This week we learn about some weird worms!

Further reading:

Otherworldly Worms with Three Sexes Discovered in Mono Lake

Bizarre sea worm with regenerative butts named after Godzilla's monstrous nemesis

Underground giant glows in the dark but is rarely seen

Giant Gippsland earthworm (you can listen to one gurgling through its burrow here too)

Further watching:

A giant Gippsland earthworm

Glowing earthworms (photo by Milton Cormier):



This sea worm's head is on the left, its many "butts" on the right [photo from article linked to above]:



A North Auckland worm [photo from article linked to above]:



A giant beach worm:



Show transcript:
Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.
This week we continue Invertebrate August with a topic I almost saved for monster month in October. Let’s learn about some weird worms!
We’ll start with a newly discovered worm that’s very tiny, and we’ll work our way up to larger worms.
Mono Lake in California is a salty inland lake that probably started forming after a massive volcanic eruption about 760,000 years ago. The eruption left behind a crater called a caldera that slowly filled with water from rain and several creeks. But there’s no outlet from the lake—no river or even stream that carries water from the lake down to the ocean. As a result, the water stays where it is and over the centuries a lot of salts and other minerals have dissolved into the lake from the surrounding rocks. The water is three times as salty as the ocean and very alkaline.
No fish live in the lake, but some extremophiles do. There’s a type of algae that often turns the water bright green, brine shrimp that eat the algae, some unusual flies that dive into the water encased in bubbles, birds that visit the lake and eat the brine shrimp and flies, and eight species of worms that have only been discovered recently. All the worms are weird, but one of them is really weird. It hasn’t been described yet so at the moment is just going by the name Auanema, since the research team thinks it probably belongs in that genus.
Auanema is microscopic and lives throughout the lake, which is unusual because the lake contains high levels of arsenic. You know, a DEADLY POISON. But the arsenic and the salt and the other factors that make the lake inhospitable to most life don’t bother the worms.
Auanema produces offspring that can have one of three sexes: hermaphrodites that can self-fertilize, and males and females that need each other to fertilize eggs. Researchers think that the males and females of the species help maintain genetic diversity while the hermaphrodites are able to colonize new environments, since they don’t need a mate to reproduce.
When some of the worms were brought to the laboratory for further study, they did just fine in normal lab conditions, without extreme levels of arsenic and so forth. That’s unusual, because generally extremophiles are so well adapted for their extreme environments that they can’t live anywhere else. But Auanema is just fine in a non-harsh environment. Not only that, but the team tested other species in the Auanema genus that aren’t extremophiles and discovered that even though they don’t live in water high in arsenic, they tolerate arsenic just as well as the newly discovered species.
The team’s plan is to sequence Auanema’s genome to see if they can determine the genetic factors that confer such high resistance to arsenic.
Next, we go up in size from a teensy worm to another newly discovered worm, this one only about 4 inches long at most, or 10 cm. It’s a marine polychaete worm that lives inside sea sponges, although we don’t know yet if it’s parasitizing the sponge or if it confers some benefit to the sponge that makes this a symbiotic relationship. The worm was only discovered in 2019 near Japan and described in early 2022 as Ramisyllis kingghidorahi.
Almost all worms known are shaped, well, like worms.