Fish fillets

Strips of flesh sliced parallel to the backbone, beginning just behind the head; fins, bones and discoloured flesh usually removed, though skin may remain. Fillets are the most familiar retail form of fish, and their quality depends on freshness, careful handling and the cold chain. Fillet yield — typically 30–50% of whole weight — is a key economic metric, improved by precise cutting and recovery of frames for mince. Gapening, blood spots and parasites are quality defects; rapid chilling to 0°C, modified-atmosphere packaging and strict cold-chain discipline preserve the fresh appearance and flavour.