Adult amphibians are predators

Amphibians feed on insects, snails, spiders, and earthworms, thus regulating the abundance of their prey in nature. Those who swear by close-to-nature gardening are pleased to have a toad in their garden.

Amphibians swallow their prey with their eyes

Amphibians are threatened largely by their habitat destruction (draining and filling up of wetlands), water pollution, use of chemical substances (e.g. pesticides), climate change and disconnection of migration routes by roads (amphibians run over by cars). As they are endangered, they are protected. It is forbidden to kill them, poison them and destroy their habitats (Regulation on wild animal species, Reg. l. 46/2004; Red list of endangered reptile species, Official Gazette RS 82/2002).

Frog’s love hug

In frogs and toads, fertilization is external, while in tailed amphibians it is internal. The male frog or toad clings to the female (amplexsus), and as soon she starts releasing the eggs, the male fertilizes them simultaneously. During the courtship dance, the male tailed amphibian releases the spermatophore (gelatinous capsule containing sperm) into the female’s cloaca, enabling fertilization to takes place inside her body. Female newts lay fertilized eggs and wrap them individually in aquatic plants. Salamanders are viviparous – the eggs develop in the female’s body, then tadpoles are hatched (vivipary).

Amphibian eggs with gelatinous coating are deposited in the water – one by one, in lumps, clumps, strings or ribbons. The species can thus be identified  also the shape of the spawn.

Frogs call mostly in mating season. You can learn distinguish frogs by their croaking with the aid of the CD Slovenske žabe (Slovenian Frogs and Toads).

In the Fire Salamander (Salamandra salamandra), the eggs develop in the female’s body to the larval stage and are then hatched in the water. Larvae breathe in water with gills and gradually transform into adult amphibians. In the Alpine Salamander (Salamandra atra), the eggs also develop in the female’s body, except that the young are born after the metamorphosis has already been completed.

Amphibian conservation

Amphibians feed on insects, snails, spiders, and earthworms, thus regulating the abundance of their prey in nature. Those who swear by close-to-nature gardening are pleased to have a toad in their garden. 

Amphibians are threatened largely by their habitat destruction (draining and filling up of wetlands), water pollution, use of chemical substances (e.g. pesticides), climate change and disconnection of migration routes by roads (amphibians run over by cars). As they are endangered, they are protected. It is forbidden to kill them, poison them and destroy their habitats (Regulation on wild animal species, Reg. l. 46/2004; Red list of endangered reptile species, Official Gazette RS 82/2002).

Experts in Europe and around the world have recently detected the problem of amphibian extinction due to a viral disease caused by ranaviruses and fungal disease called chytridiomycosis. The latter is a disease caused by the fungus Batrachochytrium dendrobatidis from the group Chytridiomycota. Owing to this fungus, amphibian populations around the globe are in major decline. In adult amphibians (Anura and Caudata), the fungus attacks the keratin layer of the skin, while in tadpoles (Anura) it affects the mouthparts (Garner et al., 2005). The fungus has caused death and decline of amphibian populations in Spain, Germany, Australia, New Zealand, USA, Central America, South America (Hyatt et al., 2007), with individuals suffering from this disease also confirmed in Portugal, Great Britain, Italy and Switzerland (Garner et al., 2005).

Ranaviruses (Iridoviridae family, Ranavirus genus) constitute a group of viruses that infect fish, amphibians and reptiles. The commonest symptom of Ranavirus infection in amphibians is a high number of dead specimens in a short period of time. Signs of infection can be red skin (subcutaneous bleeding), limb necrosis and lethargy, although these signs are not necessarily obvious or revealed. The virus causes high mortality among amphibians. The disease most frequently develops during the summer, since the virus is most virulent at temperatures above 25°C.