Editing Protopterus

{{Short description|Genus of Lungfish}}
{{italic title}}
{{Automatic taxobox
| name = African lungfish
| fossil_range = {{Fossil range|83.6|0|earliest=99.7|ref=<ref>{{Cite web |title=Protopterus |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=91688&is_real_user=1 |access-date=2022-06-03 |website=paleobiodb.org}}</ref>}}
<small>[[Campanian]] to [[Holocene|present]]</small>
| image = Gőtehal-2.jpg
| image_caption = ''Protopterus annectens''
| parent_authority = [[Wilhelm Peters|Peters]], 1855
| taxon = Protopterus
| authority = [[Richard Owen|Owen]], 1839
| subdivision_ranks = Species
| subdivision = *[[Marbled lungfish|''P. aethiopicus'']]<br/>
*[[Gilled lungfish|''P. amphibius'']]
*[[West African lungfish|''P. annectens'']]
*[[Spotted lungfish|''P. dolloi'']]
| range_map = Protopterus map.jpg
| synonyms = * ''Protomelus'' <small>Hogg 1841</small>
* ''Rhinocryptis'' <small>Peters 1844</small>
| synonyms_ref = <ref>{{cite journal | website=Collection of genus-group names in a systematic arrangement | title=Part 7- Vertebrates | url=http://mave.tweakdsl.nl/tn/genera7.html | display-authors=etal | access-date=30 June 2016 | archive-url=https://web.archive.org/web/20161005114629/http://mave.tweakdsl.nl/tn/genera7.html | archive-date=5 October 2016 | url-status=dead }}</ref><ref name="mikko">{{cite web|website=Mikko's Phylogeny Archive|last=Haaramo|first=Mikko|year=2007|title=''Ceratodiformes – recent lungfishes'' |url=http://www.helsinki.fi/~mhaaramo/metazoa/deuterostoma/chordata/sarcopterygii/dipnomorpha/ceratodiformes.html |access-date= 3 July 2016}}</ref><ref name=FB>{{Cite web|last1=Froese|first1=R.|last2=Pauly|first2=D.|year=2017|title=Protopteridae |url=http://fishbase.org/Summary/FamilySummary.php?ID=552|website=[[FishBase]] version (02/2017)|access-date=18 May 2017}}</ref>
}}

'''''Protopterus''''' is the [[genus]] of four [[species]] of [[lungfish]] found in [[Africa]]. ''Protopterus'' is considered the [[monotypic|sole genus]] in the family '''Protopteridae''', which is  grouped with ''[[South American lungfish|Lepidosiren]]'' in the order [[Lepidosireniformes]].'''<ref>{{Cite web |title=ITIS - Report: Protopteridae |url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=161043#null |access-date=2023-03-13 |website=www.itis.gov}}</ref><ref name=":1">{{Cite web |title=FAMILY Details for Protopteridae - African lungfishes |url=https://www.fishbase.se/summary/FamilySummary.php?ID=552 |access-date=2023-03-13 |website=www.fishbase.se}}</ref><ref name=":2">{{Cite journal |last1=Van Der Laan |first1=Richard |last2=Eschmeyer |first2=William N. |last3=Fricke |first3=Ronald |date=2014-11-11 |title=Family-group names of Recent fishes |url=http://biotaxa.org/Zootaxa/article/view/zootaxa.3882.1.1 |journal=Zootaxa |volume=3882 |issue=1 |pages=1–230 |doi=10.11646/zootaxa.3882.1.1 |pmid=25543675 |issn=1175-5334|doi-access=free }}</ref><ref name=":0">{{Cite journal |last1=Kemp |first1=Anne |last2=Cavin |first2=Lionel |last3=Guinot |first3=Guillaume |date=2017-04-01 |title=Evolutionary history of lungfishes with a new phylogeny of post-Devonian genera |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=471 |pages=209–219 |bibcode=2017PPP...471..209K |doi=10.1016/j.palaeo.2016.12.051 |issn=0031-0182 |doi-access=free}}</ref>'''

== Taxonomy ==
The earliest fossils of the Protopteridae come from the [[Late Cretaceous]] ([[Campanian]]-[[Maastrichtian]]) of [[Sudan]],<ref>{{Cite web |title=Protopterus protopteroides |url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=91690&is_real_user=1 |access-date=2022-06-03 |website=paleobiodb.org}}</ref> but [[phylogenetic]] evidence indicates that it and Lepidosirenidae split at the very beginning of the [[Early Cretaceous]], around 145 Ma.'''<ref name=":0" />''' Together, their common ancestor diverged from the only other extant lungfishes in [[Neoceratodontidae]] during the [[Late Jurassic]].<ref name=":22">{{Cite journal |last1=Brownstein |first1=Chase Doran |last2=Harrington |first2=Richard C |last3=Near |first3=Thomas J. |date=2023-04-12 |title=The biogeography of extant lungfishes traces the breakup of Gondwana |journal=Journal of Biogeography |volume=50 |issue=7 |pages=1191–1198 |language=en |doi=10.1111/jbi.14609 |issn=0305-0270|doi-access=free |bibcode=2023JBiog..50.1191B }}</ref>

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.'''<ref name=":1" /><ref name=":2" /><ref name=":0" />'''

==Description==
African lungfish are elongated, [[eel]]-like fishes with thread-like [[pectoral fin|pectoral]] and [[pelvic fin]]s. They have soft [[Fish scale|scales]], and the [[dorsal fin|dorsal]] and [[Fish anatomy#Types of fin|tail fin]]s are fused into a single structure. They can either swim like eels or crawl along the bottom using their pectoral and pelvic fins.<ref name=EoF>{{cite book |editor=Paxton, J.R. |editor2=Eschmeyer, W.N.|author= Bruton, Michael N.|year=1998|title=Encyclopedia of Fishes|publisher= Academic Press|location=San Diego|pages= 70–72|isbn= 0-12-547665-5}}</ref> The largest species can reach about {{convert|200|cm|ft|abbr=on}} in length.<ref name=FB />

African lungfish generally inhabit shallow waters, such as swamps and marshes. They are also found in larger lakes such as [[Lake Victoria]]. They can survive out of water for many months by burrowing into hardened mud beneath a dried stream bed. They are carnivorous, feeding on [[crustacean]]s, aquatic insect larvae, and [[mollusc]]s.<ref name=EoF/>

==Biology==
[[File:Lungs of Protopterus dolloi.JPG|thumb|left|Lateral view of lungs of a dissected ''Protopterus dolloi'']]
[[File:PSM V63 D037 Clod of earth containing cocoon of lung fish.png|thumb|254px|right|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.<ref name=EoF/> 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 arch]]es 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.<ref>{{Cite journal |last1=Zhang |first1=Ruihua |last2=Liu |first2=Qun |last3=Pan |first3=Shanshan |last4=Zhang |first4=Yingying |last5=Qin |first5=Yating |last6=Du |first6=Xiao |last7=Yuan |first7=Zengbao |last8=Lu |first8=Yongrui |last9=Song |first9=Yue |last10=Zhang |first10=Mengqi |last11=Zhang |first11=Nannan |last12=Ma |first12=Jie |last13=Zhang |first13=Zhe |last14=Jia |first14=Xiaodong |last15=Wang |first15=Kun |date=2023 |title=A single-cell atlas of West African lungfish respiratory system reveals evolutionary adaptations to terrestrialization |journal=Nature Communications |language=en |volume=14 |issue=1 |pages=5630 |doi=10.1038/s41467-023-41309-3 |pmid=37699889 |pmc=10497629 |bibcode=2023NatCo..14.5630Z |issn=2041-1723}}</ref> The lungfish heart has adaptations that partially separate the flow of blood into its pulmonary and systemic circuits. The [[Atrium (heart)|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 (heart)|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 [[tadpole]]s, with [[external gills]], and only later develop lungs and begin to breathe air.<ref name=EoF/>

[[File:Protopterus dolloi Boulenger2.jpg|thumb|500px|left|{{center|[[Spotted African lungfish]], ''Protopterus dolloi''}}]]

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==As food==
Until the introduction of the [[Nile perch]] to the region, lungfish typically comprised a small proportion of a fisherman's catch. Transportation to market from catching sites in Lake Victoria was often done with fish sun-dried for better preservation. Human consumption of the lungfish varies by population; the [[Luo peoples]] occasionally do so but the [[Sukuma people|Sukuma]] avoid eating lungfish due to a taste which is "locally either highly appreciated or strongly disliked."<ref>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</ref> As technology advancements such as [[Longline fishing|longlines]] and [[gillnet]]s have been increasingly applied over the past 50 years, the lungfish populations there are believed to be decreasing.

==Species and subspecies==
[[File:Leopard lungfish (Protopterus aethiopicus) close - GRB.JPG|thumb|right|{{center|Marbled or leopard African lungfish, ''Protopterus aethiopicus''}}]]

The family Protopteridae and genus ''Protopterus'' contain four extant (living) species:<ref name=FB/>
 
* ''[[Protopterus aethiopicus]]'' <small>[[Johann Jakob Heckel|Heckel]], 1851</small> — marbled lungfish
** ''P. a. aethiopicus'' <small>Heckel, 1851</small>
** ''P. a. congicus'' <small>[[Max Poll|Poll]], 1961</small>
** ''P. a. mesmaekersi'' <small>[[Max Poll|Poll]], 1961</small>
* ''[[Protopterus amphibius]]'' <small>([[Wilhelm Peters|W. K. H. Peters]], 1844)</small> — gilled African lungfish or East African lungfish
* ''[[Protopterus annectens]]'' <small>([[Richard Owen|Owen]], 1839)</small> — West African lungfish
** ''P. a. annectens'' <small>(Owen, 1839)</small>
** ''P. a. brieni'' <small>[[Max Poll|Poll]], 1961</small> — southern lungfish
* ''[[Protopterus dolloi]]'' <small>[[George Albert Boulenger|Boulenger]], 1900</small> — slender lungfish or spotted African lungfish

Other extinct species are known from fossil remains:
* †''[[Protopterus crassidens]]'' <small>Churcher & de Iuliis 2001</small>
* †''[[Protopterus elongus]]'' <small>Martin 1995</small>
*†''[[Protopterus libycus]]'' <small>Stromer 1910</small>
* †''[[Protopterus nigeriensis]]'' <small>Martin 1997</small>
* †''[[Protopterus polli]]'' <small>Dartevelle & Casier 1949</small>
*†''[[Protopterus protopteroides]]'' <small>Tabaste 1962</small>
* †''[[Protopterus regulatus]]'' <small>Schall 1984</small>

==References==
{{Reflist}}
* Purves, Sadava, Orians, Heller, "Life: The Science of Biology" 7th ed. pg. 943. Courier Companies Inc: USA, 2004.
{{Sarcopterygian genera|R.}}
{{Taxonbar|from1=Q386335|from2=Q15963862}}
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[[Category:Protopteridae| ]]
[[Category:Lobe-finned fish genera]]
[[Category:Taxa named by Richard Owen]]
[[Category:Freshwater fish genera]]