Neoanchisquilla Moosa, 1991

Ahyong, Shane T., 2002, Stomatopoda (Crustacea) from the Marquesas Islands: results of MUSORSTOM 9, Zoosystema 24 (2), pp. 347-372 : 362-364

Genus Neoanchisquilla Moosa, 1991

Neoanchisquilla tuberculata Ahyong, 1998 ( Fig. 8 )

Neoanchisquilla tuberculata Ahyong, 1998: 219 , 224, 225, fig. 4. Type locality: Comoro Islands, 12°11’09”S, 44°19’03”E.

MATERIAL EXAMINED. — Nuku Hiva, stn CP1175, 8°45.0’S, 140°16.1’W, 300 m, 25.VIII.1997, 2 postlarvae tl 31-32 ( MNHN). — Stn CP1188, 8°48.6’S, 140°03.4’W, 35-55 m, 26.VIII.1997, 1

tl 56 ( MNHN). — Hiva Oa, stn CP1195, 9°02.5’S, 139°58’W, 800 m, 27.VIII.1997, 1 late pelagic larva tl 32 ( MNHN). — Stn DW1209, 9°50.2’S, 139°02.5’W, 85 m, 29.VIII.1997, 1 postlarva tl 30 ( MNHN). — Stn DW1210, 9°50.4’S, 139°00.5’W, 98-100 m, 29.VIII.1997, 1 tl 35 ( MNHN). — Stn DW1211, 9°50.2’S, 139°02.5’W, 50 m, 29.VIII.1997, 1 broken telson length 7.2, 1 postlarva broken telson length 6.4 ( MNHN). — Stn CP1212, 9°49.9’S, 139°02.2’W, 50-80 m, 29.VIII.1997, 1

tl 37, 1 tl 37, 2 postlarvae tl 32, 1 postlarva tl 32 ( MNHN). — Stn CP1228, 9°44.6’S, 138°51.5’W, 107-108 m, 30.VIII.1997, 1 tl 64 ( MNHN). — Stn CP1237, 9°41.9’S, 139°03.6’W, 95-305 m, 31.VIII.1997, 1 tl 36, 1 postlarva tl 32 ( MNHN). — Fatu Hiva, stn DW1242, 10°28.1’S, 138°41.1’W, 119-122 m, 01.IX.1997, 1 postlarva tl 32 ( MNHN). — Between Society Islands and Marquesas, RV Alis, pelagic trawl, 1997, A. Danigo coll., 4 postlarvae tl 30-33, 1 postlarva tl 32, 1 late pelagic larva tl> 34 (rostral spine broken), 2 late pelagic larvae tl> 34 (rostral spine broken) ( MNHN).

MEASUREMENTS. — Male (n = 5) tl 36-64, female (n = 2) tl 35-37, male postlarva (n = 10) tl 30-32, female postlarva (n = 4) tl 32, male late pelagic larva (n = 1) tl 34+, female late pelagic larva (n = 3) tl 32- 34+.

DISTRIBUTION. — Known only from the Comoro Islands and now the Marquesas. The remarkably discontinuous distribution likely reflects inadequate sampling effort in intermediate localities.

REMARKS

Neoanchisquilla tuberculata was previously known only from the holotype. The present series of N. tuberculata is significant for including specimens of late pelagic larvae through to adults, unknown or only partially known for most stomatopod species. Selected meristic and morphometric measurements are summarised in Table 1. The last pelagic larva ( Fig. 8A, B ) is relatively large, exceeding tl 34, and bears well developed raptorial claws, fully articulated uropodal exopod segments, fixed submedian teeth on the telson, some abdominal spines and the carapace is obtusely angled along the midline producing a V-shaped cross-section. Postlarvae ( Fig. 8 C-E) apparently settle at tl 30-32 and lack anterolateral spines on the carapace, bear the median crest on the carapace and a distinct rostral carina, seven teeth on dactylus of the raptorial claw, an undeveloped lateral process on TS5, fewer armed lateral abdominal carinae than adults, movable submedian telson teeth, additional spinules on the margins of the submedian telson denticles, no prelateral lobe or dorsal or ventral telson ornamentation except for the dorsal median carina. Both late pelagic larvae and postlarvae (excepting one postlarva) are pigmented only on maxillipeds 3-5 whereas all stages beyond postlarva have “adult” coloration. These differences in coloration are unlikely to be an artefact of preservation because pigmented juveniles and unpigmented postlarvae were often taken in the same sample.

A notable feature of postlarval N. tuberculata is that the cornea is already distinctly bilobed, unlike its congeners, N. australiensis Ahyong, 1998 , and N. semblatae Moosa, 1991 . In juvenile N. tuberculata ( Fig.8 F-H), a distinct rostral carina is present, the TS5 lateral process is present as a ventrolaterally directed spine, the lateral processes of TS6-7 are subtruncate to sinuous as in adults, the prelateral lobe of the telson is distinct and the dorsal ornamentation of the telson is evident: the accessory median carina is tuberculate and the dorsolateral carinae are irregular, becoming tuberculate; ventrally, only the post-anal carina is present. The relative length of the telson and the proximal segment of the uropodal exopod decreases with size – they are longest in late pelagic larvae and post larvae, shortest in adults.

The two largest specimens bear well-developed penes and petasmata, and agree well with the holotype including preserved colour pattern. Apparently, the tuberculate dorsal and ventral ornamentation of the telson is not fully expressed until relatively late in development because only in these two largest specimens are the ventral tubercles on the telson developed. The present adults are both smaller than the holotype and differ in bearing a faint trace of the rostral carina (in the smaller), armed lateral carinae on AS 1, and the telson and proximal segment of the uropodal exopod are proportionately longer. These differences are likely to be size related.

Juvenile N. tuberculata do not bear fully tuberculate dorsolateral carinae on the telson, but the tuberculate accessory median carina on the telson and rostral carina will prevent confusion of N. tuberculata with N. australiensis or N. semblatae , both of which lack a rostral carina, bear entire dorsolateral carinae and lack the accessory median carina on the telson. Moreover, the dorsolateral carinae of the telson in both N. australiensis and N. semblatae are sharp and distinct, whereas in juvenile N. tuberculata , they are low and blunt.

The large size of the late pelagic and post-larva is unusual in the genus, for both other species mature at a considerably smaller size than postlarval N. tuberculata . As with Reaka & Manning (1987b), it is tempting to speculate that the large larval and postlarval size (and presumably long pelagic larval cycle) indicates strong dispersal ability, explaining the wide distribution of N. tuberculata .

Figures

FIG. 8. — Neoanchisquilla tuberculata Ahyong, 1998; A, B, late pelagic larva tl 32 mm (stn CP1195); A, dorsal; B, carapace, right lateral; C-F, postlarva tl 31 mm (between Society Islands and Marquesas); C, anterior cephalon, dorsal; D, TS5-8, right dorsal; E, AS5-6, telson and uropod, dorsal; F, submedian telson teeth; G-I, juvenile tl 35 mm (stn DW1210); G, anterior cephalon, dorsal; H, TS5-8, right dorsal; I, AS5-6, telson and uropod, dorsal. Scale bar: A-E, 4 mm; F-I, 2 mm.