they pop their stalked eyes and feathery antennae out of the sand

August 28, 2019 2:02 PM

For Pacific Mole Crabs It's Dig or Die | Deep Look [YouTube, has subtitles] and article from KQED Science.

"Benjamin McInroe [...] is a Ph.D. student in UC Berkeley's Poly-PEDAL Lab, where he studies biophysics. He wants to know what makes these little creatures so proficient at digging their way through the wet sand.

McInroe hopes that he can one day copy their techniques to build a new generation of digging robots."

(Mole crabs are classified in a superfamily named hippoidea)

posted by readinghippo (13 comments total)

One time in Mexico we had rented a house on the beach. The beach had more mole crabs than was believable. We saw locals collecting them so we asked what was up, dinner we were told. So we gathered a bunch too. Had them cooked as taco filling. Okay, more crunchy than anything really. I have since seen other videos about the same topic, mole crab cookery, and they are ripe with parasites, which is a good reason to avoid, and apparently we got a good batch because many people describe the flavour as being bitter or garbage-y. So yeah, do not eat.
posted by Keith Talent at 2:21 PM on August 28, 2019 [3 favorites]

My father had a conversation with a man digging up these things on a beach in Oregon. They're known as Chocolopas on coastal Michoacán. He had a bucket to fry up for dinner. We spent some time the next day digging up these creatures to watch them dig back down. My son was tickled... he loves crabs of any sort. I'm curious to try eating some myself some day, but am happy just to observer their movement through the sand.
posted by Mister Cheese at 2:35 PM on August 28, 2019 [1 favorite]

Squee! Mole crabs! I'm only familiar with the slightly different Atlantic ones, but they are the best.

I could almost hear that one at 2:07 say "no eat plz" as it tried to bury itself in the researcher's hand.
posted by scruss at 2:45 PM on August 28, 2019 [5 favorites]

Ah, we used to catch these all the time as kids and keep them in some sand and water in an empty soda cup. My mother of course made me pour them back out when we left. It's so neat to see them up close!
posted by dame at 3:02 PM on August 28, 2019 [4 favorites]

Root Hog or Die
posted by Slithy_Tove at 3:42 PM on August 28, 2019

Ah, a Psammead
posted by babelfish at 6:17 PM on August 28, 2019

It's amazing that they're related to hippos!
posted by hippybear at 6:51 PM on August 28, 2019 [2 favorites]

Seeing the feathery antennae, it seems like the mid point between a lobster and a barnacle. I'd previously found it hard to believe a barnacle was a crustacean.
posted by bonobothegreat at 9:03 PM on August 28, 2019 [2 favorites]

readinghippo: "(Mole crabs are classified in a superfamily named hippoidea)"

hippoidea, now there's a username
posted by chavenet at 6:37 AM on August 29, 2019 [4 favorites]

This post was life-changing in that I've been digging Emerita Talpoida out of the sand in the swash zones on mid-Atlantic beaches for forty-seven years and I've spent the entirety of that time thinking that the round end was the front.

PARADIGM SHIFT, man.
posted by sonascope at 6:53 AM on August 29, 2019 [6 favorites]

Oh, wonderful! I also grew up on the east coast, and the feeling of a mole crab digging through the sand cupped in your hand only to reach your wrinkly palm is so vivid. I had no idea that they dug backwards. Thank you for this post
posted by FirstMateKate at 9:33 AM on August 29, 2019 [2 favorites]

Been going to the Nags Head area since 1960 (parents started in the 1940s) so I grew up catching mole crabs—commonly called “sand fleas.” They were gentle, charming things that tickled one’s hand (as noted above).

Last year on my annual visit I strolled the beach early and saw a couple digging at the margin with a pole-mounted basket. When I asked what they were collecting, I was shown a bucket filled with hundreds of sand fleas. They gave it a shake and the poor wee creatures went into a frenzy of digging.

Asked their purpose, I was told “sheepshead love ‘em.”

The three-year-old in me was sad for the rest of the morning.
posted by kinnakeet at 10:30 AM on August 29, 2019 [1 favorite]

These are similar to the critters we call diggers that show up on the Surf City beach in NC, where we frequently vacation. They seem to be in low abundance right now, but I hope that's a temporary thing and not another sad consequence of our warming globe. Here's what they look like.
posted by Mental Wimp at 2:20 PM on August 29, 2019 [1 favorite]