Figure 6
From: Comparative histology of muscle in free ranging cetaceans: shallow versus deep diving species

Mean fiber cross sectional area (CSA) (μm2) of Type I fibers in the shallow-diving group (D. delphis, S. coeruleoalba, S. frontalis) and deep-diving group (K. breviceps, M. europaeus, Z. cavirostris).
Right inset: Global mean fiber CSA of Type I fibers were larger for the deep-diving group of animals.