page_title: Protopterus
section_title: Biology
hierarchical_section_title: Protopterus / Biology
caption_attribution_description: Protopterus dolloi
context_page_description: Protopterus is the genus of four species of lungfish found in Africa. Protopterus is the sole genus in the family Protopteridae.
context_section_description: The African lungfish is an example of how the evolutionary transition from breathing water to breathing air can happen. Lungfish are periodically exposed to water with low oxygen content or situations in which their aquatic environment dries up. Their adaptation for dealing with these conditions is an outpocketing of the gut, related to the swim bladder of other fishes, that serves as a lung. The lung contains many thin-walled blood vessels, so blood flowing through those vessels can pick up oxygen from air gulped into the lung.
  The African lungfishes are obligate air breathers, with reduced gills in the adults. They have two anterior gill arches that retain gills, though they are too small to function as the sole respiratory apparatus. The lungfish heart has adaptations that partially separate the flow of blood into its pulmonary and systemic circuits. The atrium is partially divided, so that the left side receives oxygenated blood and the right side receives deoxygenated blood from the other tissues. These two blood streams remain mostly separate as they flow through the ventricle leading to the gill arches. As a result, oxygenated blood mostly goes to the anterior gill arches and the deoxygenated blood mostly goes to the posterior arches.
  African lungfishes breed at the beginning of the rainy season. They construct nests or burrows in the mud to hold their eggs, which they then guard against predators. When they hatch, the young resemble tadpoles, with external gills, and only later develop lungs and begin to breathe air.
caption: Spotted African lungfish, Protopterus dolloi
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS3 Macintosh", "Image DateTime": "2012:05:28 23:52:18", "Image ExifOffset": "164", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "302", "Thumbnail JPEGInterchangeFormatLength": "2371", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "2923", "EXIF ExifImageLength": "909"}