Manatees, often called “sea cows,” are large, gentle marine mammals frequently misunderstood, especially regarding their skin. Unlike many terrestrial mammals, manatees do not possess a thick coat of fur. Instead, their unique skin and a sparse covering of specialized hairs play a distinct role in their survival and interaction with their aquatic environment.
A Closer Look at Manatee Skin
Manatees are not covered in fur; their bodies are covered by a thin layer of fine, short hairs. Their skin is notably thick, wrinkled, and typically gray to brownish-gray in color, much like the skin of their distant relatives, elephants. This tough skin provides a protective outer layer for these aquatic herbivores. Its surface also continuously flakes off, which helps to prevent excessive buildup of algae and barnacles that often grow on their slow-moving bodies, maintaining a cleaner body surface.
Given their slow movements, algae frequently adhere to the manatee’s back and tail, sometimes giving them a greenish or brownish appearance. This is merely plant growth on their leathery skin. The texture of their skin, coupled with the sparse hair distribution, is an adaptation to their aquatic lifestyle, differing significantly from the dense fur coats seen on many land mammals that rely on fur for insulation or camouflage.
The Amazing Sensory Hairs
Manatees possess highly specialized sensory hairs called vibrissae, which are distributed across their faces and bodies. These hairs are not for warmth but serve as a crucial sensory system, enabling manatees to perceive their surroundings in murky waters where visibility is often limited. Each vibrissa is extensively innervated, transmitting detailed information to the brain. This makes their sense of touch exceptionally keen, with some facial vibrissae capable of discriminating textures with sensitivity comparable to human fingertips.
The vibrissae around their snout and mouth are particularly sensitive and play a significant role in feeding. These specialized bristles can extend outward, allowing manatees to investigate objects and grasp aquatic plants, such as seagrass. Beyond direct contact, vibrissae located on their postfacial body are hypothesized to detect subtle water movements, much like a fish’s lateral line system. This ability to sense hydrodynamic stimuli helps them navigate, detect obstacles, and even locate other manatees in their environment.
Other Unique Manatee Adaptations
Manatees exhibit several physical adaptations that allow them to thrive in their aquatic habitats. Unlike many marine mammals that rely on thick blubber for insulation, manatees have a surprisingly low amount of body fat and instead depend on warm water sources to regulate their body temperature. This explains their migration to warmer waters, such as natural springs or power plant outfalls, during colder months. Their large, cylindrical body shape is well-suited for movement through water.
Their paddle-like forelimbs, or flippers, are versatile tools used for steering, “walking” along the bottom, and scooping vegetation towards their mouths. The bones within their flippers are structured similarly to a human hand, highlighting their evolutionary lineage. Manatees also possess a unique dental system, characterized by continuously replaced molars that move forward like a conveyor belt as they wear down from grinding abrasive vegetation.
Manatees have the ability to hold their breath for extended periods, up to 15 to 20 minutes when resting, by slowing their heart rate and efficiently exchanging about 90% of the air in their lungs with each breath. Their lungs, which run along their backbone, also assist in buoyancy control, enabling them to adjust their position in the water.