Boxer Crab
Weirdness 9/10

The crab that carries living anemones as weapons and clones them

This crab carries a living, stinging anemone in each claw, and if it loses one it clones the other.

📋 Fact File
🐾 Crustacean🍽️ Omnivore (shares scraps with its anemones)
📏 Size
About 1-2.5 cm (up to 1 in) across the shell
About the size of your thumbnail
Lifespan
Up to about 5 years (in aquariums; wild lifespan unknown)
Not EvaluatedThis tiny crab has never been assessed for the IUCN Red List, though the coral reefs it lives on face growing pressure.
🤔 Guess first

Which one is REALLY true about the Boxer Crab?

The short version

The boxer crab holds a live stinging sea anemone in each claw and waves them at attackers like pom-poms. If it loses one, it tears the remaining anemone in half and each piece regenerates into a whole animal — one of the only known cases of an animal deliberately cloning another species.

Why it's so weird

  • The Boxer Crab carries a live stinging sea anemone in each claw and waves them at attackers like a pair of pom-poms.
  • The Boxer Crab is barely the size of a fingernail, so it lets the anemones do all the stinging for it.
  • The Boxer Crab tears its remaining anemone directly in half when it loses one, and each half into a complete animal.
  • The Boxer Crab is one of the only creatures known to deliberately clone another species.
  • The Boxer Crab carries its anemones along to fresh food as it walks, so the anemones get fed too.
📏 How big is it, really?
Boxer Crab
2 cm
Boxer Crab
a 7-year-old
1.2 m
🧒

You could line up about 61 of them along a 7-year-old!