Genus Himantura Müller & Henle, 1837

Himantura Müller & Henle, 1837:400 . Type species Raja sephen uarnak Forsskål, 1775; by subsequent designation (Jordan & Evermann 1896:82).

Definition. Large dasyatids (adults to 130–160 cm DW) characterised by the following: robust, suboval to rhombic disc with pectoral-fin apex broadly rounded to narrowly angular; snout broadly angular, moderately elongate (1.7– 2.8 times combined orbit and spiracle length); eye small and protruding; nasal curtain broadly skirt shaped; mouth narrow with 4–5 oral papillae (lateral papillae always present); tail very long, whip-like (length 2.5–3.7 times DW), its base narrow and oval to almost circular in cross section; pelvic fins small, almost entirely concealed by disc; dorsal fold and ventral folds absent; caudal sting close to tail base (distance from pectoral-fin insertion to caudalsting base 1.7–2.3 times interspiracular width); 1–3 mid-scapular thorns or in row on nape, no other scapular thorns; denticle band well developed with diffuse edge, skin on rest of disc with patchy denticles in adults; no row of enlarged median thorns on tail, small thorns and denticles posteriorly in adults; dorsal surface with strong colour pattern (spots, ocelli and/or reticulations); ventral surface white; posterior tail typically banded in young; marine, Indo– West Pacific.

Species. H. leoparda Manjaji-Matsumoto & Last, 2008, H. uarnak (Gmelin, 1789), H. undulata (Bleeker, 1852), and an undescribed species.

Remarks. The genus Himantura, which was once represented widely in the Indo– West Pacific by ~20 species, is now restricted to a group of four large Indo–Pacific species with strong colour patterns. The taxonomy of this group is under review (PL & MM) and a new species exists in Australasian seas.