Juv coris could be juv clown wrasse or juv yellow coris/ yellow wrasse.... the difference in adult and juv is that the adult eats your shrimps, and wreck havoc in your tank while the juv eat the pesky snails
Yes 6-lines do feed on them but six line wrasse diet are so wide thus chances of removing the snail through them are rather slim... Try leopard wrasse, or juv coris..... They are very good pest control fish
Nah dun have one... dun think the recent clams death are cause by the dreaded disease. Instead i feel that the main culprit is the little known pyramid snail, tiny snail that feed on clam tissue.... That are very hard to spot or even to remove and they bloom to plague population in a short time....