Pelophylax
Encyclopedia
Pelophylax is a genus
of true frog
s widespread in Eurasia
, with a few species ranging into northern Africa
. This genus was erected by Leopold Fitzinger
in 1843 to accommodate the "green frog
s" of the Old World
, which he considered distinct from the brown pond frogs of Linnaeus' genus Rana
.
They are also known as water frogs, as they spend much of the summer living in aquatic
habitat
; the pond frogs can be found more often, by comparison, on dry land, as long as there is sufficient humidity
. Yet there are species of Eurasian green frogs – the Central Asia
n P. terentievi, or the Sahara Frog
(P. saharicus) – which inhabit waterholes in the desert
.
to the Common Frog
(R. temporaria) in Rana. That genus, in the loose circumscription, eventually became a sort of "wastebin taxon
".
Around the year 2000, with molecular phylogenetic studies becoming commonplace, it was discovered that Fitzinger's assessment was correct after all – not only is Pelophylax an independent genus, but it does in fact belong to a lineage of Raninae not particularly close to Rana. But it also turned out that these Eurasian green frogs might not form a monophyletic lineage. The sheer number of species
involved in the group of Pelophylax and its closest relatives means that it will probably be some time until the definite circumscription of this genus is resolved.
In any case, it can by now be said that the Pelophylax frogs belong to a group of moderately advanced Raninae – possibly a clade
– that also includes such genera as Babina, Glandirana, Hylarana
, Pulchrana, Sanguirana, Sylvirana, as well as Hydrophylax which like Pelophylax is suspected of being not monophyletic. These genera were formerly also included in Rana by most authors, and several of them have in fact only been established in the 1990s
. And as regards the possible paraphyly
of Pelophylax, it seems that some species assigned here are very close to Hylarana, and thus it might simply be a matter of moving them to that genus. But hybridogenic speciation
is running rampant in the Old World green frogs, and this obfuscates the data gained from DNA sequence
analyses.
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Named klepta (hybridogenic species) of Pelophylax are:
In addition, one species has been described that is sometimes assigned to Pelophylax, but must be considered a nomen oblitum
:
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of true frog
True frog
The true frogs, family Ranidae, have the widest distribution of any frog family. They are abundant throughout most of the world, occurring on most continents except Antarctica...
s widespread in Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
, with a few species ranging into northern Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. This genus was erected by Leopold Fitzinger
Leopold Fitzinger
Leopold Joseph Franz Johann Fitzinger was an Austrian zoologist.Fitzinger was born in Vienna and studied botany at the university of Vienna under Nikolaus Joseph von Jacquin...
in 1843 to accommodate the "green frog
Green frog
The Green Frog is a species of frog native to the eastern half of the United States and Canada. There are two subspecies—the Bronze Frog and the Northern Green Frog.-Description:...
s" of the Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
, which he considered distinct from the brown pond frogs of Linnaeus' genus Rana
Rana
Rana may refer to:In education:* Rana Institute of Higher Education, AfghanistanIn entertainment and sports:* Rana , forthcoming Indian film* Moon , the moon Rána in Tolkien's Middle-earth...
.
They are also known as water frogs, as they spend much of the summer living in aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
; the pond frogs can be found more often, by comparison, on dry land, as long as there is sufficient humidity
Humidity
Humidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...
. Yet there are species of Eurasian green frogs – the Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
n P. terentievi, or the Sahara Frog
Sahara Frog
The Sahara Frog is a species of frog in the Ranidae family. It is found in Algeria, Egypt, Libya, Morocco, Spain, Tunisia, and Western Sahara; in French it is called grenouille verte d'Afrique du Nord, and in Spanish it is known as rana verde norteafricana.Its natural habitats are rivers,...
(P. saharicus) – which inhabit waterholes in the desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
.
Systematics and taxonomy
Most authors throughout the 19th and 20th century disagreed with Fitzinger's assessment. The green frogs were included again with the brown frogs, in line with the tendency to place any frog similar in habitusMorphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
to the Common Frog
Common Frog
The Common Frog, Rana temporaria also known as the European Common Frog or European Common Brown Frog is found throughout much of Europe as far north as well north of the Arctic Circle in Scandinavia and as far east as the Urals, except for most of Iberia, southern Italy, and the southern Balkans...
(R. temporaria) in Rana. That genus, in the loose circumscription, eventually became a sort of "wastebin taxon
Wastebin taxon
Wastebasket taxon is a term used in some taxonomic circles to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined by their lack of one or more distinct character states or by their not belonging to one or more other taxa...
".
Around the year 2000, with molecular phylogenetic studies becoming commonplace, it was discovered that Fitzinger's assessment was correct after all – not only is Pelophylax an independent genus, but it does in fact belong to a lineage of Raninae not particularly close to Rana. But it also turned out that these Eurasian green frogs might not form a monophyletic lineage. The sheer number of species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
involved in the group of Pelophylax and its closest relatives means that it will probably be some time until the definite circumscription of this genus is resolved.
In any case, it can by now be said that the Pelophylax frogs belong to a group of moderately advanced Raninae – possibly a clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
– that also includes such genera as Babina, Glandirana, Hylarana
Hylarana
Hylarana is a widespread genus of true frogs found in tropical Africa, Asia, and Australia. It includes around 86 species.-Taxonomy:Hylarana was previously considered to be a subgenus of the genus Rana. It was recognized as a distinct genus in 2005...
, Pulchrana, Sanguirana, Sylvirana, as well as Hydrophylax which like Pelophylax is suspected of being not monophyletic. These genera were formerly also included in Rana by most authors, and several of them have in fact only been established in the 1990s
1990s
File:1990s decade montage.png|From left, clockwise: The Hubble Space Telescope floats in space after it was taken up in 1990; American F-16s and F-15s fly over burning oil fields and the USA Lexie in Operation Desert Storm, also known as the 1991 Gulf War; The signing of the Oslo Accords on...
. And as regards the possible paraphyly
Paraphyly
A group of taxa is said to be paraphyletic if the group consists of all the descendants of a hypothetical closest common ancestor minus one or more monophyletic groups of descendants...
of Pelophylax, it seems that some species assigned here are very close to Hylarana, and thus it might simply be a matter of moving them to that genus. But hybridogenic speciation
Speciation
Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...
is running rampant in the Old World green frogs, and this obfuscates the data gained from DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
analyses.
Species
Including named klepta (hybridogenic species), Pelophylax sensu lato contains 25 species:- Pelophylax bedriagae – Levant Water FrogLevant Water FrogThe Levant Water Frog , formerly belonging to the genus Rana, is a southern European species of frog. They are green to brown in color with dark blotches on their dorsal side. They are cousins of the aquatic frogs and live most of the time in the water. They are not poisonous and are quite...
- Pelophylax bergeri – Italian Pool FrogItalian Pool FrogThe Italian Pool Frog is a species of frog in the Ranidae family. It is found in France and Italy.Its natural habitats are rivers, intermittent rivers, swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, and intermittent freshwater marches. It is not considered threatened...
- Pelophylax caralitanus (Arikan, 1988) (formerly in P. bedriagae)
- Pelophylax cerigensis – Karpathos FrogKarpathos FrogThe Karpathos Frog is a species of frog in the Ranidae family. It is endemic to Greece.Its natural habitats are Mediterranean-type shrubby vegetation, rivers, intermittent rivers, freshwater lakes, intermittent freshwater lakes, freshwater marshes, intermittent freshwater marshes, arable land, and...
- Pelophylax chosenicus – Seoul FrogSeoul frogThe Seoul Frog is a species of true frog found on the western Korean Peninsula, and possibly in Liaoning. It is closely related to the Eastern Golden Frog, P. plancyi, and was long considered a subspecies thereof...
- Pelophylax cretensis – Cretan FrogCretan FrogThe Cretan Frog is a species of frog in the Ranidae family.It is endemic to Greece.Its natural habitats are Mediterranean-type shrubby vegetation, rivers, intermittent rivers, swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, intermittent freshwater marches, and...
- Pelophylax demarchii (validity and taxonomic status unclear; klepton?)
- Pelophylax epeiroticus – Epirus Water FrogEpirus Water FrogThe Epirus Water Frog is a species of frog in the Ranidae family. It is found in Albania and Greece.Its natural habitats are Mediterranean-type shrubby vegetation, rivers, swamps, freshwater lakes, freshwater marshes, and plantations. It is threatened by habitat loss.-Source:* Uzzell, T. 2004. . ...
- Pelophylax fukienensis (formerly in P. plancyi)
- Pelophylax hubeiensis (may belong in P. plancyi)
- Pelophylax kurtmuelleri – Balkan FrogBalkan FrogThe Balkan Frog is a species of frog occurring in Greece and, to a lesser extent, in Albania, Montenegro, and Serbia. The species highly resembles Pelophylax ridibundus, from which it was only distinguished in 1991 by bio-acoustic analysis...
- Pelophylax lateralisPelophylax lateralisPelophylax lateralis is a species of frog in the Ranidae family. It is found in Cambodia, Laos, Myanmar, Thailand, and Vietnam. It is commonly known as Kokarit Frog, Yellow Frog or "Wood Frog"....
– Kokarit Frog, Yellow Frog, "wood frogWood FrogThe Wood Frog has a broad distribution over North America, extending from the southern Appalachians to the boreal forest with several notable disjunct populations including lowland eastern North Carolina...
" (might belong in Hylarana) - Pelophylax lessonae – Pool FrogPool FrogThe Pool Frog is a European frog. It is one of only four amphibian species recognized by the UK government as protected under its Biodiversity Action Plan. The reasons for declining populations are decreased pond habitat from human encroachment and also air pollution leading to...
- Pelophylax nigromaculatus – Dark-spotted FrogDark-spotted frogThe Dark-spotted frog, or black-spotted frog, Pelophylax nigromaculatus , is a species of true frog found in East Asia. It occurs across much of eastern and northeastern China, the Amur River valley in Russia, the Korean Peninsula, and most of Japan, although it does not occur on Hokkaidō...
(may include P. tenggerensis) - Pelophylax perezi – Perez's FrogPerez's FrogPerez's Frog is a species of frog in the Ranidae family. It is found in southern France, Portugal, Spain, and two sites in the United Kingdom; in Spain it is very abundant, as evidenced by its Spanish name rana común .Its natural habitats are temperate forests, temperate shrubland,...
- Pelophylax plancyi – Eastern Golden FrogEastern golden frogThe Eastern golden frog, Pelophylax plancyi, is a species of true frog found in northeastern China. It is closely related to the Seoul frog, Pelophylax chosenicus; P. fukienensis was initially believed to be a subspecies of P. plancyi...
(may include P. hubeiensis) - Pelophylax porosus – Daruma Pond FrogDaruma Pond FrogThe Daruma Pond Frog, Pelophylax porosus, is a species of frog in the Ranidae family. It has two subspecies, P. porosus porosus and P. porosus brevipodus. It is endemic to Japan...
- Pelophylax ridibundus – Marsh FrogMarsh FrogThe Marsh Frog is the largest frog native to Europe and belongs to the family of true frogs. It is very similar in appearance to the closely related Edible Frog and Pool Frog...
- Pelophylax saharicus – Sahara FrogSahara FrogThe Sahara Frog is a species of frog in the Ranidae family. It is found in Algeria, Egypt, Libya, Morocco, Spain, Tunisia, and Western Sahara; in French it is called grenouille verte d'Afrique du Nord, and in Spanish it is known as rana verde norteafricana.Its natural habitats are rivers,...
- Pelophylax shqipericus – Albanian Water FrogAlbanian Water FrogThe Albanian Water Frog is a species of frog in the Ranidae family. It is found in Albania and Montenegro.Its natural habitats are rivers, swamps, freshwater lakes, and freshwater marshes.-References:...
- Pelophylax tenggerensis (may belong in P. nigromaculatus)
- Pelophylax terentievi (taxonomic status unclear; klepton?)
Named klepta (hybridogenic species) of Pelophylax are:
- Pelophylax kl. esculentus – Edible FrogEdible FrogThe Edible Frog is a name for a common European frog, also known as the common water frog or green frog . It is used for food, particularly in France for the delicacy frog legs...
(P. lessonae × P. ridibundus) - Pelophylax kl. grafi – Graf's Hybrid Frog (P. perezi × P. ridibundus)
- Pelophylax kl. hispanicus – Italian Edible FrogItalian Edible FrogThe Italian Edible Frog is a hybridogenic species in the true frog family Ranidae. These frogs are the offspring of P. bergeri and either P. ridibundus or the Edible Frog The Italian Edible Frog (Pelophylax kl. hispanicus) is a hybridogenic species in the true frog family Ranidae. These frogs are...
(P. bergeri × P. ridibundus/P. kl. esculentus)
In addition, one species has been described that is sometimes assigned to Pelophylax, but must be considered a nomen oblitum
Nomen oblitum
A nomen oblitum is a technical term, used in zoological nomenclature, for a particular kind of disused scientific name....
:
- "Hyla" ranaeformis Laurenti, 1768 (= "Hyla gibbosa" Lacépède, 1788 (unavailableAvailable nameIn zoology, an available name is a scientific name for a taxon of animals that has been published conforming to all the mandatory provisions of the ICZN Code for the establishment of a zoological name....
: published in non-binomialBinomial nomenclatureBinomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
work) )