How do African lungfish reproduce during the rainy season?

African lungfish (Protopterus species) reproduce during the onset of the rainy season, which occurs in the latter half of winter.1

To spawn, these fish construct a nest in the form of a pit on the bottom of a watercourse. Once the eggs are laid, they measure approximately 3.5 to 4 mm in diameter, and larvae emerge after about one week. These young larvae possess long, fanlike external gills that allow them to breathe until their lungs are fully developed. During this early stage, the male remains in the nest to protect the young.1