Edible frog
The edible frog is a hybrid species of common European frog, also known as the common water frog or green frog.
It is used for food, particularly in France as well as Germany and Italy, for the delicacy frog legs. Females are between long, males between.
This widespread and common frog has many common names, including European dark-spotted frog, European black-spotted pond frog, and European black-spotted frog.
Distribution
Pelophylax esculentus is endemic to Europe. It naturally occurs from the northern half of France to western Russia, and from Estonia and Denmark to Bulgaria and northern Italy. The edible frog is introduced in Spain, Norway and the United Kingdom. The natural range is nearly identical to that of P. lessonae.Hybridogenesis
Pelophylax kl. esculentus is the fertile hybrid of the pool frog and the marsh frog. It reproduces by hybridogenesis.Hybridogenesis implies that during gametogenesis hybrids exclude one parental genome and produce gametes with an unrecombined genome of the other parental species, instead of containing mixed recombined parental genomes. The hybrid populations are usually propagated by mating with a sympatric parental species – P. lessonae or P. ridibundus – providing the second, discarded parental genome. Hybridogenesis is thus a hemiclonal mode of reproduction; half of the genome is transmitted to the next generation clonally, unrecombined ; the other half sexually, recombined.
For example, in the most widespread so called L–E system, edible frogs Pelophylax kl. esculentus produce gametes of the marsh frog P. ridibundus and mate with coexisting pool frogs Pelophylax lessonae – see below in the middle.
File:Hybridogenesis in water frogs.gif|none|thumb|500px|Example crosses between pool frog, marsh frog and their hybrid, edible frog. The first is the primary hybridisation generating the hybrid; the second is the most widespread type of hybridogenesis.
Because this hybrid requires another taxon as a sexual host to reproduce, usually one of the parental species, it is a klepton, hence the addition of the "kl." in the species name.
There are also known all-hybrid populations, where diploid hybrids coexist with triploid hybrids, providing L or R genomes respectively. In this situation, diploid hybrids generate not only haploid R or L gametes, but also the diploid gametes needed to recreate triploids.