List of data deficient fishes
In September 2016, the International Union for Conservation of Nature (IUCN) listed 3191 data deficient fish species. A data deficient species is one which has been categorized by the IUCN as offering insufficient information for a proper assessment of conservation status to be made. Of all evaluated fish species, 21% are listed as data deficient. The IUCN also lists 12 fish subspecies as data deficient. Of the subpopulations of fishes evaluated by the IUCN, 34 species subpopulations have been assessed as data deficient.