Harpiosquilla harpax (de Haan, 1844)

Harpiosquilla harpax (de Haan, 1844)

( Fig. 23 View FIGURE 23 )

Squilla harpax de Haan, 1844 (atlas): pl. 51, fig. 1 [ type locality Japan]; 1849: 222 (text).— Tiwari & Biswas, 1952: 358, figs. 3b, d, f.

Squilla raphidea .— Barnard, 1950: 851, fig. 1c, g.— Stephenson, 1952: 4, 5; 1953a: 43.— Stephenson & McNeill, 1955: 239– 240 (not Squilla raphidea Fabricius, 1787 ).

Harpiosquilla harpax .— Manning, 1968a: 15–18, fig. 4; 1969a: 7; 1969d: 6, 25–33, figs. 28–38; 1991: 8; 1995: 148, 153–158, pl. 28, figs. 90a, 92b, 93, 95, 96.— Yamaguchi & Baba, 1993: 179–180, fig. 11.— Ahyong & Norrington, 1997: 106.— Ahyong, et al. 1999: 38, 41, fig. 2a–d.— Ahyong & Ebach, 1999: 227–228.

Harpiosquilla malagasiensis Manning, 1978a: 30 , fig. 15 [ type locality Tamatave , Madagascar].

Harpiosquilla paradipa Ghosh, 1987: 306–308 , fig. 1 [ type locality Paradip , India].

Material examined. KZN: SAMC-A001339 , 1 ♀ (TL 200 mm), Durban , 29°52’59.9”S 31°00’00.0”E, depth and date unknown GoogleMaps ; SAMC-A019338 , 1 ♀ (TL 152 mm), Durban Bay, 29°52’59.9”S 31°00’00.0”E, 30 Aug 1946 GoogleMaps , depth unknown, dredge, NA 176B, UCT ecological survey, det. R.B. Manning ; SAMC-A019447 , 1 ♂ (TL 147 mm), ex. Transvaal Museum No. 3383, Durban Bay, 29°52’59.9”S 31°00’00.0”E, depth unknown, Oct 1918, coll. H.W. Bell-Marley. GoogleMaps SAMC-A079409 , 1 ♂ (TL 153 mm), Durban , Oct 1901 , depth unknown, coll. V. Kennard; SAMC- A079479, 1 ♀ (TL 178 mm), Durban , 29°51’18.1”S 31°03’26.0”E, 30 Aug 1945 GoogleMaps , depth unknown.

Diagnosis. Rostral plate longer than broad; triangular to cordiform; usually with slender median projection; margins usually sinuous, apex blunt. Carapace with MD carina. Raptorial claw dactylus with 8 teeth, outer margin strongly angular in adult male. TS5 IM carinae low, irregular; ventral process triangular, apex acute, posterior margin slightly convex. TS6–8 with SM and IM carinae, unarmed posteriorly. TS8 sternal keel rounded, inclined posteriorly. AS 1–5 with low or near absent SM carinae. Abdominal carinae spined as follows: SM 6, IM (1–2) 3–6 (usually 2– 6), LT 1–6, MG 1–5. Telson MD carina proximally with diffuse dark patch on either side of midline; with MG carina less than to greater than twice LT carina length, usually exceeds twice LT carina length; denticles SM 4–6, IM 9–14, LT 1; postanal carina extending midway between anal pore and posterior margin. Uropodal exopod proximal segment outer margin with 8–10 movable spines; exopod distal segment dark on inner half only.

Colour in alcohol. Overall colour reddish-brown to completely faded. Dark spots on either side of MD carina on the telson visible in most specimens. A2 scale with outer distal margin black and 0.66 dark brown distally. Uropodal exopod almost completely brown to black distally.

Colour in life (after Ahyong 2001). Overall dorsal colour light grey-brown with slightly mottled appearance. Carinae and grooves of carapace, and posterior margins of body somites black-brown. AS 6 with dark green carinae. Telson with MD carina and carinae of primary teeth green; MD carina with proximal pair of dark spots. Uropodal endopod black-brown distally. Uropodal exopod with inner half black-brown, but with demarcation between inner and outer halves diffuse. A2 scale with outer distal margin black. Raptorial claw with depression of merus yellow, flanked proximally by scattered black crescent.

Measurements. ♂ (n = 2) TL 147–153 mm, ♀ (n = 3) TL 152–200 mm. CI 300–343.A1 peduncle 0.86–0.97CL. A2 scale 0.63–0.73CL. Ahyong (2001) reported the largest known specimen at TL 262 mm from the east coast of Australia.

Distribution and habitat. Indo-West Pacific from South Africa [KZN], Madagascar and Red Sea to Taiwan, Philippines, Vietnam, Japan, New Caledonia and Australia. Associated with sand and mud substrates from shallow coastal waters to estuaries; shallow intertidal to 93 m.

Remarks. First recorded for South Africa by Barnard (1950) as Harpiosquilla raphidea Fabricius, 1798 . Subsequently, Barnard (1955) rectified his previous identification for a specimen of H. harpax from Durban Bay. Although the accounts by Manning (1995) and Ahyong (2001) describe colour in life for H. harpax to include green, the retained colour of preserved specimens is a dark reddish-brown and appears faded where the green colouration is known to be.

Features thought to be diagnostic, such as the rostral plate shape and the length of the lateral carinae of the telson relative to the marginal carinae, have been found to be variable (Ahyong 2001). Like the variation described by Ahyong (2001) for Australian specimens, the length and distinctiveness of the apical spine of the rostral plate are variable in South African specimens. Although all South African specimens examined have an apical projection, the slenderness of the projection and the length of the base varies, showing variations in rostral plate morphologies ( Fig. 23C–E View FIGURE 23 ) like those found in Australian specimens. No variability was found in the relative length of the lateral carina to the marginal carina of the telson, as the lateral carina was distinctly less than half of the marginal carina in all the specimens examined ( Fig. 23J View FIGURE 23 ). The lateral carina has been previously recorded to exceed half the marginal carina by Ahyong (2001) for specimens from Australian waters.