Abstract
The article discusses the problem of identifying a Mediterranean fish called γλαῦκος in Ancient Greek and glaucus in Latin. It was a big and well-known fish living in the Mediterranean Sea. It appears in numerous literary sources of the classical (Greek and Roman) world. After analyzing all preserved attestations of the Greco-Latin ichthyonym, the authors of the present article suggest that this fish should be identified with the Mediterranean spearfish (Tetrapturus belone Rafinesque, 1810). It is possible that the fish name γλαῦκος/glaucus referred to the roundscale spearfish (Tetrapturus georgii R.T. Lowe, 1841) and also to the Atlantic white marlin (Kajikia albida Poey, 1860, syn. Tetrapturus albidus Poey, 1860).