Crawfish Vs Shrimp: What Are the Differences?

Crawfish, more commonly known as crayfish, are a common sight in freshwater sources like rivers and streams. They’re a favorite food of many people in the southern United States and beyond. Another creature that is featured in the same cuisine as crawfish is shrimp. At a glance, these aquatic animals might seem similar, but they’re very distinct from one another. That’s why we’ve decided to show you the various differences between a crawfish vs shrimp, so you know exactly what animal you’re seeing in the water or on your plate.  

Comparing a Crawfish and a Shrimp

The Key Differences Between a Crawfish vs Shrimp

Crawfish and shrimp differ the most in size, morphology, and the type of water in which they live. Crawfish are larger than shrimp, have long, thin pincers where the shrimp have none, and exclusively live in freshwater whereas shrimp live in freshwater and saltwater.

These facts highlight the main differences between each creature. However, we are going to examine each of these unique qualities in greater depth and look at other elements that separate these animals from one another.

Crawfish vs Shrimp: Size

Shrimp are smaller than crawfish in the vast majority of cases. Crawfish weigh anywhere between 0.5lbs and 2.6lbs, but they can also grow very large. For example, the Astacopsis gouldi in Tasmania can measure about 16 inches and weighs 8lbs at its largest. These are even larger than the giant tiger prawns, the largest shrimp.

However, most shrimp weigh about 0.6-10 ounces, and they can reach lengths between 0.8 inches and 9.8 inches. The variations in size ensure that size alone is not the best way to tell these creatures apart.

Crawfish vs Shrimp: Morphology

Crawfish strongly resemble lobsters, but they share many qualities with shrimp. For example, crayfish and shrimp are both decapods, so they each have 10 legs and two body segments called the cephalothorax and the abdomen.

The greatest morphological difference between crawfish and shrimp is that crawfish have pincers and shrimp do not have them. These pincers are not as robust as those on a lobster, but they’re large enough that they have earned crawfish the moniker “the freshwater lobster.”

Also, aside from looking like a lobster, crawfish have a tough exoskeleton. In fact, this exoskeleton is harder than most shrimp. Both exoskeletons are segmented in similar fashions, and they can even integrate some of the same colors.

Nevertheless, the two creatures are easy to tell apart when you look at their body shape with respect to their claws.  

Crawfish vs Shrimp: Water Type

Crawfish live in freshwater, but shrimp live in saltwater and freshwater alike. Specifically, crawfish are usually found in bodies of water such as rivers, swamps, lakes, and even irrigation channels. Shrimp are found in oceans all around the water along with some brackish inlets.

A fair amount of confusion has stemmed from shrimp living in freshwater and saltwater. Some believe that a shrimp living in freshwater is called a prawn. However, there is no such distinction between the creatures. Prawns belong to the Dendrobranchiata suborder within the decapod order and shrimp belong to Caridea, so they’re not as closely related as people imagine.

Crawfish vs Shrimp: Phylogenic Families

Crayfish belong to the Astacoidea superfamily that includes lobsters, and shrimp belong to the infraorder Caridea. Although both creatures belong to the order Decapoda, the truth is that they are rather distant relations compared to other species. For example, the crayfish are within the same infraorder as lobsters, but they diverge from true shrimp at the Pleocyemata suborder.

Crawfish vs Shrimp: Number of Species

Crawfish have 400 species and shrimp have 1,900 species. Although not every member of these species is edible by humans, they are constantly fished from waters around the world.

Some estimates claim that about 7.4 billion pounds of shrimp are taken out of the ocean every year so they can be processed and sold as food. Fewer crawfish are taken from the waterways around the world, but it’s believed that Louisiana’s crawfish industry alone accounts for about 150 million pounds of crawfish being produced from its waters every year.

All told, shrimp and crawfish are very important animals for feeding humans. However, shrimp are more important as a species because they comprise a huge part of other animals’ diets, like whales, seabirds, dolphins, and crabs.

Crawfish vs Shrimp: Diet

Shrimp eat algae, plankton, aquatic plants, and small fish, but crawfish eat worms, algae, fish, and sometimes shrimp. Shrimp are opportunistic feeds that don’t have much in the way of the ability to attack and eat their prey.

However, crawfish have rather strong pincers that allow them to grab, crush, and tear their prey. As true predators, they have a wider variety of foods available to them in the water.

Shrimp and crawfish are both important animals in their respective food chains. They have many things in common since they belong to the same phylogenic family. Both animals are often confused with each other and a variety of other animals. Nevertheless, you should now have a better idea of how crawfish and shrimp are different from each other.

With this information in mind, you’ll know precisely how to identify these aquatic animals no matter how you encounter them!  

The photo featured at the top of this post is © rugco/Shutterstock.com