Generally, fresh seafood, especially shrimp, is sold in shells in supermarkets. If you meet Argentine red shrimp without a head, it is likely that the head is black. It's a little stale. I have to process it before I sell it. When buying shrimp, it is recommended to buy fresh whole shrimp, which will taste better when cooking. Argentine red shrimp is often so red because it lives on the bottom of the sea, which makes it rich in iodine, phosphorus and precious astaxanthin. The content of astaxanthin in Argentina is 9 times that of common shrimp.