Exoglossum maxillingua

"Cutlips minnows" is also used for the genus Exoglossum as a whole.

Cutlips minnow
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Exoglossum
Species:	E. maxillingua
Binomial name
Exoglossum maxillingua (Lesueur, 1817)
Synonyms
Cyprinus maxillingua Lesueur, 1817

Exoglossum maxillingua (cutlips minnow) is an olive-green medium-sized minnow (average 6 inches) of North America with a distinguishing lower jaw. Isolated from all other minnows by its three-lobed lower jaw with the middle lobe sticking out like a tongue. The range of this species is from the St. Lawrence and Lake Ontario south into Virginia. It is listed as "threatened" in the Canadian province of Ontario, but may never have been common there as this is the most northerly of its range. It is found in running streams and seems to prefer clear, stony pools but not rapids. The distinctive mouth of the cutlips lets it feed on minuscule shellfish which it scrapes from rocks. Although molluscs appear to be its primary food, it also eats insect larvae and diatoms. An interesting feeding behavior of this species is "eye-picking" when food is scarce or competition is high. The Cutlips will pluck out the eyes of conspecifics or other species as a supplement to its regular diet. A nest builder, the cutlips male constructs a nest of stone, some of which are up to 18 inches across. Spawning happens late in spring when the male attempts to crowd females over its nest. The cutlips is not a popular bait species due to its softened coloration but it takes a hook without much difficulty and is favored in some areas as a choice panfish.