Gill - Invertebrate Gills

Invertebrate Gills

Respiration in the Echinodermata (includes starfish and sea urchins) is carried out using a very primitive version of gills called papulae. These thin protuberances on the surface of the body contain diverticula of the water vascular system. Crustaceans, molluscs, and some insects have gills that are tufted or plate-like structures at the surface of the body.

The gills of other insects are tracheal, and also include both thin plates and tufted structures, and, in the larval dragon fly, the wall of the caudal end of the alimentary tract (rectum) is richly supplied with tracheae as a rectal gill. Water pumped into and out of the rectum provides oxygen to the closed tracheae. Aquatic insects use a tracheal gill, which contains air tubes. The oxygen in these tubes is renewed through the gills.