Anglerfish:

The order Lophiiformes conteains about 322 species of mostly benthic shallow-water species. One of the classic characteristics of many fish in this order is the modified first dorsal-fin spine.  The spine often resembles a lure of some kind.  The classic example is that of the anglerfish.  Other common representatives of this group include the goosefishes, monkfishes, frogfishes, sea-mice, sea-toads, handfishes, coffinfishes, and batfishes. 

More information on Lophiiformes

• Tree of Life contains an very scientific overview of the order Lophiiformes