Areosquilla indica ( Hansen, 1926 )

Ahyong, Shane T. & Wassenberg, Theodore J., 2015, The rare mantis shrimp Areosquilla indica (Hansen, 1976) (Crustacea, Stomatopoda) from the Great Barrier Reef: first Australian records of the genus and species, Zootaxa 4000 (4), pp. 492-496 : 494-495

Areosquilla indica ( Hansen, 1926)

( Fig. 1 )

Squilla indica Hansen, 1926: 12 –14, pl. 1: fig. 4a–c [part, holotype only; type locality: Lohio Bay, Buton Strait, Indonesia].— Chopra 1934: 35 –38, fig. 5; 1939: 150–151.

Oratosquilla indica .— Manning 1968: 135; 1971: 3.— Moosa 1974: 16.— Nguyen & Pham 1995: 137. Areosquilla indica .— Manning 1976: 5 –6, fig. 2.— Moosa 1991: 194; 2000: 436, tab. 1.— Ahyong & Moosa 2004: 92.

Material examined. QM W43298, 1 male (damaged, TL ~ 40 mm; CL 8.5 mm), 13°32.7'S, 144°04.5'E, 21 m, SBD2009267, site 2790, RV Lady Basten, 18 January 2005; QM W43306, 1 female (TL 35 mm), 13°35.7'S, 144°02.7'E, 47 m, epibenthic sled, SBD2009242, site 1743, RV Lady Basten, 18 January 2005;

QM W43297, 1 female (TL 35 mm), 15°27.9'S, 145°32.1'E, 32 m, trawl, SBD2008344, site 2572, RV Gwendoline May, 17 October 2004; QM W43299, 1 female (TL 34 mm), 16°45.9'S, 146°04.5'E. 40 m, trawl, SBD2018178, site 1960, 11 October 2004; QM W43599, 1 female (TL 34 mm), 16°54.9'S, 146°08.1'E, 40 m, SBD2002458, site 878, RV Lady Basten, 30 September 2003; QM W44373, 1 female (TL 41 mm), 16°45.9'S 146°04.5'E, 40 m, prawn trawl, SBD2006777, site 1960, 11 October 2004; QM W27950, 1 male (TL 38 mm), 1 female (TL 37 mm), E of Wardle Reef, SE of Cairns, Queensland, Australia, 17°26'S, 146°42'E, 41 m, dredge, site 806, 20 September 2003; QM W43303, 1 female (TL 38 mm), 17°30.3'S 146°29.1'E, 36 m, dredge, site 2663, RV Lady Basten, 29 April 2004.

Description of Australian material. Dorsal surface finely rugose. Eye extending beyond midlength of antennular peduncle segment 1; cornea bilobed, distinctly broader than, and set obliquely on stalk; CI 368–389. Ocular scales truncate, separate.

Antennular somite dorsal processes with blunt apices (in lateral view). Antennular peduncle 1.25–1.33CL. Antennal scale slender; 0.48–0.52CL.

Rostral plate elongate, triangular, median carina absent, apex rounded. Carapace anterior width 0.37–0.42CL; anterolateral spine not reaching anteriorly to level of base of rostral plate; intermediate, lateral, marginal and reflected marginal carinae distinct; median carina without anterior bifurcation; posterior margin with low, obtuse median prominence.

Raptorial claw dactylus with 7 teeth; outer margin broadly curved, with shallow basal concavity; carpus dorsal carina undivided; merus outer inferodistal angle unarmed, rounded.

Mandibular palp absent. Maxillipeds 1–2 with epipod. Maxilliped 5 basal segment with small ventrally directed tooth.

Pereopod 1–3 basal segment unarmed; endopod segments fused, distal segment slender.

Thoracic somites 6–8 submedian and intermediate carinae distinct.

Thoracic somite 5 lateral process bilobed; anterior lobe a slender spine directed anterolaterally; posterior lobe on higher plane, short, directed laterally. Thoracic somites 6–7 lateral processes strongly bilobed; somite 6 lateral process lobes with rounded apices, anterior lobe narrower than posterior; somite 7 anterior lobe triangular, posterior lobe rounded, wider than anterior lobe. Thoracic somite 8 lateral process apex angular.

Abdominal somites 1–5 with distinct submedian, intermediate, lateral and marginal carinae; submedian carinae parallel; carinae spined as follows: submedian (5)6, intermediate (4)5–6, lateral (4)5–6, marginal (3–4)5. Abdominal somite 6 sternum posterior margin unarmed.

Male pleopod 1 endopod hook process with blunt apex, shorter than tube process; posterior 'endite' present.

Telson flattened, about as long as wide; submedian, intermediate and lateral teeth each with dorsal carina; submedian teeth with fixed apices; prelateral lobe longer than margin of lateral tooth; denticles submedian 5–7, intermediate 7–11, lateral; outer intermediate denticle distinctly larger than adjacent denticles; median carina interrupted proximally, posterior spine prominent; dorsolateral surface smooth or with rows of shallow pits, without supplementary longitudinal carinae; ventrolateral carina extending posteriorly almost to base of lateral denticle; postanal carina absent.

Uropodal protopod terminal spines, slender, dorsally and ventrally carinate, inner longer; lobe on outer margin of inner spine rounded, as wide as or wider than adjacent spine; protopod inner margin crenulate, with small point anterior to endopod articulation. Uropodal exopod proximal segment outer distal margin with 7–9 graded movable spines, distalmost spine not reaching midlength of distal exopod segment; distoventral margin with 2 spines, outer longer; exopod distal segment ovate, elongate, shorter than proximal segment.

Remarks. Prior to this study only seven specimens of A. indica were known: the male holotype from Indonesia ( Hansen 1926; Moosa 1974), one female from the Nicobar Islands ( Chopra 1934), a male and female from the Maldives ( Chopra 1939), one female from New Caledonia ( Moosa 1991), one female from Nhatrang Bay, Vietnam ( Nguyen & Pham 1995) and one male from the Natunas, Indonesia ( Ahyong & Moosa 2004). The present series from Australia thus includes more specimens of A. indica than the total previously recorded. They conform well in most respects to published accounts but also exhibit wider morphological variation than previously reported. The lobe between the primary spines of the uropodal protopod becomes proportionally narrower with increasing body size: wider than the adjacent spine in specimens up to 34–35 mm, and usually as wide as the adjacent spine in larger specimens. The corneal indices range from 368 to 389 (370–397; Manning 1976). Abdominal spination encompasses the reported range ( Manning 1976; Moosa 1991), but with greater variation. Thus, the spination of the submedian carinae of abdominal somite 5 is variable, being present, absent or present only on one side, as is the spination of the marginal carinae of somites 3 and 4. All males examined are mature, having well-developed penes and a fully modified pleopod 1 endopod.

Areosquilla indica is unique in the genus for having seven teeth on the dactylus of the raptorial claw; A. interstincta has six teeth and A. hanseni eight ( Manning 1976). The only other species among the genera of the Oratosquilla -group with seven teeth on the dactylus of the raptorial claw is Erugosquilla septemdentata ( Ahyong, 1994) from Indonesia; E. septemdentata , however, is readily separated from A. indica by genus characters such as the presence of a mandibular palp and epipods on maxillipeds 3 and 4.

The discovery of Areosquilla indica in Great Barrier Reef waters raises the Australian stomatopod fauna to 152 species and 68 genera ( Ahyong 2001, 2008, 2009, 2012 b, 2013, 2014).

Habitat. Sandy-mud; 21–47 m in Australia; previously reported range 22–46 m ( Moosa 1991).

Distribution. Maldives and Nicobar Islands, Indonesia, Vietnam, New Caledonia and now the Great Barrier Reef, Australia.

Figures

FIGURE 1. Areosquilla indica (Hansen, 1926), male, TL 38 mm (QM W 27950). A, anterior cephalothorax; B, right eye; C, right dorsal process of antennular process, lateral view; D, left raptorial claw; E, right thoracic somites 5 – 8, dorsal view; F, right thoracic somite 5, lateral view; G, thoracic somite 8 sternal keel, right lateral view; H, posterior abdominal somites, telson and right uropod; I, right uropod, ventral view; J, right pleopod 1 endopod, anterior view. Scale A – F, H, I = 2.0 mm; G, J = 1.0 mm.