Narrow interorbital distance (29-65 thousandths of SL), usually less than the diameter of the orbit (60-104 thousandths of SL), versus usually equal to or wider than the orbit diameter in other Opsanus species. Similar to O. phobetron, both usually have the posterior part of lower half of the mouth darkly pigmented in specimens over 7 cm SL. Upper lateral-line papillae 26, lower 23. Pectoral fin glands 12, starting between uppermost 2 pectoral fin-rays (Ref. 41041).