Meet the slimy green ribbon worm that horrified the Internet

Most of us are familiar with the segmented worms we see on sidewalks after a rain, in compost piles, or at the end of a fishhook. But there are other worms out there, and they get a lot bigger than a red wiggler.

Just so you know, these worms are fishing worms, not ribbon worms.

Total Fisherman

There are at least 1,000 or more species of ribbon worms (phylum Nemertea), sometimes called “proboscis worms” in the world. Most of them are found in the world’s oceans, although about 12 species are found in freshwater in the tropics and sub-tropics, while a dozen more live on land in cool, damp places, like under rotting logs.

Ribbon worms are so plentiful in the environment, they outnumber primates three to one. And they also come in a vast rainbow of colors and sizes. As a matter of fact, there is one ribbon worm called the “bootlace ribbon worm” that can grow to 197 feet long. That’s over half the length of a football field.

With its highly developed muscles, ribbon worms can not only contract, bringing itself to less than a tenth of their extended length, but they can also expand, allowing then to engulf other kinds of worms, fish, crabs, crustaceans, and snails that are much wider than they are. They are occasionally called “pythons of the sea.”

Ribbon worm filmed in Roatan, Honduras at Calvin’s Crack on a rainy overcast day with low ambient lighting.

CarolandLou

Most ribbon worms are only an inch or so in circumference, and usually only reach about six or seven feet in length, so running across a monster ribbon worm would be a rare event. But one thing that sets these worms apart is their proboscis. The proboscis is an unusual muscular structure inside the worm’s body at the front end. When attacking prey, they can compress their bodies, pushing out the proboscis like the finger of a latex glove that’s inside-out.

The proboscis can vary among the different species of ribbon worms, with some being sticky, or having suckers to hold on to prey. Some species have a sharp spike, called a stylet, that allows them to stab their prey. If that’s not enough to freak you out, some of the ribbon worms are also poisonous and taste very bad. Several species contain a tetrodotoxin, just like pufferfish venom, that can induce paralysis and death by asphyxia.

Most ribbon worms have a protective coating of mucus that keeps them from drying out. This slippery mucus also helps them to navigate through the mud and rocks of the ocean floor. All in all, ribbons worms are but another of the ocean’s fascinating creatures.