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Whack! Jab! Crack! It’s a Blackback Land Crab Smackdown | Deep Look
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Whack! Jab! Crack! It’s a Blackback Land Crab Smackdown | Deep Look

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Lauren: Hi there, it’s Lauren. You’re about to watch the last Deep Look
of 2018. If you want to get the inside track on what’s
coming in January, join our community on Patreon! Link in the description. Curiosity Stream: Thanks to Curiosity Stream
for supporting PBS Digital Studios. Lauren: Scoring that prime beach spot can
be tough. Everyone’s fighting for the best real estate. These Black… back… um… Blackback…land… These, uh, crabs, come from the Dominican
Republic. They live in dense colonies on the beach. Each male establishes a territory and defends
a burrow — with a pretty impressive set of claws. Those claws have serrated edges. And they sure can pinch. The goal here is basically to tear your opponent
limb from limb. Every joint is a potential weak spot. This guy is already at a disadvantage. With that broken claw, his flank’s open
to attack. When his opponent goes for a leg… Yowch! But don’t worry. It’s not as bad as it looks for him. See how the leg comes off cleanly, right here? There’s a seam where two of the upper leg
segments meet. He let it go, on purpose. That’s how these crabs cry uncle. By the end of the fight, he’s lost six of
his eight legs. Awkward… He can barely get back to his den like the
rest of the crabs do at the end of the day. But he’s not stuck that way. Losing legs is pretty normal around here. Within a week, they begin to regrow. New limb buds sprout in the open sockets of
his shell. Each is a complete leg in miniature, all coiled
up inside a thin sac. But to really get back on his feet, the crab
will have to start fresh. Don Mykles at Colorado State University studies
what happens next – the process called molting. Crabs wear their hard skeletons on the outside,
but underneath their soft bodies are always growing. So, they have to go through one crazy-looking
growth spurt. Normally, it happens about once a year. But this is an emergency. For the next eight weeks in its den, the crab
secretes enzymes under its shell that start the separation process. And it begins to build a new shell in a paper-thin
layer under the old one. Then, the crab packs up and moves out. He gulps air into his body to create enough
internal pressure to pop the top of his old shell. Then, he slides himself out the back and unfurls
those new legs. His body is still flexible. In a restaurant, he’d be called soft-shell
crab right now. A couple of weeks, and his new shell will
harden, then, he’ll be ready for a rematch. As in, blackback land crab … payback. Curiosity Stream: Thank you to Curiosity Stream
for supporting PBS Digital Studios. Curiosity Stream is a subscription streaming
service that offers documentaries and nonfiction titles from a variety of filmmakers, including
Curiosity Stream originals. In “The Health of Our Oceans,” renowned
marine biologist Dr. Sylvia Earle reveals how the growing threats from ocean pollution
and overfishing could create devastating consequences for mankind. You can learn more at curiositystream.com/deeplook
and use the code deeplook during the signup process. Lauren: So the gland that actually controls
molting is in the crab’s eyestalks, which explains why they’re so well protected. Looking for more videos to spark your love
of learning? Check out a new mega-playlist for the PBS
Digital Studios Network, updated every week. Link in the description. Thanks.

100 thoughts on “Whack! Jab! Crack! It’s a Blackback Land Crab Smackdown | Deep Look”

  4. I did not know until now that it is not just lizard can grow back their body parts but also this crab too. Great videos!

    Reply

  8. Once I found several exo-skeletons from some crabs on a beach
    Their little eye sacks were still attached on!
    Soon I gave them some shell hats

    Reply

  22. Narrator was so proud of herself at the end there. "blackback.. land crab… *pride intensifies* …payback" haha

    Reply

  35. So what you’re saying I can always take of their legs and eat it and they will regrow so I can eat more? Or is there no meat in their legs?

    Reply

  87. there was a thumb nail glitch with the video and the thumb nail was of SCP-096 vs SCP-173, yet the title of the video still fit the thumbnail.

    Reply

  97. We've been searching the stars for alien lifeforms for who knows how long when they have been here all along on our shores, walking sideways. Always, walking sideways. scuttle scuttle

    Reply

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