crustacean

Everyday

A crustacean is an animal with a hard outer shell, jointed legs and no backbone, which usually lives in water, such as a crab, lobster, shrimp, prawn or crayfish. tree →

In the lessons

In science lessons on animal groups, crustaceans are invertebrates and arthropods, like insects and spiders; woodlice are crustaceans that live on land. They grow by shedding their shell (moulting). In food safety some people are allergic to crustaceans (shellfish). Phrases: crustaceans such as crabs, a shellfish allergy.

Examples

• A crab is a crustacean. tree →
• Lobsters, shrimps and prawns are all crustaceans. tree →
• Woodlice are crustaceans that live on land. tree →
• A crustacean has a hard shell and jointed legs. tree →
• Crustaceans grow by shedding their old shells. tree →
• We found small crustaceans in the rock pool. tree →
• Some people are allergic to crustaceans. tree →

Note

Countable: a crustacean, crustaceans. Pronounced krus-TAY-shun. Trap: woodlice are not insects; they are crustaceans. Shellfish include both crustaceans and molluscs (like mussels).