Difference Between Shellfish and Crustaceans

Shellfish vs Crustaceans

It is easy to understand the difference between Shellfish and Crustaceans once you learn the species that are classified under each of these. Both shellfish and crustaceans are无脊椎动物and have very simple, soft bodies withexoskeletons. Exoskeleton is important to protect their internal bodies. Most of the species areaquaticand found in bothfreshwater and marine waterhabitats. However, certain shellfish are found in terrestrial habitats. Both shellfish and crustaceans are important as a food source for humans. Here, you may have noticed that all what is said up to now are similarities, not the difference. So, are they one and the same? Not really. The similarities are due to the fact that crustaceans are also a kind of shell fish. Let’s learn about these two creatures and the difference between them in little more detail.

What are Shellfish?

Shellfish is a broad term used forcrustaceans and软体动物with exoskeletonsor calcareous shells. Crustacean shellfish includecrabs,prawns, shrimps,crayfishandlobsters, whilst mollusk shellfish includesmussels, oysters,cockles, scallops,clams, etc. Most species of shellfish are found in marine habitats. Most of the shellfish species are used as food sources by humans because of their high nutrient contents. However, shellfish cause most common food allergic reactions in the body.

What are Crustaceans?

Crustaceans are a group ofarthropodsthat have aprominentcephalothorax and abdomen. Thepresence of carapace, which enclose the cephalothorax is unique to all the crustaceans. Biramous appendages are found on all the body segments. Thelarvaeof crustaceans is callednauplius. There are about 67,000 species present in this class. All the crustaceans are found only in marine and freshwater environments. The head of crustaceans contains two pairs of antennae, one pair of mandibles and two pairs of maxillae. They also possess stalkedcompound eyesfor vision andgillsas respiratory organs. Smaller crustaceans feed onplanktons, thus play an important role in the primary food chains. Example for crustaceans include, prawns, lobsters, crabs, shrimps and barnacles. Larger crustaceans are economically important as a food source.

What is the difference between Shellfish and Crustaceans?

• Shellfish includes crustaceans and mollusks (most crustaceans are considered as shellfish).

•甲壳类动物几丁质的外骨骼,whereas shellfish have either chitinous or calcareous exoskeleton.

• Shellfish includes crabs, prawns, shrimps, crayfish, lobsters, mussels, oysters, cockles, scallops, calms, whereas crustaceans include prawns, lobsters, crabs, shrimps and barnacles.

Images Courtesy:Clubshell musselandHomarus gammarusvia Wikicommons (Public Domain)