like what others say, it's virtually indestructable(to pain's techniques, to naruto/kyubi's corroding chakra), the katsuyu clones only died when their chakra were all sucked by the shinju roots
there seems to be only one of katsuyu, and only by having two summoners (tsunade+sakura) then they can summon 1/10 of her real size
You must be registered for see images
which means the katsuyu clones we've seen here and in pain's invasion were small but still enough to heal/protect everybody (pain invasion/4th shinobi war)
You must be registered for see images
someone had a thread on this
You must be registered for see links