Maximum length of females over 65 cm; of males about 45 cm. This is a yellowish-brown or greyish fish with a highly compressed body and characteristic thumb -prints on its sides, which have been attributed by most to St Peter but by some to St Christopher. (The touch of whichever saint may have imparted to the species its solitary habits, but not an ascetic attitude, for the John Dory uses its extendable mouth to engulf other fish voraciously.)