| Pool frog | |
|---|---|
 | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | Anura |
| Family: | Ranidae |
| Genus: | Pelophylax |
| Species: | P. lessonae |
| Binomial name | |
| Pelophylax lessonae (Camerano, 1882) | |
| Synonyms[3] | |
| |
Thepool frog (Pelophylax lessonae) is aEuropeanfrog in the familyRanidae. Itsspecific name was chosen by the ItalianherpetologistLorenzo Camerano in 1882, in order to honour his masterMichele Lessona.
The pool frog is a small frog which rarely grows to more than 8 cm (3.1 in) long, although females can grow up to 9 cm (3.5 in). Males are typically around 5 cm (2.0 in) long, while females are around 6–6.5 cm (2.4–2.6 in) long. These frogs are brown or green, with dark blotches along their backs, a pair of ridges running from each eye and a cream or yellow stripe down the middle of the frog's back. Thevocal sacs on the male are cream or even white.[4]
The pool frog is found across most of central Europe from the west coast of northern France to the Western part of Russia. There are also small populations of pool frogs in the United Kingdom, Spain, Sweden and Norway.[1] Pool frogs were previously thought to be a non-native species in the UK, but studies have shown that English pool frogs are related to the Swedish and Norwegian populations.[4]
The pool frog is found in damp areas with dense vegetation, or in calm, slow flowing rivers, ponds, bogs or marshes.[4]
According toAmphibiaweb populations of this frog survive in urban areas and even fisheries. The creation of new ponds and other bodies of water leads to increased dispersal and a growth in the population of these frogs.[5]
Pelophylax lessonae is one of only fouramphibianspecies recognized by theUK government as protected under itsBiodiversity Action Plan. The reasons for declining populations are decreasedpond habitat fromhuman encroachment and alsoair pollution leading to over-nitrification of pond waters.
The pool frog has not always been recognised as a native British species. Part of the reason for this is that specimens are known to have been introduced from southern Europe (though not from Scandinavia). However research has now shown that the potentially native UK pool frogs are closely related to Scandinavian frogs, not to frogs from further south. A native origin is most likely.[6]
TheHerpetological Conservation Trust website states that "The Pool Frog is aEuropeanfrog and was formerly recorded from two sites inEast Anglia although it was lost from one of these in the middle of the 19th century. It was presumed extinct in the wild at the last remaining site by 1995. A single individual known from this population survived in captivity until 1999. Other populations have become established in the UK and it is known that some of these included individuals of British origin in their founding stock."
AnEnglish Nature reintroduction project is underway inBreckland, where pool frogs were introduced to a single site in 2005.
Theedible frogPelophylax kl.esculentus is a hybridogenetichybrid of the pool frogPelophylax lessonae and themarsh frogP. ridibundus. Its populations are maintained however through other crossings byhybridogenesis.[7]
