Whelk or Conch?

[Tarc83]

I bought this at my lfs a few days ago as a FL fighting conch and found it eating a snail or what look like eating a snail. I need help to identify if it is a conch or a whelk

 

[gnasher]

That's a crown conch. They're not true conchs though, they eat meat.

 

[pagojoe]

Yep. It's called a conch, but it's not very closely related to the true conchs (strombids).