CBP may challenge an NES classification if the species could reasonably fall under a named heading (e.g., flatfish or salmonids). Importers should retain scientific species identification — ideally from the foreign supplier's documentation or a third-party lab — to defend the NES classification and avoid reclassification and associated duty adjustments.

Yes. Certain tropical reef fish — particularly large predatory species like barracuda and some groupers — carry elevated ciguatoxin risk. FDA may detain or refuse shipments of species with known ciguatera associations, and importers should assess species-specific risk before sourcing. Consult a licensed customs broker or regulatory counsel for current FDA guidance on high-risk species.