Lewis & Short

ămĭa, ae, f., and ămĭas, ae, m., = ἀμία, the tunny, a sea-fish: (piscem) amiam vocant cujus etc., Plin. 9, 15, 19, § 49.
The form amias: acc. amian, Lucil. ap. Varr. L. L. 7, § 47 Müll.; cf. Paul. ex Fest. p. 21 ib.