In the US, shrimp is the most commonly eaten seafood, followed by fish such as tuna, salmon, and tilapia, with crab and clams being the only other shellfish in the top 10.1 Other common seafood include lobsters, mussels, oysters, and scallops.
In case you were wondering, shrimp and prawns are indeed different species, but both come in a variety of sizes and taste very similar. Thus, for all intents and purposes, it is not really crucial to know the difference and they can be used interchangeably.2
Shrimp can be farmed or wild caught, both of which can be sustainable or not depending on how the shrimp was raised/caught. That said, look for certifications from the Marine Stewardship Council or the Best Aquaculture Practices label to help you decide. Otherwise, wild caught shrimp from North America is probably your best bet.3 To avoid contaminants, do not purchase farmed shrimp from Asia.4
If you buy frozen shrimp, thaw overnight in the fridge or run them under cold water in a colander until thawed. Be careful not to overcook shrimp - depending on the preparation method, shrimp cooks in just minutes (it is done when pink and opaque). A lot of frozen shrimp has been peeled and deveined already, but if it hasn't been, it isn't difficult to learn how to peel and deveine shrimp.
Lobster and crab can be purchased fresh, frozen, and of course, live. Live lobsters and crabs are often boiled (or even steamed) while still alive, but if you cannot stomach that, you can also kill them shortly before preparing them.
Fresh mollusks (e.g. clams, oysters, mussels, and scallops) must be properly cleaned and opened with a knife or by steaming. Mollusks can be enjoyed raw or cooked.
Nutrition DNA
The nutrition DNA of seafood. For example, you can see that 100g seafood covers 84% of your daily need of Cholesterol and 68% of the recommended Selenium intake. Hover over the bars to see which nutrient is covered.