Anglerfish are the members of the order Lophiiformes. They are bony fish named for their characteristic mode of predation, wherein a fleshy growth from the fish’s head (the esca) acts as a lure; this is considered analogous to angling. Some anglerfish are pelagic (live in the open water), others are benthic (bottom-dwelling). Some live in the deep sea (e.g. Ceratiidae) and others on the continental shelf (e.g. the frogfishes Antennariidae and the monkfish/goosefish Lophiidae). They occur worldwide. Pelagic forms are most laterally (sideways) compressed whereas the benthic forms are often extremely dorsoventrally compressed (depressed) often with large upward pointing mouths.
L. Brent Vaughan Hill's Practical Reference Library Volume II (NewYork, NY: Dixon, Hanson and Company, 1906)