Elthusa sigani Bruce, 1990

(Fig. 8 A, B)

Elthusa sigani Bruce, 1990: 270–276, figs. 16–18.— Van der Wal, Smit & Hadfield, 2019: 1–37.

Type material. Female holotype, Queensland Museum (QM W13080). For paratype details see Bruce (1990).

Type locality. Australia, south-eastern Queensland, North Stradbroke Island, Moreton Bay (Bruce 1990) .

Type host. Siganus spinus (Linnaeus, 1758) (see Bruce 1990).

Material examined. 1 matured ♁ (8.34 mm TL, 5.16 mm W), Leg 4, ST 110, EEZ, 04°39.03’N; 104°53.43’E, 14 June 2016, from Russell's lionfish ( Pterois russelli), coll. Muhammad ‘ Arif bin Samshuri, SEAFDEC crew (UMT Crus 01191) .

Host. Reported from the families Siganidae: Siganus spinus (Linnaeus, 1758) (Bruce 1990) and Scorpaenidae: Pterois russelii Bennett, 1831 (present material).

Distribution. Australia, Moreton Bay, (Bruce 1990); Peninsular Malaysia, South China Sea (present material).

Remarks. Elthusa sigani is reported from Malaysian waters for the first time and being characterised by even body; rostrum broad; antennula and antenna subequal in length; antennulae separate; coxae visible dorsally (particularly coxae 5–7); uropods rounded, not exceeding pleotelson posterior margin; wide pleon. E. sigani has similar coxal and pleon morphology (see Bruce 1990) with E. raunaudii (Milne-Edwards, 1840) but can be differentiated by the difference in body size (> 20 mm vs. ≤ 13 mm); pereopods 5–7 morphology (proximal carina with a boss vs. smooth carina); body surface (harder exterior vs. softer exterior). Our specimen mostly agrees with the illustrations given by Bruce (1990), but it is not as twisted as Bruce’s (1990) female specimen.