Diagnosis: Smoothly curved incision of shell material subparallel to a growth line, originating at the growth margin, and extending posteriorly. The incision is often visible at equivalent growth stages on both valves of a bivalved animal but may look different on opposite valves, if present, depending on the relative convexity of each valve. Incisions vary in length and location on the shell surface depending on how large the prey was at the time of the attack.

Strophodonta demissa with predation trace and associated repair scar on the right side of the specimen subparallel to the growth lines.