Here's why they can hold their breath for so long:
* Large blood volume: They have a significantly larger blood volume than other mammals, allowing them to store more oxygen.
* Efficient oxygen use: Sperm whales have a unique ability to slow their heart rate and metabolism while diving, conserving oxygen.
* Myoglobin: They have a high concentration of myoglobin in their muscles, which stores oxygen.
* Special adaptations: They have a special organ called the "spermaceti organ" that helps them regulate buoyancy and may also be involved in diving.
While other whale species like the Cuvier's beaked whale can also stay underwater for long periods (around 90 minutes as well), their average dive times are significantly shorter.