Recently Discovered Diversity in Breviciptid Frogs
Callulina kreffti , Nieden, 1911.
Photo Credit: Michele Menegon
Frogs of the family Brevicipitidae are endemic to Sub-Saharan Africa from Ethiopia southward to Angola and South Africa and is composed of five genera (Balebreviceps, Breviceps, Callulina, Probreviceps, Spelaeophryne) and more than 26 species. They were long considered part of the family Microhylidae. They are bizarre little frogs, most have rounded bodies with tiny legs, and members of the genus Breviceps (the most specious genus) use sticky skin secretions produced in their numerous skin glands, to hold amplexing pairs together because their legs are too short for the male to clasp the female. Breviceps eggs are laid in burrows and undergo direct development. Recent investigations of the more arboreal genus Callulina has revealed the sky island clade to have more species than previously thought, and the newly described species have small ranges, and show a high degree of endemism in the Eastern Arc Mountains, a global biodiversity hotspot. The number of species before 2004 was one, C. kreffti was described by Fritz Nieden in 1911. C. kreffti was thought to have a continuous distribution throughout the montane forests of the Eastern Arc Mountains with its type locality at Amani in the East Usambara. However, specimens from other localities have proven not to be conspecific with C. kreffti. The northern Eastern Arc range has turned out to have numerous distinct species restricted to small, limited ranges. Five separate species have been described to date: C. kisiwamsitu de Sá et al., 2004, C. dawida Loader et al., 2009a, C. laphami Loader et al.,2010a, C. shengena Loader et al. 2010a, and C. stanleyi Loader et al., 2010a. Michelle Menegon and colleagues (2008) listed four undescribed species of Callilina from the Nguru Mountains based upon preliminary morphological and molecular data. Now, two of those species have been described by Loader et al. (2010b). Callulina hanseni is from the Maskati side of the Nguru South Forest Reserve, Tanzania; and Callulina kanga is from the Kanga Forest Reserve, Mwomero District, Morogoro Region, Tanzania. Both species were found in shrubs and trees and C. hanseni was collected as high as 10 m above the ground. Both species inhabit primary montane rainforest. Thus there are now 8 species recognized in the genus Callinia, whereas there was only on prior to 2004; and there are more species in this genus yet to be described.
de Sá, R., S. P. Loader, and A. Channing. 2004. A new species of Callulina (Anura: Microhylidae) from the West Usambara Mountains, Tanzania. Journal of Herpetology, 38, 219–222.
Loader, S. P., G. J. Measey, R. D. de Sá, and P. K. Malonza. 2009a. A new brevicipitid species (Anura: Brevicipitidae: Callulina) from the fragmented forests of the Taita Hills, Kenya. Zootaxa, 2123, 55–68.
Loader, S. P., D. J. Gower, W. Ngalason, and M. Menegon. 2010a. Three new species of Callulina (Amphibia: Anura: Brevicipitidae) highlight local endemism and conservation plight of Africa's Eastern Arc forests. Zoological Journal of the Linnean Society, 160, 496–514.
Loader, S. P., D. J. Gower, H. Muller, and M. Menegon. 2010b. Two new species of Callulina (Amphibia: Anura: Brevicipitidae) from the Nguru Mountains, Tanzania. Zootaxa 2694: 26–42
Menegon, M., N. Doggart, and N. Owen. 2008. The Nguru Mountains of Tanzania, an outstanding hotspot of herpetofaunal diversity. Acta Herpetologica, 3, 107–127.