These are exceptionally large farmed Black Tiger shrimp (Penaeus monodon) sold by the pound at Costco's seafood counter. The "U-4" count designation means there are under 4 shrimp per pound, making these among the largest shrimp sizes commercially available.

Sold whole with heads on, these shrimp retain their full flavor and impressive visual presentation. The head-on format is preferred by many cooks because the heads and shells contribute rich depth to stocks, bisques, and sauces. Black Tiger shrimp are recognizable by their distinctive dark stripes across a gray-blue shell, and they turn a vibrant orange-red when cooked.

Black Tiger shrimp have a firm, meaty texture and a mild, sweet flavor that holds up well to grilling, steaming, sautéing, and baking. Their size makes them ideal for centerpiece dishes such as grilled whole shrimp, shrimp scampi, or Thai-style preparations with aromatics. They are farmed and sold raw.