Nuptial pad

Nuptial pad (arrow) on thumb of Pelophylax esculentus

A nuptial pad (also known as thumb pad, or nuptial excrescence[1]) is a secondary sex characteristic present on some mature male frogs and salamanders.[2][3][4][5] Triggered by androgen hormones, this breeding gland (a type of mucus gland) appears as a spiked epithelial swelling on the forearm and prepollex that aids with grip, used primarily by males to grasp (or clasp) females during amplexus.[6] They can also be used in male-male combat in some species.[6]

Historical background

Austrian biologist Paul Kammerer experimented on midwife toads' nuptial pads.[7] He used the offsprings' apparent enlargening from generation-to-generation as evidence of Lamarckian evolution.[8]

Species examples

Many amphibian species manifest nuptial pads for use in amplexus, an example being the Rough-skinned newt, Taricha granulosa.[9]

See also

Notes

  1. William E. Duellman; et al. (1994). Biology of Amphibians. JHU Press. p. 696. ISBN 978-0801847806.
  2. "Science & Nature - Wildfacts - Common frog, grass frog". BBC. 2008-07-25. Retrieved 2011-07-14.
  3. "Mertensiella caucasica". AmphibiaWeb. 1999-10-03. Retrieved 2011-07-14.
  4. "Ommatotriton ophryticus". AmphibiaWeb. 2005-10-26. Retrieved 2011-07-14.
  5. "Pleurodeles waltl". AmphibiaWeb. 2002-05-25. Retrieved 2011-07-14.
  6. 1 2 F. Harvey Pough ... (2004). Herpetology. Upper Saddle River, NJ: Pearson/Prentice Hall. pp. 67–8. ISBN 0-13-100849-8.
  7. Koestler, Arthur (1971). The Case of the Midwife Toad. Random House.
  8. Archived September 17, 2008 at the Wayback Machine
    • C. Michael Hogan. 2008. Rough-skinned Newt (Taricha granulosa), Globaltwitcher, ed. Nicklas Stromberg
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