You're listening to shortwave from NPR.

To peer into the soul of a sea cucumber, don't look to its face.

It doesn't have one.

Gently turn that blobby body around and gaze deep into its marvelous multifunctional anus.

This is Catherine Wu, a science writer for the Atlantic.

The sea cucumber's posterior is so much more than an exit hole for digestive waste.

It is also a makeshift mouth that gobbles up bits of algae, a faux lung, lottish with

tubes that exchange gas with the surrounding water, and a weapon that in the presence of

danger can launch a sticky stringy web of internal organs to entangle predators.

And if you haven't guessed already, this episode, yes, is about the anus.

Because the anus is an evolutionary marvel, and the anus of a sea cucumber is a spectacular

example.

It can even, on occasion, be a home for shimmering pearlfish, which wriggle inside the bum when

it billows open to breathe.

It would not be inaccurate to describe a sea cucumber as an extraordinary anus that just

so happens to have a body around it.

Now the anus doesn't get as much respect as it deserves, partially because of our human

taboos around them.

Or as Katie puts it, we've turned anuses across the tree of life into cultural underdogs,

and scientific ones too.

I imagine it's a little weird for some of these people to go into a poster session and

just be like, hey, do you want to look at pictures of all these anuses I've been looking

...