Euryplacidae

CASTRO, PETER & NG, PETER K. L., 2010, Revision of the family Euryplacidae Stimpson, 1871 (Crustacea: Decapoda: Brachyura: Goneplacoidea), Zootaxa 2375 (1), pp. 1-130 : 9-17

Key to genera of Euryplacidae

1. Male abdomen clearly narrow, slender, T-shaped ( Fig. 1C, D ); Indo-West Pacific distribution (but one species introduced in the Mediterranean Sea).................................................................................................................................. 2

– Male abdomen clearly triangular ( Fig. 1A, B ) or proportionally wide, not slender, T-shaped; tropical and subtropical Atlantic and Eastern Pacific distribution ................................................................................................................... 10

2. Orbits, eye peduncles short, eye peduncles as short as or slightly longer than corneas .............................................. 3

– Orbits, eye peduncles long, eye peduncles much longer than corneas ......................................................................... 7

3. Corneas reniform, dorsoventrally flattened ( Fig. 36B ); G1 with arrowhead-shaped apex ( Fig. 38D, E ) ...................... ................................................................................................................................................................. Psopheticoides

– Corneas spherical, not dorsoventrally flattened (e.g. Figs. 3B ; 16C ); G1 with acuminate apex (e.g. Figs. 14A; 20A, D ) .................................................................................................................................................................................. 4

4. Sulcus posterior to orbits extending along anterior border of carapace between anterolateral borders ( Fig. 34E ) ........ ....................................................................................................................................................................... Platyozius

– No sulcus extending along anterior border of carapace between anterolateral borders (if sulcus present it is short, not extending between anterolateral borders) ..................................................................................................................... 5

5. P5 dactylus, propodus proportionally slender (e.g. Fig. 2 ), with only scattered setae; conspicuous tomentum on chelipeds ................................................................................................................................................................. Eucrate

– P5 dactylus, propodus proportionally wide, with many long setae ( Figs. 37A ; 49A ); no conspicuous tomentum on chelipeds ...................................................................................................................................................................... 6

6. Each side of carapace with two short, inconspicuous anterolateral teeth ( Figs. 37A, B ; 38I, J ) ....... Systroplax n. gen.

– Each side of carapace with two acute, conspicuous anterolateral teeth ( Fig. 49A, B ) ................................... Xenocrate

7. One short anterolateral tooth posterior to outer orbital tooth on each side of carapace (e.g. Figs. 21A ; 23A ), transverse depression (postorbital ridge) posterior to each orbit (except in one species) ....................... Henicoplax n. gen.

– Two or three anterolateral teeth posterior to outer orbital tooth on each side of carapace, carapace without transverse depression posterior to orbits ....................................................................................................................................... 8

8. First anterolateral tooth minute, inconspicuous, leaving wide, straight margin between outer orbital tooth and second (largest) anterolateral tooth ( Fig. 28A, D ), thus having only two large anterolateral teeth posterior to outer orbital tooth on each side of carapace ...................................................................................................................... Heteroplax

– First anterolateral tooth large, conspicuous, thus having three large anterolateral teeth posterior to outer orbital tooth on each side of carapace ............................................................................................................................................... 9

9. Anteroexternal margin of third maxillipeds auriculiform ( Fig. 41A ) ................................................ Trissoplax n. gen.

– Anteroexternal margin of third maxillipeds angular ( Figs. 29D ; 30C )........................................................ Machaerus

10. Outer orbital tooth short, inconspicuous ( Fig. 31A–C ) ................................................................................. Nancyplax

– Outer orbital tooth conspicuous ................................................................................................................................. 11

11. Conspicuous (abundant, long) tomentum on merus, carpus, propodus of cheliped (e.g. Figs. 44A, D ; 48A, C )....... 12

– Short tomentum on chelipeds, never long, abundant throughout cheliped ................................................................ 13

12. Two anterolateral teeth posterior to outer orbital tooth on each side of carapace ( Figs. 44A ; 45A ) ....... Trizocarcinus

– Only one anterolateral tooth posterior to outer orbital tooth on each side of carapace ( Figs. 47A, B ; 48A ) ................ .............................................................................................................................................................. Villoplax n. gen.

13. Two broad, short anterolateral teeth posterior to outer orbital tooth on each side of carapace (e.g. Figs. 16A ; 17A ); corneas spherical (e.g. Fig. 16C ) ..................................................................................................................... Euryplax

– One acute, long anterolateral tooth posterior to outer orbital tooth on each side of carapace ( Fig. 19A ); corneas reniform, dorsoventrally flattened ( Fig. 19A, B ) .................................................................................................... Frevillea

Genus Eucrate De Haan, 1835

Cancer (Eucrate) De Haan, 1835: 36 (type species Cancer (Eucrate) crenatus De Haan, 1835 , by monotypy; gender feminine) [Opinion 85, Direction 37].

Cancer (Galene) — White, 1849: 144.

Pilumnoplax Stimpson, 1858: 93 (39); 1907: 90 (type species Pilumnoplax sulcatifrons Stimpson, 1858 , subsequent designation by Rathbun, 1918; gender feminine).

Eucrate — Haswell 1882b: 86 [diagnosis]. — De Man 1887: 88 [discussion]. — Alcock 1900: 292 [in list], 298 [in key], 298. — Tesch 1918: 157. — Stebbing 1920a: 238; 1920b: 268. — Barnard 1950: 282 [in key], 295. — Balss 1922a: 137; 1957: 1656. — Sakai 1939: 555 [in key], 561; 1976: 523 [in key], 535. — Campbell 1969: 117. — Guinot 1969b: 508 [discussion]; 1971: 1080 [list of species]. — Serène & Lohavanijaya 1973: 70 [list of species]. — Takeda & Shimazaki 1974: 60 [discussion]. — Tirmizi & Ghani 1996: 76 [diagnosis]. — Davie, 2002: 198 [diagnosis]. — Karasawa & Kato 2003a: 151 [in list]; 2003b: 130 [in list], 139 [in list]. — Ng & Castro 2007: 44 [in list], 45 [discussion]. Ng et al. 2008: 78, 79 [in list]. — De Grave et al. 2009: 33 [in list].

Diagnosis. Carapace (e. g. Figs. 2 ; 3A ) trapezoidal, almost as wide as long, dorsal surface smooth without clear indication of regions or with variously developed setose grooves, depressions (median frontal notch, shallow depression posterior to each orbit extending laterally to anterolateral teeth), convex; anterolateral borders arched; front wide, straight, lamelliforn or truncate, typically with median notch ( Fig. 3B–D ; absent or inconspicuous in E. alcocki , E. formosensis ). Two or 3 typically low teeth (second may be acute, dorsally salient) posterior to rounded or triangular outer orbital tooth. Short (shorter than front), wide, spherical orbits ( Fig. 3B ); 2 notches on thick supraorbital border; short median lobe, outer notch on thick suborbital border ( Fig. 3C, D ); eye peduncles short, as long as or slightly longer than corneas ( Fig. 3B ); large, spherical corneas. Basal antennal article immobile, with disto-lateral process so that orbital hiatus is closed excluding antennal flagellum from orbit ( Fig. 3B–D ; Campbell 1969: fig. 1C). Anteroexternal margin of third maxilliped merus angular or auriculiform. Cheliped fingers moderately stout, slightly longer than swollen propodus, dark or light in colour; carpus with tooth on inner margin; dense, short tomentum on anterior margin of carpus in most species. Dorsal margins of ambulatory legs (P2–P5; Fig. 3A ) meri, carpi, propodi unarmed (granular in some species), dactyli slender, smooth, setose; P5 propodus slender, dactylus long, slender, with shallow longitudinal depression, fringed with scattered, long setae. Thoracic sternum wide ( Fig. 3C, G ); thoracic suture 2/3 complete, convex, close to anterior margin of sternum ( Fig. 3C ); 3/4 deep, short, interrupted; 4/5, 6/7, 7/8 interrupted, 5/6 complete ( Figs. 3G ; 11F ); median groove on thoracic sternites 7, 8 ( Fig. 3G ). Sterno-abdominal cavity of male deep, nearly reaching anterior margin of sternite 4 ( Fig. 11E ). Press-button of male abdominal-locking mechanism ( Fig. 11E ) as tubercle near thoracic suture 4/5 (small tubercle present in pre-adult females). Male abdomen ( Fig. 3C ) narrow, slender (T-shaped), lateral margins of somites 4–6 abruptly narrowing from somite 3 to transversely narrow, pointed telson; somite 3 reaching inner margins of P5 coxae ( Fig. 3F ); no portions of thoracic 8 exposed by closed abdomen, somite 2 transversely almost as long as somite 3. G1 long, slender, sinuous (straight in E. tripunctata Campbell, 1969 ; Fig. 15J), acuminate apex, with small denticles (e.g. Figs. 11E ; 14A, B, D, E); G2 less than one-third of G1, apex with 2 unequal acute or obtuse processes (e.g. Fig. 14C, F). Male genital opening (gonopore) coxal ( Guinot 1969b: fig. 35); coxo-sternal disposition of long penis, protected by concave posterior portion of thoracic sternite 7 ( Fig. 11E ). Vulva ( Fig. 3G ) ovoid, extending across anterior portion of sternite 6 close to median axis of thorax; covered by soft membrane, sternal vulvar cover absent.

Type species. Cancer (Eucrate) crenatus De Haan, 1835 (by monotypy, gender feminine) [Opinion 85, Direction 37].

Remarks. De Man (1887: 88) stated that the genus Eucrate “is a very natural one, distinguished not only by its entire physiognomy, but also by the structure of the external antennae”. Heteroplax was nevertheless considered a junior synonym of Eucrate by some authors, although most preferred to keep both as independent genera (see Remarks for Heteroplax below). Eucrate , presumed to be in the Goneplacinae , was included in the Euryplacinae by Guinot (1969b: 508). Campbell (1969) revised the genus but essentially restricted his work to Australian species. His work left several unanswered questions, particularly the status of the poorly understood E. sulcatifrons Stimpson, 1858 .

The G1 and G2 respectively, are remarkably similar among the species of Eucrate . The long and slender G1 is invariably sinuous ( Fig. 11E ; straight in E. tripunctata ; Fig. 15J), with small denticles along the distal portion and an acuminate apex (e.g. Fig. 14A, B, D, E). Sakai (1976: 537) nevertheless points out differences in the extension of the spinular portion of the G1 of three species. These differences, as well as the relative size and distribution of the spinules, are not clear cut and appear to be related to the size of the individuals. The short G2 is also very similar among the Eucrate species (e.g. Fig. 14C, F), and in most details, among all euryplacids.

Table 1 summarizes differences between Eucrate and the other genera of the Euryplacidae .

Species included.

Eucrate alcocki Serène , in Serène & Lohavanijaya, 1973

= Eucrate maculata Yang & Sun, 1979

Eucrate crenata (De Haan, 1835)

= Pilumnoplax sulcatifrons Stimpson, 1858

Eucrate dorsalis ( White, 1849)

= Eucrate hamiltoni McCulloch, 1908

= Galene ? laevimanus Lucas , in Jacquinot & Lucas, 1853

Eucrate formosensis Sakai, 1974

Eucrate indica n. sp.

Eucrate sexdentata Haswell, 1882

Eucrate solaris Yang & Sun, 1979

Eucrate tripunctata Campbell, 1969

The genus is restricted to the Indo-West Pacific region.

Species excluded from Eucrate De Haan, 1835 :

Eucrate affinis Haswell, 1882 [= Trissoplax dentata ( Stimpson, 1858) ]

Eucrate costata Yang & Sun, 1979 [= Trissoplax dentata ( Stimpson, 1858) ]

Eucrate haswelli Campbell, 1969 [= Trissoplax dentata ( Stimpson, 1858) ]

Key to species of Eucrate

1. Third (excluding outer orbital tooth) anterolateral tooth absent (only slight elevation may be present), carapace with relatively long posterolateral borders (e.g. Fig. 4 ) ...................................................................................................... 2

– Third (excluding outer orbital tooth) anterolateral tooth present, even if short, sometimes barely noticeable in large individuals, carapace without relatively long posterolateral borders (e.g. Fig. 12 )...................................................... 5

2. Conspicuous frontal notch present; large purple-pink spots on anterior two thirds of dorsal surface of carapace ( Campbell 1969: fig. 1B) .......................................................................................................................... E. sexdentata

– Frontal notch absent or barely noticeable; variously shaped red-brown spots, dots or many small dots on anterior half of dorsal surface of carapace......................................................................................................................................... 3

3. Anterior half or most of carapace and chelipeds with small red-brown dots ( Fig. 2E ), larger dots in small individuals ( Fig. 2F ) .................................................................................................................................................. E. formosensis

– Median portion of carapace with large, irregular dark red-brown spots; small red-brown spots on anterior third of carapace and chelipeds ( Fig. 2C, D ) ............................................................................................................................ 4

4. Median portion of carapace with one large, rounded spot in centre, typically flanked on each side and anteriorly by smaller spots ( Fig. 2C ); western Pacific in distribution ................................................................................. E. alcocki Median portion of carapace with two large, irregular, red-brown spots in centre, typically flanked by two smaller, vertically placed spots ( Fig. 2D ); Indian Ocean in distribution ............................................................. E. indica n. sp.

5. P5 propodus noticeably short, wide ( Figs. 12 , 13C ; Campbell 1969: fig. 4G); three anterolateral teeth short, second and third nearly equal ( Fig. 13B–D ) ......................................................................................................... E. tripunctata

– P5 propodus slender, not wide; three anterolateral teeth of varying size, first much smaller than second................... 6

6. First anterolateral tooth very short, nearly disappearing in large individuals ( Fig. 6A–C ; Campbell 1969: fig. 6B, K); typically one large spot on central region of carapace ( Figs. 5A, B, D ; 6A ) ................................................ E. dorsalis

– First anterolateral tooth well developed, not noticeably reduced in size; carapace with reticulated pattern of spots or two spots on anterior half ............................................................................................................................................. 7

7. Ventral surface of cheliped meri with conspicuous, high tubercles; intricate, reticulated pattern of dots, spots across carapace, chelipeds, ambulatory legs ( Fig. 7C–F ) (preserved specimens with two triangular or hexagonal patterns on mesogastric region) ......................................................................................................................................... E. solaris

– Ventral surface of cheliped meri smooth or with short granules; small dots on anterior third of carapace and on chelipeds plus two small, oval, red-brown spots may be present on branchial region of carapace at some distance from each other ( Fig. 2A ) ........................................................................................................................................ E. crenata

Figures

FIGURE 1. Variation in the shape of the male abdomen among the genera of Euryplacidae. A, Trizocarcinus dentatus (Rathbun, 1893); male (14.7 mm × 20.2 mm) (MNHN-B20990), Mexico, Gulf of California; B, Machaerus oxyacanthus (Monod, 1956), male (19.0 mm × 30.3 mm) (MNHN-B10242), Sierra Leone; C, Systroplax angusta (Rathbun, 1914), male (32.3 mm × 37.2 mm) (MNHN-B29377), Fiji; D, Eucrate solaris Yang & Sun, 1979, male (23.3 mm × 28.1 mm) (ZRC 2008.1333), Philippines, Bohol, Panglao. Abbreviations: a3 = abdominal somite 3.

FIGURE 2. Fresh colours of Eucrate species. A, B, E. crenata (De Haan, 1835); A, male (22.5 mm × 27.1 mm) (ZRC 2002.0493), China, Qingdao; B, male, Hong Kong, not preserved; C, E. alcocki Serène, in Serène & Lohavanijaya, 1973, ovigerous female (18.4 mm × 21.4 mm) (ZRC 2003.0621), Thailand, Pattani, Thailand; D, E. indica n. sp., female, Persian Gulf, not preserved; E, F, E. formosensis Sakai, 1974; E, female (22.2 mm × 27.1 mm) (ZRC 1993.739), Taiwan, Kaohsiung, Taiwan; F, juvenile, northern Taiwan, not preserved. Photo credits: B by D. Poon; D by R. Naderloo (Forschunginstitut Senckenberg, Frankfurt); E by K. Li.

FIGURE 3. Eucrate crenata (De Haan, 1835); A–F, male neotype of Pilumnoplax sulcatifrons Stimpson, 1858 (34.0 mm × 49.1 mm) (QM W27449), Hong Kong, New Territories, Tolo Channel; G, female (22.1 mm × 27.1 mm) (ZRC 2002.0493), China, Qingdao. A, overall view; B, frontal view showing orbits and antennae; C, anterior portion of male thoracic sternum and abdomen; D, third maxillipeds, antennules, antennae and orbits; E, outer surface of right chela; F, posterior portion of male thoracic sternum and abdomen; G, female thoracic sternum and vulvae. Abbreviations: a1–a6 = male abdominal somites 1–6, respectively; cx5 = coxa of fifth pereopod (P5); s3–s7 = thoracic sternites 3 to 7, respectively; t = telson; v = vulva.

FIGURE 4. Variation in colour patterns of carapace of Eucrate species. A–C, Eucrate alcocki Serène, in Serène & Lohavanijaya, 1973; A, female (15.1 mm × 17.7 mm) (ZRC 2003.0605), Gulf of Thailand; B, male (19.2 mm × 23.3 mm) (ZRC 1998.1055), Gulf of Thailand; C; male paratype of Eucrate maculata Yang & Sun, 1979 (= E. alcocki) (15.9 mm × 18.7 mm) (BMNH J79139), China, Fujian Province, Dongshan; D–F, Eucrate indica n. sp.; D, male (22.8 mm × 28.3 mm) (ZRC 2001.0867), India, Tamil Nadu, fish landing opposite Vellar estuary; E, male holotype (23.4 mm × 28.3 mm) (ZRC 1998.1058), Thailand, Andaman Sea, Phuket I.; F, female (22.8 mm × 28.3 mm) (ZRC 2001.0867), India, Tamil Nadu, fish landing opposite Vellar estuary.

FIGURE 5. Eucrate dorsalis (White, 1849); A, male paralectotye (NHM 1850.112) as originally illustrated in White (1849: pl. 6, fig. 2), Australia, Queensland; B, C, dry male paralectotype of Cancer (Galene) dorsalis White, 1849 (36.6 mm × 46.5 mm; NHM 1850.112), Australia, Queensland; D, dry male lectotype of Cancer (Galene) dorsalis White, 1849 (20.2 mm × 24.8 mm; NHM 1852.71), Australia, Queensland; Galene? laevimanus Lucas, in Jacquinot & Lucas 1853; E, F, dry male lectotype (28.7 mm × 36.5 mm) (MNHN-B2960); A, D, E, overall views; B, F, dorsal views of carapaces; C, ventral view of carapace. Photo credits: B–D by P. Crabb (NHM); E, F by J.-F. Dejouannet (IRD, Paris).

FIGURE 6. Eucrate dorsalis (White, 1849); A, female (31.7 mm × 40.7 mm) (QM W12788), Australia, Queensland, Townsville Closure; B–F, male (39.0 mm × 46.7 mm) (QM W3191), Australia, Queensland, Bundaberg. A–B, overall views; C, frontal view showing orbits and antennae; D, outer surface of right chela; E, anterior portion of male thoracic sternum and abdomen; F, posterior portion of male thoracic sternum and abdomen.

FIGURE 7. Fresh colours of Eucrate species. A, Galene? laevimanus Lucas, in Jacquinot & Lucas, 1853 [= E. dorsalis (White, 1849]), male lectotype (28.7 mm × 36.5 mm) (MNHN-B2960) (after Lucas, in Jacquinot & Lucas 1853: pl. 6 fig. 2); B, E. dorsalis (White, 1849), Queensland, Australia; C–F, E. solaris Yang & Sun, 1979; C, male (23.3 mm × 28.1 mm) (ZRC 2008.1333), Philippines, Bohol, Panglao; D, female (26.2 mm × 31.5 mm) (ZRC 2008.1335), Vanuatu, Santo; E, male (19.5 mm × 23.5 mm) (ZRC 2001.0537), Philippines, Bohol, Panglao; F, male (23.6 mm × 28.1 mm) (ASIZ-74626), Penghu Bay, Taiwan. Photo credit: B by Queensland Museum.

FIGURE 11. Eucrate solaris Yang & Sun, 1979; A, female allotype (21.3 mm × 27.0 mm) (BMNJ-J79137), China, Guangxi Province, Beibu Bay; B, C, F, female (21.4 mm × 26.2 mm) (ZRC 2001.0023), Taiwan, I-Lan County, Tahsi; D, E, male (23.3 mm × 28.1 mm) (ZRC 2008.1333), Philippines, Bohol, Panglao. A, B, overall views; C, frontal view showing orbits and antennae; D, anterior portion of male thoracic sternum and abdomen; E, male sterno-abdominal cavity and G1; F, female thoracic sternum and vulvae. Abbreviations: a2, a3 = male abdominal somites 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); G1 = first male pleopod; mg = median groove; p = penis; pb = press-button of the male abdominal-locking mechanism; s4–s8 = thoracic sternites 4 to 8, respectively; sc = sterno-abdominal cavity; t = telson; v = vulva.

FIGURE 12. Fresh colours of Eucrate tripunctata Campbell, 1969. A, female (34.9 mm × 45.5 mm) (ZRC 2003.0606), Thailand, Gulf of Thailand (specimen slightly tilted when photographed); B, male (24.3 mm × 29.4 mm) (ZRC 2003.0606), Thailand, Gulf of Thailand; C, male (37.5 mm × 47.2 mm) (ZRC 2003.0606), Thailand, Gulf of Thailand; D. female (13.6 mm × 16.0 mm) (ZRC 2002.0248), Singapore; E, F, male (7.0 mm × 8.3 mm) (ZRC 2008.066), Singapore.

FIGURE 13. Eucrate tripunctata Campbell, 1969; A, female (29.6 mm × 37.6 mm) (QM W1070), Australia, Queensland, Moreton Bay; B, male (26.7 mm × 33.8 mm) (QM W1070), Australia, Queensland, Moreton Bay; C–F, male (38.0 mm × 48.9 mm) (ZRC 2003.0191), Thailand, Gulf of Thailand. A–C, overall views; D, frontal view showing orbits and antennae; E, anterior portion of male thoracic sternum and abdomen; F, outer surface of right chela.

FIGURE 16. Euryplax nitida (Stimpson, 1859); A–F, male neotype of Heteroplax nitidus Stimpson, 1859 (7.1 mm × 11.3 mm) (UF 15166), Florida, Gulf of Mexico, west of St. Petersburg. A, overall view; B, outer surface of chelae; C, frontal view showing orbits and antennae; D, anterior portion of male thoracic sternum and abdomen; E, sternal protection of penis; F, posterior portion of male thoracic sternum and abdomen. Abbreviations: a1–a3, a6 = male abdominal somites 1, 2, 3, 6, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; G1 = first male pleopod; mg = median groove; p = penis; s4–s8 = thoracic sternites 4 to 8, respectively; t = telson.

FIGURE 17. Euryplax nitida Stimpson, 1859; A, C, G, male (7.2 mm × 10.4 mm) (RMNH D 15769), Florida, Marco Beach; B, D, female (USNM 276579), Gulf of Mexico, off Florida; E, F, male (13.9 mm × 23.2 mm) (MNHN-B8732), Brazil, Dertero (?). A, B, dorsal views of carapaces; C, third maxillipeds; D, anterior portion of male sterno-abdominal cavity and G1; E, anterior portion of male thoracic sternum and abdomen; F, posterior portion of male thoracic sternum and abdomen; G, posterior portion of male sterno-abdominal cavity and G2. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; G1 = first male pleopod; G2 = second male pleopod; mg = median groove; p = penis; pb = press-button of male abdominal-locking mechanism; s4–s8 = thoracic sternites 4 to 8, respectively.

FIGURE 19. Frevillea hirsuta (Borradaile, 1916); A, H, female (13.3 mm × 19.9 mm) (MNHN-B30601), West Indies, Guadeloupe, off Basse Terre; B–G, male (16.6 mm × 24.9 mm) (MNHN-B30601), West Indies, Guadeloupe, off Basse Terre. A, overall view; B, frontal view showing orbits and antennae; C, third maxillipeds; D, anterior portion of male thoracic sternum and abdomen; E, outer view of right chela; F, male sterno-abdominal cavity, G1, and penis; G, posterior portion of male abdomen; H, female thoracic sternum and vulvae. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; G1 = first male pleopod; mg = median groove; p = penis; pb = press-button of male abdominal-locking mechanism; s4–s7 = thoracic sternites 4 to 7, respectively; sc = sterno-abdominal cavity.

FIGURE 20. Gonopods of Euryplax and Frevillea species. A–C, Euryplax nitida Stimpson, 1859; A, B, G1; C, G2 (after Guinot 1969b: figs. 56, 57); D–F, Frevillea hirsuta (Borradaile, 1916): D, E, G1; F, G2 (after Guinot 1969b: figs. 58, 59).

FIGURE 21. Henicoplax eriochir n. sp.; A–D, male holotype (5.2 mm × 8.8 mm) (MNHN-B12511), Persian Gulf; E, F, ovigerous female paratype (5.4 mm × 8.9 mm) (MNHN-B12511), Persian Gulf. A, overall view; B, E, ventral views of carapaces; C, posterior portion of male thoracic sternum and abdomen; D, male sterno-abdominal cavity; F, female thoracic sternum and vulvae. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; G1 = first male pleopod; G2 = second male pleopod; mg = median groove; p = penis; s4– s8 = thoracic sternites 4 to 8, respectively; tm = tuft of tomentum on cheliped merus; v = vulva.

FIGURE 23. Henicoplax nitida (Miers, 1879); female holotype of Heteroplax? nitidus Miers, 1879 (6.1 mm × 9.3mm) (NHM 78.11), Straits of Korea. A, overall view; B, third maxillipeds; C, frontal view showing orbits and antennae; D, female thoracic sternum and vulvae. Abbreviations: mg = median groove; s4–s7 = thoracic sternites 4 to 7, respectively; v = vulva.

FIGURE 28. Heteroplax transversa Stimpson, 1858; male (5.4 mm × 8.5 mm) (CBM-CZ 7310), Japan, Seto Inland Sea. A, overall view; B, frontal view showing orbits and antennae; C, third maxillipeds; D, anterior portion of male thoracic sternum and abdomen; E, posterior portion of male thoracic sternum and abdomen; F, outer views of chelae. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5).

FIGURE 29. Machaerus atlanticus (Miers, 1881); A, B, male (6.5 mm × 8.9 mm) (MNHN-B 10238), Senegal, Joal; C, D, ovigerous female (6.0 mm × 8.2 mm) (MNHN-B10239), Senegal. Gorée I. A, C, overall views; B, anterior portion of male thoracic sternum and abdomen; D, female thoracic sternum and vulvae. Abbreviations: s4–s6 = thoracic sternites 4 to 6, respectively; v = vulva.

FIGURE 30. Machaerus oxyacanthus (Monod, 1956); male (19.0 mm × 30.3 mm) (MNHN-B10242), Sierra Leone. A, overall view; B, frontal view showing orbits and antennae; C, third maxillipeds; D, outer surface of left chela; E, male thoracic sternum and abdomen; F, male sterno-abdominal cavity, G1, and penis; G, posterior portion of male thoracic sternum and abdomen. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; G1 = first male pleopod; G2 = second male pleopod; g = male gonopore; p = penis; s4–s8 = thoracic sternites 4 to 8, respectively.

FIGURE 31. Nancyplax vossi Lemaitre, García-Gómez, von Sternberg & Campos, 2001; A–D, male paratype (12.1 mm × 17.2 mm) (USNM 308994), Suriname; E–G, female paratype (12.1 mm × 17.9 mm) (USNM 308994), Suriname. A, overall view; B, frontal view showing orbits and antennae; C, third maxillipeds; D, anterior portion of male thoracic sternum and sterno-abdominal cavity; E, outer surface of right chela; F, male sterno-abdominal cavity and penis; G, female thoracic sternum and vulvae. Abbreviations: cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; g = male gonopore; mg = median groove; p = penis; pb = press-button of male abdominal-locking mechanism; s4–s8 = thoracic sternites 4 to 8, respectively; v = vulva.

FIGURE 34. Platyozius laevis (Borradaile, 1902); A, male holotype of Pseudozius (Platyozius) Borradaile, 1902 (5.0 mm × 6.0 mm) (UMZC), Maldives, Suvadiva Atoll (after Borradaile 1902: fig. 45); B, male holotype of Pseudozius (Platyozius) Borradaile, 1902 (5.0 mm × 6.0 mm) (UMZC), Maldives, Suvadiva Atoll; C, topotypic female of Pseudozius (Platyozius) Borradaile, 1902 (7.5 mm × 9.5 mm) (UMZC), Maldives; D, male (6.0 mm × 7.5 mm) (MNHN- B30534), Seychelles; E, female (12.5 mm × 16.0 mm) (UF 1534), French Polynesia, Tuamotu Archipelago, Rangiroa Atoll; F, female (6.3 mm × 7.7 mm) (MNHN-B30534), Seychelles. Abbreviation: pr = postorbital ridge. Photo credits: B, C by T.-Y. Chan (NTOU).

FIGURE 36. Psopheticoides sanguineus Sakai, 1969; male (21.3 mm × 26.5 mm) (ZRC 2004.0752), Philippines, Bohol, Panglao. A, overall view; B, frontal view showing orbits and antennae; C, third maxillipeds; D, outer surface of right chela; E, anterior portion of male thoracic sternum and abdomen; F, posterior portion of male thoracic sternum and abdomen; G. female sternum and vulvae. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); s4–s7 = thoracic sternites 4 to 8, respectively; vc = sternal vulvar cover.

FIGURE 37. Systroplax angusta (Rathbun, 1914); A–C, G, female (27.8 mm × 31.4 mm) (MNHN-B29377), Fiji; D–F, male (32.3 mm × 37.2 mm) (MNHN-B29377), Fiji. A, overall view; B, frontal view showing orbits and antennae; C, third maxillipeds; D, outer surface of left chela; E, anterior portion of male thoracic sternum and abdomen; F, posterior portion of male thoracic sternum and abdomen; female sternum and vulvae; G, female sternum and vulvae. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; mg = median groove; s4–s7 = thoracic sternites 4 to 8, respectively; v = vulva.

FIGURE 38. Gonopods of Platyozius, Psopheticoides, and Systroplax; carapace of Systroplax. A–C, Platyozius laevis (Borradaile, 1902), male (6.1 mm × 7.8 mm) (ZRC 2007.0707), Maldives, Laamu Atoll; D–F, Psopheticoides sanguineus Sakai, 1969, male (21.9 mm × 27.8 mm) (ZRC 2008.1357), Philippines, Bohol, Balicasag I.; G–J, Systroplax angusta (Rathbun, 1914); G, G1 (after Guinot 1989: fig. 39D); H, male (32.3 mm × 37.2 mm) (MNHN-B29377), Fiji; I, J, variation in anterolateral borders of carapace (after Guinot 1989: fig. 39A, C). A, B, D, E, right G1, dorsal view; C, F, H, right G2, dorsal view. Scale bars: A, D, 1.0 mm; B, E, 0.5 mm; C, F, H, 0.2 mm; G, 0.1 mm.

FIGURE 41. Trissoplax dentata (Stimpson, 1858); A–D, F, male neotype of Heteroplax dentatus Stimpson, 1858 (16.4 mm × 21.5 mm) (QM W27400), Hong Kong, Tolo Harbour; E, male (20.0 mm × 26.2 mm), Singapore, Changi Point; G, female (8.7 mm × 11.5 mm) (ZRC 2000.2240) (ZRC 2008.1236), Singapore. A, frontal view showing third maxillipeds; B, frontal view showing orbits and antennae; C, anterior portion of male thoracic sternum; D, posterior portion of male thoracic sternum and abdomen; E, outer surface of right chela; F, male sterno-abdominal cavity, G1 and penis; G, female thoracic sternum and vulvae. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; G1 = first male pleopod; G2 = second male pleopod; mg = median groove; p = penis; s4–s7 = thoracic sternites 4 to 7, respectively; vc = sternal vulvar cover.

FIGURE 44. Trizocarcinus dentatus (Rathbun, 1893); male (14.7 mm × 20.2 mm) (MNHN-B20990), Mexico, Gulf of California. A, overall view; B, frontal view showing orbits and antennae; C, third maxillipeds; D, outer surface of right chelae; E, anterior portion of male thoracic sternum and abdomen; F, posterior portion of male thoracic sternum and abdomen; G, male sterno-abdominal cavity, G1, and penis. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); es7 = episternite 7; G1 = first male pleopod; mg = median groove; p = penis; s6–s8 = thoracic sternites 6 to 8, respectively.

FIGURE 45. Trizocarcinus tacitus Chace, 1940; female (20.6 mm × 29.4 mm) (MNHN-B30602), West Indies, Guadeloupe. A, overall view; B, female thoracic sternum and vulvae. Abbreviations: mg = median groove; md = median depression; s4–s7 = thoracic sternites 4 to 7, respectively; v = vulva.

FIGURE 47. Villoplax peruvianus (Garth, 1973); A, B, female holotype of Trizocarcinus peruvianus Garth, 1973 (13.1 mm × 19.1 mm) (AHF 699; now LACM); C, D, male paratype of Trizocarcinus peruvianus Garth, 1973 (19.9 mm × 28.7 mm) (AHF 705; now LACM); Perú, off Paita. A, overall view; B, dorsal view of carapace; C, frontal view showing orbits and antennae; D, ventral view of carapace. Abbreviations: a3 = male abdominal somite 3; es7 = episternite 7; s4– s7 = thoracic sternites 4 to 7, respectively; t = telson. Photo credits: J. Martin (LACM).

FIGURE 48. Villoplax peruvianus (Garth, 1973); male paratype of Trizocarcinus peruvianus Garth, 1973 (10.0 mm × 28.9 mm) (LACM), Perú, off Paita. A, overall view; B, frontal view showing third maxillipeds, orbits, and antennae; C, outer surface of right chela; D, male abdomen; E, F, G1; G, G2 (after Garth 1973: fig. 5). Abbreviations: a2, a3 = male abdominal somites 2 and 3, respectively.

FIGURE 49. Xenocrate peculiaris Ng & Castro, 2007; A–G, male holotype (34.0 mm × 39.1 mm) (NMCR), Philippines, Bohol; H, female paratype (36.9 mm × 42.2 mm) (ZRC 2008.0427), Philippines, Bohol. A, overall view; B, third maxillipeds; C, frontal view showing orbits and antennae; D, outer surface of left chelae; E, anterior portion of male thoracic sternum and abdomen; F, posterior portion of male thoracic sternum and abdomen; G, male sterno-abdominal cavity and G1; H, female thoracic sternum and vulvae. Abbreviations: a1–a3 = male abdominal somites 1, 2, 3, respectively; cx5 = coxa of fifth pereopod (P5); G1 = first male pleopod; mg = median groove; pb = press-button of male abdominal-locking mechanism; s4–s7 = thoracic sternites 4 to 7, respectively; v = vulva.