The edible frog (Pelophylaxkl.esculentus)[1][2] is a hybrid species of common European frog, also known as the common water frog or green frog (however, this latter term is also used for the North American species Rana clamitans).
It is used for food, particularly in France as well as Germany and Italy, for the delicacy frog legs.[3] Females are between 5 and 9 cm (2.0 and 3.5 in) long, males between 6 and 11 cm (2.4 and 4.3 in).
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,[4] Norway[5] and the United Kingdom.[6] The natural range is nearly identical to that of P. lessonae.[7]
Hybridogenesis implies that during gametogenesis hybrids (of RL genotype) exclude one parental genome (L or R) and produce gametes with an unrecombinedgenome of the other parental species (R or L, respectively), instead of containing mixed recombined parental genomes.[9][10][12] The hybrid populations are usually propagated by mating (backcrosses) with a sympatric parental species – P. lessonae (LL) or P. ridibundus (RR) – providing the second, discarded parental genome (L or R respectively).[9][10][12] Hybridogenesis is thus a hemiclonal mode of reproduction; half of the genome is transmitted to the next generation clonally, unrecombined (intact); the other half sexually, recombined.[13][11][12]
For example, in the most widespread so called L–E system, edible frogs Pelophylax kl. esculentus (RE) produce gametes of the marsh frog P. ridibundus (R) and mate with coexisting pool frogs Pelophylax lessonae (L gametes) – see below in the middle.[9][12]
Because this hybrid requires another taxon as a sexual host to reproduce, usually one of the parental species, it is a klepton,[14][15][16] hence the addition of the "kl." (for klepton) in the species name.[17]
There are also known all-hybrid populations, where diploid hybrids (LR) coexist with triploid (LLR or LRR) hybrids, providing L or R genomes respectively. In this situation, diploid hybrids (LR) generate not only haploid R or L gametes, but also the diploid gametes (RL) needed to recreate triploids.[9][10]
^Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler 2006. The amphibian tree of life. Bulletin of the American Museum of Natural History. Number 297. New York. Issued March 15, 2006.
^Sergius Kuzmin, David Tarkhnishvili, Vladimir Ishchenko, Tatjana Dujsebayeva, Boris Tuniyev, Theodore Papenfuss, Trevor Beebee, Ismail H. Ugurtas, Max Sparreboom, Nasrullah Rastegar-Pouyani, Ahmad Mohammed Mousa Disi, Steven Anderson, Mathieu Denoël, Franco Andreone (2009). "Pelophylax ridibundus". IUCN Red List of Threatened Species. 2009: e.T58705A11825745. doi:10.2305/IUCN.UK.2009.RLTS.T58705A11825745.en. Retrieved 6 November 2023.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Dubois, Alain (2009). "Asexual and metasexual vertebrates. Book review". Alytes. 27 (2). ISSCA (International Society for the Study and Conservation of Amphibians): 62–66. Retrieved 2015-06-22. John C. Avise, 2008.–Clonality. The genetics, ecology, and evolution of sexual abstinence in vertebrate animals. New York, Oxford University Press: i-xi + 1-237. ISBN978-0-19-536967-0.
^Dubois, A.; Günther, R. (1982). "Klepton and synklepton: two new evolutionary systematics categories in zoology". Zool. Jahrb. Syst. (Zoologische Jahrbücher. Abteilung für Systematik, Ökologie und Geographie der Tiere). 109. Jena; Stuttgart; New York.: Gustav Fischer Verlag: 290–305. ISSN0044-5193.
^Polls Pelaz, Manuel (October 1990). "The Biological Klepton Concept (BKC)". Alytes. 8 (3). ISSCA (International Society for the Study and Conservation of Amphibians): 75–89. Archived from the original on 2014-07-14. Retrieved 2015-06-22.