Italian hybrid frog
| Italian hybrid frog | ||||||||||||
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Italian hybrid frog ( Pelophylax "hispanicus" ) |
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| Scientific name | ||||||||||||
| Pelophylax "hispanicus" | ||||||||||||
| ( Bonaparte , 1839) |
The Italian hybrid frog ( Pelophylax "hispanicus" or Rana "hispanica" ) belongs to the family of real frogs (Ranidae) within the order of the frog auger. In addition, it is counted according to appearance, way of life and relationships to the water frogs , which are now placed by many authors in their own genus Pelophylax . This taxonomic complex, which is difficult to understand , is not a biological species , but a hybridogenic hybrid of the sea frog ( Pelophylax ridibundus ) and the Italian water frog ( Pelophylax bergeri ). The form occurs in almost all of Italy, including Sicily . The scientific species epithet hispanicus ("Spanish") is therefore misleading. It is often put in quotation marks to express the fact that this is not a real nature. Alternatively, the spelling Pelophylax kl. hispanicus possible, whereby kl. stands for "Klepton" (compare: pond frog ).
features
It is a medium-sized water frog, its body proportions are between that of its parent species Pelophylax bergeri and sea frog. The inner heel hump is shorter and flatter than that of the Italian water frog. The upper side is greenish to brownish in color and has black spots. A light dorsal line can be seen. There are small white, sometimes pale yellow to pale gray spots on the inner thighs. The intensity of the colored spots is often less than that of P. bergeri .
The males have paired dark gray sound bladders (the Italian water frogs are whitish). During the breeding season, their thumb callus is dark in color. However, the degree of pigmentation of the oestrus calluses varies. Presumably the forelimbs are more pronounced in the males than in the females.
A clear field biological differentiation of the taxon from the Italian water frog is often not possible. The determination is the most reliable in terms of molecular biology.
distribution and habitat
The Italian hybrid frog is found in almost all of Italy (mainland south of the Po Valley) as well as in Sicily - its area is congruent with its parent species P. bergeri (apart from Corsica, where it was released). South of an imaginary line from Genoa to Rimini, it is the only water frog taxon in Italy alongside the Italian water frog.
Pelophylax "hispanicus" inhabit the same habitats as P. bergeri and usually occur syntopically with them. Due to their high degree of heterozygosity , they are said to have an even greater adaptability and ecological plasticity.
Systematics
The Italian hybrid frog has both genetic makeup of the Italian water frog (these are similar to those of the small water frog , Pelophylax lessonae ) and the sea frog. It seems entirely diploid to be present only the animals ridibundus - Genome inherit when they propagate with the Italian water frog. They are therefore also dependent on backcrossing with Pelophylax bergeri . The inheritance pattern is simpler here than in the pond frog ( Pelophylax "esculentus" ), where triploid individuals also occur, which enable reproduction without the presence of both parent species.
Since the sea frog is absent in Italy, the question arises as to how hybridization could have come about at all. There are two theses for this. Either Pelophylax bergeri occurred further north before the last Ice Age , so that the cross between it and the sea frog would have taken place outside of what is now Italy. The hybrid Pelophylax "hispanicus" would then have immigrated to Italy. Another explanation is that the sea frog genome of the Italian hybrid frog could not come directly from sea frogs, but from another hybridogenic hybrid of water frogs, the pond frog ( P. "esculentus" ). This would have acted as a representative transmitter of the ridibundus genome without P. bergeri and P. ridibundus ever meeting each other .
Individual evidence
- ↑ Jörg Plötner: The West Palearctic Water Frogs - From Martyrs of Science to Biological Sensation . Supplement to the magazine f. Feldherpetologie 9, Bielefeld 2005, page 108. ISBN 3-933066-26-3
literature
- Andreas Nöllert, Christel Nöllert: The amphibians of Europe . Franckh Kosmos Verlag, Stuttgart 1992, ISBN 3-440-06340-2 .
- Jörg Plötner: The western Palearctic water frogs - from martyrs of science to a biological sensation . Supplement to the magazine f. Feldherpetologie 9, Bielefeld 2005. ISBN 3-933066-26-3
Web links
- Pelophylax hispanicus inthe IUCN 2013 Red List of Threatened Species . Posted by: Franco Andreone, Claudia Corti, Roberto Sindaco, Antonio Romano, 2008. Retrieved November 19, 2013.