Crustaceans are a very diverse group of invertebrate animals that include active animals such as crabs, lobsters, shrimp, krill, copepods, amphipods, and more sessile creatures such as barnacles. Arthropoda is the largest phylum in the Animal Kingdom. It includes about ...

Crustaceans absorb oxygen, as do (almost) all other creatures on earth. Because they are aquatic creatures, they use the same respiratory system as fish and oxygen to breathe through ghills. Gels, crustacean respiratory organs, are very similar to the lungs ...

Are crustaceans only in water? Most crustaceans are aquatic, living in marine or freshwater environments, but some groups have adapted to terrestrial life, such as terrestrial crabs, terrestrial crabs, and wood lice. Marine crustaceans are as ubiquitous in the oceans ...

: any of a large class (Crustacea) of mainly aquatic mandibular arthropods that have a chitinous or calcareous and chitinous exoskeleton, a pair of often heavily modified appendages in each segment, and two pairs of antennae including lobsters, shrimp, crabs, ...