I wouldn't. That's the short answer. Most angels, even Centropyge sp. are nippers especially on clams. Having said that I've seen individuals that were model citizens, and others that were a menace.
I had a coral beauty that ate Xenia by the truckload but left everything else alone. Another tank I maintain had a
flame angel that picked at fleshy corals like Scolymia, Trachyphillia but left things like Platygyra and Sarcophyton alone - so we just adapted the coral population to accomodate.
I've got a customer with a coral tank with an Imperator angel - he sent me pix (gorgeous!) and I asked if the angel bothered anything and he said no but he keeps the angel well fed.
If you do opt for the clam, keep a close eye and if there's any trouble, be prepared to remove one or the other.
Jenn
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Member of the "J" Crowd & the BRW Crowd!
LFS Owner:
Imagine Ocean

Just keep skimming, just keep skimming, just keep skimming, skimming skimming! What do we do? We skim, skim, skim!