Range: Cosmopolitan Habitat: Stone and coral dens on the ocean floor Size: Up to 10 feet (3m) long Diet: Fish and crustaceans Threats: Fish as juveniles Life span: Up to five years

Transcript:

Today on Animal Fact Files we’re discussing bobbit worms. Be sure to strike that subscribe button, and thank you to laszlo erik for today’s request. Bobbit worms, aka nightmare fuel. There are plenty of news stories about these animals secretly inhabiting the tanks of aquarium enthusiasts for years unbeknownst to the aquarium owners. If that’s not a good backbone for a horror story, then I’ve been eating some rotten creepypasta. But nobody, not even the scientific community, can really agree on exactly what a bobbit worm actually is.

Some people say they’re a specific species, but even that one species has classification issues involving individuals who differ so vastly from their conspecifics that scientists wonder if they should even be considered the same taxon. Others say they’re just the longest of the bristle worms - or basically the ones that can be longer than the tallest humans are tall. There are also individuals who say they shouldn’t even be called bobbit worms altogether because the origin of their name is thought to be based around a famous United States court case from the early 1990s involving… well… you’ll just have to google that yourself.

Considering the implications of that case and the myths that have arisen in regards to these worms due to that case’s details, not to mention the confusion around the name in general, we’re apt to agree with others that bobbit worms may be in need of a name change. Plus, bobbit just sounds like a disease you want to be cured of, and, though these worms are somewhat horrifying, they’re also exceptionally fascinating and deserve a cooler name. The alternative name for a bobbit worm is sand striker, and that’s what we’ll be using for the rest of this episode because it more appropriately describes exactly what these worms do.

For clarification, we’re talking about any species from the Eunice genus, of which there are somewhere around 350 species, though that could always change with new discoveries. These are segmented worms, like earthworms, and spend most of their lives living in sand, though they can also be seen hiding in stone and coral dens or even making their way through mud. They’re known from tropical marine waters though they can be found almost worldwide as benthic, or ocean bottom dwelling creatures typically staying no deeper than 650 feet (200 meters) below the ocean’s surface.

They’re nocturnal animals and will position themselves in sand, mud, or a den that hides the majority of their bodies leaving only their five tentacles exposed. When a passing fish or crustacean brushes against one of these tentacles, the sand striker will snap its jaws around it’s prey in an instant and inject venom to help with digestion. The prey is usually dragged below the substrate or into the den where it is consumed, though some accounts note that smaller sand strikers are more focused on easier prey such as detritus and even soft corals.

Though these worms are often hidden within their habitats they can sport a wide variety of colors and patterns. Some of them may even appear iridescent giving them a rainbow sheen. Pfft. Here we were saying narwhals are the unicorns of the ocean, but they still aren’t rainbow colored!

For mating, sand striker females will release a pheromone to alert male sand strikers in her area that she’s ready to procreate. When the couple meets up (or sometimes all the couples, it can be a group thing) they will simultaneously release sperm and eggs into the water column at which point the eggs will become fertilized and eventually hatch into planktonic larvae. This is when the worms are most likely to be eaten by all manner of other seafaring animals. If they can find a safe place, like some poor soul’s aquarium, sand strikers are able to live for years.

For more facts on bobbit worms, 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.