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Brachyura

Ocean crabs are a diverse group of marine crustaceans that belong to the order Decapoda. They have a hard exoskeleton and five pairs of legs and range in size from small to large. Ocean crabs can be found in a variety of colors and habitats and are omnivorous, feeding on a variety of foods including plants, algae, and small invertebrates. They are social animals and use their claws and legs for defense and capturing food. There are thousands of known species of ocean crabs, including those in the families Grapsidae, Majidae, Portunidae, and Xanthidae.
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Ocean crabs have a hard exoskeleton and five pairs of legs. They range in size from small species that are less than an inch in length to large species that can grow up to about 4 feet in length. 

Ocean crabs can be found in a variety of colors, including red, orange, yellow, green, blue, and brown.

Ocean crabs have two types of claws. The larger, more powerful claw is called the crusher claw, while the smaller, weaker claw is called the cutter claw. The crusher claw is used to crush and break up food, while the cutter claw is used to cut and tear food into small pieces. Both claws are essential for the crab to feed itself, and they are also used for defense against predators. The claws are also used for digging for food, constructing burrows and as an anchor when the crab is stationary.

Ocean crabs are found in the oceans all around the world, in both shallow and deep waters. They can be found in a variety of habitats, including coral reefs, rocky shores, sandy beaches, and muddy estuaries.


Ocean crabs are omnivorous and will eat a variety of foods, including plants, algae, and small invertebrates. Some species of ocean crabs are scavengers and will feed on dead plants and animals, while others are predatory and will hunt and capture live prey.


Ocean crabs are social animals and can often be found in large groups. They use their claws and legs to defend themselves and to capture food. Some species of ocean crabs are also able to swim using their legs or by using their claws to paddle through the water.


There are many different species of ocean crabs, and they can be divided into several families based on their characteristics. Here is more information about some of the families of ocean crabs:

  • Grapsidae: This family includes the mud crabs, which are small to medium-sized crabs that are found in the intertidal zone of tropical and subtropical regions.
  • Majidae: This family includes the spider crabs, which are named for their long, spindly legs. 
  • Portunidae: This family includes the swimming crabs, which are found in the shallow waters of the Atlantic, Pacific, and Indian oceans. 
  • Xanthidae: This family includes mud crabs and the mangrove crabs, which are found in the intertidal zone of tropical and subtropical regions.