samadinia longispina n. gen., n. sp. superficially resembles species like Rochinia strangeri Serène & Lohavanijaya, 1973 , and R. kotakae Takeda, 2001 , in having long pseudorostral spines and a long lateral branchial spine. These two species, however, have weaker hepatic spines, smooth carapaces and the regions have distinct tubercles. The new species also resembles R. paulayi Ng & Richer de Forges, 2007, in having long, subequal hepatic and lateral branchial spines; but all the carapace regions of R. paulayi also have long spines, absent in S. longispina n. gen., n. sp.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Epialtidae

Genus

Samadinia

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