When still in larval form, the beetles vary in size from about 1 to 5 cm (half an inch to two inches). The larvae's bodies are shaped like crescents, with the tail long and covered with thin hairs. Six legs
As soon as the beetles come to the stage in life in which they mature to adulthood, the larva crawl from the water on the sturdy legs, and bury themselves in the mud for pupation. After about a week, or longer in some species, they emerge from the mud as adults.
Adult Dytiscidae, particular of the genus Cybister, are edible. In Mexico, C. explanatus are eaten
Large but slow on land and not particularly fierce as adults, they are also eaten with relish by many mid-sized birds, mammals and other larger predators. The larvae are usually safer, due to their camouflage and ability to escape by water jet; they can be quite hard to catch and may become apex predators in small ponds.