High-speed swimming. Enhanced power in yellowfin tuna.

Abstract

Tuna are distinctive among bony fish for their elite swimming ability and their muscle anatomy, having loins of red, aerobic fibres deep within the body where other fish have only white, anaerobic fibres1,2. Here we record the performance of the red muscle of yellowfin tuna in vitro and in vivo to show how this specialized muscle architecture can double the cruising power of these fish, revealing a functional link between this biomechanical design and high-speed swimming.