GONEPLACIDAE 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 : 615-617

Family GONEPLACIDAE MacLeay, 1838

Gonoplacidae MacLeay, 1838: 64. — Dana 1851: 285 [diagnosis]; 1852: 308 [diagnosis], 310, 1425 [diagnosis], 1493 [in list], 1496 [in list]. — Haswell 1882: 85 [diagnosis]. — Alcock 1900: 286, 297. — Borradaile 1907: 468 [in list], 482 [in key], 485 [key to species]. — Calman 1909: 315 [in list].

Goneplacidae – Stebbing 1910: 312. — Rathbun 1918: 14 [in key], 15 [diagnosis, key to genera]; 1937: 265 [diagnosis]. — Tesch 1918: 4. — Sakai 1939: 366 [in key], 554; 1965: 165; 1976: 321, 522. — Stephensen 1946: 226 [male pleopods]. — Barnard 1950: 77 [in key], 281 [diagnosis]. — Monod 1956: 340. — Balss 1957: 1655. — Edmondson 1962: 2. — Serène 1964: 188 [discussion]. — Williams 1965: 201 [key to genera]. — Glaessner 1969: R445, R524 [diagnosis]. — Guinot 1969a: 242; 1969b: 507; 1971: 1078 [list of subfamilies, genera, and species]; 1979: 223, 241 [male gonopods]. — Takeda & Shimazaki 1974: 59 [discussion]. — Ingle 1980: 108 [diagnosis]. — Rice 1980: 337, 360 [in key], 378 [larvae]. — Manning & Holthuis 1981: 159. — Abele & Felgenhauer 1982: 323 [diagnosis]. — Bowman & Abele 1982: 24 [in list]. — Williams 1984: 17 [in key], 431. — Dai et al. 1986: 364 [diagnosis], 365 [key to species]. — Dai & Yang 1991: 186 [in key], 393 [diagnosis, key to species]. — Chen 1998: 265. — Ng 1998: 1058, 1114 [diagnosis]. — Tirmizi & Ghani 1996: 76 [diagnosis]. — Guinot & Bouchard 1998: 660 [abdomenlocking mechanism]. — Martin & Davis 2001: 75. — Ng et al. 2001: 32 [discussion]. — Chen & Sun 2002: 32, 35. — Davie 2002: 189 [diagnosis]. — Hsueh & Huang 2002: 113 [key to subfamilies] (part). — Karasawa & Kato 2003b: 130 [in list], 137 [diagnosis]. — Poore 2004: 433 [diagnosis]. — Števčić 2005: 67 [diagnosis]. — Karasawa & Schweitzer 2006: 26 [in list], 57 [diagnosis]. — Ng & Manuel-Santos 2007: 40 [discussion], 44 [diagnosis], 45.

Gonoplaceae – H. Milne Edwards 1852: 154.

Carcinoplacidae – Stimpson 1858: 93 (39).

Galénides – A. Milne-Edwards 1862: 40.

Carcinoplacinae – Miers 1886: 222.

Carcinoplacini – Ortmann 1894: 684 [as “Untergruppe”]; 1896: 416, 445 [diagnosis; as “Subsection”].

EXTANT SUBFAMILY INCLUDED . — Goneplacinae MacLeay, 1838 (including Carcinoplacinae H. Milne Edwards, 1852 ).

FOSSIL SUBFAMILIES INCLUDED . — Carinocarcinoidinae Karasawa & Kato, 2003 (family status in Karasawa & Schweitzer [2006]).

Icriocarcininae Števčić, 2005 (questionable subfamily status).

TYPE GENUS. — Goneplax Leach, 1814 .

DIAGNOSIS ( Goneplacinae [including Carcinoplacinae , but excluding Euryplacinae Stimpson, 1871 and Mathildellinae Karasawa & Kato, 2003 ]). — Carapace transversely rectangular, subquadrate, or trapezoidal; front narrow to wide, typically lamellar, straight. Dorsal surface smooth. Varying number of anterolateral teeth posterior to outer orbital angle (sometimes none but typically 1 or 2). Notch between frontal margin, inner edge of supraorbital border slight in some species. Orbits moderately to conspicuously wide, long; fissure in supraorbital border absent. Eye peduncle of varying length; cornea round to elongated. Antennules fold transversely, separated by septum (septum absent in Neommatocarcinus ). Basal antennal article short to relatively long, subcylindrical; lying freely in orbital hiatus, not reaching front. Thoracic sternum wide. Median sulcus on thoracic sternite 4 absent; sutures 4/5, 5/6 interrupted medially, 6/7, 7/8 interrupted medially or complete. Anterior end of sterno-abdominal cavity anterior to thoracic sternite 4. Prolongation of male episternite 7 present; thoracic sternite 7 laterally covered with thoracic sternite 8; thoracic sternite 8 without supplementary plate, portions of varying size left visible or covered by abdomen. Cheliped (P1) fingers varying from dark to light in colour; ambulatory legs (P2-P5) compressed. Male abdomen with 6 freely articulated somites plus telson (somites 3-5 fused for total of 4 somites plus telson in Neommatocarcinus ); narrower than sternum, somite 3 being narrower than thoracic sternite 7; fills space between coxae of P5; telson typically slightly longer than wide. Abdomen-locking mechanism with medium-size button on edge of thoracic sternite 5 pairing with shallow socket on underside (ventral surface) of abdominal somite 6. Male opening coxal, with soft, free penis arising directly from P5 coxa (sclerified proximal portion in Neommatocarcinus ) but coxosternal condition since protected for short distance and in varying degrees by sternum. G1 slender or stout. G2 long, typically with long flagellum (short in some species). Female abdomen with 6 freely articulated somites plus telson; locking mechanism of immature individuals consisting of medium-size button on edge of thoracic sternite 5; vulva of varying size, shape on thoracic sternite 6, vulvar cover present in some species.

REMARKS

The differing views on the taxonomy and phylogeny of the taxa in question basically stem from disagreements on the relative importance of particular characters. Obviously needed is a comprehensive and rigorous revision that includes morphological as well as molecular and larval characters. As far as morphological characters are concerned, stress should be placed on biologically significant structures such as those directly involved in reproduction, as in the case of the external reproductive structures (see Reproductive structures and the taxonomy of the Goneplacidae , p. 755). There is, however, very limited information on the larval development of goneplacids, knowledge that has so far shed little light on the phylogenetic relationships of the taxa comprising the family (see Rice 1980: 337, 354; Wear & Fielder 1985:62). The same can be said about the molecular characterizations of goneplacids.

A comprehensive revision of the taxa included here as comprising the Goneplacidae (i.e. Goneplacinae [including Carcinoplacinae ]) may ultimately show that some or all of these taxa are perhaps best treated as independent families under the superfamily Goneplacoidea , an arrangement already followed by d’Udekem d’Acoz (1999), and in part by Števčić (2005) and Karasawa & Schweitzer (2006), who raised the Goneplacinae to family status (see Remarks for subfamily Goneplacinae below). The question of which taxa actually make up the Goneplacidae is unfortunately not as “simple” as indicated by Števčić (2005: 138). Not all taxa included in his conception of the family share, for instance, the interrupted sternal sutures 4/5 to 7/8 and the “long G2” as stated. The presence of additional, strong synapomorphies should clearly establish, or challenge, the monophyly of the family.

The subfamily Euryplacinae is treated here as a family independent of the Goneplacidae , a status previously suggested by Guinot (1969b) and followed by Števčić (2005) and Karasawa & Schweitzer (2006). Prominent among its diagnostic characters are the conspicuously narrow male abdomen, slender and long G1, and short G2 (see Ng & Castro 2007). Table 2 summarizes the most important diagnostic characters of the Euryplacidae in comparison with those of the subfamilies of the Goneplacidae sensu stricto, including the Carcinoplacinae , which is treated here as part of the Goneplacinae .