they're called mole crabs, and we've got them here in CA, they inhabit most beaches, the ones i get can be around 2 inches
i've kept them in a 24 gallon nano cube with no problems (except for the mantis shrimp!
) the current of the nano cube allows them to filter feed, and the tank was cycled so i think they had plankton and things floating around to snack on, but adding maybe marine snow occasionally or some brine shrimp might not be a bad idea!
my blue lobster and peacock mantis shrimp love them! the lobster molted twice in one month due to his diet! but be careful if you live in a polluted area, then these little guys may have diseases in them!
PS: If you live in CA don't bother trying to get the big ones until the summer/spring time, otherwise they're smaller than 1 cm during the winter, probably same in Florida, trust me, i've been doing this since i was 5 yrs old!
