Branchial chamber

The branchial chamber in decapods and some other crustaceans is the area of the body containing the branchiae, or gills. In shrimp-like decapods, water enters the chamber from the edges of the carapace. In crab-like decapods, it enters from respiratory channels near the chelipeds.^[1][2]

Illustration of the gills, or branchia, of the lobster. The carapace which encloses the branchial chamber has been cut away.