Good Vibrations: How Fiddler Crabs Mate

The male European fiddler crab attracts his mate by performing a courtship dance. New research published in the Journal of Experimental Biology https://journals.biologists.com/jeb/article/228/7/jeb249323/367607/Constraints-on-percussive-seismic-signals-in-a says that dance isn't just notable for its visuals — it's notable for its vibrations, too. Researchers observed four different stages of the crab's courtship dance, each stage escalating the amount of seismic vibrational output. "It's 'come and find me in my underground house, ladies,'" says Beth Mortimer https://www.biology.ox.ac.uk/people/beth-mortimer, a study author and biologist at the University of Oxford. Interested in more seismic vibration communication? Send us an email at [email protected] mailto:[email protected]. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave http://plus.npr.org/shortwave. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:19Emily Kwong?

  You're listening to Short Wave from NPR.

• 0:24Speaker 02

  Hey, Short Wavers. Rachel Carlson here.

• 0:26Emily Kwong?

  And Emily Kwong.

• 0:27Speaker 02

  With our biweekly Science News roundup, featuring the hosts of All Things Considered. And today, we have Elsa Cheng. Hello, hello. Boo boo. Welcome. Thank you for having me. OK, tell me what I am learning about today. So first, how fiddler crabs drum their mating songs into the sand.

• 0:45Emily Kwong?

  It'll be so romantic. And then we have a dinner for you. Chicken nuggets, but grown in the lab.

• 0:50Speaker 02

  Ew? Yum. Ew? Yum. OK. And a drug-like LSD without the trip. What's the point? You'll see.

• 0:59Emily Kwong?

  It's like a very elaborate date provided by science.

• 1:02Speaker 02

  All that on this episode of Short Wave, the science podcast from NPR.

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• 2:01Speaker 04

  All right, guys. To start us off, tell me all about these fiddler crabs that apparently do not fiddle. They drum? What?

• 2:08Emily Kwong?

  I'll explain. So if you haven't seen a European fiddler crab before, it looks like a classic cartoon crab. It's about the size of your palm, but its most distinctive feature is that the males have one big claw and one little itty-bitty claw.

• 2:21Speaker 04

  Oh.

• 2:22Emily Kwong?

  And they use these claws as part of their courtship dance when they're looking to attract a mate.

• 2:26Speaker 05

  And they do a very adorable kind of waving behavior. So the male will sit for hours on the sand waving his claw up and down. But we know from previous work on fiddler crabs that they can court even in the dark. So we know that the visual component wasn't everything with their courtship, that there was a component moving through the ground.

• 2:50Speaker 04

  A component moving through the ground. I imagine she's talking about drumming here?

• 2:56Emily Kwong?

  Drum roll. Yes, correct. This is Beth Hornberger. She's an associate professor of biology at the University of Oxford.

• 3:04Speaker 02

  And Beth was part of a team that put down geophones, so little sensors, to observe and record the vibrations these fiddler crabs were creating in the sand. It's super dune-like, sandworm-esque to me. The team published their research last week in the Journal of Experimental Biology, and they saw that this dance had four different stages.

• 3:22Speaker 04

  Wait, wait. Okay, I just have to say, I'm taking batata dance classes right now, and I am so intrigued by how few men have rhythms. So I'm very curious how this drumming works.

• 3:30Emily Kwong?

  These crabs have a rhythm.

• 3:34Speaker 04

  All right, what are the four stages of this courtship dance? What do they sound like?

• 3:39Emily Kwong?

  Okay, stage one, they wave their claws in the air adorably. Then the male crab alternates waving and body dropping. Then they're waving and dropping it low, yeah, simultaneously, which creates this kind of thump. And then if all of that is successful, and the female crab approaches, that's when the male does this underground drumming.

• 4:04Speaker 04

  That's amazing. I mean, a guy who can dance and has rhythm definitely is sexy. So I would be, I would be drawn to this, this drumming crab.

• 4:14Emily Kwong?

  I think I would too, honestly. And in each of these courtship steps, the crabs were increasing their seismic vibrations.

• 4:22Speaker 05

  So they're escalating the amount of seismic information that they're generating as they go through their courtship routine.

• 4:29Emily Kwong?

  Beth said, though, they still don't know how females respond to that seismic information.

• 4:33Speaker 04

  Oh, I'll tell them.

• 4:36Emily Kwong?

  Yeah. Elsa Chang fiddler crab will let them know whether they're interested in the rhythm or the loudness of the drumming, like what is sexy to them? We don't really know, but now that researchers have all of these recordings, they at least understand the steps of the routine and these invisible vibrations a lot better.

• 4:54Speaker 04

  Okay.

• 4:56Speaker 04

  Hard transition. We're going from seismic vibrations during crab courtship to growing chicken nuggets in a laboratory. Why are people trying to grow chicken nuggets at all?

• 5:10Emily Kwong?

  Lots of reasons, actually. For one, there is 8.2 billion people on the planet, more than ever, and people need to eat.

• 5:17Speaker 04

  True.

• 5:18Emily Kwong?

  So there's been this massive effort in countries around the world to figure out if they can grow meat tissue in the lab.

• 5:23Speaker 06

  So that we can reduce the pains we've generated on many of the animals. And also we can optimize the environmental impact by growing those meat in a very controlled condition.

• 5:37Emily Kwong?

  Yeah, so it's good for the planet to figure this out, perhaps. This is Ming Hao Ni at the University of Tokyo. He and a team of researchers there have successfully grown in the lab a whole cut of chicken meat, over 10 grams in weight and one centimeter thick, about the size of a chicken nugget.

• 5:52Speaker 04

  But the question is, is it juicy chicken meat? All right, well, first, how do they even manage to do this?

• 5:58Emily Kwong?

  Yeah, it's so cool. So meat is just muscle. Like, that's what you're eating when you eat chicken.

• 6:03Speaker 04

  Chicken muscle.

• 6:03Emily Kwong?

  Mm-hmm.

• 6:04Speaker 04

  Yeah. Yeah, love me some chicken muscle.

• 6:06Emily Kwong?

  Yeah, yeah. And chicken muscle is made up of this rudimentary cell called a myoblast. So what Ming Hao and the team wanted to do is figure out how to get the myoblasts to naturally fuse together and form chicken myo tubes, which give the meat its aroma and chewiness.

• 6:21Speaker 04

  So cool. How did they even figure this out?

• 6:24Speaker 02

  Ming Hao and his team used this special machine called a hollow fiber bioreactor. It delivered nutrients and oxygen to the myoblasts, mimicking blood vessels in the animal body. And after a few days, the myoblast started to grow and form this cultured meat. The team published their results in the Cell Press journal, Trends in Biotechnology, this week.

• 6:43Speaker 04

  I mean, I feel like I've heard stuff like this elsewhere. I assume there are other researchers trying to grow meat in labs. What makes these particular chicken nuggets so special?

• 6:54Speaker 02

  True, there are, but a lot of lab-grown meat on the market is artificially assembled. So the myoblasts are fused together. And this work demonstrates a way for labs to grow meat into one large tissue, thicker than a centimeter. So it does bring us closer to a world where a whole lab-grown chicken breast could be scientifically possible.

• 7:12Speaker 04

  Okay. So from crab courtship to chicken muscle to drugs without the trip, such as LSD. I mean, why, Rachel, would I ever want to take a drug like LSD but not have the psychedelic effect? Like, what's the whole point?

• 7:28Speaker 02

  I know. It sounds like an oxymoron, but you've probably heard researchers are studying psychedelic therapy for patients with depression, PTSD, lots of other things. But people with conditions like schizophrenia are usually advised not to take psychedelics. So even if it turns out that these drugs do help treat certain mental health conditions, a lot of patients would be left behind.

• 7:49Emily Kwong?

  Yeah, so given this, researchers looked at a molecule that has a similar structure to LSD and just removed the trip, which in theory would make this kind of treatment accessible to more people. And their study was published this week in the Proceedings of the National Academy of Sciences.

• 8:03Speaker 04

  Wait, so I don't get it. These researchers, they just like chop off the trippy part of the LSD molecule?

• 8:09Speaker 02

  Kind of. One of the researchers told me that I should think of each molecule like a car.

• 8:14Speaker 04

  Okay.

• 8:15Speaker 02

  This is David Olson. He's the director of the Institute for Psychedelics and Neurotherapeutics at the University of California-Davis.

• 8:21Speaker 07

  You could chop off the top of the car and create a convertible. You could add a spoiler, but you're fundamentally creating a new car. You are changing the shape of the car. But what we did here is we took LSD and we essentially did a molecular tire rotation. We just moved two atoms. We swapped them.

• 8:42Speaker 02

  And David says they named this new molecule JRT after the grad student who first synthesized it Jeremy R. Tuck.

• 8:49Emily Kwong?

  Oh, good for Jeremy.

• 8:51Speaker 04

  Okay, but what are the chances people would actually start taking these drugs anytime soon?

• 8:57Speaker 02

  Yeah, so the study published this week tested JRT on mice, not people. And another researcher I spoke to who wasn't involved in the study, Anahita Basirnia, says while it's a promising step in the field, we still don't know how it would translate to humans and whether it would actually be non-halucinogenic. So there's a lot more we need to learn.

• 9:15Emily Kwong?

  Yeah, and if you want to hear more about new research in psychedelics, Rachel Carlson over here just reported this amazing three-part mini-series for Short Wave. Go check it out.

• 9:23Speaker 04

  We love a Rachel-reported series, don't we?

• 9:26Speaker 02

  Thanks, Elsa. It's so fun having you here.

• 9:29Emily Kwong?

  Yeah, good luck with those bachata lessons. The crabs are cheering you on.

• 9:33Speaker 04

  Oh, I love it. Maybe they'll dance with me and have more rhythm than the guys in my class.

• 9:36Emily Kwong?

  Let's hope so.

• 9:37Speaker 02

  We can only hope. You can hear more of Elsa on Consider This, NPR's afternoon podcast about what the news means for you. This episode was produced by Hannah Chin and Catherine Fink. It was edited by Patrick Jaren-Watsononin.

• 9:54Emily Kwong?

  Tyler Jones checked the facts. I'm Emily Kwong.

• 9:56Speaker 02

  And I'm Rachel Carlson. Thanks for listening to Short Wave, the science podcast from NPR.

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