vascular folds in the gill filaments are called
With the exception of some aquatic insects, the filaments and lamellae (folds) contain blood or coelomic fluid, from which gases are exchanged through the thin walls. The blood carries oxygen to other parts of the body.Carbon dioxide passes from the blood through the thin gill tissue into the water.Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including mollusks, crustaceans, insects, fish, and amphibians.n the larval dragon fly, the wall of the caudal end of the alimentary tract (rectum) is richly supplied with tracheae as a rectal gill, and water pumped into and out of the rectum provides oxygen to the closed tracheae.