The male of the fiddler crabs has one of its claws abnormally enlarged. With this cumbersome large claw, the male feeding and movement ability is compromised. On top of that, their large claws make them easier to be spotted by predators and to some extent, decrease their survival chances. Hence the question was: Why then does male fiddler crabs have one abnormally large claws if it is so disadvantage to them? The answer is in LOVE...
Biologically speaking, this is called sexual selection, where in this case, the female fiddler crabs have a "WEIRD" preferences to mate with males with one abnormally large claws. Hence the results: Male offspring also have one large claws. Thus, this traits are passed on to subsequent generations. Males with claws which are both normal sized will therefore not be able to find mate and hence not able to reproduce. (Note: Love lesson no. 1 from nature: Love may not always be logical)
Pictures of some of the 'hermit crab':
Other organisms featured on the tour:
Assortment of Sea cucumbers
Knobby Cake Sea Star