Carcinoplax, H. MILNE EDWARDS, 1852

Castro, Peter, 2007, A reappraisal of the family Goneplacidae MacLeay, 1838 (Crustacea, Decapoda, Brachyura) and revision of the subfamily Goneplacinae, with the description of 10 new genera and 18 new species, Zoosystema 29 (4), pp. 609-774 : 625-627

KEY TO SPECIES OF CARCINOPLAX H. MILNE EDWARDS, 1852

1. Only one well developed, anteriorly curved anterolateral tooth posterior to outer orbital tooth on each side of carapace (see Guinot 1989: pl. 13, fig. F, as Carcinoplax eurysternum ) ................................................................................................. Carcinoplax ischurodous

— Two anterolateral teeth posterior to outer orbital angle (one or two anterolateral teeth may be greatly reduced or even obsolete in some large individuals) ............................ 2

2. Adults attain large size (cl more than 30-40 mm) and have reduced outer orbital and anterolateral teeth (obsolete in largest individuals), rounded anterolateral borders (carapace becoming spherical), and much enlarged chelipeds (P1) with conspicuously elongated meri, propodi ............................................................................................................. 3

— Adults do not attain large size (cl less than 30-40 mm) and do not show progressive reduction in outer orbital (if present) and anterolateral teeth with corresponding rounded anterolateral borders and chelipeds (P1) with conspicuously elongated meri, propodi ...................... 7

3. Low, conspicuous granules on carapace. Dark red-brown carapace, bright red-brown markings on chelipeds (P1). Small individuals with triangular, acute first and curved, acute second anterolateral teeth (see Guinot 1989: pl. 1, fig. D) .......... Carcinoplax longimana

— No conspicuous granules on carapace. Carapace not dark-red brown. Small individuals with narrow, acute anterolateral teeth, or small, blunt first anterolateral teeth ............. 4

4. Small- to medium-size individuals with two narrow, acute, spine-like anterolateral teeth below acute, conspicuous outer orbital tooth on each side of carapace (see Guinot 1989: pl. 1, figs G, H; Hsueg & Huang 2002: fig. 6A). Carapace nearly quadrate, with red, round spot on dorsal surface in most individuals (see Hsueg & Huang 2002: fig. 8B) ... ........................................................................................................ Carcinoplax indica

— Small- to medium-size individuals with blunt first anterolateral tooth, second tooth curved, acute. Carapace globose .............................................................................................. 5

5. Outer orbital angle with short, triangular tooth. Second anterolateral tooth salient, usually hook-like (see Chen 1984: figs 2-1 to 2-4) ....................................... Carcinoplax sinica

— Outer orbital angle without tooth. Second anterolateral tooth short (more conspicuous in small individuals) ................................................................................................... 6

6. Wide, purple-red vertical band across carapace from front to posterior border (see Hsueg & Huang 2002: fig. 8C). G1 with flat, truncated tip ( Guinot 1989: fig. 21A). Western Pacific Ocean ( Japan to Indonesia) in distribution ................................. Carcinoplax purpurea

— No purple-red band across carapace. G1 with pointed tip ( Guinot 1989: fig. 8A, B). Red Sea in distribution ......................................................................... Carcinoplax monodi

7. Carapace, chelipeds (P1), and ambulatory legs (P2-P5) covered with conspicuous setae ... 8

— Carapace, chelipeds (P1), and/or ambulatory legs (P2-P5) may have sparse setae, short tomentum, or mostly or completely devoid of conspicuous setae, or tomentum ......... 9

8. Conspicuous, acute tubercles on proximal portion of P1 propodi (may be absent in large individuals) (see Hsueh & Huang 2002: fig. 5E). Dark portion of about one quarter of fingers. Acute tooth on distal portion of ambulatory leg (P2-P5) meri (see Chen 1998: fig. 4-2; Hsueh & Huang 2002: fig. 5C). No conspicuous colour pattern ..................... ................................................................................................ Carcinoplax spinosissima

— Conspicuous, low, blunt tubercles on proximal portion of P1 propodi (see Guinot 1989: pl. 6, fig. H). Dark portion of about one half of fingers. Distal portion of ambulatory legs (P2-P5) meri smooth. Orange reticulated lines on P1 and carapace (clear when setae are removed) ........................................................................................... Carcinoplax nana

9. Carapace, chelipeds (P1), and ambulatory legs (P2-P5) covered with short tomentum (large individuals only on ambulatory legs) (see Hsueh & Huang 2002: fig. 7A) ........... ................................................................................................... Carcinoplax tomentosa

— Carapace, chelipeds (P1), and ambulatory legs (P2-P5) not covered with conspicuous short tomentum ....................................................................................................... 10

10. Outer orbital angle without tooth or eminence. Two thin, spine-like anterolateral teeth (see Figs 4A ; 5 ) .............................................................. Carcinoplax tenuidentata n. sp.

— Outer orbital angle ends in lobe or tooth. Anterolateral teeth not thin, spine like ..... 11

11. Front with slight median notch (see Guinot 1989: fig. 17) ......... Carcinoplax confragosa

— Front straight, without distinct median notch .......................................................... 12

12. Conspicuous, well developed anterolateral teeth, with acute, anteriorly-oriented or hook- like tips .................................................................................................................... 13

— Relatively small, blunt anterolateral teeth (see Figs 7 ; 10 ) ......................................... 17

13. Ambulatory legs (P2-P5) long, relatively slender, distal end of merus of folded P5 extending beyond tip of second anterolateral tooth ................................................................... 14

— Ambulatory legs (P2-P5) short, distal end of merus of folded P5 only reaching or barely reaching tip of second anterolateral tooth ................................................................. 15

14. Two conspicuous, wide horizontal ridges on dorsal surface of carapace (see Fig. 3 ) ........ .............................................................................................. Carcinoplax cracens n. sp.

— Dorsal surface of carapace without conspicuous ridges .................. Carcinoplax longipes

15. Two conspicuous, wide horizontal ridges on dorsal surface of carapace .......................... ................................................................................................... Carcinoplax inaequalis

— Dorsal surface of carapace without conspicuous ridges ............................................. 16

16. Outer orbital angle prominent, often with raised, tooth-like prominence (see Guinot 1989: pl. 8, figs A, B). Chelipeds (P1), particularly propodi, inflated (see Guinot 1989: pl. 9, fig. F, as C. verdensis ) .......................................................... Carcinoplax specularis

— Outer orbital angle flattened, inclined outwardly (see Guinot 1989: fig. 38, pl. 9, figs A, B). Chelipeds (P1), particularly propodi, slender (see Guinot 1989: pl. 9, fig. C) .......... .................................................................................................... Carcinoplax abyssicola

17. Outer, dorsal surface of cheliped (P1) propodi and carpi with conspicuous granular tubercles (see Fig. 8 ). Ambulatory legs (P2-P5) relatively short (see Fig. 7 ), distal end of merus of folded P5 only reaching tip of second anterolateral tooth ..... Carcinoplax tuberosa n. sp.

— Outer, dorsal surface of chelipeds (P1) smooth. Ambulatory legs (P2-P5) relatively long (see Fig. 10 ), distal end of merus of folded P5 extending beyond tip of second anterolateral tooth ................................................................................... Carcinoplax velutina n. sp.

Figures

FIG. 4. — Carcinoplax tenuidentata n. sp., ♂ holotype, cl 9.1 mm, cw 10.8 mm, Bligh Water, Fiji, MUSORSTOM 10, stn CP 1320, 290-300 m (MNHN-B 29496): A, dorsal surface of the carapace; B, abdomen; C, left G1, dorsal view; D, left G2, ventral view. Scale bars: A, 5 mm; B, 3 mm; C, D, 1 mm.

FIG. 5. — Carcinoplax tenuidentata n. sp., ♂ holotype, cl 9.1 mm, cw 10.8 mm, Bligh Water, Fiji, MUSORSTOM 10, stn CP 1320, 290-300 m (MNHN-B 29496).

FIG. 7. — Carcinoplax tuberosa n. sp.,♂ holotype,cl 6.9 mm, cw 8.8 mm,Matthew and Hunter islands,New Hebrides Ridge,VOLSMAR, stn DW 5, 700 m (MNHN-B 29829).

FIG. 10. — Carcinoplax velutina n. sp., ♂ holotype, cl 11.4 mm, cw 14.7 mm, Moruroa atoll, French Polynesia, SMSRB collections, stn 397, 680 m (MNHN-B 29826).

FIG. 3. — Carcinoplax cracens n. sp., ♂ holotype, cl 18.9 mm, cw 25.6 mm, off southeastern coast of New Caledonia, SMIB 5, stn DW 94 (MNHN-B 29430).

FIG. 8. — Carcinoplax tuberosa n. sp.,♂ holotype,cl 6.9 mm, cw 8.8 mm,Matthew and Hunter islands,New Hebrides Ridge,VOLSMAR, stn DW 5, 700 m (MNHN-B 29829), left cheliped (P1).