Reinstatement and redescription of the monocle bream Scolopsis regina Whitley 1937 (Perciformes: Nemipteridae)

The validity of Scolopsis regina Whitley 1937, described from a single specimen from Australia and long treated as a junior synonym of Scolopsis monogramma (Cuvier in Cuvier and Valenciennes 1830), is confirmed in this study. The two species share the following features: 45–48 lateral-line scales; 9–11 total gill rakers on first gill arch; no anteriorly projecting suborbital spine; scaled dorsal area of head reaching anteriorly to between anterior margin of eye and posterior nostril; bony ridge of opercle and lower limb of preopercle scaled; scaled lateral area of head extending to just behind eye; and two longitudinal blue bands connecting anterior margins of eyes when fresh. However, S. regina is distinguished from S. monogramma by having 18–20 (modally 19) scale rows below the lateral line [vs. 17–20 (18) in S. monogramma], 6 or 7 (7) preopercular scale rows below eye [5 or 6 (6)], two distinct brown bands across dorsum of snout after preservation (lower band indistinct), a distinct suborbital blue band from lower margin of eye to upper-jaw lip when fresh (blue band indistinct or absent) and the blue band becoming a distinct brown band after preservation (band disappearing), caudal-fin base dark blue when fresh (yellow), a blue longitudinal band on upper caudal-fin lobe (absent), relatively long upper and lower caudal-fin lobes (relatively short), and a relatively wide marginal blue band posteriorly on caudal fin (relatively narrow). Scolopsis regina is distributed off northern Australia, whereas S. monogramma occurs in East and Southeast Asian waters.