Neaxius glyptocercus (von Martens, 1869)

(Figs. 25, 26)

Selected synonymy (for full synonymy see Sakai 2011):

Axius glyptocercus von Martens 1869: 613.

Axius (Neaxius) glyptocercus .— De Man 1925: 50, fig. 1; Poore & Griffin 1979: 236, fig. 8. Axia acantha A. Milne-Edwards 1878: 110 .

Eiconaxius acanthus .— De Man 1898: 700, pl. 34 fig. 57–57a.

Axius (Neaxius) acanthus .— Borradaile 1903: 537; Poore & Griffin 1979: 235, fig. 7; Tirmizi 1983: 85, figs. 1, 2. Eiconaxius taliliensis Borradaile 1900: 420, fig. 15a–c.

Axius acanthus var. mauritianus Bouvier 1915: 196, fig. 7; Fourmanoir 1955: 31, fig. 4. Axius (Neaxius) acanthus var. mauritiana .— De Man 1925: 50.

Neaxius glyptocercus .— Sakai & Saint Laurent 1989: 30; Sakai 2011: 326, figs. 61, 62. Neaxius acanthus .— Sakai & Saint Laurent 1989: 30; Mukai & Sakai 1992: 47, figs. 1–3; Kensley et al. 2000: 212, figs. 5, 7F. Neaxius trondlei Ngoc-Ho 2005: 59, figs. 6, 7.

Material examined. Indonesia. 1 male (ZRC 2014.0742), western Lombok, Sira, seagrass flat with some muddy areas, burrow, suction pump and digging/sieving, 0.2–0.5 m, leg. D.L. Rahayu et al., 13 May 2014 [LB-St4-17]; 1 male (MZB Cru 4059), same collection data [LBSt4-01]; 1 male (RMNH. CRUS.D.56756), same collection data [LB-St4-38]; 1 male, 1 female (MZB Cru 4060), southern Lombok, Teluk Sekotong, seagrass flat, burrow, suction pump and digging/sieving, 0.2–0.5 m, leg. D.L. Rahayu et al., 14 May 2014 [male: LB-St6-02, female: LB-St6- 26].

Description. See von Martens (1869), De Man (1898, as Eiconaxius acanthus (A. Milne-Edwards, 1878)), Borradaile (1900, as Eiconaxius taliliensis Borradaile, 1900), Bouvier (1915, as Axius acanthus var. mauritiana Bouvier, 1915), De Man (1925), Poore & Griffin (1979), Mukai & Sakai (1992, as Neaxius acanthus), Ngoc-Ho (2005, as Neaxius trondlei Ngoc-Ho, 2005), and Sakai (2011).

Habitat. Seagrass flats in the lower intertidal and shallow subtidal, usually with abundant rubble / gravel component; in deep burrows with smooth walls (lined with mucus) and vertical, perfectly rounded entrance hole.

Distribution. Indo-West Pacific: from Madagascar to Japan, Indonesia, Australia, New Caledonia and French Polynesia (Sakai 2011 and references therein; but see below).

Remarks. We tentatively follow Sakai’s (2011) concept of a single morphologically variable species, Neaxius glyptocercus, with N. acanthus, N. taliliensis, N. acanthus var. mauritianus, and N. trondlei all being junior synonyms of N. glyptocercus . However, following the key in Poore & Griffin (1979) and Ngoc-Ho (2006: tab. 2), all specimens from Lombok correspond to N. acanthus, e.g., in the presence of spines along the cervical groove, on the second antennal article, and on the ventral margin of the second pereiopod merus (all supposed to be unarmed in N. glyptocercus). The male specimens from Lombok also match very well the male specimen from Ceram illustrated by Tirmizi (1983: figs. 1, 2). Therefore, we feel that a molecular analysis of N. glyptocercus (s. l.), including as many specimens as possible from various Indo-West Pacific localities, is needed to confirm Sakai’s (2011) synonimisations.