Miyakella nepa (Latreille, 1828)

Miyakella nepa (Latreille in Latreille, Le Peletier, Serville & Guérin, 1828)

( Fig. 26 View FIGURE 26 )

Squilla nepa Latreille in Latreille, Le Peletier, Serville & Guérin, 1828: 471 [type locality Xiamen , China, by neotype selection

(Ahyong 2001)].— Haswell, 1882: 208–209.— Kemp, 1913: 3, 10, 22, 30, 195, pl. 4: fig. 49.— Holthuis, 1941: 245–246.—

Stephenson, 1953a: 41.— Stephenson & McNeill, 1955: 243.— Manning, 1968a: 31–32, fig. 10. Squilla edwardsi Giebel, 1861: 320 [ type locality Insel Banka, Indonesia]. Squilla laevis .— Stephenson, 1960: 61 (not Squilla laevis Hess, 1865 ). Squilla wood-masoni .— Stephenson & McNeill, 1955: 244 (not Squilla woodmasoni Kemp, 1911 ). Oratosquilla nepa .— Manning, 1968a: 31–32, fig. 10; 1971b: 3.— Moosa, 1986: 410; 1991: 212.— Manning, 1991: 12. Miyakea nepa .— Manning, 1995: 216, figs. 130a, b, 131d, e, 132–134, pl. 37.—Ahyong et al., 1999: 47, 52, fig. 6a–d.—Ahyong,

2001: 279–281, fig. 136. Miyakella nepa .— Ahyong & Low, 2013: 99–100.

Material examined. KZN: SAMC-A019449 , 1 ♀ (TL 75 mm), Durban , 29°53’05.5”S 30°59’59.9”E, depth and date unknown, ex. Albany Museum Collection No. 255, coll GoogleMaps . R. A. Hunter. Eastern Cape : SAMC-A079461 , 1 ♂ (TL 160 mm), banks of Mtakatya River , 31°51’03.6”S 29°16’24.5”E, Oct 1975, river bank, coll. Mr. J. Gardiner Alexandria GoogleMaps .

Diagnosis. Carapace with portion of MD carina between cervical groove and anterior bifurcation simple, not finely bicarinate. AS 4 with SM carinae usually posteriorly spined. Abdominal carinae spined as follows: SM (3– 4)5–6 (usually 4–6), IM 3–6, LT (1–2)3–6, MG 1–5. AS 2 and 5 with dark transverse mid-dorsal patch. Telson denticles SM 2–3, IM 7–11, LT 1. Uropodal exopod outer margin with 8–10 movable spines.

Colour in alcohol. Completely faded.

Colour in life (after Ahyong 2001). Overall dorsal colour olive grey-green. Carinae and grooves of carapace, carinae and posterior margins of body somites dark green. Telson with MD carina and carinae of primary teeth dark green with dark transverse band medially. Uropodal protopod with terminal spines pink; exopod distal segment dark blue-green distally; exopod proximal segment yellow with dark inner proximal infusion.

Measurements. ♀ (n = 1) TL 75 mm. CI 550. A1 peduncle 0.91CL. A2 scale 0.58CL. Anterior carapace width 0.55CL. Kemp (1913) reported specimens up to TL 166 mm.

Distribution and habitat. South Africa and Mozambique through to Vietnam, Taiwan, Philippines, New Caledonia, French Polynesia and Australia. Found predominantly on level sandy to mud substrate in shallow water, 0– 37 m.

Remarks. The specimens from South Africa agree well with the description of the neotype (Ahyong 2001), as well as previously published accounts ( Kemp 1913; Manning 1968a, 1995). Although not visible on the present ethanol stored material, the dark transverse patches positioned mid-dorsally on abdominal somites 2 and 5 are a diagnostic feature ( Kemp 1911) which can distinguish M. nepa from M. holoschista .

There are differences in colour accounts between Barnard’s (1950) first record of the species from South Africa and more recent species accounts from Madagascar ( Manning 1968a) and Australia (Ahyong 2001). While Manning (1968a) agrees with Ahyong’s (2001) colour description, Barnard (1950) records overall dorsal colour to be pale biscuit with orange to red on carapace keels, abdominal somites and telson. A similar colour combination is mentioned in Kemp’s (1913) account of the species, where a small portion of the specimens from Thoothukudi, India, preserved in formalin showed a similarly positioned ‘rosy red’ to purple colouration. But it is important to note that that these differences in colour accounts may be the result of specimen preservation techniques.

The variation in rostral plate shape and abdominal spination for M. nepa is well-documented ( Manning 1968a; Ahyong 2001). The rostral plate has been recorded to be either subtruncate or triangular with a rounded or transverse apex for Madagascan specimens ( Manning 1968a). Both specimens examined herein have a subtruncate rostrum with rounded apex ( Fig. 26C View FIGURE 26 ). The presence of spines on the SM carina of AS 3 has only been recorded for specimens of M. nepa from Madagascar ( Manning 1968a) and some specimens from Singapore (Ahyong 2001). All other accounts, including the present series, do not report such spination. Further variation in abdominal spination has been observed for Australian material, where the SM carina of AS 4 is sometimes unarmed on one or both sides of the AS 4 (Ahyong 2001).