Maryland darter

Maryland darter
The Maryland Darter
Conservation status
Extinct  (IUCN 3.1)[1]
Endangered (ESA)[2][3]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Percidae
Genus:	Etheostoma
Subgenus:	†Mooreichthys
Species:	†E. sellare
Binomial name
†Etheostoma sellare (Radcliffe & W. W. Welsh, 1913)
Synonyms
Hadropterus sellaris Radcliffe & Welsh, 1913[4]

The Maryland darter (Etheostoma sellare) is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is considered one of the rarest freshwater fish species in the world, due in part to its incredibly limited geographic range and difficulty of detection. The last sighting of one was in 1988. The Maryland darter is named after the only state in which it is known to occur. The species was long known only by two specimens until being "re-discovered" in 1962. From 1965 into the 1980s, the species was believed to have been confined to a single riffle in Deer Creek. Possible explanations for the decline of the species center around widespread habitat degradation and reduction in water quality resulting from increasing rates of urbanization within the watershed. While the IUCN has declared the species extinct,^[1] the United States Fish and Wildlife Service has not, and keeps it on the Endangered Species List.^[2][5]