 The genera in which the males have normal mandibles, called fishflies, form the subfamily Chauliodinae.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.The larvae are aquatic, active, armed with strong sharp mandibles, and breathe by means of abdominal branchial filaments.