Squalogadus modificatus, the tadpole whiptail, also known as the roundhead tadpole grenadier, is a species of rattail found in the Atlantic and Pacific Oceans where it occurs at depths of from 600mto1740mm (2,000feetto5,710feetm). This species grows to a length of 35cm (14inches) TL. It is the only known member of its genus.