The blue whale’s heart is the largest of any animal, weighing on the order of hundreds of kilograms and roughly comparable in size to a small car, with powerful beats that can be detected at great distances.
Size and mass
Measured and reported specimens indicate a blue whale heart can measure several feet across and weigh on the order of 100–200 kg, making the organ visually and physically comparable to a small automobile in scale and mass.
Anatomy and function
The heart’s enormous chambers and thick muscular walls pump vast volumes of blood to supply the whale’s massive body; a single stroke moves hundreds of litres and supports oxygen delivery during deep dives and long transits, matching the demands of a creature that can exceed 25 metres in length.
Heartbeat and sound
Because of its size and the low frequency of each contraction, a blue whale’s heartbeat produces powerful, low‑frequency pulses that have been reported to be audible underwater at distances of kilometres and in some popular accounts detectable up to about 3 km under favourable conditions.
Biological significance
The enormous heart is a clear example of how physiological systems scale in very large animals: slower resting heart rates, tremendous stroke volumes and specialised circulatory adaptations allow blue whales to dive deeply, conserve oxygen and sustain their huge metabolisms while feeding on vast amounts of tiny prey such as krill.
Quick related facts
- Weight: up to around 180 kg (reported ranges vary).
- Size: roughly the size of a small car; several feet in each dimension.
- Audibility: heartbeats can be extremely loud and low frequency, heard kilometres away underwater in some reports.