Protopterus

Source: Wikipedia, the free encyclopedia.

African lungfish
Temporal range: 83.6–0 
Ma[1]
Campanian to present
Protopterus annectens
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Sarcopterygii
Class: Dipnoi
Order: Ceratodontiformes
Family: Protopteridae
Peters, 1855
Genus: Protopterus
Owen, 1839
Species
Synonyms[2][3][4]
  • Protomelus Hogg 1841
  • Rhinocryptis Peters 1844

Protopterus is the

Lepidosireniformes.[5][6][7][8]

Taxonomy

The earliest fossils of the Protopteridae come from the

phylogenetic evidence indicates that it and Lepidosirenidae split at the very beginning of the Early Cretaceous, around 145 Ma.[8] Together, their common ancestor diverged from the only other extant lungfishes in Neoceratodontidae during the Late Jurassic.[10]

Some papers suggest grouping Protopterus and Lepidosiren together in the family Lepidosirenidae, as their Cretaceous divergence is relatively recent compared to the Carboniferous origins of other lungfish families. However, most taxonomic authorities retain them as distinct families.[6][7][8]

Description

African lungfish are elongated,

pectoral and pelvic fins. They have soft scales, and the dorsal and tail fins are fused into a single structure. They can either swim like eels or crawl along the bottom using their pectoral and pelvic fins.[11] The largest species can reach about 200 cm (6.6 ft) in length.[4]

African lungfish generally inhabit shallow waters, such as swamps and marshes. They are also found in larger lakes such as

Biology

Lateral view of lungs of a dissected Protopterus dolloi
Clod of mud containing the cocoon of lung fish

The African lungfish is an example of how the evolutionary transition from breathing water to breathing air can occur. Lungfish are periodically exposed to water with low oxygen content or encounter situations in which their aquatic environment dries up. To cope with these conditions, they have developed an adaptation in the form of an outpocketing of the gut, similar to the swim bladder found in other fishes. This specialized structure functions as a lung.[11] Within the lung, numerous thin-walled blood vessels allow the blood to absorb oxygen from the air that is gulped into the lung.

They are obligate air breathers, with reduced gills in the adults. There are two anterior

gill arches that retain gills, though they are too small to function as the sole respiratory apparatus, and may be more important for carbon dioxide elimination. About 90% of their oxygen is acquired via their lungs, and the remaining ~10% via the gills and skin.[12] 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.[11]

Spotted African lungfish
, Protopterus dolloi

As food

Until the introduction of the

gillnets
have been increasingly applied over the past 50 years, the lungfish populations there are believed to be decreasing.

Species and subspecies

Marbled or leopard African lungfish, Protopterus aethiopicus

The family Protopteridae and genus Protopterus contain four extant (living) species:[4]

Other extinct species are known from fossil remains:

References

  1. ^ "Protopterus". paleobiodb.org. Retrieved 2022-06-03.
  2. ^ "Part 7- Vertebrates". Collection of genus-group names in a systematic arrangement. Archived from the original on 5 October 2016. Retrieved 30 June 2016.
  3. ^ Haaramo, Mikko (2007). "Ceratodiformes – recent lungfishes". Mikko's Phylogeny Archive. Retrieved 3 July 2016.
  4. ^ a b c Froese, R.; Pauly, D. (2017). "Protopteridae". FishBase version (02/2017). Retrieved 18 May 2017.
  5. ^ "ITIS - Report: Protopteridae". www.itis.gov. Retrieved 2023-03-13.
  6. ^ a b "FAMILY Details for Protopteridae - African lungfishes". www.fishbase.se. Retrieved 2023-03-13.
  7. ^
    PMID 25543675
    .
  8. ^ .
  9. ^ "Protopterus protopteroides". paleobiodb.org. Retrieved 2022-06-03.
  10. ISSN 0305-0270
    .
  11. ^ .
  12. ^ A single-cell atlas of West African lungfish respiratory system reveals evolutionary adaptations to terrestrialization
  13. ^ Kees (P. C.) Goudswaard, Frans Witte, Lauren J. Chapman, Decline of the African lungfish (Protopterus aethiopicus) in Lake Victoria (East Africa) East African Wild Life Society, African Journal of Ecology, 40, 42-52, 2002
  • Purves, Sadava, Orians, Heller, "Life: The Science of Biology" 7th ed. pg. 943. Courier Companies Inc: USA, 2004.