Manatees are large, gentle aquatic mammals, often called “sea cows” for their herbivorous diet and slow, grazing nature. They possess a distinctive appearance, characterized by a streamlined, barrel-shaped body that tapers to a paddle-like tail, and two forelimb flippers. Their skin is thick and finely wrinkled, sometimes appearing green or brown from algae growth.
Manatees: Dedicated Plant Eaters
Manatees are strict herbivores. Their diet fuels their substantial body size, with adults weighing around 1,000 pounds and measuring 9-10 feet long. They consume a wide variety of aquatic vegetation from both freshwater and saltwater environments.
Their diet includes seagrasses like turtle grass, manatee grass, and shoal grass, which are staples in coastal areas. In freshwater habitats, they feed on plants such as water hyacinths, water lettuce, hydrilla, and water celery. Manatees spend a significant portion of their day grazing on these plants. An average adult manatee can consume 4% to 15% of its body weight in aquatic vegetation daily, which translates to 100 to 200 pounds of plants.
How Manatees Forage
Manatees have specialized adaptations and behaviors that enable them to efficiently consume plants. Their most notable feature is a prehensile upper lip, which is split into two sides that can move independently. This muscular lip acts like a “grasping hand” or “salad tongs,” allowing them to tear and pull plants into their mouths. Stiff whiskers, called vibrissae, around their mouth also assist in feeling for food, especially in murky water.
They use their forelimb flippers to help gather vegetation and guide it towards their mouths. Manatees can even use their flippers to “walk” along the bottom or dig for roots in the mud. Behind their lips, instead of front teeth, manatees have horny, ridged pads on the roof of their mouth that work with their lower jaw to break down vegetation. Their molars, which are flat and rough-textured, then grind the food. Their molars are continuously replaced throughout their lives in a process known as “marching molars,” where new teeth emerge at the back of the jaw and move forward.
The Ecological Role of Their Diet
The grazing habits of manatees contribute to the health and structure of their aquatic ecosystems. By consuming large quantities of aquatic vegetation, they act as “gardeners of the sea,” helping to prevent the overgrowth of seagrasses and other plants. This grazing behavior promotes the diversity and health of seagrass beds, which are habitats and food sources for many other marine organisms.
Their feeding also contributes to nutrient cycling within these environments. The decline of seagrass beds directly impacts manatee populations, leading to starvation events. Protecting these seagrass habitats is therefore closely linked to manatee conservation efforts and the overall well-being of coastal ecosystems.