Miyakella holoschista ( Kemp, 1911 )

Miyakella holoschista ( Kemp, 1911)

( Fig. 25 View FIGURE 25 )

Squilla holoschista Kemp, 1911: 97 [type locality Madras, India, by lectotype designation ( Ahyong et al. 2008)].— Kemp, 1913: 64, pl. 4, figs. 50–53.— Barnard, 1950: 849, fig. 2b.

Oratosquilla holoschista .— Manning, 1969a: 15.

Miyakea holoschista .— Manning, 1995: 214, figs. 130c, d, 131a–c.—Ahyong, 2001: 279 (list).— Ahyong et al., 2008: 138–139, fig. 109.

Miyakella holoschista .— Ahyong & Low, 2013: 99–100.

Material examined. KZN: SAMC-A001326 , 1 ♀ (TL 61 mm), off south head of Tugela River , 29°13’59.9”S 31°30’00.0”E, 16 Jan 1901, 22–26 m, stat. PF 11428, S.S. Pieter Faure , det. K. H. Barnard (1950) GoogleMaps ; SAMC-A019342 , 1 ♀ (TL 75 mm), Durban , stat. NAD 40W, 29°34’00.0”S 31°39’00.0”E, 9 Sep 1961, 118 m GoogleMaps , UCT Ecological Survey, det. R. B. Manning (1969a).

Diagnosis. Carapace with portion of MD carina between cervical groove and anterior bifurcation finely bicarinate, not simple. AS 4 SM carinae unarmed posteriorly. Abdominal carinae spined as follows: SM 5–6, IM 3–6, LT (1–2) 3–6, MG 1–5. Telson denticles SM 2–3, IM 9–11, LT 1. Uropodal exopod proximal segment outer margin with 8–10 movable spines.

Colour in alcohol. Completely faded.

Colour in life. Overall green colouration, closely resembling M. nepa being grey-green ( Kemp 1913). Carinae and grooves of carapace, carinae and posterior margins of abdominal somites dark green. Telson with median carina and carinae of primary teeth dark green. Uropodal exopod proximal segment yellow.

Measurements. ♀ (n = 2) TL 61–75 mm. CI 660–705.A1 peduncle 0.74–0.80CL.A2 scale length 0.55–0.56CL. Anterior carapace width 0.48–0.52CL.

Distribution and habitat. Indo-West Pacific from South Africa to east coast of India, Sri Lanka, Sunda Straits, Vietnam and Taiwan. Found in shallow water on level sand or mud substrates at 22–118 m (present study).

Remarks. Both specimens of M. holoschista examined were included in Barnard’s (1950) and Manning’s (1969a) reviews of the regional stomatopod fauna. The present specimens agree in most respects with Kemp’s (1911, 1913) accounts. Manning (1969a) describes several differences from the original species description. These differences include a larger eye, and structural differences in the raptorial claw carpus and the lateral processes of TS5 and 6; these observations are confirmed in the present study. The cornea of the South African specimens appears proportionally larger than in the Indian specimens examined by Kemp (1913), with corneal index 660–705, compared to 800–900 in Kemp’s larger specimens, which may be within the expected range due to allometric changes in eye size relative to total length. Two tubercles are present on the carpus of the raptorial claw and while the posterior lobe of the TS5 lateral process appears more slender, the anterior lobe of TS6 lateral process appears more truncate.

Misidentifications of M. holoschista as M. nepa are common throughout the literature ( Stebbing 1917; Gravier 1937; Manning 1995). Miyakella holoschista can be distinguished by the form of the MD carina of the carapace being finely bicarinate anteriorly in front of the cervical groove. The species also has never been recorded to have spined SM carinae of AS 4 (usually present in M. nepa ). In living material, the presence of the dark patches on AS 2 and 5 aids in distinguishing the two species. Miyakella nepa is frequently observed with these patches, while in M. holoschista they are always absent ( Kemp 1913). No male collected from South African waters was available for examination. Both female specimens examined did not exhibit abdominal spination of LT carinae on AS 1, as previously recorded. The proximal segment of the uropodal exopod displayed 9 movable spines in the present series.