The natural history of African lungfishes

TLDR: As obligatory air‐breathers able to survive temporary and sometimes extended desiccation of a habitat, lungfishes are often permanent residents in areas from which most actinopterygian fishes are excluded.

Abstract: Remarkably little is known about the biology of the four Protopterus species, apart from certain detailed studies on their nesting behavior and estivating habits. What information we do have indicates that the species are essentially omnivorous carnivores (especially as predators on molluscs) and that they occupy a wide variety of habitats both lentic and lotic. As obligatory air-breathers able to survive temporary and sometimes extended desiccation of a habitat, lungfishes are often permanent residents in areas from which most actinopterygian fishes are excluded. All four species are able to survive prolonged dry periods. The methods they employ in so doing are varied, and include the secretion of subterranean cocoons, lying-up in water-filled subsurface burrows, or simply burrowing into moist regions of the substrate. Some populations of at least two species live in permanent water and so do not estivate, although they apparently retain the ability to do so. Three of the four species spawn in some form of seemingly constructed or prepared nest. The architecture of these nests shows marked inter- and intraspecific variability and is likely to be determined largely by various environmental factors. All three species show some type of parental care. The breeding biology of the fourth species, P. amphibius, is still unknown. Other aspects of the breeding biology and behavior of Protopterus require a great deal more investigation, as does the biology of the young.