Crustacean < 99% TOP-RATED >

are a vast and diverse group of invertebrate animals

: A hard, chitinous outer shell that provides protection and structural support. Many species further harden this shell through calcification . crustacean

: Their bodies are usually segmented, often featuring a cephalothorax (a fused head and trunk). Diverse Habitats and Ecological Roles are a vast and diverse group of invertebrate

Crustaceans are primarily , found in nearly every marine and freshwater environment on Earth. With over 45,000 to 52,000 known species distributed

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

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

The most well-known crustaceans belong to the order , characterized by five pairs of legs: