Crayfish are small, freshwater crustaceans commonly used in southern American cooking. They are often reddish or brown and have segmented bodies made up of two main sections.
Depending on the region, crayfish may go by several different names. These include crawfish, crawdaddies, craydids, and even freshwater lobsters.
That last one may be the most different, but there is a reason for it.
Crayfish are very similar to lobsters, as well as various other crustaceans. They belong to the Decapod order, which contains over 15,000 species of animals.
Learn more about nine other animals similar to the crayfish in the list below.
1. California Spiny Lobster
Scientific name: Panulirus interruptus
Similarity: Though part of different infraorder, spiny lobsters and crayfish share physical similarities.
“True” lobsters are part of the infraorder Astacidea alongside crayfish. Spiny lobsters lack the claws of these true lobsters. But they’re still only one taxonomic step removed from crayfish.
The two are part of the Pleocyemata suborder and share the same body types and active periods. They both have multi-segmented bodies and several pairs of swimming and walking legs.
Both animals are also nocturnal, meaning they’re most active at night.
Furthermore, spiny lobsters and crayfish have the same gill structure as each other. This separates them from crustaceans in the Dendrobranchiata suborder.
Instead of “tree-like” gills, pleocyemates have flat plates under their exoskeletons.
2. Cherry Shrimp
Scientific name: Neocaridina davidi
Similarity: Cherry shrimp and crayfish are both small, reddish creatures that live in freshwater areas.
Cherry shrimp and crayfish are disparate crustaceans, but they look very much alike. They’re both very tiny, averaging between less than an inch and just below six inches long (10-150 mm).
They also have red shells while in the wild, which is a rarer color in shrimp than it is crayfish. This makes them more like crayfish than most other species.
Shrimp live in either fresh or saltwater while most crayfish prefer fresh water. But the cherry shrimp in particular prefers freshwater like its crayfish cousins.
3. Chinese Mitten Crab
Scientific name: Eriocheir sinensis
Similarity: This crab lives in freshwater like most crayfish and is a popular food source in Singapore.
Their round shape and furry claws make this crab seem very different from a crayfish at first. However, there are similarities. Crayfish and the Chinese mitten crab are both freshwater crustaceans.
Also known as hairy crabs, these crustaceans begin life in saltwater to brackish water. As they reach maturity, they migrate to freshwater.
In addition, hairy crabs are a popular seasonal food in Singapore. Both true crayfish and certain lobsters that share the name are also very popular in that area.
4. Coconut Crab
Scientific name: Birgus latro
Similarity: A hermit crab that can match a giant crayfish for its size and lifespan.
On average, crayfish are very tiny creatures, only reaching about 7 inches long.
Yet one species can reach up to 16 inches (120 mm) or more: the Tasmanian giant freshwater crayfish. It’s not only the largest crayfish, but the largest known freshwater vertebrate.
These crayfish can also live for a very long time; the oldest known specimen was 60 years old. Another crustacean that matches this crayfish’s size and age is the coconut crab.
These hermit crabs can reach 70 years old and are massive, reaching over three feet (one meter) wide. They are also record-holders for their size. Coconut crabs are the largest terrestrial arthropods in the world.
5. Flathead Lobster
Scientific name: Thenus orientalis
Similarity: A “walking” crustacean that shares the same name as crayfish in certain areas of the world.
Flathead lobsters are a type of slipper lobster.
These are not “true” lobsters, as they lack the signature front claws. However, they’re still members of Pleocyemata, putting them somewhat close to crayfish.
Strangely, these lobsters are still interchangeable with crayfish in Singapore. Both animals go by the name “crayfish” in that region.
Flathead lobsters and true crayfish are also popular parts of Singaporean cuisine. This is also true of crayfish in the American south.
6. Gray Hermit Crab
Scientific name: Pagurus pollicaris
Similarity: Both crustaceans are part of the suborder Pleocyemata and lay eggs in the same way.
At first, hermit crabs and crayfish may not seem alike. But they are very close cousins in the Pleocyemata suborder. All pleocyemates have segmented bodies and lay fertilized eggs that the females incubate.
They are also “walking” or “crawling” decapods. This means they don’t use swimming as their primary mode of transportation.
Crayfish and hermit crabs do still have swimming legs, which hang at the back under their tails. This is where their fertilized eggs stick until they’re ready to hatch.
On the front half of their bodies are the pereiopods or walking legs. These provide their main method of movement.
7. Maine Lobster
Scientific name: Homarus americanus
Similarity: Crayfish look much like smaller lobsters with red coloring and without the large claws.
Another member of Pleocyemata, the Maine lobster is a famous part of New England cuisine. This is similar to the crayfish’s place of honor in southern cuisine, especially Cajun.
Furthermore, Maine or American lobsters have the same elongated body type. Their bodies also consist of exactly 20 segments. On their front are the pereiopods, their walking legs.
True lobsters with claws, like this lobster, are some of the closest relatives to crayfish. Both animals belong to the infraorder Astacidea, within the Pleocyemata suborder.
8. Norway Lobster
Scientific name: Nephrops norvegicus
Similarity: This true lobster is closer in size to crayfish than others and molts their shell the same way.
Also known as langoustine or scampi, the Norway lobster is much smaller than traditional Maine lobsters. They only grow to an average of 10 inches (25 cm) long; this isn’t much bigger than the 6.9-inch (17.5 cm) crayfish.
Due to their exoskeletons, crayfish and Norway lobsters have to molt in order to grow. Molting is the process of shedding the outer protective layer while a new one grows in its place.
Norway lobsters and crayfish can even regenerate. If they lose limbs or suffer damage, they can regrow those parts.
9. Ohio River Shrimp
Scientific name: Macrobrachium ohione
Similarity: This species of shrimp lives in freshwater rivers like crayfish and has two sets of antennae.
Though many shrimp species live in the ocean, there are several that prefer freshwater. The Ohio river shrimp is one of these species, although there are not many in the Ohio river anymore.
Pollution and dams have led to the decline of this shrimp’s population in some areas. However, it’s still abundant in Louisiana, where crayfish are also common.
Finally, crayfish and Ohio river shrimp have two sets of antennae at the front of their heads. One pair is always longer than the other. These antennae are extra sensitive to smells, vibrations, and also touch.
Many crustaceans, especially those with the same taxonomies, look very like each other. Sometimes the only way to tell them apart is their size.
Crayfish are a type of crustacean that has a lot in common with several others. They have the segmented bodies that all Decapods have, so they have physical similarities to shrimp, lobsters, and even hermit crabs.
They also have similar egg-laying traits, molting abilities, and well-defined walking legs.
In short, crayfish can look a lot like some of the animals in this list. Even when their appearance is different, they can also share some of the same habits.
Use this list to learn what crayfish have in common with other crustaceans throughout the world.