Crab Vs Lobster: Are The Two Really Related? How Are They Different?

Supriya Jain
Sep 01, 2023 By Supriya Jain
Originally Published on Nov 17, 2021
Edited by Jade Scott
Fact-checked by Sudeshna Nag
crab on the beach
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Age: 3-18
Read time: 7.5 Min

Oceans are vast water worlds where several varieties of animals and plants reside on the seafloor.

The depths of oceans are home to different species of animals. Two of the most famous ones are crabs and lobsters. King crabs and lobsters belong to the family of decapod crustaceans but there are certain differences in terms of their appearance.

Crab species members like the king crab have a thick shell, called the exoskeleton, which covers their entire body, including the small tail. Since they are invertebrates, it is their exoskeleton that helps them to function properly and provides protection from predators. Crabs have around five pairs of legs and are omnivores.

There are different species of crabs that have distinct characteristics. The marine crab, for instance, has gills and breathes underwater but true land crabs have cavities that function as lungs, allowing them to breathe on land.

Lobsters also belong to the order of Decapoda. They are found in various colors including brown, red, orange, and blue. Lobsters too have shells on their body for protection.

They are omnivores and love to eat clams, mollusks, worms, and some plants. The American lobster has a lifespan of around 100 years while their Caribbean counterparts have a lifespan of around 20 years and their average litter size is 12.

Interestingly, lobsters have their teeth in the stomach and their brains are said to be located in the throat.

After reading about the differences between the species of crab and lobster, why not also read about hermit crab habitat and different types of crabs?

What is the difference between crab and lobster?

Crabs and lobsters are both shelled animals. They both belong to Crustacea. Animals belonging to Crustacea have a strong exoskeleton that molds when they become older and grow in size. Even though crabs and lobsters have certain commonalities among them, they are different sea creatures. The most visible difference can be seen in their appearance.

Both crabs and lobsters have five pairs of legs. Lobsters and crabs tend to have 10 legs out of which the front two legs are called claws. King crabs walk sideways with their claws held high. When they walk sideways, they are aware of their surroundings and can quickly assess dangers that might come their way.

While crabs are round in structure, lobsters are long. Lobsters and crabs have different ways of moving towards their destination. Crabs tend to move sideways and lobsters move backward and forward. Both crabs and lobsters can be found in freshwater but it is more common to find them in the sea.

Crabs vs lobsters are not that difficult to identify and understand. They are unique and, therefore, possess certain distinct characteristics. Some male crabs and female crabs live alone while others live in a group. However, lobsters always live alone.

Although both lobsters and crabs eat animals, lobsters eat a wider variety. Sometimes they even eat small crabs and lobsters when under stress. There are different varieties of crabs that exist in the sea like the snow crab, rock crab, king crab, and spider crab, among others.

Varieties of lobsters are also found worldwide. There are varieties including the Australian lobster, spiny lobsters, Reef lobster, marine lobster, and some more. These crustaceans are the most favored in seafood cuisine, not only in coastal areas but in cities as well.

Crab and lobster are cooked differently and are served as seafood after the meat inside the shells is completely cooked. Seafood is a great source of protein and the crustaceans are delicious. Their exoskeleton is removed slowly after boiling it, to ensure that the exoskeleton becomes easy to crack and remove.

Crabs Vs Lobsters Vs Scorpion

Crabs, lobsters, and scorpions are a deadly combination as scorpions are poisonous animals that can lead to deadly attacks. Crabs and lobsters are commonly found in the sea while scorpions live on the ground.

Scorpions can stay alive and move around in the water for two days while lobsters and sea crabs can remain on land for extended periods of time. Both male and female crabs roam around on the seafloor.

Scorpions are very fast and poisonous. The tail of a scorpion is much longer than the tails of crabs and lobsters. While lobsters are somewhat related to cockroaches, scorpions are closer to the sand family of spiders. Crabs have five pairs of legs, with two legs converted into claws, which is the same as lobsters.

Scorpions have eight legs along with their pincers. Lobsters have huge claws, larger than that of crabs. Male and female crabs and lobsters roam around the seafloor.

Lobsters and crabs walk slowly and use their first pair of legs to grab their prey. As both the species move slowly, they are able to reach get near to their food undetected. This allows lobsters and crabs to use their claws to get hold of the prey.

All species of crabs are known to walk sideways but scorpions and lobsters move forward and backward. While crabs can roam on tropical beaches, scorpions usually need absolute sandy areas like deserts.

Scorpions have a muscular tail. They use this muscular tail to fight against other creatures. All these creatures have several species and each species has certain distinct members.

Colourful Tropical Rock lobster under water

Social Behavior Patterns Of Crabs Vs Lobsters

The social behavior of crabs requires an understanding of their nature. All species of crabs, be it a snow crab or king crab, all communicate with each other using their pincers.

The males are usually more aggressive and engage in physical aggression to win over the female crab. They are family-oriented and crabs work to ensure that they are able to provide proper food and shelter for their family. 

During the mating season, the females tend to stay in holes until the breeding season comes to an end while the male crab goes around looking for food and offers protection.

Lobsters, on the other hand, prefer to live alone. Interestingly, they do not die because of old age. They can, in fact, live up to 100 years if not eaten as seafood.

They continue to get stronger and more fertile with age. People around the world love to eat lobsters and enjoy their enriched taste.

These creatures of the sea have small tails and belong to the crustacea family. These male and female marine creatures tend to live under the rocks or find burrows for themselves under the sea. Both these animals belong to a family of shell creatures.

Lobsters are more dangerous compared to crabs as they live alone and have fewer vulnerabilities. Compared to most sea creatures, the abdomen of crabs is very small. Both the snow crab and king crab make excellent seafood and have a tender abdomen.

The difference between crab and lobster arises in the way they relate to and form their families. This difference between crab and lobster exists because they are separate animals with individual needs and capabilities to fulfill those needs. In a world where people want to eat them, these differences between crab and lobster seem like a survival instinct.

Differences In Eating Habits

There is a difference in the eating habits of crabs and lobsters. These differences between crab and lobster include their tendency to eat plants and small sea animals. Crabs can eat algae, fungi, bacteria, other crustaceans, and sometimes even small insects.

Lobsters, on the other hand, are slightly different. They are more inclined towards eating fish, plants, and small insects like worms. They eat the shredded skin of other animals when they are molting and even eat members of their own species if they are agitated or held captive. Lobsters can also attack other lobsters if provoked to do so.

Habitat Differences

Unlike lobsters, which are only found in the muddy and sandy seafloors, crabs can be found in freshwater as well as in the seas. They love the tropical and subtropical regions as well.

The differences in these shell animals of the sea seem to be of no consequence when compared to the subspecies within them. The food they eat everywhere in the world is connected to their local habitats. There are several species of lobsters and crabs that are found in various habitats across the world.

Do lobsters eat crabs?

Lobsters love to hunt at night. They are not scavengers and tend to eat fresh food unless they know that fresh food is in fact a bit scarce. There are numerous things that lobsters eat. They are omnivores, so they consume both plants and animals.

Lobsters are vicious creatures. They are known to eat other lobsters when extremely angry or held in captivity. Apart from a wide range of plants and insects, lobsters eat other sea animals as well. These most often include small fish, crabs, clams, and sea urchins, among others. So, yes, lobsters eat crabs.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for crab vs lobster then why not take a look at how long do crabs live or hermit crab facts.

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Written by Supriya Jain

Bachelor of Commerce, Master of Business Administration specializing in Marketing

Supriya Jain picture

Supriya JainBachelor of Commerce, Master of Business Administration specializing in Marketing

As a skilled member of the Kidadl team, Shruti brings extensive experience and expertise in professional content writing. With a Bachelor's degree in Commerce from Punjab University and an MBA in Business Administration from IMT Nagpur, Shruti has worked in diverse roles such as sales intern, content writer, executive trainee, and business development consultant. Her exceptional writing skills cover a wide range of areas, including SOP, SEO, B2B/B2C, and academic content.

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Fact-checked by Sudeshna Nag

Master of Arts specializing in History

Sudeshna Nag picture

Sudeshna NagMaster of Arts specializing in History

Having earned a Master's degree in History from the Presidency University in Kolkata, Sudeshna was able to refine these skills and broaden her knowledge base. Not only is she an accomplished fact-checker, but she is also deeply invested in gender research, societal interactions, and mental health. Her professional repertoire also includes experience in translation between Bengali and English content

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