Rough-Toothed Dolphins (Steno bredanensis) as Predators of Mahimahi (Coryphaena hippurus)

We present details of four separate observations of rough-toothed dolphins (Steno bredanensis) apparently preying on adult-sized (>= 1m) mahimahi (Coryphaena hippurus) in the eastern Pacific. We cite similar sightings from Hawai'i and some additional behavioral observations (synchronized swimming, food sharing, regular association with flotsam), and suggest that rough-toothed dolphins may be specialized predators on large mahimahi.