Nuptial pad explained

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 mucous gland) appears as a spiked epithelial swelling on the forearm and prepollex that aids with grip, which is used primarily by males to grasp (or clasp) females during amplexus.^[6] They can also be used in male–male combat in some species.

Historical background

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

Examples

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

Notes and References

1. Book: William E. Duellman. Biology of Amphibians . 1994 . JHU Press . 978-0-8018-4780-6 . 55 . etal.
2. Web site: Science & Nature – Wildfacts – Common frog, grass frog . BBC . 2008-07-25 . 2011-07-14.
3. Web site: Mertensiella caucasica . AmphibiaWeb . 1999-10-03 . 2011-07-14.
4. Web site: Ommatotriton ophryticus . AmphibiaWeb . 2005-10-26 . 2011-07-14.
5. Web site: Pleurodeles waltl . AmphibiaWeb . 2002-05-25 . 2011-07-14.
6. Book: 67–68. 0-13-100849-8. F. Harvey Pough . Andrews RM . Cadle JE . Crump ML . Savitsky AH . Wells KD . 2004 . Pearson/Prentice Hall. Upper Saddle River, NJ . Herpetology . 3rd.
7. Book: Koestler, Arthur . The Case of the Midwife Toad . 1971 . Random House .
8. http://home.nycap.rr.com/useless/kammerer
9. Web site: C. Michael Hogan . 2008 . Rough-skinned Newt (Taricha granulosa) . Globaltwitcher, ed. Nicklas Stromberg . https://web.archive.org/web/20090527153302/http://www.globaltwitcher.com/artspec_information.asp?thingid=43182 . 2009-05-27 .