Why does a whale's heart beat 9 times per minute?

A whale's heart beats slowly, averaging about 9 times per minute, to efficiently pump blood throughout its massive body while conserving energy. This low heart rate is an adaptation to their size and the need for oxygen during deep dives, where they can hold their breath for extended periods. Additionally, the slower heartbeat allows for a more effective distribution of oxygen to vital organs during these long dives. Overall, this physiological trait reflects the whale's unique adaptations to its aquatic environment and lifestyle.