For about two or three days each year in early July, crabs are everywhere. Thousands of red and purple carapaces and gigantic claws swarm Tamarindo’s shorelines in a mass exodus. They click and clack around the beaches, roads and even parking lots. The Tamarindo estuary overflows with them. And these aren’t just any ordinary crabs – they are huge, angry-looking creatures the size of a small melon.

So what are these things, and where do they come from? Here are 9 things I bet you didn’t know about land crabs in Costa Rica.


1) This species is a nocturnal burrowing crab that exists all year round; but they come out en masse during the day for a few days per year to mate.

2) Their average lifespan is about 11 years (which is surprising, considering how many end up smashed on the side of the road). They reach sexual maturity after about 4 years.

3) If you’re wondering if you can eat them, the answer is yes (at least according to local beachcombers). Many Costa Ricans who have grown up in Guanacaste swear they taste delicious if prepared correctly.

4) These land crabs live most of their adult lives in mangroves and wet forests, burrowed within tunnels 3-5 inches wide and up to 5-feet deep.

5) They can be found as far as 5 miles away from the ocean.

6) Land crabs are mostly vegetarian. They subsist mainly on seeds, fruit, berries, leaves and vegetable matter (although they’ll occasionally snack on small insects).

7) Younger crabs are more vibrant in color. Older crabs look more dull and grey. Females tend to be less vibrant than males.


8) Apparently, in some circles these unique-looking creatures are captured and kept as pets. They can be purchased for about $20 a piece.

9) While I could not find an exact species for this particular crab, they are likely related to what are known as “Halloween crabs,” or “tajalines” here in Costa Rica. The specimens seen in Tamarindo are probably closely related to the species Gecarcinus quadratus. (Note that the crabs in here in Guanacaste have white claws, while Geocarcinus quadratus is typically pictured as having purple claws.)

Photo credits: Genna Marie of Tamarindo Family Photos