Three-coloured harlequin toad

The three-color Stummelfußfrosch ( Atelopus tricolor, Synonyms: Atelopus rugulosus, Atelopus willimani ) belongs to the Stummelfußfröschen ( Atelopus ). It is also called three-color harlequin frog or three-color harlequin toad. The genus Atelopus belongs to the family of toads ( Bufonidae ).

• 4.1 tetrodotoxin
• 4.2 Bufodienolide

Description

The males are 20.4 to 27 mm and females 36 mm. They have a slender body with long limbs. The skin is soft and warty. The belly is yellow with black - bluish irregular points. He has stripes on the flanks and on the jaw in the same mustard yellow color. Back and limbs are dark brown or black - bluish with mustard - yellow dots. Palms and soles are red, which is a good identification.

Population

The three-color Stummelfußfrosch is marked on the Red List as endangered, since a decrease in the population is observed. There is a decrease in population by 30 % over the next decade expected, as with other Atelopus species in the same region, which is probably caused by chytridiomycosis. This danger is not so strong as occurred in other species. The main hazard is currently the loss of habitat by small farmers and increased water pollution. In some areas also provide the introduced trout pose a threat to the frogs, since they

Habitat

Atelopus tricolor thrives in moist forest areas and spawning in rivers. The males form groups of 4-10 individuals. At night, keep the frogs at a height of 0.3 to 1.2 meters.

Distribution area

Eastern Andes such as Peru and Bolivia at altitudes of 600-2500 m, eg Mercaptans Valley in Peru, Amazonas, on the slopes of the eastern Andes, Puno, La Paz, Cochabamba.

Protection

Atelopus tricolor is "endangered" in the IUCN classified category. In recent years he has been a rarity in Peru, is recognized by national category also at risk. In Bolivia, its presence was confirmed only until 1992, according to national category there are data deficient (as of 2005).

Substances

Tetrodotoxin

Many frogs of the genus Atelopus have tetrodotoxin on the skin. It can not be considered to be proven that this toxin produces tricolor Atelopus, however, it is one of the possible toxins, which can be found in this species. It is generally believed that the tetrodotoxin is produced by symbiotic bacteria which live on the frogs. In frogs, which are grown under laboratory conditions, the toxin does not occur. The Tetrodotoxin is a neurotoxin, which has an alkaloid with guanidine partial structure. This poison was discovered among other puffers, porcupine fish, crabs, snails and starfish. The tetrodotoxin can block the voltage-activated sodium channels. Thus the triggering of an action potential is prevented. This causes motor and sensory paralysis. The poison is one of the strongest non-protein toxins. The LD50 in mice intraperitoneally 10 micrograms / kg, sc 16 mcg / kg orally and 332 mcg / kg.

The tetrodotoxin can be used for pain management. It is a possible material for the treatment of cancer. It can also be used as an antagonist for the batrachotoxin alkaloids toxin of poison dart frogs. Here, however, it does not come immediately to a blockade of the damage caused by the batrachotoxin state of excitement, but to strengthen the heart muscle.

Bufodienolide

Other poisons, which occurs in the species of Atelopus are Bufodienolide and their related substances. These toxins appear to be produced by the frog, as they are also found in the captive frogs. Bufodienolide have been detected in the skin different Atelopus species, as well as previously in toads of the genus Bufo. Detection was by experiments in which inhibits Na / K -ATPase, or the binding of tritiated ouabain to Na / K -ATPase was inhibited.