Range: Oceans worldwide Habitat: Seafloor from shallow to abyssal waters Size: Less than 1 inch - more than 6 feet (2.54cm-1.8m) long Diet: Algae, plankton, invertebrates, and more Threats: Fish, sea slugs and snails, crustaceans, sea cucumbers, and humans Life span: Five to ten years

Transcript:

Today on Animal Fact Files we’re talking about sea cucumbers. Though their common name may be based on a plant species, and they kind of look like weird, spiky versions of said plants, these are definitely animals.

In their adult form, sea cucumbers certainly won’t provide the same refreshing taste their namesake does, but they are eaten by people! In many parts of the world sea cucumbers are considered a delicacy. And in the ocean, sea cucumber eggs and larvae provide meals to animals. Adult sea cucumbers are eaten, too, but they have some special defense tactics to avoid predators which we’ll be discussing later in the video.

Predators to sea cucumbers include fish, sea slugs and snails, crustaceans, and even their own relatives. Sea cucumbers are echinoderms. While they may be much squishier than the animals related to them, sea cucumbers are kin to sand dollars, sea urchins, sea stars, and other echinoderms.

There are about 1,200 classified species of sea cucumbers, and they’re found throughout the world’s oceans. Most sea cucumbers are benthic animals that live on the ocean’s bottom. Here they may hide among coral and rock formations, scoot along sand, or even burrow under it. They can be found from intertidal zones to the deep abyss with some species known from some of the deepest parts of the ocean! There are even some sea cucumber species that swim in the open ocean.

Sea cucumbers are often found in large groups. This helps with breeding. For the most part, sea cucumbers are either male or female - though, like sea urchins, it’s basically impossible to tell which is which from the outside. Sea cucumbers are generally broadcast spawners meaning their eggs become fertilized externally. Living in a large group provides more opportunities for fertilization. In this scenario, the parent sea cucumbers don’t provide any further care except for releasing chemicals that attract their young back to the group as they develop if you want to count that.

Other sea cucumber species do provide a bit more care by brooding their eggs. The eggs may either be kept externally on the body or internally until they hatch and are released as larvae. There are other species, still, who can reproduce asexually. In this case, the sea cucumbers split themselves into two parts and each part grows into a living individual. And sea cucumber regeneration doesn’t stop there!

If a sea cucumber is attacked by a predator, the echinoderm can expel its guts through its anus as a distraction tactic. These organs are left behind and later regrown inside the body of the sea cucumber of the course of a few days to weeks. And sometimes a predator doesn’t even have to be part of the ordeal, the sea cucumbers will do it just because!

When not trailing entrails reaching lengths longer than their own bodies, sea cucumbers are generally cucumber shaped, though there are species, like sea apples, who appear more round and others with even more abnormal adaptations. Weird shapes aside, sea cucumbers do all have food gathering tentacles around their mouths. These may be coated in mucus and periodically trailed through the sea cucumber’s mouth, they may also shovel in sediment which is processed and expelled in much the same way an earthworm moves through the dirt.

In size, adult sea cucumbers can range from less than an inch (2.54 centimeters) in length to more than six feet (1.8 meters)! The girthiest sea cucumbers may have over nine inch (24 centimeters) diameters. In the wild, sea cucumbers are known to reach from five to ten years of age!

For more facts on sea cucumbers, check out the links in the description. Thank you to JaKoby LeVan and Enrico Caponnetto for today’s request. Give a thumbs up if you learned something new today, and thank you for watching Animal Fact Files.