Aside from size and species limits on collecting for your own tank, there are often times blanket laws that cover animals in general that one might need to be aware of. For example, in most states it's illegal to keep any animal found naturally in captivity without proper permits. People usually view that law in regrads to animals like deer, raccoons and the like. However, in most states this applies to fish found in the waters as well. So just because one has a fishing permit, catches a legal species of legal size doesn't mean he or she can keep it as a pet.
This applies to purchased animals as well. For example, a shark caught in some other country legally may be imported legally and sold legally....however due to that particular animals habitat ranging into local waters, it is then illegal due to the blanket rules.
Does this make scense or am being too confusing? I'm all for keeping sharks (obviously). I just want to make sure it gets done correctly.