bobf
Fishaholic
Are there any PEACEFUL crabs then? Which has the least disadvantages for a friendly reef tank?
Porcelain and boxer(Pom Pom) crabs are peacfull.
I have a porcelain crab - interesting little beast which eats algae with his big claws and is a filter feeder too.
Has adapted inner claws with very fine filaments between the 'fingers' (bit like the fronds on a feather duster/spiral worm) which he holds over his head to collect passing stuff. Mostly nocturnal and comes out as soon as the halides go off (actinics still on) and climbs to a high point in a strong flow position if he's filter feeding, or potters about if he's after algae.
Picture below from here
Porcelain crab