Hippos, large semi-aquatic mammals in Africa, possess a complex set of teeth. While often associated with their massive tusks, they have a full array of dentition. Their teeth serve various purposes, from processing their herbivorous diet to defense and social interactions.
The Basics of Hippo Teeth
Adult common hippos typically have between 36 and 42 teeth, including incisors, canines, premolars, and molars. Their most striking teeth are the canines and incisors, which are often referred to as tusks. These large teeth grow continuously throughout a hippo’s life. The lower incisors protrude forward, while the curved lower canines are the longest and most tusk-like, reaching up to 50 cm in length. Upper incisors can grow up to 40 cm long.
Hippo teeth, like those of most mammals, are composed of dentin with an outer layer of enamel. While their canines form tusks, the molars and premolars, located further back in the mouth, are flat and ridged. These “cheek teeth” are used for grinding food.
Functions of Hippo Teeth
A hippo’s teeth perform various functions related to feeding, defense, and intraspecific combat. Despite their intimidating dental structure, hippos are primarily herbivores, consuming large quantities of grass. Their molars are essential for grinding plant matter, as hippos pull vegetation with their lips before moving it to their flat-ridged molars for chewing. However, their large incisors and tusks can hinder efficient side-to-side chewing, limiting them to an up-and-down mashing motion.
The prominent canines and incisors are not primarily used for eating but serve as weapons. Hippos use these sharp teeth for defense against predators like lions and crocodiles. They are also used in fights with other hippos, particularly males battling for territory or mating rights. These aggressive displays, which include wide jaw openings, can result in serious injuries among competing hippos.
Dental Development and Lifespan
A hippo’s incisors and canines, including the tusks, grow continuously throughout its entire lifespan. This continuous growth means these teeth are constantly being sharpened as they slide past each other when the hippo opens and closes its mouth. While the tusks grow indefinitely, the premolars and molars do not.
The constant use of their molars for grinding vegetation leads to wear and tear over time. Although protected by enamel, these teeth can become significantly worn, which can hinder a hippo’s ability to properly chew and process food. Severe wear on molars can compromise a hippo’s feeding efficiency and may contribute to starvation in older individuals.