Amphibians are animals closely related to water, especially for spawning and tadpoles development. These live breathing the oxygen dissolved in water through the gills. After the metamorphosis, the adults breathe air through the lungs, but also through the skin should therefore always be moist to allow gas exchange. For this reason,the adults always keep near water or in wetlands.
Adult amphibians are carnivorous, feeding mainly insects and snails, unlike tadpoles that are mostly vegetarians. They hibernate from November to February, hiding in some hole in the ground or deep.
Amphibians most common in the stagnant water of resurgence area are two green frogs species: the pool frog (Pelophylax lessonae) and the green frog (Pelophylax esculentus). These two species are difficult to distinguish between them in terms of morphology and determination require an accurate analysis of the genetic heritage.
In the stagnant water live also two species of newt: the smooth newt (Lissotriton vulgaris meridionalis) and the Italian crested newt (Triturus carnifex). The latter is included in the Annexes of the Habitats Directive as species of Community interest.
The other species of amphibians of resurgences generally live in moist woods and near the waters only during the breeding season. At the edge of the woods and hedges lives the Italian tree frog (Hyla intermedia), up to 5 cm long, which is endemic to Italian. It is the only amphibian capable of climbing trees and vegetation with the help of adhesive discs on their fingers.
In the wet woods there are also the common toad (Bufo bufo) and two species of red frogs: the agile frog (Rana dalmatina) and italian agile frog (Rana latastei). The latter is a species endemic to the Po-Venetian plain, but is also present north-western Istria.
It is included in the Annexes of the Habitats Directive as species of Community interest and in the Red List of Animals of Italy as an endangered species because of the reduction and fragmentation of wetlands.
For the same reason is also mentioned in this list theyellow-bellied toad (Bombina variegata), who attends the stagnant water and temporary pools that form after rain, in which lay their eggs. Because of the high temperatures that develop in this type of water, the development of eggs and tadpoles is very fast. It is curious the anti- predatory behavior of adults of this small amphibian: in case of danger it quickly show the yellow-bellied black and frightening as the predator.
Among the amphibians should be mentioned also common spadefoot (Pelobates fuscus insubricus), a subspecies of pelobate endemic in Northern Italy, 5-6 cm long and similar to a small frog. Its characteristic is the vertical elliptical pupil. It was once common, today it is very rare and has disappeared from most of the Padano-Venetian plain due to the restriction of wetlands. Its presence in the resurgences area is still to be confirmed. It is included in the Habitats Directive as a priority species of Community interest, which implies the obligation of Member States of the European Union to protect in particular environments where they live.
All species of amphibians present in the region, with the exception of exotic species introduced by man, are protected by the Regional Law 9/2007 that prohibite capture, killing intentional noise, damage and destruction of breeding sites and the holding and the trading operation.