Tricolor stubby foot frog
| Tricolor stubby foot frog | ||||||||||||
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| Atelopus tricolor | ||||||||||||
| Boulenger , 1902 |
The three-colored stump foot frog ( Atelopus tricolor , syn .: Atelopus rugulosus , Atelopus willimani ) belongs to the stubby foot frogs ( Atelopus ). It is also called the three-color harlequin frog or three-color harlequin toad. The genus Atelopus belongs to the toad family (Bufonidae).
description
The males are 20.4 to 27 mm and the females 36 mm. They have a slim body with long limbs. The skin is soft and warty. The belly is yellow with black-bluish irregular points. It has stripes on the flanks and on the jaw in the same mustard yellow color. The back and limbs are dark brown or black-bluish with mustard-yellow spots. The palms and soles of the feet are red, which is a good sign of identification.
population
The three-colored stumpy-footed frog is marked as endangered on the Red List because a decline in the population has been observed. The population is expected to decrease by 30% over the next decade, as is the case with other Atelopus species in the same region, which is likely caused by chytridiomycosis . This threat has not yet emerged as severe as with other species. The main threat at the moment is the loss of habitat by smallholders and increased water pollution. In some areas, the introduced trout also pose a threat to the frogs.
Habitat
Atelopus tricolor lives in humid forest areas and spawns in flowing waters. The males form groups of 4 to 10 individuals. At night, the frogs stay at a height of 0.3 to 1.2 meters.
Distribution area
Eastern Andes such as Peru and Bolivia at altitudes of 600 to 2500 m, e.g. B. Mercapta Valley in Peru, Amazon on the slopes of the eastern Andes, Puno, La Paz, Cochabamba.
protection
Atelopus tricolor is classified in the IUCN “endangered” category. In recent years it has become a rarity in Peru , where it is also endangered according to the national category. In Bolivia , his presence was only confirmed until 2003; according to the national category, the data there are poor (status 2005).
Substances
Tetrodotoxin
Many frogs of the genus Atelopus have tetrodotoxin on their skin. It cannot be considered proven that Atelopus tricolor produces this toxin, but it is one of the possible toxins that can be found in this species. It is generally believed that the tetrodotoxin is produced by symbiotic bacteria that live on the frogs. The toxin does not occur in frogs that have grown up under laboratory conditions. The tetrodotoxin is a neurotoxin which has an alkaloid with a guanidine partial structure. This poison has been discovered in puffer fish , porcupine fish, crabs, snails and starfish, among others . The tetrodotoxin can block the voltage-activated sodium channels . This prevents an action potential from being triggered . This causes motor and sensory paralysis. The poison is one of the strongest non-protein poisons. The LD50 in mice is 10 µg / kg intraperitoneally, 16 µg / kg subcutaneously and 332 µg / kg orally.
The tetrodotoxin can be used for pain therapy. So it is a possible substance for cancer therapy. It can also be used as an antagonist for the alkaloid toxin batrachotoxin of the poison dart frogs. However, this does not immediately block the state of excitement caused by the batrachotoxin, but strengthens the heart muscle.
Bufodienolide
Other poisons that occur in the Atelopus species are bufodienolides and their similar substances. These toxins appear to be produced by the frog as they are also found in the captive frogs. Bufodienolides have been found in the skin of various Atelopus species, as well as previously in toads of the genus Bufo . The detection was carried out by experiments in which the Na + / K + -ATPase was inhibited or the binding of tritium-ouabain to the Na + / K + -ATPase was inhibited.
Individual evidence
- ↑ a b Ranas Arlequines, 2005, J. Vincente et al. (eds.), Conservation International. 158 pages
- ↑ a b c IUCN. International Union for Conservation of Nature. Red List. (Stand 2013)
- ↑ (PDF) Notes on amphibians recently collected in the Yungas de La Paz region, Bolivia. Retrieved August 5, 2019 .
- ↑ a b Moczydlowski, EG The molecular mystique of tetrodotoxin. Toxicon 63 (2013) 165-183
- ^ A b Dally, JW Ernest Guenther Award in Chemistry of Natural Products. Amphibian skin: A remarkable source of biologically active arthropod alkaloids. J. Med. Chem. 2003, 46, 445-452
- ↑ Hagen, NA et al. Tetrodotoxin for moderate to severe cancer pain: a randomized, double blind, parallel design multicenter study. J Pain Symptom Manage. 2008. 35: 420-429.
- ↑ Chemgapedia Batrachotoxin. URL: http://www.chemgapedia.de/vsengine/vlu/vsc/de/ch/8/bc/vlu/biotoxine/tiergifte.vlu/Page/vsc/de/ch/8/bc/biotoxine/pfeilgift. vscml.html (as of July 4, 2013).
- ↑ JW Daly: Thirty years of discovering arthropod alkaloids in amphibian skin. J. Nat. Prod., 61, pp. 162-172, 1998
literature
- S. Lötters et al .: Reinforcing and expanding the predictions of the disturbance vicariance hypothesis in Amazonian harlequin frogs: a molecular phylogenetic and climate envelope modeling approach. Biodivers. Conserv., 19, pp. 2125-2146, 2010
Web links
- Atelopus tricolor inthe IUCN 2013 Red List of Threatened Species . Posted by: Antonio Salas, Roberto Ibáñez, Alessandro Catenazzi, Juan Carlos Chaparro-Auza, Ariadne Angulo, Steffen Reichle, Jörn Köhler, Ignacio De la Riva, Stefan Lötters, Claudia Cortez, Wilfredo Arizabal, 2004. Accessed November 20, 2013.