Gonodactylus smithii Pocock, 1893

Gonodactylus smithii Pocock, 1893

( Fig. 10 View FIGURE 10 )

Gonodactylus smithii Pocock, 1893: 475 , pl. 20B [ type locality Arafura Sea].— Manning, 1968a: 44–46.— Cappola & Manning, 1995: 277–278.— Manning, 1995: 20, 76–80, pls. 11, 12, figs. 9e, 10c, 11d, 27c, 32–35.— Ahyong & Norrington, 1997: 101–102.—Ahyong, 2001: 72–75, fig. 36; 2005: 160.— Poupin et al., 2019: 7, fig. 2C. Gonodactylus chiragra var. anancyrus Borradaile, 1900: 395 , 397, 401 [ type localities Talili Bay, New Britain and Lifou, Loyalty Islands]. Gonodactylus minikoiensis Ghosh, 1990: 201 , 202, fig. 1 [ type locality Minikoy Island, Lakshadweep].

Gonodactylus arabica Ghosh, 1990: 201 , 205, figs. 2, 3e [ type locality Kavaratti , Lakshadweep].

Material examined. KZN: SAMC-A015633 , 1 ♂ (TL 57 mm), Sodwana Bay, 27°31’00.1”S 32°40’59.9”E, 23 Jul 1976, 13.5 m, stat. RW 13, coll GoogleMaps . R. Winterbottom , det. S. Ahyong ; SAMC-A01563,7 2 ♂ (TL 34–45 mm), Sodwana Bay, 27°31’00.1”S 32°40’59.9”E, 1 Aug 1976, RW 24, same as above GoogleMaps ; SAMC-A015636 , 1 ♂ (TL 29 mm), 2 ♀ (TL 19–26 mm), Sodwana Bay, 27°13’00.1”S 32°46’59.9”E, 28 Jul 1976, RW 22, same as above GoogleMaps .

Diagnosis. Ocular scales broad, flattened, separate, together as broad as, or broader than, half rostral plate width. Rostral plate basal portion with anterior margins concave; anterolateral angles acute, but not spiniform; lateral margins strongly divergent anteriorly; apical spine longer than base. Telson with LT tooth indicated by shallow notch in margin of telson between anterolateral angle and apex of IM tooth; dorsal carinae often sharp or crested dorsally; MD carina usually armed posteriorly with stout spine, but often obsolete in adult males; accessory MD carinae forming “anchor”; with 12–18 SM denticles. Uropodal exopod proximal segment outer margin with 10–13 movable spines.

Colour in alcohol. Body colour faded blue-green, but with some evidence of mottling on margin of abdominal somites. Raptorial claw with ‘meral spot’ dark red to purple; propodus blue distally; dactylus pink. Uropodal protopod with purple dorsal spot basally.

Colour in life (after Ahyong 2001). Overall or mottled light green to dark green. ‘Meral spot’ of raptorial claw dark-red to purple, outlined with white; propodus blue distally; dactylus pink. Uropodal protopod with bright-red dorsal spot basally; setae on exopod and endopod often purple. A2 scale clear yellow.

Measurements. ♂ (n = 4) TL 29–57 mm, ♀ (n = 3) TL 19–27 mm. A1 peduncle 0.57–0.68CL. A2 scale 0.51– 0.73CL. AWCLI 767–828. The largest known specimen is a TL 90 mm ♀ from Australia.

Distribution and habitat: Indo-West Pacific from Okinawa, New Caledonia, Australia, Vietnam and South China Sea to Madagascar and South Africa; 0–14 m ( Ahyong 2005) on coral and rocky reefs (Ahyong 2001, 2005). Ahyong & Norrington (1997) documented their foraging behaviour on reef flats at low tide in Australia. Manning’s (1968a) account from Madagascar reports specimens from the shallow intertidal to 80 m.

Remarks. Gonodactylus smithii is distinguishable from other species in the genus by the slender telson carinae and shape of the rostral plate with strongly divergent lateral margins. The latter feature has been known to vary in the degree of sharpness of the rostral plate anterolateral corners, where the acuteness of the anterolateral angles increases with increasing body size (Ahyong 2001). This is apparent in the present series for the TL 19 mm and TL 57 mm males illustrated ( Fig. 10A, D View FIGURE 10 ). The degree of sharpness of the median carina apex is also observed to vary with size. The median carina was armed with a stout spine in the small male examined (TL 19 mm) ( Fig. 10J View FIGURE 10 ), while the spine was absent in the large male (TL 57 mm) ( Fig. 10K View FIGURE 10 ).

The present material agrees well with previous published accounts of specimens of a similar size. First recorded for southern Africa in Madagascar ( Manning 1968a), G. smithii specimens larger than TL 23 mm have one notable variation of the uropod endopod compared to specimens from the eastern Indian Ocean and western Pacific ( Ahyong & Norrington 1997; Ahyong 2001). Specimens from Madagascar have the inner margin of the uropodal endopod sinuous instead of convex. Gonodactylus smithii has been documented from coral reef habitat in Sodwana Bay, South Africa ( Ahyong 2005). South African specimens re-examined herein exhibit the same variation of uropod endopod as the Madagascan material, furthering the observed heterogeneity of the species already suggested by Ahyong (2005).

ODONTODACTYLIDAE Manning, 1980 View in CoL

Odontodactylidae Manning, 1980: 366 View in CoL , 369.

Diagnosis (after Ahyong 2012). Eyes subglobular. Rostral plate rounded to trapezoid. Raptorial claw with subterminal ischiomeral articulation; propodus occlusal margin non-pectinate, without proximal movable spines; dactylus with short teeth on occlusal margin and strongly-inflated heel on outer proximal margin. Telson and AS 6 fully articulating, not fused. Distal segment of uropodal exopod articulating at distal end of proximal segment; distal movable spines on outer margin of proximal segment not recurved anteriorly.

Composition. Odontodactylus Bigelow, 1893 .

Remarks. While all species of Odontodactylidae are ‘smashers’, they differ from Gonodactylidae and Protosquillidae by having teeth on the inner margin of the dactylus of the raptorial claw. This is the first account of the family from South Africa.