Hippopotamuses are large, semi-aquatic mammals known for their immense bulk. Their distinctive dental structure is a striking feature. Their unique teeth play several important roles in their lives.
Understanding Hippo Dentition
Hippos possess a distinctive set of teeth, primarily their lower canines and lower incisors. The lower canine teeth, often referred to as tusks, can grow to an impressive length of up to 50 centimeters (about 20 inches) in adult hippos, curving outward from the jaw. In contrast, their lower incisors are shorter, measuring around 25 to 30 centimeters (10 to 12 inches) long.
Male hippos develop larger and more robust canines than females, a difference especially noticeable in mature individuals. This size disparity is linked to the teeth’s primary functions, which often involve male-on-male competition. These substantial teeth are distinct from the flatter molars and premolars located further back in the mouth, which are adapted for grinding plant matter.
Purpose of Their Lengthy Teeth
Despite their formidable appearance, the long canines and incisors of hippos are not primarily used for consuming their plant-based diet. Hippos are grazers, and they use their broad, muscular lips to pluck grasses, which are then ground by their rear molars. Instead, these prominent teeth serve different, important purposes.
The elongated canines and incisors are important tools for defense against predators like lions and crocodiles. These teeth are also important for social interactions and territorial disputes among hippos themselves. Male hippos engage in aggressive encounters to establish dominance and defend their territories, using their tusks as weapons during these confrontations. They display their teeth as a warning, often opening their mouths wide in a threatening yawn to deter rivals.
Continuous Growth and Wear
A key aspect of hippo dentition is the continuous growth of their incisors and canines throughout their lives. Unlike many mammals whose teeth stop growing, hippo tusks and incisors continue to extend. This constant growth necessitates a mechanism to prevent them from becoming overly long and unmanageable.
Hippos have a unique self-sharpening system for these teeth. As the hippo moves its jaw, the upper and lower canines and incisors grind against each other. This abrasive action hones their edges, maintaining sharpness and effectiveness. This continuous wear also helps to control their length, preventing them from growing so long that they impede the hippo’s ability to close its mouth or feed.