Facts About Invertebrate Butts You Didn’t Know You Needed

A group of science communicators declared March 1-8, 2022 InverteButt Week. What inspired this cheeky holiday? Scientists recently announced that the marine worm Ramisyllis multicaudata has hundreds of butts. It lives inside of sponges and branches over the course of its life, with each branch developing its own butt. This inspired the team to create the comic below and start the Twitter hashtag #InverteButtWeek. They also encourage others to take a crack at it.

A comic shows four animals and describes the number of butts each one has.
Bird and Moon Comics

More than 90 percent of all animal species are invertebrates. They live on every continent and in every body of water on Earth. Insects, jellyfish, lobsters, worms, clams, and squid are just a few examples of invertebrates. There’s a lot of butts to choose from. 

Many have answered the booty call. Everyone from experts posting about their research to enthusiasts sharing photos. Fun facts include that sea anemones have a butt that is also their mouth. Bees waggle their butts to communicate. Wasp larvae don’t have butts. Some moths can inflate their butts to attract mates. Beetles can mimic the butts of ants to blend in with the colony. One species of crab lives inside urchin butts. The anal tubes of ancient crinoids are often the only fossilized remnants found.

Spider biologists noticed a lack of representation and have rectified the situation. Now we know that spider butts spin silk for webs and house most of their internal organs, including their heart and lungs. Some spider butts mimic the faces of the ants they prey on. As a defense mechanism some spider butts mimic ladybugs, which are known to taste bad. Some spider butts display bright colors to signal that they are venomous. Male peacock spiders display their colorful butts in a dance to impress mates.

Infographic describing a spectrum of butts in the animal kingdom
@franzanth @spissatellas @RosieRiots

Twitter is full of videos, photos, drawings, infographics, and other educational assets. Here’s hoping InverteButt Week becomes an annual tradition. We like this fun and creative science communication, and we cannot lie.

Featured Image: @RosemaryMosco