Crustacean -

Crustaceans are primarily , found in nearly every marine and freshwater environment on Earth.

: Because their shells are rigid, crustaceans must periodically shed and regrow them to accommodate growth. crustacean

The most well-known crustaceans belong to the order , characterized by five pairs of legs: Crustaceans are primarily , found in nearly every

belonging to the subphylum within the phylum Arthropoda . With over 45,000 to 52,000 known species distributed worldwide, they range from familiar seafood like to microscopic copepods and terrestrial woodlice . Key Characteristics Crustaceans are primarily

: They typically possess two pairs of antennae (antennules and antennae) and specialized mouthparts that function as jaws.