Tonight i noticed a nassarius snail on my clam i tried pulling him off but the clam closed on him i tried to pull him out but could'nt i noticed a dark brown substance looked like an aptasia almost that i am thinking came from the clam,after a while the snail got away , the clam is closed up super tight my question is do snails attack clams also do clams give off toxins that could be harmful to people since my hands were in the tank and i do hav cuts on my hands. Also do clams recover easily from something like this.Sorry if these are dumb questions not familar with clams.