Raoulserenea oxyrhyncha ( Borradaile, 1898 )

Raoulserenea oxyrhyncha ( Borradaile, 1898)

( Fig. 16 View FIGURE 16 )

Pseudosquilla oxyrhyncha Borradaile, 1898: 37 , pl. 6: figs. 9–9d [ type locality Rotuma, Fiji].— Holthuis, 1941: 264–266, fig. 4.

Raoulserenea oxyrhyncha .— Manning, 1995: 116.—Ahyong, 2001: 123–125, fig. 61; 2005: 163; 2012: 247; 2014: 253.— Ahyong & Davie, 2002: 70.— Ahyong & Erdmann, 2003: 335–336.—Ahyong & Caldwell, 2017: 613, fig. 2E.

Material examined. KZN: SAMC-A044726 , 1 ♂ (TL 30.5 mm), Sodwana, 27°31’00.1”S 32°40’59.9”E, 25 Jul 1976, 13.5 m, stat. RW 15, coll GoogleMaps . R. Winterbottom, det. S. Ahyong ; SAMC-A015618 , 1 ♂ (TL 35 mm), Sodwana, 27°31’00.1”S 32°40’59.9”E, 24 Jul 1976, 13.5 m, stat. RW 14, same as above GoogleMaps .

Diagnosis. Cornea distinctly broader than stalk, trapezoid in dorsal view. Rostral plate ovoid, with short anterior spine. Carapace dorsum with pair of dark ‘eyespots’ with diffuse margins surrounded at most by pale spots or diffuse paler patches, not merging to form a continuous light ring. Raptorial claw propodus with pale spots. Thoracic and abdominal somites uniformly coloured, diffusely banded or mottled, without distinctly reticulated colour pattern. AS 1–2 posterolaterally rounded. AS 3–4 posterolaterally angular. AS 5 with posterolateral spine. Uropodal exopod proximal segment outer margin with 11 movable spines.

Colour in alcohol. Body colouration mostly faded yellowish pink. Carapace with pair of black ‘eyespots’, pale blotches surrounding ‘eyespots’ just visible. AS 1 with dark spot adjacent to pleural plate. Raptorial claw with movable spines of propodus and dactylus mottled pink. AS 5 posterior margin and AS 6 SM and LT spines tipped pink. Telson SM and IM teeth tipped with dark pink. Uropodal protopod and endopod with mottled dark pink patches, exopod with movable spines on outer margin purple.

Colour in life. Body and carapace ranging in colour from uniform to mottled.

Measurements. ♂ (n = 2) TL 30.5–35.0 mm. CI 350–400. A1 peduncle 0.55–0.74CL. A2 scale 0.44–0.46CL. PLDI 400–480. AWCLI 660–700.

Distribution and habitat. Cocos-Keeling Islands (eastern Indian Ocean) to Indonesia, Papua New Guinea, Guam, Rotuma ( Fiji), Moorea, French Polynesia and South Africa; 0–13.5 m ( Ahyong 2005). Associated with coral reef systems of rock/rubble substrata from shallow water; 0– 23 m.

Remarks. Although known to vary in general colour pattern, the pair of large dark spots in R. oxyrhyncha are always present on the carapace and surrounded at most by several diffuse pale patches. The characteristic‘eyespots’ are never surrounded by a distinct pale ring, as reported by Ahyong & Caldwell (2017) for R. ornata and R. komaii . However, the body and carapace of R. oxyrhyncha has been recorded to vary from uniform colouration to light and dark mottled banding (Ahyong 2001; Ahyong & Erdmann 2003; Ahyong & Caldwell 2017).

Raoulserenea oxyrhyncha and R. komaii are presently considered morphologically indistinguishable and can be identified by colouration alone. It has been suggested that the two species may represent colour variants of the same species (Ahyong 2001), but in this study R. oxyrhyncha and R. komaii are treated as separate species. The uniform colour variant of R. oxyrhyncha resembles that of R. moorea Ahyong & Caldwell, 2017 , but the species can easily be distinguished by the presence of an apical spine on the rostral plate of R. oxyrhyncha specimens, absent in R. moorea .

Both male specimens of R. oxyrhyncha examined herein were reported on by Ahyong (2005). Although the colour is faded in the present series, Ahyong (2005) remarked that the specimens exhibit the same colour pattern as the holotype of Raoulserenea oxyrhyncha from Rotuma, Fiji. The holotype, as well as the present specimen, exhibit subtle mottling on the body and the carapace bears pale patches surrounding the dark eyespots.

TAKUIDAE Manning, 1995 View in CoL

Takuidae Manning, 1995: 119 View in CoL . [ Type genus Taku Manning, 1995 ].

Diagnosis (after Ahyong 2001).A2 protopod dorsally with fixed, anteriorly directed spine.Raptorial claw ischiomeral articulation of subterminal; dactylus without teeth on inner margin, outer basal margin strongly inflated into blunt heel; propodus without proximal movable spines. AS 6 articulating with telson. Articulation of uropodal exopod segments subterminal. Distal spines on outer margin of uropodal exopod strongly recurved anteriorly.

Composition. Mesacturus Miers, 1880 ; Mesacturoides Manning, 1978b ; Taku Manning, 1995 .

Remarks. All takuid species occur in the Indo-West Pacific. Only one species and genus known from South Africa.