Crustaceans – “Insects of the Sea” Section 30.4

Features of crustaceans Nauplius – larval stage Appendages are branched at the ends Two pairs of antennae Usually three pairs of chewing appendages Appendages located on the cephalothorax and abdomen Respiration through gills

Nauplius – the larval stage of crustaceans

Habitats Most are marine – crabs, lobster, shrimp Some are small or microscopic – krill and plankton Some live in freshwater – crayfish A few are terrestrial – isopods (roly-poly)

Krill

Plankton

Isopod

Decapods Five pairs of walking legs Shrimp, lobsters, crabs, crayfish Have a cephalothorax Chelipeds – large pincers in crayfish and lobsters

Shrimp

Lobster

Crabs

Crayfish

Sessile crustaceans Barnacles attach to a submerged object and remain Hard plates protect the body They feed through the open plates

Barnacles

Barnacles feed through open plates