Statommatia malagasy Ng & Castro, 2016, n. sp.
Creators: name: Ng, Peter K. L.
name: Castro, Peter
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Chasmocarcinidae
Statommatia
Statommatia malagasy

description: Statommatia malagasy n. sp.
(Figs. 16 E, F; 26C; 33E; 42N; 45G, H; 54C; 61C; 77I ‒L; 88B; 91F)
Type material. Holotype male (9.9 × 12.4 mm) (MNHN-IU-2014-12806), Madagascar, southwest of Point Barrow, ATIMO VATAE, stn CP3590, 25°03’S, 43°59’E, 300‒309 m, 11.05.2010.
Paratypes: ATIMO VATAE: 3 paratype males (7.7 × 9.2 mm, 8.8 × 11.0 mm, 9.2 × 11.7 mm), 3 paratype females (6.8 × 8.1 mm, 8.3 10.2 × 10.2 mm, 8.1 × 9.4 mm [photographed] (MNHN-IU-2014-4370), southwest of Point Barrow, stn CP3590, 25°03’S, 43°59’E, 300‒309 m, 11.05.2010; 1 paratype male (6.7 × 8.2 mm), 2 paratype females (ZRC 2015.215), stn CP3583, 25°31’S, 44°16’E, south Madagascar, 296‒302 m, 10.05.2010; 1 paratype ovigerous female (6.9 × 8.6 mm) (ZRC 2015.265, ex MNHN-IU-2014-17792), south of Point Barrow, stn DW3582, 25°32’S, 44°16’E, south Madagascar, 10.05.2010.— MIRIKY: 3 paratype females (7.9 × 9.3 mm, 8.0 × 9.3mm, 7.5 × 9.2 mm) (MNHN-IU-2010-1029), Narendry Bay, stn CP3289, 14°29’S, 47°26’E, 332‒379 m, 14.07.2009.
Diagnosis. Carapace (Fig. 16 E, F) subtrapezoidal, convex dorsally, 1.2–1.3 wider than long; front bilobed, with shallow median cleft; anterolateral margins arcuate, minutely granular with granules higher along lateral margins, without distinct lobes or teeth. Eye peduncle (Fig. 26 C) filling orbit, short, immobile; cornea reduced, with reduced pigmentation. Posterior margin of epistome (Fig. 26 C) with semicircular median lobe with deep median fissure, semicircular lateral margins. Third maxilliped (Fig. 33 E) merus subquadrate, ischium subrectangular, slightly longer than merus. Proportionally short ambulatory legs (Fig. 16 E, F); P5 merus 0.7 cl. Chelipeds (Figs. 16 E, F; 45G, H) subequal in length, slightly dissimilar in females, heteromorphic in males; fingers of minor chela (Fig. 45 H) subcircular in cross-section, scissor-like, cutting margins with small teeth; dactylus of major chela of males (Fig. 45 G) curved, forming wide, round gap when closed, reduced teeth. Ventral surface of cheliped merus with row of 5, 6 large pointed tubercles along outer margin (Fig. 42 N). Inner margin of cheliped carpus with short distal tooth (Fig. 16 E, F). Fused thoracic sternites 1, 2 (Fig. 54 C) semicircular, broad, long. Male pleon (Figs. 54 C; 61C) with proportionally short telson. G1 (Fig. 77 I‒K) slender, slightly curved, with short spinules. G2 (Fig. 77 L) about 1/2 G1 length, curved, slender, distal segment proportionally short. Female telson (Fig. 88 B) proportionally long. Sterno-pleonal cavity of female (Fig. 91 F) deep, vulvae relatively close together, located on outer margins of cavity close to suture 5/6.
Remarks. Statommatia malagasy n. sp. is externally similar to S. apta, notably in the form of the carapace and chelipeds. It can be distinguished from S. apta, however, by its proportionally shorter and stouter ambulatory legs, especially the merus (Fig. 16 E, F) (relatively more slender and longer in S. apta, Fig. 16 A‒C), somite 6 of the male pleon is more quadrate, being not much wider than long (Fig. 54 C) (rectangular, being distinctly wider than long in S. apta; Fig. 54 A, B), presence of sharp teeth on the ventral surface of the cheliped meri (low granules in S. apta), and the G1 is more slender and longer (Fig. 77 I‒K) (relatively stouter and shorter in S. apta, Fig. 77 A‒C). Their known ranges are widely separated, with S. malagasy n. sp. in Madagascar and S. apta in Philippines.
Distribution. Known only from Madagascar. Depth: 296‒ 379 m.
description: Published as part of Ng, Peter K. L. & Castro, Peter, 2016, Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea), pp. 1-182 in Zootaxa 4209 (1) on page 77, DOI: 10.11646/zootaxa.4209.1.1, http://zenodo.org/record/272646