[medio]

Other day I took a couple of photos of a Semaphore Crab - Heloecius cordiformis

http://farm8.staticflickr.com/7070/6...964c635b4d.jpg

According to my book and looking at images on the web, this is a juvenile because of the bright colouring of the claws. As the crab reaches maturity, it becomes a more uniform shade of drab purple.

My question is why the young crabs would have the bright colours? Doesn't seem smart to draw attention to yourself when you're only small. Can't be a mating/courtship thing either.

Suggestions?