What Do Blue Crabs Eat?

Written by Kirstin Harrington
Published: January 25, 2023
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Blue crabs, sometimes known as Chesapeake blue crabs or Atlantic blue crabs, are excellent swimmers, in great part because of their fifth set of legs, which is designed like paddles. With their frequently brilliant blue claws and olive-colored shell, they are remarkable creatures.

The adult female blue crab has red tips on her claws. Males can grow to a width of seven to eight inches, whereas females are slightly smaller. In this article, we’ll talk about what these crustaceans eat, where they live, and what makes them different from other crab species! 

Where Do Blue Crabs Live?

The little blue crab larvae start out in the ocean, where they develop and go through numerous molts before returning to the Bay. A crab matures between a year and 18 months after being born.

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North and South America’s Atlantic coasts are home to blue crabs. Blue crabs can be found in Nova Scotia, Canada, Uruguay and the south of Argentina. Large blue crab concentrations can also be found in the Gulf of Mexico, particularly in Louisiana, which matches the Chesapeake Bay regarding blue crab productivity. 

Why do these animals reside here, then? Beyond the wide range of animal and vegetable food available along the coastline, they appreciate the warm coastal waters. Blue crabs favor brackish water mixtures over pure salt or fresh water, and the warm temperatures are perfect for mating.

Additionally, blue crabs have been spotted in European and Japanese waters; they probably traveled there as part of ship ballast. It is unclear what impact blue crabs, a non-native species, will have on the area.

What Do Blue Crabs Eat?

Blue crab under water walking on sandy bottom

Blue crabs play an important role in Chesapeake bay’s delicate ecosystem.

©Jen Helton/Shutterstock.com

These crustaceans are considered scanners and hunters. Blue crabs frequently consume other crabs but also clams, oysters, bugs, mussels, worms, freshly deceased fish, and other types of crustaceans. 

They use their sharp, pointed pinchers to reach the nutrient-rich center of hard-shelled creatures. They use them to tear apart otherwise closed organisms, including clams, oysters, and mussels. If climate change escalates, it is expected that one of the most vulnerable ecosystems, the Chesapeake Bay, which is home to blue crabs, will experience a rise in carbon pollution. 

This alteration will impact the foods available to blue crabs and their development. Blue crabs will likely develop larger shells due to an increase in carbon pollution in the ocean. The Blue Crabs will consequently become bigger and more ferocious predators. Blue crabs that are aggressive and large can eat an increasing number of oysters.

During times of overpopulation, as has occurred recently, notably in the Chesapeake Bay, the elimination of blue crabs significantly impacts the ecology where the crabs once roamed and fed. Blue crabs play an important role in the bay’s delicate ecosystem by managing the populations of the animals and seafood they eat.

What Eats Blue Crabs?

These crabs prey on bigger animals, including sea turtles, birds, and occasionally bigger fish in their estuaries and coastline lagoons. Blue crabs, on the other hand, are smaller and more susceptible to a larger range of attackers when they are birthed or in their larval stage, including small fish and jellyfish

Humans also actively exploit these crabs for their flavorful meat, which has become a crucial component of the Gulf’s economy. An important percentage of the market for blue crab in the United States comes from Gulf-based fisheries, including Louisiana.

Blue Crab Identification and Mating

The blue crab - (Callinectes sapidus)

The blue crab (

Callinectes sapidus



All sexes have sapphire-colored claws, but females have red accents on the points of their pincers as an extra color show. Similarly, if you turn a blue crab over, you may see the sex by looking at the crab’s “apron.” 

The belly’s folded area, known as the apron, has three distinct forms. Male abdomens are T-shaped, juvenile female aprons are triangular, and older female aprons are rounded and circular. Blue crabs mate during the month of October.

Females only mate with a man after they attain sexual maturity. During their lifetime, males will pair with a variety of females. A mound of eggs forms underneath the female crabs’ apron after mating. Up to 2 million eggs may be present in this mass, also known as a sponge. 

The eggs are discharged into the sea in around two weeks, and currents carry them into the water.

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

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About the Author

Kirstin is a writer at A-Z Animals primarily covering animals, news topics, fun places, and helpful tips. Kirstin has been writing on a variety of topics for over five years. She has her real estate license, along with an associates degree in another field. A resident of Minnesota, Kirstin treats her two cats (Spook and Finlay) like the children they are. She never misses an opportunity to explore a thrift store with a coffee in hand, especially if it’s a cold autumn day!

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