|A Note on Shellfish|
Shellfish itself isn't useful for stock, but the shells of lobsters, shrimps, and crabs add a briny flavor.
Although there's no reason you can't make stock from fillets, steaks, or whole fish, it's a waste. Instead, save your fish scraps in the freezer, buy them from us, or do both. If you really want to use intact fish for stock, use the cheapest you can find. The only fish you shouldn't use are the high-fat kinds like mackerel, herring, and salmon.