Is Lobster Considered A Fish?

Lobsters are a colorful type of shellfish widely known as delicious seafood, which most consider a tasty, and for the most part quite pricey, treat. Although lobsters are considered a seafood delicacy and a type of shellfish, this does not necessarily mean they can be considered fish.

A lobster is, in fact, not considered a fish but rather a marine crustacean. Lobsters fall into the category of crustaceans rather than fish because they are biologically different. Like crabs, lobsters, too, have a segmented body with a few pairs of legs, claws, and a hard exoskeleton.

Lobsters, although primarily known as a seafood delicacy, are a type of marine crustacean classified as Arthropoda, along with similar sea critters such as crabs, shrimps, barnacles, and insects. A lobster actually shares more physical characteristics with a woodlouse than it does with a fish. Lobsters can be split into two sub-categories based on their physical features – true lobsters or spiny lobsters.

Are Lobsters Considered Fish?

Although lobsters are a type of shellfish, they are not considered to be actual fish. This is due to the biological and physical differences between them. Despite their many physical differences, lobsters and fish have certain things in common.

The Differences Between Lobsters And Fish

Unlike lobsters, fish have various sets of fins, which they use to maneuver themselves around in the water with the help of their muscular bodies. However, most lobsters have a few pairs of legs and can propel themselves forward using the muscles in their tails. The outside of a fish is also covered with scales, whereas a lobster has a hard outer shell covering called an exoskeleton.

Although lobsters and fish both have gills, lobsters can stay alive out of water for much longer than fish. Fish can typically survive out of water anywhere from ten minutes to three hours, depending on the size of the fish, whereas lobsters can survive out of water for up to 48 hours if their gills remain moist.

Another major difference between lobsters and fish is their eyes. The eyes of fish are similar to those of mammals such as birds but have a slightly more spherically shaped lens, whereas lobsters, like insects, have compound eyes, which do not give the lobster very clear visuals; however, they are excellent at detecting motion, especially in the dark which aids them when they are hunting prey at night.

The Similarities Between Lobsters And Fish

Besides the fact that lobsters and fish share the same ocean habitat, they also share the same internal respiratory system. Just like fish, the gills found on lobsters extract oxygen from the seawater to allow them both to breathe underwater.

The Differences Between True Lobsters And Spiny Lobsters

The division of lobsters into sub-categories is due to various species of lobsters existing in different ocean habitats and having physical characteristics which differ from species to species. The differences in lobsters’ physical characteristics also directly impact their commercial importance in the seafood industry.

Ocean Habitat Of True Lobsters And Spiny Lobsters

All types of lobsters can be found dwelling at the bottom of the ocean, between rocks and small crevices. They are bottom feeders which feed on the decaying flesh of other shellfish. The main difference in the habitat of true lobsters and spiny lobsters is the ocean water temperature in which they are found.

True lobsters are found in colder ocean waters such as those off the coast of South Africa, Australia, and New Zealand. Spiny lobsters are also called rock lobsters and are found in warmer ocean waters such as areas in the North-eastern and North-western Atlantic Oceans. In the seafood industry, lobsters are either categorized as “cold water” or “warm water” lobsters as their commercial importance differs.

The Physical Differences Between True And Spiny Lobsters

Both true lobsters and spiny lobsters have five sets of legs; however, the first set differs between the two. The first set of legs of lobsters are claws, and true lobsters have a much bigger set of claws than those of the spiny lobsters. Therefore, true or “warm water” lobsters are much more sought after in the seafood industry than spiny lobsters, as there is more meat that can be harvested from the claws.

The size of the claws is, however, not the only physical difference between these two categories of lobsters. The spiny lobsters get their name due to their long, thick antennae, which give them a “spiny” appearance. Unlike their spiny lobster counterparts, true lobsters have much smaller and thinner antennae.

The Difference Between Lobsters In The Seafood Industry

As with any commercial industry, more is always better when it comes to output quantity. True lobsters have more edible meat than spiny lobsters, as it has a lot of meat that can be harvested from the claws and the rest of the body. The only edible meat that comes from a spiny lobster is that which can be harvested from its tail.

The taste and color of the meat also vary between these two categories of lobster. True lobsters have much whiter and tastier meat than spiny lobsters. This results from the temperature of the water they are found in. The colder waters allow lobsters not to absorb the salt in the ocean water, making the meat sweeter than that of lobsters found in warmer waters.

The meat’s quantity, taste, and color make the true or “cold water” lobsters the more sought-after option in the seafood industry.


A lobster is, in fact, not considered a fish but rather a marine crustacean. Lobsters are similar to fish in terms of the fact that both organisms share the same ocean habitats and have the same respiratory organs known as gills which they use to breathe underwater. However, they differ greatly in their biological structure as they have different external physical structures and features.

Lobsters can be categorized into either true lobsters and spiny or “rocky” lobsters. The main differences between these types of lobsters are the temperature of their ocean habitat, the size of their front set of claws, and the size and thickness of their antennae. True lobsters are more popular in the seafood industry as they yield a bigger quantity of whiter, tastier meat than spiny lobsters.


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