Hingemouth

The hingemouth (Phractolaemus ansorgii) is a small freshwater fish that is found only in west central Africa, the sole member of the family Phractolaemidae of the family Kneriidae.

Hingemouth
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Gonorynchiformes
Family:	Phractolaemidae Boulenger, 1901
Genus:	Phractolaemus Boulenger, 1901
Species:	P. ansorgii
Binomial name
Phractolaemus ansorgii Boulenger, 1901
Synonyms
Phractolaemus spinosus Pellegrin, 1925

The mouth can extend like a small trunk, thus the name, and has just two teeth, both in the lower jaw. Its mouth can extend up to 30% of the hingemouth's head length. It has highly flexible lips, and its mouth is mainly supported by cartilage and other connective tissues.^[2] The swim bladder has two compartments, and can function as a lung, allowing the hingemouth to survive in oxygen-poor environments.^[3]