Adults bluish grey to olivaceous brown in color, commonly pale anteriorly and on cheek and throat; short irregular lines on sides of body; diagonal lines on horn; lip edges blue (Ref. 3145). Subadults with dark spots on head and body (Ref. 3145). Juveniles lack the prominent horn of adults (Ref. 1602).

Description: Characterized further by having whitish caudal fin; sometimes with broad pale zone on anterior body; pair of bony plates on caudal peduncle developing knife-like keels in adults; greatest depth of body 2.3 (subadults)-2.7 in SL (Ref. 90102).