Whether served in tacos, with pasta or on their own, we love tucking into a plate of juicy shrimp. We mean prawns. Or wait, what do we mean? Crustaceans can be confounding. And while we wish the prawns vs. shrimp debate boiled down to a question of size, it’s a bit more complicated than that. Because while there are scientific differences between the two (that have nothing to do with size), the answer may actually depend on where you are. Read on for a full crustacean education.
So, what’s the difference between shrimp and prawns?
Both shrimp and prawns are decapods (i.e., crustaceans with 10 legs) but they have anatomical differences that relate to the structure of their gills and claws. The bodies of shrimp have plate-like gills with claws on the two front sets of legs, while prawns have branch-like gills and an extra set of claws, with the frontmost pair being more pronounced than those of shrimp. But even when looking at raw shellfish, it would take a trained eye to notice any of these differences—all of which are practically imperceptible once the seafood specimen has been cooked. The only way to distinguish prawn from shrimp without a careful anatomical examination is that the former has a slightly straighter body, whereas the segmented bodies of shrimp give them a more curved appearance.
Here’s another difference between the two: While shrimp and prawns can be found in both salt and freshwater, most varieties of shrimp are found in saltwater while most prawns live in freshwater (especially the types of prawns we typically eat).
What about size? You may have heard that shrimp are smaller than prawns and while this tends to true in most cases, it’s not a good way to tell these crustaceans apart since there can be large shrimp that are bigger than your standard prawn. So yeah, distinguishing between these guys is no easy feat.
Can you taste the difference?
Not really. While different varieties of shrimp and prawns may vary in taste and texture depending on their diet and habitat, there is no distinct difference in flavor between the two which means that they can easily be substituted for one another in recipes.
And which one should I order at a restaurant?
Well, that depends on where you are. Here’s where it gets extra confusing: Although there are scientific distinctions between prawns and shrimp, that information has very little bearing on how the two terms are used (i.e., interchangeably) in the world of cooking and dining. Per the experts at Cook’s Illustrated: “In Britain and in many Asian countries, it’s all about size: Small crustaceans are shrimp; larger ones, prawns.” If you look at the facts, this just isn’t true—but the misconception is so prevalent that it might as well be. In other words, when you encounter prawns on a menu—even in the United States—there’s a decent chance that the term was chosen to indicate a larger species of shellfish (even if the crustacean in question is actually just a jumbo shrimp).
To further complicate matters, geography also comes into play when it comes to these two terms in recipes and restaurant settings alike. For example, “prawn” is more likely to be used across the board in southern states (including as a descriptor for small shellfish), while shrimp is the preferred catch-all term for crustaceans in the northeast.
The bottom line
The factual differences between prawns and shrimp are far more likely to come up in a game of trivia than in your kitchen, so what’s the takeaway? First, if you’re ordering at a restaurant and size matters to you, check with your server to determine the size of the shellfish in a dish regardless of whether you see the word shrimp or prawn on the menu. That said, the flavor of any given crustacean has to do with the species (and what it was eating before you eat), not its size or body structure. For this reason, it’s totally fine to use prawns and shrimp interchangeably in recipes—a conclusion that the Cook’s Illustrated test kitchen also confirmed but with one caveat: It doesn’t matter if you use shrimp or prawn, just make sure the shellfish count is the same as what the recipe calls for so cooking times aren’t affected.