There are few crustaceans as misunderstood as the shrimp and the prawn. Some people think they’re the same thing; others think they differ only by size; others think they’re simply called different things in different countries, or regions, or states. And yet: all of these people are wrong! Shrimp and prawns are completely different creatures. Yes, they’re both decapods—which means they have external skeletons and 10 legs—but that’s where the similarities end. Shrimp belong to the sub-order Pleocyemata, and prawns belong to the sub-order Dendrobranchiata. Let’s explore what this difference means, shall we?
GILLS: As you may remember from ninth-grade biology, gills are structured in a way that maximizes their surface area. Shrimp have plate-like gills, which consist of flat, layered arrangements; prawns have branching gills, which is where I’m assuming the “branchiata” part of their name comes from.
CLAWS AND PINCERS: Shrimp have claws on two pairs of their legs, and their front pincers are the largest. Prawns have claws on three pairs of their legs, and their second pincers are larger than their front ones.
BODY STRUCTURE: Let’s say these decapods have four distinct areas of their body: the head, the thorax (the area right behind the head), the abdomen (the “torso”), and the tail. In prawns, the head overlaps with the thorax, which overlaps with the abdomen—much like shingles on a roof. In shrimp, the thorax overlaps with both the head and the abdomen, like a cummerbund.
HABITAT: Prawns live in fresh water, while shrimp can come from either fresh water or salt water (though the majority of species come from salt water). Fun fact: the colder the water the shrimp is from, the smaller the size! (I always thought the tiny shrimp in Scandinavian-esque shrimp salads were creepy, and I no longer do.)
SIZE: Generally speaking, prawns are larger than shrimp—though this can differ depending on the species.
TASTE: Anyone who tries to tell you that shrimp and prawns taste different is wrong. Sure, some prawns are sweeter than shrimp, and vice versa—but it’s really dependent on the species, rather than the sub-orders as a whole.