Definition: Mouthparts modified into long or short, sclerotized piercing devices that are used to penetrate the host/prey/substrate to gain access to food, and liquids are transported through the food canal with the aid of a pressure gradient created by a sucking pump.
Definition: A shallow stretch of a river or stream, where the current is above the average stream velocity and where the water forms small rippled waves as a result. It often consists of a rocky bed of gravels or other small stones.