Restoring the True Form of the Gigantic Blue Whale for the First Time, and Mass Estimation

Abstract

AbstractUsing photographs of swimming blue whales and mounted skeletons, the body form of the largest known animal is correctly restored, no previous effort having been entirely accurate in part because of the absence of rigorous technical efforts prior to this study. The maximum total length/depth ratio is about 7.5-8.1, with the greatest depth in the chest forward of midlength. There is a subtle ventral concavity between the chest and abdomen. The chest is broader than deep, contradicting mounted skeletons in which the ribs are articulated too vertically so that the chest is falsely deeper than broad. The tip of the mandible is fairly blunt, although the throat pouch is streamlined when cruising, the head is very large. The result is an elongated, tear drop, hydrodynamically optimized shape. A volume based mass estimate based on the restoration is close to that observed in harvested blue whales relative to length, and indicates that the largest individuals reach ~200 tonnes.