Poison dart frog

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Poison dart frogs
Dendrobates azureus (top) and Dendrobates leucomelas
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Suborder: Neobatrachia
Superfamily: Dendrobatoidea
Family: Dendrobatidae
Cope, 1865
Subfamilies and genera
Distribution of Dendrobatidae (in black)

Poison dart frog is the common name of a group of frogs in the family Dendrobatidae. They are native to Central and South America.

Unlike most frogs, these are active during the day. They often have brightly-coloured bodies, which act as warning colouration. Although all dendrobatids are at least somewhat toxic in the wild, levels of toxicity vary greatly from one species to the next, and from one population to another. Many species are critically endangered. Blue poison dart frogs are poisonous because they eat ants and other small insects that have toxins in their bodies. If an animal eats the frog, it will become very sick.

Toxicity[change | change source]

Many poison dart frogs secrete alkaloid toxins through their skin. Alkaloids in the skin glands of poison frogs serve as a chemical defense against predation, and they are therefore able to be active alongside potential predators during the day. About 28 structural classes of alkaloids are known in poison frogs.[1][2][3] The most toxic of poison dart frog species is Phyllobates terribilis. It is argued that dart frogs do not synthesize their poisons, but sequester the chemicals from arthropod prey items, such as ants, centipedes and mites – the diet-toxicity hypothesis.[4][5] Because of this, captive-bred animals do not possess significant levels of toxins as they are reared on diets that do not contain the alkaloids sequestered by wild populations. Nonetheless, the captive-bred frogs retain the ability to accumulate alkaloids when they are once again provided an alkaloid-containing diet.[6]

Most wild species are not lethal to their predators, but rather taste foul enough that frogs are released immediately. Despite the toxins used by some poison dart frogs, some predators have developed the ability to withstand them. One is the snake Leimadophis epinephelus, which has developed immunity to the poison.[7]

Taxonomy[change | change source]

Dart frogs are the focus of major phylogenetic studies, and undergo taxonomic changes frequently. [8] Family Dendrobatidae was revised taxonomically in 2006 and contains 12 genera, with about 170 species.[9][10]

Colour morphs[change | change source]

Some poison dart frogs species include a number of colour morphs that emerged as recently as 6,000 years ago.[11]

Predation may have influenced the evolution of polymorphism in O. granulifera,[12] while sexual selection appears to have contributed to differentiation among the Bocas del Toro populations of Oophaga pumilio.[13][14][15]

References[change | change source]

  1. "AmphibiaWeb – Dendrobatidae". AmphibiaWeb. http://amphibiaweb.org/lists/Dendrobatidae.shtml. Retrieved 2008-10-10.
  2. Heying, H. (2003). "Dendrobatidae". Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Dendrobatidae.html. Retrieved 2008-09-18.
  3. Cannatella, David (1995). "Dendrobatidae. Poison-arrow frogs, Dart-poison frogs, Poison-dart frogs". The Tree of Life Project. http://tolweb.org/Dendrobatidae/16956/1995.01.01. Retrieved 2008-10-23.
  4. Darst C. et al 2005. Evolution of dietary specialization and chemical defense in Poison Frogs (Dendrobatidate): a comparative analysis. The American Natural 165: 56–69.
  5. Daly J.W. et al (1994). "First occurrence of tetrodotoxin in a Dendrobatid Frog (Colostethus-Inguinalis), with further reports for the Bufonid Genus Atelopus". Toxicon 32 (3): 279–285. doi:10.1016/0041-0101(94)90081-7 . PMID 8016850 .
  6. Saporito R. et al 2007. "Oribatid mites as a major dietary source for alkaloids in poison frogs". Proceedings of the National Academy of Sciences of the United States of America 104 (21): 8885–8890. doi:10.1073/pnas.0702851104 . PMC 1885597 . PMID 17502597 .
  7. C.W. Myers, J.W. Daly, and B. Malkin (1978). "A dangerously toxic new frog (Phyllobates) used by the Emberá Indians of western Colombia, with discussion of blowgun fabrication and dart poisoning". Bulletin of the American Museum of natural history 161 (2): pp. 307–365 + color pls. 1–2.
  8. Grant, T. et al 2006. "Phylogenetic systematics of dart-poison frogs and their relatives (Amphibia: Athesphatanura: Dendrobatidae)". Bulletin of the American Museum of Natural History (American Museum of Natural History) 299 (299): 1–262. doi:10.1206/0003-0090(2006)299[1:PSODFA]2.0.CO;2 . ISSN 0003-0090 . http://digitallibrary.amnh.org/dspace/bitstream/2246/5803/1/B299.pdf.
  9. "Amphibian Species of the World". The American Museum of Natural History. http://research.amnh.org/herpetology/amphibia/names.php?taxon=&family=Dendrobatidae&subfamily=&genus=&commname=&authority=&year=&geo=0&dist=&comment=. Retrieved 2008-10-10.
  10. F. Harvey Pough ... (2004). Herpetology. Upper Saddle River, NJ: Pearson/Prentice Hall. pp. 92. ISBN 0-13-100849-8 .
  11. Summers K. et al 1999. "Visual mate choice in poison frogs". Proceedings. Biological sciences / the Royal Society 266 (1434): 2141–5. doi:10.1098/rspb.1999.0900 . PMC 1690338 . PMID 10649631 .
  12. Wang, I. J. (2011). "Inversely related aposematic traits: reduced conspicuousness evolves with increased toxicity in a polymorphic poison-dart frog". Evolution 65 (6): 1637–1649. doi:10.1111/j.1558-5646.2011.01257.x . PMID 21644954 .
  13. Maan, M. E.; M. E. Cummings (2008). "female preferences for aposematic signal components in a polymorphic poison frog". Evolution 62 (9): 2234–2345. doi:10.1111/j.1558-5646.2008.00454.x . PMID 18616568 .
  14. Reynolds, R. G.; B. M. Fitzpatrick (2007). "Assortative mating in poison-dart frogs based on an ecologically important trait". Evolution 61 (9): 2253–2259. doi:10.1111/j.1558-5646.2007.00174.x . PMID 17767594 .
  15. Tazzyman, I. J.; Y. Iwassa (2010). "Sexual selection can increase the effect of random genetic drift—a quantitative genetic model of polymorphism in Oophaga pumilio, the strawberry poison-dart frog". Evolution 64 (6): 1719–1728. doi:10.1111/j.1558-5646.2009.00923.x . PMID 20015236 .
  • Grant, Taran. "Poison dart frog." World Book Advanced. World Book, 2013.Web. 10 Jan. 2013.

Other websites[change | change source]

Dyeing Poison Frog. ARKive, n.d. Web. 17 Jan. 2013. <http://www.arkive.org/>.