As of July 2017, the International Union for Conservation of Nature (IUCN) listed 1,000 critically endangered fish species, including 87 which are tagged as possibly extinct.
Additionally 3191 fish species (21% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status.
As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN.
[4] This is a complete list of critically endangered fish species and subspecies evaluated by the IUCN.
There are 145 species, one subspecies, and one subpopulation in the order Cypriniformes assessed as critically endangered.