How can a hippo hold its breath for so long?

Hippopotamuses can hold their breath underwater for up to five minutes due to their ability to slow their heart rate and reduce oxygen consumption. They have specialized adaptations, including a high tolerance for carbon dioxide and the ability to close their ears and nostrils while submerged. Additionally, their bodies are equipped with a unique respiratory system that allows them to breathe efficiently when they surface. This combination of physiological traits enables them to thrive in aquatic environments.