The four large wings are translucent, smoky grey, or mixed, and the anterior pair is slightly longer than the posterior one.

The larvae are aquatic, active, armed with strong sharp mandibles, and breathe by means of abdominal branchial filaments.

When full sized — which can take several years — they leave the water and spend a quiescent pupal stage on the land, in chambers dug under stones or logs, before metamorphosis into the sexually mature insect.

The summer fishfly, Chauliodes pectinicornis, is perhaps the best-known of these in North America; its immense mating swarms in the Upper Mississippi River region fill the air on a few summer nights each year much like mayflies in certain regions of Europe, leaving millions of carcasses to be cleaned up the next day.

[2] These 36 genera belong to the family Corydalidae: Data sources: i = ITIS,[3] c = Catalogue of Life,[4] g = GBIF,[5] b = Bugguide.net[6]