A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as only consisting of living members kept in captivity or as a naturalized population outside its historic range. Classification requires exhaustive surveys conducted within the species' known habitat with consideration given to seasonality, time of day, and life cycle. Once a species is classified as EW, the only way for it to be downgraded is through reintroduction.
Leptocaris stromatolicolus is a species of harpacticoid copepod in the family Darcythompsoniidae. It is found in Central America.
Monolistra bolei is a species of isopod in the family Sphaeromatidae.
Monolistra calopyge is a species of isopod in the family Sphaeromatidae.
Monolistra schottlaenderi is a species of isopod in the family Sphaeromatidae.
Monolistra spinosissima is a species of isopod in the family Sphaeromatidae.
Nitocrella is a genus of copepod. Although most other genera in the family Ameiridae are marine, species of Nitocrella are almost exclusively found in subterranean fresh water or brackish water. More than 80 species are included in the genus, including two which are listed as vulnerable species on the IUCN Red List:
Nitocrella stochi is a species of harpacticoid copepod in the family Ameiridae.
Skistodiaptomus carolinensis is a species of calanoid copepod in the family Diaptomidae.
Skistodiaptomus sinuatus is a species of calanoid copepod in the family Diaptomidae.
Spelaeoecia bermudensis is a species of ostracod in the family Deeveyidae.
Thermosphaeroma cavicauda is a species of isopod in the family Sphaeromatidae. It is found in Mexico.
Thermosphaeroma dugesi is a species of isopod in the family Sphaeromatidae. It is found in Mexico.
Thermosphaeroma macrura is a species of isopod in the family Sphaeromatidae. It is found in Mexico.
Thermosphaeroma milleri is a species of isopod in the family Sphaeromatidae. It is found in Mexico.
Thermosphaeroma smithi is a species of isopod in the family Sphaeromatidae. It is found in Mexico.
Tropodiaptomus falcatus is a species of calanoid copepod in the family Diaptomidae.
Tropodiaptomus madagascariensis is a species of calanoid copepod in the family Diaptomidae.
Tropodiaptomus worthingtoni is a species of calanoid copepod in the family Diaptomidae.
Alzoniella slovenica is a species of very small or minute freshwater snail with an operculum, an aquatic gastropod mollusk in the family Hydrobiidae, which are sometimes known as the snouted water snails.
