Aqaballianassa lewtonae (Ngoc-Ho, 1994)

Poore, Gary C. B., 2023, New records, one new genus and 21 new species of Callianassidae (Crustacea, Axiidea) from the Indo-West Pacific, Memoirs of Museum Victoria 82, pp. 167-255 : 170-173

Aqaballianassa lewtonae ( Ngoc-Ho, 1994)

Figures 3 , 4

Callianassa lewtonae Ngoc-Ho, 1994: 52–54, fig. 1.— Sakai,

1999: 47.— Sakai, 2005: 90. Biffarius lewtonae .— Tudge et al., 2000: 143.—Davie, 2002: 457. Trypaea lewtonae .— Sakai, 2011: 402. Aqaballianassa lewtonae .— Poore et al., 2019: 91, 136, 142.—

Robles et al., 2020: figs 1, 3, 6.

Material examined. Australia. Qld, Britomart Reef, 18° 7' S, 146° 38' E, reef front, 15 m, NMV J22659 (holotype ovigerous female, 5.0 mm). Pandora Reef, 18° 49' S, 146° 26' E, reef flat, 1 m, NMV J22684 (paratype female, 4.0 mm). Qld, NE of Townsville, 18° 43' S, 146° 45' E, 34 m, MNHN Th-1247 (paratype, ovigerous female, 5 mm). Lizard I., Casuarina Beach, UF 17514 (ovigerous female, 4.7 mm), UF 17583 (male, 3.1 mm). NT, Arafura Sea: 9° 47.947' S, 135° 22.024' E, 92 m, calcareous mud (CSIRO stn SS05/2005/002/BS002), AM P.74527 (female, 2.9 mm with Sacculina plus male and female Bopyridae ; female 3.5 mm); 9° 47.593' S, 135° 16.636 E, 85 m, muddy sand (CSIRO stn SS05/2005/012/GR019), AM P.74476B (3 females, 3.0 mm); 9° 22.547' S, 134° 3.585' E, 121 m, calcareous mud (CSIRO stn SS05/2005/022/GR038), AM P.74498 (female, 1.8 mm); 9° 52.788' S, 135° 21.891' E, 69 m, sandy mud (CSIRO stn SS05/2005/003/ GR005), AM P.74499 (5 specimens, 2.1–3.1 mm); 9° 52.788' S, 135° 21.891'E, 69 m, sandy mud (CSIRO stn SS05/2005/003/GR005), AM P.74505 (female, 3.2 mm); 9° 50.035' S, 135° 17.74' E, 83 m, (CSIRO stn SS05/2005/007/BS003), AM P.74513 (1 male, 2 females, 2.8–3.0 mm); 9° 47.986' S, 135° 22.997' E, 91 m, calcareous mud (CSIRO stn SS05/2005/002/GR003), AM P.74514 (3 females, 2.5– 3.3 mm); 9° 48.774' S, 135° 15.412' E, 82 m, sandy mud (CSIRO stn SS05/2005/010/GR017), AM P.74523 (female, 2.9 mm); 9° 50.126' S, 135° 17.766' E, 83 m, muddy fine sand (CSIRO stn SS05/2005/007/ GR011), AM P.74525 (female, 3.2 mm); 9° 44.316' S, 135° 15.947' E, 102 m, calcareous mud (CSIRO stn SS05/2005/064/GR084), AM P.74528 (female, 3.8 mm); 9° 47.94'S, 135° 22.024' E, 92 m, calcareous mud (CSIRO stn SS05/2005/002/BS002), AM P.74539 (female, 3.8 mm); 9° 49.294' S, 135° 19.599' E, 83 m, calcareous mud (CSIRO stn SS05/2005/009/GR015), AM P.74541 (1); 9°52.788' S, 135°21.891' E, 69 m, sandy mud (CSIRO stn SS05/2005/003/GR005), AM P.74478 (juvenile, 3.6 mm); 9° 47.986' S, 135° 22.007' E, 91 m, calcareous mud (CSIRO stn SS05/2005/002/GR002), AM P.74449 (1). Papua New Guinea. Madang Province, W of Tab I., 05° 10.2' S, 145° 50.4' E, 1–3 m (PAPUA NIUGINI stn PR243), MNHN IU-2013- 7080* (female, 5.6 mm), MNHN IU-2013-7090 (female, 3.4 mm), MNHN IU-2013-7112 (female, 3.9 mm). New Britain, Kavieng Lagoon, Nago I. wharf, sand, 02° 36.3' S, 150° 46.2' E, 3–12 m (KAVIENG 2014 stn KR06), MNHN IU-2013-8835* (male, 3.7 mm). Kavieng Lagoon, in front of market, silty rocks with algae, 02° 34.7'S, 150° 47.5' E, 1–2 m (KAVIENG 2014 stn KZ16), MNHN IU-2014- 2779* (male, 2.6 mm), MNHN IU-2014-2780 (female, 3.0 mm). New Ireland, E of North Cape, dead reef on top, sand and coral bommies, 02° 33.2' S, 150° 48.4' E, 5–20 m (KAVIENG 2014 stn KZ10), MNHN IU-2014-10001 (6 specimens, 1 with isopod Bopyridae ), MNHN IU-2016-8152*# (male, 5.9 mm), MNHN IU-2016-8153*# (ovigerous female, 3.9 mm), MNHN IU-2016-8155* (ovigerous female, 4.2 mm).

Diagnosis. Major cheliped merus 1.5 times as long as wide, lower margin with distally directed proximal tooth; propodus palm 1.3 times as long as carpus, as long as wide, with oblique gape (wider than base of each finger) bearing short flange-like tooth; fixed finger as long as palm; dactylus longer than fixed finger. Uropod endopod oval, 1.3 times as long as greatest width; upper face with 1 or 2 subproximal and 2 subdistal short spiniform setae; anterior margin curved distally; curved anterodistal margin with 3–6 short spiniform setae; exopod wider or as wide as length of anterior margin. Telson as long as wide, tapering to about 0.7 greatest width; posterolateral margins with 5–10 short spiniform setae.

Supplementary description. Branchiostegal sclerite incompletely separated from branchiostegite proper. Rostrum variable, blunt in smallest individuals, one third as long as eyestalk, to tapered, more than half or almost as long as eyestalk in largest individuals. Eyestalk with obscure or prominent distomedial lobe beyond cornea. Antennal peduncle as long as antennular peduncle; scaphocerite slightly longer than wide, with rounded apex. Mandibular molar calcified, chalky-white, with swollen projection lacking sharp edge; incisor with few teeth. Male minor cheliped three-quarters length of major cheliped; ischium, merus lower margins unarmed; propodus palm 0.7 times as long as carpus, as long as wide, with gape (narrower than base of each finger), fixed finger as long as palm, with irregular teeth on cutting edge; dactylus as long as fixed finger. Female major cheliped ischium lower margin with 5 teeth; merus twice as long as wide, lower margin with distally directed spine; propodus palm 1.25 times as long as carpus, 1.1 times as long as wide, with oblique gape (narrower than base of each finger) bearing mesial tubercle, fixed finger half as long as palm; dactylus stout, overreaching fixed finger.

Male pleopod 1 uniarticulate, curved, tapering over distal third, with few subdistal setae. Male pleopod 2 rami elongate, uniarticulate; exopod 12 times as long as width at base, longer than endopod.

Distribution. Sahul Shelf, Eastern Coral Triangle, Northeastern Australian Shelf ( Australia, NT, Qld, northern Great Barrier Reef [type locality: Britomart Reef]; Papua New Guinea); 1– 20 m.

Remarks. Ngoc-Ho’s (1994) figures only vaguely indicated the branchiostegal sclerite that characterises the genus; the three type specimens listed are all females. Here, the male and female chelipeds, setation of the uropod and telson, and male pleopods are illustrated for the first time. The holotype is an ovigerous female (5.0 mm) whose major cheliped is more elongate and lacks a meral tooth. Aqaballianassa lewtonae is distinguished from other species of the genus by the telson, as long as wide and clearly tapering. The length of the rostrum varies in length from obtusely triangular to well exceeding the eyestalks. While the uropodal exopod is consistently squarish, as is the case for most species, the endopod varies in width.

Aqaballianassa amplimaxilla ( Sakai, 2002) and A. nieli ( Sakai, 2002) , both based on numerous damaged individuals from the Andaman Sea and incompletely described, are possible synonyms of A. lewtonae .

Sakai (2011) placed the species in Trypaea without explanation. Aqaballianassa lewtonae and A. papua sp. nov. occurred at the same station (KR06) in the Kavieng Lagoon.

Figures

Figure 3. Aqaballianassa lewtonae (Ngoc-Ho, 1994). a–c, Australia, Qld, NMV J22659, holotype, ovigerous female, 5.0 mm; d, Australia, Qld, NMV J22684, paratype, female, 4.4 mm. e–i, Papua New Guinea, Madang, MNHN IU-2016-8152, male, 5.9 mm; j–m, Papua New Guinea, Madang, MNHN IU-2016-8155, ovigerous female, 4.2 mm; n, o, Australia, Qld, UF 17583, male, 3.1 mm. a, b, d, e, k, anterior carapace, eyestalk, antennular, antennal peduncles; c, e, f, telson, uropod (short robust setae and facial setae only shown, marginal setae not shown); g, male major cheliped (left, mesial); h, male minor cheliped (right, mesial); i, j, male pleopods 1, 2; l, m, mandible (mesial, posterior views); n, female major cheliped (right, mesial); o, left uropodal endopod. Scale bars = 1 mm.

Figure 4. Aqaballianassa lewtonae (Ngoc-Ho, 1994). Australia, NT, Arafura Sea. AM P.74541, ovigerous female, 2.7 mm: a, b, carapace, antennular, antennal peduncles (lateral, dorsal views); c, telson, uropod (marginal setae not shown); d, maxilliped 3; e, major (left, mesial) cheliped; f, minor (right, mesial) cheliped; g–i, pereopods 2, 3, 5. AM P.745539, ovigerous female, 3.7 mm: j, major cheliped (right, mesial). Scale bars = 1 mm.