Fishflies are members of the subfamily Chauliodinae, belonging to the megalopteran family Corydalidae. They are aquatic insects, and their larvae live in water. Fishflies are most easily distinguished from their closest relatives, dobsonflies, by the jaws (mandibles) and antennae. Fishfly mandibles are not particularly noticeable or distinctive, and the males have feathery antennae similar to many large moths. Fishflies are quite large, with a wingspan of 2.5 to 3 inches (6 to 8 cm) . They are omnivorous or predatory, using their stout mouth pincers for grasping and chewing. Fishflies lay their eggs upon vegetation overhanging streams, whence the larvae, as soon as hatched, drop into the water, and go about preying upon aquatic animals. When ready to transform to pupae, they crawl out upon the bank and are then found in cavities under stones or even under the bark of trees. Fishflies are usually light-colored (gray, tan, rusty), and wings of most species are clear, gray, or light-colored. Fishflies are a sign of a healthy ecosystem, as they only emerge in places that have clean water, good oxygen levels, and not a lot of pollution.