Examinations of two boxfishes, Ostracion immaculatus Temminck and Schlegel, 1850 and O. cubicus Linnaeus, 1758, based on 37 and 12 specimens respectively, revealed that they are distinguished from each other by the depth of anterior portion of body (36.5-42.1% SL in O. immaculatus vs. 30.8-35.3% in O. cubicus). This morphological character is helpful to identify the two species when their color faded away in preserved specimens.
