Gonodactylaceus falcatus ( Forskål, 1775 )

Ahyong Kumejima, Shane T., 2012, Stomatopod Crustacea of the KUMEJIMA 2009 Expedition, Japan *, Zootaxa 3367, pp. 232-251 : 234

Gonodactylaceus falcatus ( Forskål, 1775)

( Fig. 1A–F)

Cancer falcatus Forskål, 1775: 96 [type locality: Djeddah, Red Sea, by neotype selection ( Manning & Lewinsohn 1981)].

Gonodactylus glabrous . — Fukuda 1908: 511, pl. 2, fig. 2; 1910: 141; 1913: 72. — Komai 1927: 340 [not G. glabrous ( Brooks, 1886) ].

Gonodactylus falcatus . — Utinomi 1956: 92, pl. 46, fig. 5 (colour plate). — Manning 1965: 260. — Moosa 1989: 224.

Gonodactylus chiragra var. mutatus Lanchester, 1903: 450 [type locality: Furnadu Velu , Miladumadulu Atoll, Maldive Islands, 6°00'N, 73°10'E].

Gonodactylus glaber var. rotundus Borradaile, 1907: 211–212 , pl. 22: fig. 2 [type locality: Coetivy , Seychelles, 7°08'S, 56°16'E, and Zanzibar, 6°10'S, 39°12'E].

Gonodactylus insularis Manning & Reaka, 1982: 347–351 , figs. 1, 2 [type locality: Kidrenen Island, Enewetak, 11°22'50"N, 162°10'30"E]. — Moosa 1989: 224.

Gonodactylus aloha Manning & Reaka, 1981a: 190–200 , figs. 1–3 [type locality: Oahu, Hawaiian Islands].

Gonodactylus siamensis Manning & Reaka, 1981b: 479–482 , fig. 1 [type locality: Sattahip , Gulf of Thailand, 12°40'N 100°52'E].

Gonodactylus takedai Moosa, 1989: 225–226 , fig. 1 [type locality: Miyanohama, Chichi-jima, Ogasawara Islands].

Gonodactylaceus gravieri Manning, 1995: 42 , 43, 46–48, fig. 13 [type locality: Poulo Condore , Vietnam].

Gonodactylaceus falcatus . — Ahyong 2001: 35–38, fig. 17. — Osawa et al. 2004: 7. — Hamano, 2005: 12, 21–22, fig. 2-5a–d. — Ahyong 2007: 334; 2012: 19–22, figs 7, 8.

Material. RUMF-ZC-01241, 1 male (TL 33 mm), 26° 19.351 –19.305´N, 126° 49.673 –49.768´E, 14 m, dredge 18, 11 Nov 2009; RUMF-ZC-01242, 2 males (TL 12, 19 mm), 1 female (TL 19 mm), 26° 19.907 –20.056´N, 126° 43.191 –42.622´E, 67.5–76.0 m, dead coral rubble, dredge 45, 16 Nov 2009; RUMF-ZC-01243, 1 male (TL 32 mm), 26° 20.409 –20.018´N 126° 49.675 –49.224´E, 5.1– 4.5 m, dead coral branches, rubble, dredge 52, 17 Nov 2009; RUMF-ZC-01244, 1 male (TL 20 mm), 1 female (TL 27 mm), 26° 19.456 –19.400´N, 126° 49.450 –49.182´E, 4.5–9.0 m, dead coral blocks, trawl 54, 17 Nov 2009; RUMF-ZC-01245, 1 female (TL 18 mm), 26° 19.442 –19.378´N, 126° 49.211 –49.198´E, 4.7–9.5 m, dredge 55, 17 Nov 2009; RUMF-ZC-01246, 2 males (TL 21–41 mm), 4 females (TL 26–42 mm), 26°19.360´N 26°19.294´N, 126°49.204´E 126°49.192´E, 7.5– 4.7 m, dead coral blocks, rubble, dredge 56, 17 Nov 2009; RUMF-ZC-01247, 1 male (TL 14 mm), 26° 19.622 –19.424´N, 126° 49.511 –49.450´E, 9.4–12.5 m, rubble, seaweed, dredge 57, 17 Nov 2009; RUMF-ZC-01248, 1 female (TL 18 mm), 26° 19.553 –19.463´N, 126° 49.510 –49.491´E, 9.1–13.3 m, sand, dredge 58, 17 Nov 2011; AM P87561 , 1 male (TL 33 mm), 1 female (TL 26 mm), 26° 20.307 –20.158´N, 126° 49.360 –49.334´E, 5.1–6.4 m, trawl 59, 18 Nov 2009; ZRC 2011.0823 , 2 females (TL 10, 27 mm), 26° 19.095 –18.898´N, 126° 49.008 –48.969´E, 10.1–17.1 m, sand, mud, dredge 68, 19 Nov 2009.

Remarks. Gonodactylaceus falcatus is widely distributed in the Indo-West Pacific and has already been reported from Japanese waters, including the Ryukyus. All males exceeding TL 12 mm exhibit sexually modified endopods on pleopod 1. The overall body colouration of G. falcatus is highly variable but also sexually dimorphic. In males, each somite usually has a transverse row of 4–6 dark spots or patches that become proportionally larger with increasing size; females lack these dark patches; the meral spot of raptorial claw in both sexes is yellow ( Fig. 1A–F).

Distribution. Western Indian Ocean to Hawaii (introduced) including Australia, New Zealand and Japan; intertidal to at least 23 m ( Ahyong 2001).