The marsh frog (''Pelophylax ridibundus'') is a species of water frog native to

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and parts of western

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Description

The marsh frog is the largest type of frog in most of its range, with males growing to a size around 100 mm (3.9 in) SVL and females slightly larger (4 in) SVL. There is a large variation in colour and pattern, ranging from dark green to brown or grey, sometimes with some lighter green lines; a lighter line on the back is generally present. The frog will usually be darker coloured in early

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a h ...

to absorb heat more efficiently. Tadpoles can reach up to 190 mm (7.3 in) in length, but this usually occurs in places with long winters where the tadpole has time to grow.

Distribution and habitat

They occur in a large part of Europe starting from western

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

and spreading out into the

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and about a quarter into

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

. There are also isolated populations in

Saudi Arabia Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in Western Asia. It covers the bulk of the Arabian Peninsula, and has a land area of about , making it the fifth-largest country in Asia, the second-largest in the Ara ...

and the

Russian Far East The Russian Far East (russian: Дальний Восток России, r=Dal'niy Vostok Rossii, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in Northeast Asia. It is the easternmost part of Russia and the Asian continent; and is admin ...

, along with some introduced populations in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and ...

and other places. These frogs are very lenient in their habitats, and are able to inhabit a majority of different types of water bodies. Marsh frogs hibernate during the winter either underwater or in burrows, and are able to use the

magnetic field A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...

of the

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to locate breeding ponds.

Diet

Adult marsh frogs have a large head that is able to devour a wide variety of prey, mostly arthropods and other invertebrates. In an analysis of 53 adults in

Thrace Thrace (; el, Θράκη, Thráki; bg, Тракия, Trakiya; tr, Trakya) or Thrake is a geographical and historical region in Southeast Europe, now split among Bulgaria, Greece, and Turkey, which is bounded by the Balkan Mountains to ...

flies Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced m ...

made up 40% and

beetles Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describe ...

20% of their diet. These frogs have been found to climb onto

water buffalo The water buffalo (''Bubalus bubalis''), also called the domestic water buffalo or Asian water buffalo, is a large bovid originating in the Indian subcontinent and Southeast Asia. Today, it is also found in Europe, Australia, North America, So ...

so they could eat the flies attracted to it, hinting at a possible mutualistic relationship. As tadpoles, they eat a wide range of organic matter including

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular micr ...

detritus In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts comm ...

, decaying plants, and dead animals.

Hybridogenesis

There are known three hybridogenetic hybrids of the marsh frog: * edible frog ''Pelophylax'' kl. ''esculentus'' (usually genotype RL):
pool frog ''P. lessonae'' (LL) × ''P. ridibundus'' (RR) * Graf's hybrid frog ''Pelophylax'' kl. ''grafi'' (PR):
Perez's frog ''P. perezi'' (PP) × ''P. ridibundus'' (RR) or
Perez's frog ''P. perezi'' (PP) × edible frog ''P.'' kl. ''esculentus'' (RE)
(it is unclear which one crossing was the primary hybridization) * Italian edible frog ''Pelophylax'' kl. ''hispanicus'' (RB):
Italian pool frog ''P. bergeri'' (BB) × ''P. ridibundus'' (RR) Their populations are maintained however through other crossings by

hybridogenesis Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...

. In places where they were introduced, marsh frogs may pose a threat to the native '' Pelophylax'' by diluting the gene pool, but there is evidence that although they may hybridize they do not affect the overall population that greatly.

References

External links

* * Listen t
''Pelophylax ridibundus'' call sound
{{Taxonbar, from=Q319393 Pelophylax Amphibians of Afghanistan Amphibians of Iran Amphibians of the Middle East Vertebrates of the Arabian Peninsula Amphibians of Europe Amphibians described in 1771 Taxa named by Peter Simon Pallas