Mahi-mahi, Coryphaena hippurus (old male). From plate 60 of Oceanic Ichthyology by George Brown Goode and Tarleton H. Bean, published 1896.

Source: https://commons.wikimedia.org/wiki/File:Coryphaena_hippurus_(adult_male).jpg

The mahi-mahi or common dolphinfish (Coryphaena hippurus) is a surface-dwelling ray-finned fish found in off-shore temperate, tropical and subtropical waters worldwide. Also widely called dorado and dolphin, it is a member of the Coryphaenidae family. Mahi means very strong in Hawaiian. The name mahimahi means very strong in Hawaiian.