Slowest heartbeat in a mammal
- Who
- Blue whale, Balaenoptera musculus
- What
- 4–8 total number
- Where
- Antarctica
- When
- Not applicable
The mammal that is presumed to have the slowest heartbeat of any warm-blooded animal is the blue whale (Balaenoptera musculus), with four to eight beats per minute. This is dependent upon whether the whale is diving or not. The rate may drop to two beats per minute, or rise to a high of 37 beats per minute.
By comparison the average adult human heart beats at 70 beats per minute. Blue whales also have the largest heart of any animal on the planet and their heartbeat can be heard up to 32 km (19 miles) away underwater.