Tenagopelta brachyphallus 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
Tenagopelta
Tenagopelta brachyphallus

description: Tenagopelta brachyphallus n. sp.
(Figs. 17 C, D; 26G; 33H; 47C, D; 54G; 61F; 79F‒J; 88D; 91H)
Type material. Holotype male (6.1 × 6.9 mm) (NMV J61680) [photographed], Western Australia, “ Chasmocarcinops, det. A. McCallum 2009 ”), L23 west transect, Western Australia, 17°31’03”S –17°31’43”S to 118°51’10”E–118°50’44”E, 405 m, M.F. Gomon coll., 16.06.2007.
Paratypes: 1 male (6.9 × 7.6 mm) (NMV J54594); 3 females (6.9 × 7.6 mm, 5.2 × 5.6 mm, 7.4 × 8.1 mm) (NMV J54594) [“ Camatopsis rubida, det. C.G.B. Poore 2006”], Western Australia, off Ningaloo North, 21°58’42”S, 113°49’12”E to 21o59’03”S, 113o49’12”E, 170–177 m, 10.12.2005; 1 female (6.9 × 7.6 mm) [photographed], 2 females (5.2 × 5.6 mm, 7.4 × 8.1 mm) (NMV J61680) [“ Chasmocarcinops, det. A. McCallum 2009 ”], L23 west transect, 17o31’03”S, 118o51’10”E to 17o31’43”S, 118o50’44”E, 405 m, M.F. Gomon coll., 16.06.2007.
Diagnosis. Carapace (Fig. 17 C, D) subtrapezoidal, globose, 1.1 wider than long; front bilobed, with shallow median cleft; anterolateral margins arcuate, minutely granular, low tubercle on each anterolateral margin in holotype, small individuals (absent in large specimens). Eye peduncle (Fig. 26 G) tightly filling orbit, short, mobile; cornea reduced, pigmented. Posterior margin of epistome (Fig. 26 G) with broad semicircular median lobe with deep median fissure, semicircular lateral margins. Third maxilliped (Fig. 33 H) merus quadrate, ischium rectangular, about same length as merus. Chelipeds (Figs. 17 C, D; 47C, D) subequal in length, slightly dissimilar in females, heteromorphic in males; fingers of minor chela (Fig. 47 D) subcircular in cross-section, not distinctly laterally flattened, gently tapering to tip, scissor-like, cutting margins with distinct sharp teeth; major chela of males (Fig. 47 C) with most proximal dactylar tooth enlarged. Ventral surface of cheliped merus with 3 large teeth (sometimes additional small teeth or large tubercles) on outer margin in both sexes. Inner margin of cheliped carpus with long distal tooth (Fig. 17 C, D). Proportionally long ambulatory legs (Fig. 17 C, D); P5 merus 0.8 cl. Meri of P2, P3 with minute teeth. Fused thoracic sternites 1, 2 (Fig. 54 G) semicircular, broad, short. Male pleon (Figs. 54 G; 61F) with proportionally short telson. G1 (Fig. 79 F‒I) short, stout, distal half short, stout straight, with short spinules; tip sharp. G2 (Fig. 79 J) longer than G1, curved, slender, distal segment long, curved. Female telson (Fig. 88 D) proportionally short. Sterno-pleonal cavity of female (Fig. 91 H) deep, vulvae widely separated on outer margins of cavity close to suture 5/6.
Etymology. The name alludes to the relatively short G1 of the species. The name is used as a noun in apposition.
Remarks. Specimens of T. brachyphallus n. sp. were collected from waters that are shallower (about 400 m) than its two congeners.
There is slight variation in the five specimens. In the holotype, paratype male and one paratype female (6.9 × 7.6, NMV J61680), there is a short but distinct tooth on each anterolateral margin. This tooth is strongly reduced in a small paratype female (5.2 × 5.6 mm, NMV J61680) and completely absent in the largest paratype female (7.4 × 8.1 mm, NMV J61680).
Distribution. Known only from Western Australia. Depth: 170– 405 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 82, DOI: 10.11646/zootaxa.4209.1.1, http://zenodo.org/record/272646