0303.46.00.00 - Southern bluefin tunas (Thunnus maccoyii)

This HTS classification covers frozen Southern bluefin tunas, specifically identified by the scientific name *Thunnus maccoyii*. These tunas are distinguished by their origin and species, making them a distinct category within the broader group of frozen tunas. The classification applies to whole fish or those not yet processed into fillets or other meat forms, aligning with the scope of heading 0303 for frozen fish.

The primary distinction of this category from its siblings lies in the specific species of bluefin tuna. While other subheadings cover Atlantic and Pacific bluefin tunas (*Thunnus thynnus*, *Thunnus orientalis*), this classification is exclusively for the Southern bluefin tuna (*Thunnus maccoyii*). This genetic and geographic specificity is a critical factor in accurate customs classification, ensuring trade data reflects distinct tuna varieties.

As this is a leaf node, there are no further subcategories within 0303.46.00.00. The classification ends at this specific identification of the Southern bluefin tuna species. Therefore, any frozen tuna falling under this heading must meet the criteria of being the Southern bluefin species, and not any other tuna variety listed under sibling subheadings within 0303.4.