Caecilian

Order Gymnophiona

Amphibian

Transcript:

Today on Animal Fact Files we’re talking about caecilians. Though they might be mistaken for worms because they live underground or snakes because they don’t have any limbs, caecilians are neither. These are amphibians. Classified in their own order, caecilians aren’t closely related to any other living amphibian species such as frogs or salamanders, though one look at them can probably explain why! They’re entirely unique. Sometimes caecilians are commonly referred to as “naked snakes”, but since that might be a little confusing, we’re going to avoid that common name. The name caelian is derived from the latin word meaning “blind” and this is for good reason. These amphibians have extremely reduced eyes that are hidden beneath either a layer of skin or even a skull. Caecilians spend most of their time underground, so they don’t really need to have fantastic vision. With the exception of a handful of aquatic species, caecilians burrow beneath the surface of the earth, and this a large reason why most of us have never even heard of them. Believe it or not, caecilians live all throughout the tropics of the world including central and south America, south and southeast Asia, and central Africa. They’re not found in Australia, though… guess the Aussies can’t have every weird animal.

There are nearly 200 species of caecilians throughout the world. The shortest caecilians are about 4 inches (10.16cm) long while the largest are 5 feet (1.5m) in length making them longer than the height of an average twelve year old. Generally they appear grey, blue, or purplish in color, but some species come in bright oranges and yellows. These vibrant hues may be an indicator to predators like snakes and birds to stay away from toxic, untasty skin. Caecilians’ bodies look like they’re segmented like an earthworm, and, for some species, within the groves of these ring shapes are scales - a primitive amphibian trait that is not found in most, if any, other amphibians. Caecilians also have tentacles; they’re the only amphibians with these structures and they use them to survey their surroundings.

Although they’re relatively blind, caecilians are excellent hunters and enjoy meals of earthworms, termites, caterpillars, snakes, fish and eels in the case of the aquatic species, and even each other. While the adults don’t take kindly to another caecilian eating them, it’s actually encouraged in the young of some species. All caecilians produce offspring with the mating of a male and a female, but there are different ways their babies are born. Some are born as eggs that hatch into larvae which metamorphose into adults. Pretty normal and a lot like the salamander life cycle we discussed in our axolotl episode. But, caecilian reproduction methods don’t end there. Some species are born viviparous - or live and not within an egg. On their way out, the baby caecilians will eat the lining of their mother’s oviduct. Oh, it doesn’t stop there, either! In other species, the mother will lay a clutch of eggs and guard it until the babies hatch. They’ll stay with their mother for the next four to six weeks all the while eating her dead skin which is packed with large fat cells. Motherly love in the animal world gets real, y’all.

Currently, it’s unknown how long caecilians live in the wild, though some have survived more than a decade housed in zoos. There’s a deficit in caecilian research due to their elusive nature. Of the almost 200 species, a handful are classified as threatened or endangered in the wild, but for most there isn’t sufficient data to classify their population status. It’s possible they’re under stress from habitat loss like many other amphibian species today, but until more research is performed this will remain uncertain.

For more facts on caecilians check out the links in the description. Give a thumbs up if you learned something new today, and thank you for watching Animal Fact Files.