GONEPLACINAE MACLEAY, 1838

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 : 621-622

KEY TO GENERA OF GONEPLACINAE MACLEAY, 1838

1. Carapace distinctively quadrate, with anterolateral borders only slightly rounded and at a nearly 90° angle and no anterolateral teeth (see Clark & Ng 2006: fig. 2). Cornea of eye small, spherical ................................................................................................ Notonyx

— Carapace of various shapes (hexagonal, transversely rectangular, ovoid) but never distinctively quadrate, with rounded anterolateral borders typically having one or two anterolateral teeth posterior to outer orbital margin (no anterolateral teeth but carapace oval, not quadrate, in very large adults in some species). Cornea of eye large, not reduced, clearly spherical or reniform ................................................................................................................. 2

2. Eye peduncles short, as long as or only slightly longer than cornea, much shorter than front. Cornea always spherical, not elongated or reniform .......................................... 3

— Eye penduncles long, clearly longer than cornea, sometimes as long as or longer than front (if eye penduncles short, cornea is distinctively reniform, being dorso-ventrally flattened and almost completely divided into anterior and posterior portions). Cornea elongated or reniform ................................................................................................................. 6

3. Two anterolateral teeth posterior to outer orbital angle (one or the two anterolateral teeth may be greatly reduced or even obsolete in some large individuals; always one tooth in Carcinoplax ischurodous ( Stebbing, 1923) [see Guinot 1989: pl. 13, fig. F, as Carcinoplax eurysternum ]) .............................................................................................................. 4

— Only one anterolateral tooth posterior to outer orbital angle (shallow lobe or carina, but no tooth, may be present anterior to each anterolateral tooth) .................................... 5

4. G1 slender, thin (dorso-ventrally flattened). Vulva greatly expanded, without vulvar cover (see Fig. 1 ). Sternal suture 6/7 incomplete .................................................. Carcinoplax

— G1 stout, thick. Vulva relatively small, vulvar cover in large mature females (see Figs 14 ; 15 ; 18 ) (not found in small mature females of P. surugensis ( Rathbun, 1932)) . Sternal suture 6/7 complete .......................................................................... Pycnoplax n. gen.

5. One long, horn-like, acute, dorsally oriented anterolateral tooth on each side of carapace (blunt tooth anterior to anterolateral tooth in males). G1 stout, tip conspicuously truncated ........................................................................................... Menoplax n. gen.

— One short, triangular or slightly elongated anterolateral tooth on each side of carapace (shallow lobe or carina, but no tooth, may be present anterior to anterolateral tooth). G1 slender, tip typically pointed (truncated in Thyraplax truncata n. sp., see Fig. 25C ) ....... .......................................................................................................... Thyraplax n. gen.

6. Carapace, pereopods, eye peduncles with conspicuous setae ............ Entricoplax n. gen.

— Carapace, pereopods, eye peduncles without conspicuous setae (naked or only with sparse setae) .......................................................................................................................... 7

7. Eye peduncles conspicuously long, almost always more than half front (0.4-1.2 front width). Carapace conspicuously wider than long (often 1.5 as long as wide or more) .............. 8

— Eye peduncles not conspicuously long, not more than half front (0.2-0.5 front width). Carapace conspicuously quadrate or nearly circular, approximately as wide as long .... 16

8. Cornea elongated, not conspicuously dorso-ventrally flattened, distal margin spherical without being nearly divided into anterior and posterior portions .............................. 9

— Cornea reniform (dorso-ventrally flattened and almost completely divided into anterior and posterior portions) ............................................................................................. 13

9. Anterolateral teeth in median portion of carapace (see Fig. 35A ). Carapace of adults small (cl rarely more than 4.5 mm) ................................................................................... 10

— Anterolateral teeth (if present) in upper, anterior portion of carapace. Carapace of adults not small (cl more than 7-8 mm) ............................................................................. 11

10. G2 short (see Fig. 39C ), much shorter than G1. Broad suborbital tooth ....................... ................................................................................................... Microgoneplax n. gen.

— G2 long, slender, longer than or as long as G1. Short or obsolete suborbital tooth ........ .................................................................................................................... Singhaplax

11. Eye peduncle clearly not much longer than carapace front. Outer orbital teeth anteriorly oriented. Anterolateral teeth present (except some individuals of Goneplax rhomboides ( Linnaeus, 1758)) ........................................................................................... Goneplax

— Eye peduncle long, much longer than carapace front. Outer orbital teeth straight or nearly straight. Anterolateral teeth obsolete (except obtuse prominence in Ommatocarcinus fibriophthalmus Yokoya, 1933 ) .................................................................................. 12

12. Male abdomen with 6 somites plus telson; antennules divided by median septum ......... ........................................................................................................... Ommatocarcinus

— Male abdomen with 4 somites plus telson, somites 3-5 fused; antennules not divided by septum ............................................................................................ Neommatocarcinus

13. P5 dactylus dorso-ventrally flattened, broad. G2 with nearly coiled flagellum ............... .................................................................................................... Goneplacoides n. gen.

— P5 dactylus slender. G2 with slightly curved flagellum, straight tip .......................... 14

14. G2 much shorter than G1. G1 bent in adult males. Suborbital teeth obsolete. Iridescent region at distal end of eye peduncle .............................................. Paragoneplax n. gen.

— G2 about same size of G1. G1 straight. One or two short suborbital teeth on each orbit. No iridescent region at distal end of eye peduncle .................................................... 15

15. Long basal antennular articles do not fit into antennular fossae (see Serène & Umali 1972: fig. 73). Anterolateral teeth obsolete. Vulva without vulvar cover ...... Hadroplax n. gen.

— Relatively short basal antennular articles that fit into antennular fossae. Anterolateral teeth present (obsolete or reduced in Neogoneplax costata n. sp.; see Figs 30A ; 31 ). Vulva with vulvar cover (see Fig. 32 ) ............................................................... Neogoneplax n. gen.

16. Carapace subquadrate. G1 stout, proximal portion broad, nearly triangular ( Guinot 1990: figs 44, 45, 47, 48, 50, 52, 53). Vulva small, with small vulvar cover (see Fig. 47 ) ......... .................................................................................................................... Psopheticus

— Carapace subcircular. G1 slender, proximal portion not expanded (see Fig. 48B ). Vulva much expanded, without vulvar cover (see Figs 48 ; 49 ) ................... Exopheticus n. gen.

Figures

FIG. 1. — Carcinoplax longimana (de Haan, 1833), ♀, cl 29.1 mm, cw 37.8 mm, off northeastern Taiwan, TAIWAN 2001, stn CP 81, 205 m (MNHN-B 29648), thoracic sternum and vulva.

FIG. 14. — Pycnoplax surugensis (Rathbun,1932) n. comb.,♀, cl 10.0 mm,cw 14.5 mm,South China Sea off Philippine Is, MUSORSTOM 2, stn CP 26, 299-320 m (MNHN-B 30056), thoracic sternum and vulva.

FIG. 15. — Pycnoplax bispinosa (Rathbun, 1914) n. comb., ♀, cl 11.2 mm, cw 13.4 mm, Tablas Strait, west of Mindoro, Philippine Is, MUSORSTOM 3, stn CP 120, 219-220 m (MNHN-B 30058), thoracic sternum, vulva, vulvar cover, and remains of sperm plug.

FIG. 18. — Pycnoplax victoriensis (Rathbun,1923) n. comb., ♀, cl 12.1 mm,cw 14.6 mm,off Victoria,Australia,stn SS01/00 187,500 m (NMV J52213), thoracic sternum, vulva, vulvar cover, and remains of sperm plug.

FIG. 25. — Thyraplax truncata n. sp., ♂ holotype, cl 8.7 mm, cw 11.6 mm, Fiji, BORDAU 1, stn CP 1481, 441-506 m (MNHN-B 29547): A, dorsal surface of the carapace; B, abdomen; C, left G1 (with rhizocephalan parasite, Thompsonia sp.), dorsal view; D, left G2 (with rhizocephalan parasite, Thompsonia sp.), ventral view. Scale bars: A, 5 mm; B, 3 mm; C, D, 1 mm.

FIG. 35. — Singhaplax dichotoma n. sp.,♂ holotype,cl 4.0 mm, cw 6.1 mm, Kai Is, Indonesia,KARUBAR,stn DW 29 (MNHN-B 30069): A, dorsal surface of the carapace; B, left G1, ventral view; C, right G2, ventral view. Scale bars: A, 5 mm; B, C, 1 mm.

FIG. 39. — Singhaplax styrax n. sp., ♂ holotype, cl 4.1 mm, cw 6.7 mm, Kai Is, Indonesia, KARUBAR, stn DW 18 (MNHN-B 29211): A, dorsal surface of the carapace; B, left G1, ventral view; C, left G2, ventral view. Scale bars: A, 5 mm; B, C, 1 mm.

FIG. 30. — Neogoneplax costata n. sp.: A, B, ♂ holotype,cl 10.4 mm,19.1 mm,Balicasag I., off Panglao I., Philippine Is (ZRC 2004.0723); A, dorsal surface of the carapace; B, abdomen; C, D, ♂ paratype, cl 12.8 mm, cw 24.5 mm (ZRC 2004.0721); C, left G1, dorsal view; D, left G2, ventral view. Scale bars: A, 5 mm; B, 3 mm; C, D, 1 mm.

FIG. 31. — Neogoneplax costata n. sp., ♂ holotype, cl 10.4 mm, 19.1 mm, Balicasag I., off Panglao I., Philippine Is (ZRC 2004.0723).

FIG. 32. — Neogoneplax costata n. sp., 1 ovig.♀ paratype,cl 11.9 mm,cw 22.8 mm,Balicasag I., off Panglao I., Philippine Is,200-300 m (ZRC), thoracic sternum, vulva, and vulvar cover.

FIG. 47. — Psopheticus stridulans Wood-Mason, 1892, ♀, cl 22.8 mm, cw 28.1 mm, Tanimbar Is, Indonesia, KARUBAR, stn CP 77, 352-346 m (MNHN-B 30057), thoracic sternum and vulva, vulvar cover, and remains of sperm plug.

FIG. 48. — Exopheticus insignis (Alcock, 1900) n. comb., ♂ holotype, cl 22.4 mm, cw 30.9 mm, Bligh Water, Fiji, MUSORSTOM 10, stn CP 1320, 290-300 m (MNHN-B 29369): A, dorsal surface of the carapace; B, abdomen; C, left G1, dorsal view; D, left G2, ventral view. Scale bars: A, B, 5 mm; C, D, 1 mm.

FIG. 49. — Exopheticus insignis (Alcock, 1900) n. comb.,♀, cl 22.7 mm,cw 31.5 mm,South China Sea off Philippine Is, MUSORSTOM 2, stn CP 20, 192-185 m (MNHN-B 30059), thoracic sternum and vulva.