Red algae on trochus snails?

[mrbacony]

I just received my 10 pack of trochus snails from WWC. Three or four of them came with this red algae, looking stuff on their shells. Any idea what this is, and is it invasive? Thanks.

 

[Timfish]

I'm of the opinion all the invasive alga are always present in aquaria. It's the equilibrium of the ecosystem that either retards or promotes their growth. So while it might be a rapidly reproducing species of algae on your trochus I wouldn't hesitate to put them in my tank. (I would point out I wouldn't use trochus to deal with algae, urchins work much better.) If it bothers you, you could VERY GENTLY AND CAREFULLY (you need to avoid getting any H2O2 on the snail itself) use a toothbrush dipped in H2O2 to remove the algae

 

[mrbacony]

Thanks for that. I did go ahead and put them in my tank. Almost immediately, my Emerald crab started picking the algae off the shell. He has pretty much cleaned it up overnight.