The rectum of larval dragonflies as jet-engine, respirator, fuel depot and ion pump

The rectum of larval dragonflies serves various functions such as swimming by jet-propulsion, breathing, storage of lipid and glycogen, and osmoregulatory salt uptake. All of them are more or less causally connected with rectal ventilation. For each function specialized cells are present and the morphology and physiology of these are discussed.