Open Access Open Access  Restricted Access Subscription or Fee Access


Caecilita Wake & Donnelly, 2010 (Amphibia: Gymnophiona) is not lungless: implications for taxonomy and for understanding the evolution of lunglessness 



According to current understanding, five lineages of amphibians, but no other tetrapods, are secondarily lungless and are believed to rely exclusively on cutaneous gas exchange. One explanation of the evolutionary loss of lungs interprets lunglessness as an adaptation to reduce buoyancy in fast-flowing aquatic environments, reasoning that excessive buoyancy in such an environment would cause organisms being swept away. While not uncontroversial, this hypothesis provides a plausible potential explanation of the evolution of lunglessness in four of the five lungless amphibian lineages. The exception is the most recently reported lungless lineage, the newly described Guyanan caecilian genus and species Caecilita iwokramae Wake & Donnelly, 2010, which is inconsistent with the reduced disadvantageous buoyancy hypothesis by virtue of it seemingly being terrestrial and having a terrestrial ancestry. Re-examination of the previously only known specimen of C. iwokramae and of recently collected additional material reveal that this species possesses a reasonably well-developed right lung and is a species of the pre-existing caecilian genus Microcaecilia Taylor, 1968. We therefore place Caecilita in the synonymy of Microcaecilia, and re-evaluate the plausibility of the reduced disadvantageous buoyancy hypothesis as a general explanation of the evolution of lunglessness.


amphibian, Atretochoana, buoyancy, Guyana, lunglessness


Beachy, C.K. & Bruce, R.C. (1992) Lunglessness in plethodontid salamanders is consistent with the hypothesis of a mountain stream origin: a response to Ruben and Boucot. American Naturalist, 139, 839–847.

Bickford, D., Iskandar, D. & Barlian, A. (2008) A lungless frog discovered in Borneo. Current Biology, 18, R374–R375.

Bruce, R.C., Beachy, C.K., Lenzo, P.G. Pronych, S.I. & Wassersug, R.J. (1994) Effects of lung reduction on rheotactic performance in amphibian larvae. Journal of Experimental Zoology, 268, 377–380.

Gower, D.J., Doherty-Bone, T.M., Loader, S.P., Wilkinson, M., Kouete, T.M., Tapley, B., Orton, F., Daniel, O.Z., Wynne, F., Flach, E., Müller, H., Menegon, M., Stephen, I., Browne, R.K., Fisher, M.C., Cunningham, A.A. & Garner, T.W.J. (2013) Batrachochytrium dendrobatidis infection and lethal chytridiomycosis in caecilian amphibians (Gymnophiona), EcoHealth, 10, 173–178.

Hoogmoed, M.S., Maciel, A.O. & Coragem, J.T. (2011) Discovery of the largest lungless tetrapod, Atretochoana eiselti (Taylor, 1968) (Amphibia: Gymnophiona: Typhlonectidae), in its natural habitat in Brazilian Amazonia. Boletim do Museu Paraense Emílio Goeldi. Ciências Naturais, 6, 241–262.

Hutchison, V.H. (2008) Amphibians: lungs' lift lost. Current Biology, 18, R392–R393.

Limaye, A. (2006) Drishti - Volume Exploration and Presentation Tool. Poster presentation. Vis 2006, Baltimore.

Nussbaum, R.A. & Wilkinson, M. (1995) A new genus of lungless tetrapod: a radically divergent caecilian (Amphibia: Gymnophiona). Proceedings of the Royal Society B, 261, 331–335.

Reagan, N.L. & Verrell, P.A. (1991) The evolution of plethodontid salamanders: did terrestrial mating facilitate lunglessness? American Naturalist, 138, 1307–1313.

Ruben, J.A. & Boucot, A.J. (1989) The origin of the lungless salamanders (Amphibia: Plethodontidae). American Naturalist, 134, 161–169.

Ruben, J.A., Reagan, N.L., Verrell, P.A. & Boucot, A.J. (1993) Plethodontid salamander origins: a response to Beachy and Bruce. American Naturalist, 142, 1038–1049.

Wake, M.H. & Donnelly, M.A. (2010) A new lungless caecilian (Amphibia: Gymnophiona) from Guyana. Proceedings of the Royal Society B, 277, 915–922.

Wilder, I.W. & Dunn, E.R. (1920) The correlation of lunglessness in salamanders with a mountain brook habitat. Copeia, 1920, 63–68.

Wilkinson, M. (1989) On the status of Nectocaecilia fasciata Taylor, with a discussion of the phylogeny of the Typhlonectidae (Amphibia: Gymnophiona). Herpetologica, 45, 23–36.

Wilkinson, M. & Nussbaum, R.A. (1997) Comparative morphology and evolution of the lungless caecilian Atretochoana eiselti (Taylor) (Amphibia: Gymnophiona: Typhlonectidae). Biological Journal of the Linnean Society, 62, 39–109.

Wilkinson, M. & Nussbaum, R.A. (2006) Caecilian phylogeny and classification. In: Exbrayat, J.-M. (Ed.), Reproductive biology and phylogeny of Gymnophiona. Science Publishers Inc, Enfield, Jersey, Plymouth, pp. 39–78.

Wilkinson, M., O'Connor, A. & Nussbaum, R.A. (2013) Taxonomic status of the neotropical caecilian genera Brasilotyphlus Taylor, 1968, Microcaecilia Taylor, 1968 and Parvicaecilia Taylor, 1968 (Amphibia: Gymnophiona: Siphonopidae). Occasional Papers of the Museum of Zoology, University of Michigan, 744, 1–12.

Wilkinson, M., San Mauro, D., Sherratt, E. & Gower, D.J. (2011) A nine-family classification of caecilian amphibians. Zootaxa 2874, 41–64.


  • There are currently no refbacks.

ISSN 1175-5326 (Print Edition) & ISSN 1175-5334 (Online Edition)
Published by Magnolia Press, Auckland, New Zealand
A founding journal of Biotaxa