NewsLocal News


Zach at the Zoo: Meet the Japanese Giant Spider Crab

The largest crustacean in the world
Posted at 9:40 AM, May 23, 2024

OMAHA, Neb. (KMTV) — In this week's edition of Zach at the Zoo, we are better introduced to Omaha Henry Doorly Zoo & Aquarium's Japanese Giant Spider Crabs — the largest crustacean in the world, growing up to ten feet!

  • “I mean, they look alien and they feel alien, and they’re from the bottom of the ocean which is as close to something alien you could probably get here.”
  • The zoo four Japanese giant spider crabs. We learn all about them.
  • IN THE VIDEO: the crabs are fed and we get a close look at one of the crab's old shell.


“I mean, they look alien and they feel alien, and they’re from the bottom of the ocean which is as close to something alien you could probably get here,” Senior Aquaist Ben Morrow said.

Four of these alien-like creatures call Omaha home – one of the few places you’d be able to see them.

“These guys can be a thousand feet under the water, commonly, and after that point it’s really hard for us to know," Morrow shared. "But they very likely go much deeper.”

They are Japanese Giant Spider Crabs – and called giant for a reason.

“This part of their body, the sulfa thorax is what we call it, is actually going to stay relatively this size for the rest of its life," Morrow explained. "But its legs will get incredibly big. They can be ten foot, which is extreme, but imagine that walking around on the floor of the ocean.”

We were able to get our hands on one. Well, the closest thing to one.

“So this is a spider crab molt. This isn’t alive or anything but this did actually come from our animal.”

Morrow added, “You can think of this as a sheet of armor. It’s their exoskeleton and as they grow they shed it, so they can grow bigger and bigger.”

While they come out stronger on the other side -- molting is when they are most at risk.

"You’re extremely soft and able to be eaten by everything," Morrow said. "So, they have to grow incredibly fast in about a day to three days, and then re-harden their shell.”

Morrow told us they are able to grow faster by absorbing water – like a puffer fish.

"Then they re-harden on top of that size, and as they actually put on muscle and mass, they push the water out.”

But the shell doesn’t protect them against people.

In Japan, they are on the menu, which made the species vulnerable for a bit. But, new fishing regulations have helped the species grow again.

How about the crabs’ menu?

“These guys are omnivores. You can think of them as vultures of the seabed. So, anything that dies, something that got eaten and little bits fell to the floor, these guys are going to be cleaning those up," Morrow said. "They’ll eat little bits of algae, kelp, and all sorts of animals.”

The crustacean’s two little antennas, also called feelers, are constantly moving – searching for that next meal.

"They know it’s that direction, and they can wander off and find it. Which is a cool thing to see," Morrow shared. “Little pom-poms. Pew, pew!”

You can see them wave their pom poms inside the Scott Aquarium.