Mixing angelfish and Tridacnid clams is risky business. Things might seem harmonious at first, but over time the angel might develop a taste for the clam’s mantle tissue. This usually just results in the clam withdrawing into its shell for long periods of time. Unfortunately though, the long term interactions between clams and angelfish will likely end up in either the clam dying, or potentially even the angel meeting its demise. In a fairly isolated incident, an angelfish in a local hobbyists tank began nipping at a clam. It got too close and the clam closed down tight on the fish. The angel obviously died within minutes, and the ordeal caused enough issues for the clam that it also died a short time later.