Lungfishes

Note external gills on this young African lungfish (P. aethiopicus)

LUNGFISHES

Lungfishes (Sarcopterygii, Dipnoi) are considered to be the most primitive living fishes.

There are three families and six extant species of these ancient fishes. Four species are found in the family Protopteridae (African lungfishes) and one species each in Ceratodontidae (Australian lungfish) and Lepidosirenidae (South American lungfish).

The Australian lungfish (Neoceratodus forsteri) is considered the most primitive extant species of lungfish, with the African and South American species more derived and more closely related.

As their name suggests, members of this group possess 1 lung (Ceratodontiformes) or 2 lungs (Lepidosireniformes) which they use to breathe atmospheric oxygen. When young, lungfishes possess external gills, which are lost (in most species) as the fish develops. Members of Lepidosireniformes are capable of estivation, a state of dormancy and low metabolism during periods of desiccation.

As lungfish develop from juveniles to adults, their teeth fuse together to form tooth plates which they use to chew their food (all lungfishes are omnivorous).

Click on photos below for more information on each group of lungfishes. More images coming soon!