Manatees are large, gentle marine mammals. These aquatic creatures are herbivores, meaning their diet consists exclusively of plant material. Their feeding habits play a role in maintaining the balance of aquatic ecosystems where they reside.
Mainstay of Their Diet
Manatees primarily consume a wide variety of aquatic vegetation found in both freshwater and saltwater environments. In coastal areas, their diet largely includes seagrasses such as turtle grass, manatee grass, and shoal grass, which form extensive underwater meadows. When in freshwater habitats like rivers and springs, they feed on plants like water hyacinths, water lettuce, hydrilla, eelgrass, and coontail. Manatees also consume various types of algae, supplementing their plant-based intake.
To sustain their large body mass, manatees require a substantial amount of food daily. An adult manatee can consume approximately 10 to 15% of its body weight in vegetation each day, which can translate to 100 to 150 pounds of plants for an average-sized individual. This necessitates spending a significant portion of their day, typically between six to eight hours, grazing on available plant matter.
Florida manatees have been observed to feed on over 60 different species of plants, demonstrating their adaptable foraging behavior. This flexibility in their diet allows them to thrive in diverse aquatic landscapes, from coastal waters to inland waterways. The availability and variety of these plant sources are important for their health and energy.
Feeding Habits and Adaptations
Manatees possess unique anatomical features that enable them to efficiently gather and process their plant-based diet. Their prehensile upper lip, split into two independent halves, is a distinctive feeding adaptation. This allows them to grasp and pull plants with precision, similar to an elephant’s trunk.
Their front flippers also assist in feeding, helping to manipulate and guide vegetation towards their mouths. They can use these flippers to scoop up plants or “walk” along the bottom, bringing food within reach. Behind their flexible lips, manatees have horny, ridged pads on the roof of their mouth and lower jaw that help tear and break down fibrous plant material into smaller pieces.
Manatees have a continuous tooth replacement system, known as “marching molars.” Their molars, used for grinding tough plant matter, constantly grow at the back of the jaw and move forward. As front molars wear down from chewing abrasive vegetation, they fall out, and new teeth emerge from behind. This lifelong process ensures they always have functional teeth.
Occasional and Accidental Intake
While manatees are primarily herbivores, their diet can occasionally include small amounts of animal matter, typically ingested unintentionally. As they graze on aquatic plants, tiny invertebrates like snails, crustaceans, or other small organisms living within the vegetation or seabed may be accidentally consumed. These instances are not deliberate hunting or a sought-after food source.
Manatees do not intentionally eat fish, meat, or human-provided food. Their digestive systems are specifically adapted for processing plant material, with a long intestinal tract designed to break down tough cellulose.
Feeding manatees human food is harmful to their health and natural behaviors. Such actions can lead to dependency on humans, alter their foraging patterns, and expose them to foods that are not part of their natural diet and may cause digestive issues. Accidental ingestion of marine debris, such as fishing line or plastic, can cause blockages and internal injuries.