Nestled in a moist dirt burrow in the forested hills of Kenya, Africa, a 3-inch-long (75-mm), pale, serpentine creature uncoils as it awakens. It wriggles around in search of something to satisfy its hungry, growling belly.
Before long it finds the healthiest, tastiest meal it could have—its own mother’s skin! The young caecilian (say-sill-yen) gets to work, peeling away and eating thin layers. Don’t worry, God gave this gracious mother specially designed skin cells that are thick, fatty, and nutritious, so her little one can eat without hurting her.
Not all caecilian species eat their mother’s skin, but they are the only members of the animal kingdom known to have this behavior. But that is not all that is special about this worm-like creature.
At first sight, you might think this young caecilian would make good fishing bait, but don’t let his segmented skin fool you. Unlike a worm, the caecilian is an amphibian, so he has a backbone, and as he grows, he turns bright blue, which is a typical color for a caecilian. He could continue to grow up to 1 foot (30 cm) long. In time, he will set off to find other forms of food.
He will then force his thick bony skull through the soil hunting for an ant to eat. Because of all the time this caecilian spends below the surface of the ground, he has tiny eyes with a protective skin covering. But that’s no problem—he doesn’t actually use his eyes for seeing. Instead, the caecilian has two small tentacles located between its eyes and nostrils that help him navigate through the soil. These nubby points also enhance the caecilian’s sense of smell, pinpointing a potential meal nearby. If it’s not an ant, it will be something just as tasty, such as insect larvae or a termite. Once upon its prey, the caecilian will use its inward-curving teeth to grasp hold of its meal and swallow it whole.
Like its fellow amphibians, such as salamanders and frogs, this African Boulengurula caecilian is cold-blooded. He also has moist skin, which he likes to keep that way, so he doesn’t venture out above the ground where the air and sun might dry out his skin.
The Boulengurula is one of nearly two hundred species of caecilians located throughout the tropical forests of Asia, South America, and Africa. Caecilians live in the deep underground, though, so it’s a challenge to find them. It often takes hours of digging and scooping of dirt over miles of terrain just to find one.
Unlike other amphibians, their elusive nature has left scientists wondering about many caecilian habits and lifestyles. How long do caecilians live? Do they migrate? Are they aggressive, fighting each other for food or territory? Biologists just don’t know the answers to these questions, but they aren’t giving up.
One thing is certain—the more biologists dig for answers, the more the secretive caecilian will surprise them.