Filleting

The filleting technique begins with a diagonal incision behind the pectoral fin down to the backbone, followed by a horizontal cut along the backbone from head to tail, lifting the fillet away from the ribs. Pin bones (intramuscular Y-bones) in many species (salmon, pike, trout) must be located by running a finger along the fillet and removed with needle-nose pliers or tweezers. Skin removal requires the knife angled flat between skin and flesh. Round fish (salmon, tuna) yield two fillets; flatfish (sole, flounder) yield four smaller fillets from both sides of the dorsal and ventral surfaces. Yield percentage (fillet weight/whole fish weight) averages 35–40% for round fish but varies from 25% in spiny reef fish to 55% in salmon.