Snail ID

[b.j.]

My friend recently went on vacation and found some snails and some clams. He put maybe ten of the snails in his tank and 4 clams. My question is , are these good snails? The second on is there are barnicals on the clams will they take over his tank? I wanted to ask you guys becuase I needed backup to tell him that just becuase it lives in the ocean dosn't mean it is good for your tank!
The snails have black bodies, and striped antenas.

 

[sickboy]

The snail with the black base and silver swirl on top looks like a margarita snail, but I'm not sure on the others or the clams.

 

[samurai_sushi]

The bivalves kinda look like mussels.

 

[renogaw]

snails look like periwinkles, which are no good for our tanks. they are tidal snails which close up once the water recesses, and stay closed until the tide comes back in. if they crawl out of your water (or, when rather) he'll have to keep on popping them back in. plus they reproduce like mad WITH natural predators, what will they do without em?
you should explain to him that the animals near your beaches are used to colder waters which keep more oxygen in the water than a reef tank. putting them into warmer waters makes them sorta have to work harder to get the oxygen. plus, there could be diseases, parasites, etc that he just introduced.

 

[b.j.]

Thanks for the help guys