© 2007 Twan Leenders (1 of 15)
Distribution and Habitat
Country distribution from AmphibiaWeb's database: El Salvador, Guatemala, Honduras, Mexico, Nicaragua
Life History, Abundance, Activity, and Special Behaviors
D. mexicanus constructs its own burrow (Wake 2003). Modes of locomotion include internal concertina motion and lateral undulation (Summers and O'Reilly 1997).
Sexual maturity occurs at two to three years of age. How mates are attracted and whether they undergo courtship is not known. As is the case for all caecilians, Dermophis mexicanus has internal fertilization, with the male extruding the rear part of the cloaca into the female's cloaca to transfer sperm. Although males can produce sperm nearly year-round (11 months; Wake 1995), females in a given population show synchronous development of embryos in the oviduct, implying that there is a short and synchronized breeding period but no sperm storage. Embryos are small (2 mm in diameter) and feed on the egg yolk supply for only about three months of gestation before the yolk supply is exhausted. At that point the mother makes a nutritious secretion from internal oviduct glands. Fetal caecilians move around within the oviduct and have specialized dentition with which they scrape the oviduct skin in order to stimulate and ingest the mother's nutritive secretion. The dentition is shed at birth and a quite different adult dentition is rapidly acquired within a few days. Fetuses also have elaborate tri-branchiate gills (Wake 2003).
Pregnancies are 11 months long and this species is viviparous. Females give birth to three to sixteen young when the rainy season begins in May/June. Newborns measure 10-15 cm in length, while the mother herself is only 30-45 cm long (Wake 2003).
Trends and Threats
Relation to Humans
Possible reasons for amphibian decline
General habitat alteration and loss
Bemis, W. E., Schwenk, K., and Wake, M. H. (1983). ''Morphology and function of the feeding apparatus in Dermophis mexicanus (Amphibia: Gymnophiona).'' Zoological Journal of the Linnean Society, 77, 75-96.
Savage, J. M., and Wake, M. H. (2001). ''Reevaluation of the status of taxa of Central American caecilians (Amphibia: Gymnophiona) with comments on their origin and evolution.'' Copeia, 2001(1), 52-64.
Summers, A. P., and O'Reilly, J. C. (1997). ''A comparative study of locomotion in the caecilians Dermophis mexicanus and Typhlonectes natans (Amphibia: Gymnophiona).'' Zoological Journal of the Linnaean Society, 121, 65-76.
Wake, M. H. (2003). ''Mexican caecilian, Dermophis mexicanus.'' Grzimek's Animal Life Encyclopedia, Volume 6, Amphibians. 2nd edition. M. Hutchins, W. E. Duellman, and N. Schlager, eds., Gale Group, Farmington Hills, Michigan.
Wake, M.H. (1980). "Reproduction, growth, and population structure of the Central American caecilian Dermophis mexicanus (Amphibia: Gymnophiona)." Herpetologica, 36, 244-256.
Wake, M.H. (1995). ''The spermatogenic cycle of Dermophis mexicanus (Amphibia: Gymnophiona).'' Journal of Herpetology, 29, 119-122.
Written by Peera Chantasirivisal (Kris818 AT berkeley.edu), UC Berkeley
First submitted 2005-09-27
Edited by Kellie Whittaker (2009-09-21)
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