Tenagopelta brachyphallus, Ng, Peter K. L. & Castro, Peter, 2016

Ng, Peter K. L. & Castro, Peter, 2016, Revision of the family Chasmocarcinidae Serène, 1964 (Crustacea, Brachyura, Goneplacoidea), Zootaxa 4209 (1), pp. 1-182 : 82

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.

Figures

FIGURE 17. Overall dorsal view of species of Tenagopelta n. gen. A, T. pacifica n. sp., Philippines: holotype male 10.3 × 11.9 mm (NMCR); B, T. pacifica n. sp., Philippines: female 9.2 × 10.4 mm (ZRC 2015.187); C, T. brachyphallus n. sp., Australia: holotype male 6.1 × 6.9 mm (NMV J 61680); D, T. brachyphallus n. sp., Australia: female 6.9 × 7.6 mm (NMV J 61680); E, T. potens, Papua New Guinea: male 10.3 × 12.1 mm (ZRC 2015.241); F, T. potens, Papua New Guinea: female 11.3 × 13.1 mm (ZRC 2015.241); G, T. potens, New Caledonia: female 7.4 × 8.5 mm (MNHN-IU- 2013 - 9469).

FIGURE 26. Frontal view of species of Statommatia n. gen. and Tenagopelta n. gen. A, Statommatia apta, Philippines: holotype 7.8 × 9.4 mm (USNM 46389); B, Statommatia apta, Philippines: male 5.9 × 7.1 mm (ZRC 2015.239); C, Statommatia malagasy n. sp., Madagascar: holotype male 9.9 × 12.4 mm (MNHN-IU- 2010 - 4370 a); D, Statommatia knudseni, New Caledonia: holotype male 4.7 × 6.9 mm (ZMUC CRU- 6974); E, Statommatia granulosa n. sp., New Caledonia: holotype male 4.1 × 4.7 mm (MNHN-IU- 2013 - 9454); F, Tenagopelta pacifica n. sp., Philippines: holotype male 10.3 × 11.9 mm (NMCR); G, Tenagopelta brachyphallus n. sp., Australia: holotype male 6.1 × 6.9 mm (NMV J 61680); H, Tenagopelta potens, Papua New Guinea: male 11.8 × 13.8 mm (MNHN-IU- 2011 - 1504).

FIGURE 33. Third maxilliped of species of Statommatia n. gen. and Tenagopelta n. gen. A, Statommatia apta, Philippines: holotype male 7.8 × 9.4 mm (USNM 46389); B, Statommatia apta, Philippines: male 5.9 × 7.1 mm (ZRC 2015.239); C, Statommatia knudseni, New Caledonia: holotype male 4.7 × 6.9 mm (ZMUC CRU- 6974); D, Statommatia pubescens, South China Sea: holotype male 5.0 × 7.9 mm (after Chen 1998: fig. 23 - 5); E, Statommatia malagasy n. sp., Madagascar: holotype male 9.9 × 12.4 mm (MNHN-IU- 2010 - 4370 a); F, Statommatia granulosa n. sp., New Caledonia: holotype male 4.1 × 4.7 mm (MNHN-IU- 2013 - 9454); G, Tenagopelta pacifica n. sp., Philippines: holotype male 10.3 × 11.9 mm (NMCR); H, Tenagopelta brachyphallus n. sp., Australia: holotype male 6.1 × 6.9 mm (NMV J 61680); I, Tenagopelta potens, Papua New Guinea: male 11.8 × 13.8 mm (MNHN-IU- 2011 - 1504).

FIGURE 47. Chelae of species of Tenagopelta n. gen. A, B, T. pacifica n. sp., Philippines: holotype male 10.3 × 11.9 mm (NMCR); C, D, T. brachyphallus n. sp., Australia: paratype male 6.9 × 7.6 mm (NMV J 54594); E ‒ H, T. potens, Papua New Guinea: male 11.8 × 13.8 mm (MNHN-IU- 2011 - 1504); I, J, T. potens, Papua New Guinea: male 8.8 × 10.0 mm (ZRC 2015.242).

FIGURE 54. Anterior thoracic sternum and male pleon of species of Statommatia n. gen. and Tenagopelta n. gen. A, Statommatia apta, Philippines: holotype 7.8 × 9.4 mm (USNM 46389); B, Statommatia apta, Philippines: male 5.9 × 7.1 mm (ZRC 2015.239); C, Statommatia malagasy n. sp., Madagascar: holotype male 9.9 × 12.4 mm (MNHN-IU- 2010 - 4370 a); D, E, Statommatia knudseni, New Caledonia: holotype male 4.7 × 6.9 mm (ZMUC CRU- 6974); F, Tenagopelta pacifica n. sp., Philippines: holotype male 10.3 × 11.9 mm (NMCR); G, Tenagopelta brachyphallus n. sp., Australia: holotype male 6.1 × 6.9 mm (NMV J 61680); H, Tenagopelta potens, Papua New Guinea: male 11.8 × 13.8 mm (MNHN-IU- 2011 - 1504).

FIGURE 79. Gonopods of species of Tenagopelta n. gen. A ‒ E, T. pacifica n. sp., Philippines: paratype male 10.2 × 11.4 mm (ZRC 2015.212); F ‒ J, T. brachyphallus n. sp., Australia: holotype male 6.1 × 6.9 mm (NMV J 61680); K ‒ N, T. potens, Papua New Guinea: male 11.8 × 13.8 mm (MNHN-IU- 2011 - 1504). A, F, K, ventral view of left G 1; B, G, L, dorsal view of left G 1; C, H, M, ventral view of distal part of left G 1; D, I, N, dorsal view of distal part of left G 1; E, J, O, left G 2. Scales: A, B, E, F, G, J, K, L, O = 0.5 mm; C, D, H, I, M, N = 0.1 mm.

FIGURE 88. Female thoracic sternum and pleon of species of Statommatia n. gen., Tenagopelta n. gen., Microtopsis and Megaesthesius. A, Statommatia apta, Philippines: female 8.5 × 10.6 mm (ZRC 2015.238); B, Statommatia malagasy n. sp., Madagascar: paratype female 9.4 × 8.1 mm (ZRC 2015.215); C, Tenagopelta pacifica n. sp., Philippines: female 9.2 × 10.4 mm (ZRC 2015.187); D, Tenagopelta brachyphallus n. sp., Australia: female 6.9 × 7.6 mm (NMV J 61680); E, Microtopsis takedai, Japan: paratype female 3.6 × 2.7 mm (ZRC 2012.0146); F, Megaesthesius sagedae, Singapore: female 3.0 × 3.6 mm (ZRC 2013.1804); G, Megaesthesius migmus, Philippines: paratype female 3.9 × 4.5 mm (ZRC 2015.245); H, Alainthesius bertrandi n. sp., Papua New Guinea: female 5.6 × 6.9 mm (MNHN-IU- 2013 - 9012). Vulvae exposed in E.

FIGURE 91. Vulvae of species of Hephthopelta, Angustopelta n. gen., Chinommatia n. gen., Statommatia n. gen. and Tenagopelta n. gen. A, Hephthopelta lugubris, Australia: ovigerous female 6.3 × 6.6 mm (NMV J 61083); B, Angustopelta aurita, Philippines: female 8.7 × 10.0 mm (ZRC 2015.253); C, Angustopelta robusta n. sp., Vanuatu: paratype female 13.4 × 15.1 mm (MNHN-IU- 2010 - 5616); D, Chinommatia cavimanus, Philippines: female 7.6 × 9.0 mm (ZRC 2015.228); E, Statommatia apta, Philippines: female 8.5 × 10.6 mm (ZRC 2015.238); F, Statommatia malagasy n. sp., Madagascar: paratype female 9.4 × 8.1 mm (ZRC 2015.215); G, Tenagopelta pacifica n. sp., Philippines: female 9.2 × 10.4 mm (ZRC 2015.187); H, Tenagopelta brachyphallus n. sp., Australia: female 6.9 × 7.6 mm (NMV J 61680).