Genetic and cytogenetic diversity in hochstetter’s frog, leiopefma hochstetteri, and its importance for conservation management

Abstract

Abstract Hochstetter’s frog, Leiopetma hochstetteri, is now reduced to a series of isolated populations of variable size and extent. Although the species is not considered endangered, some of these isolates may be threatened or vulnerable. In a genetically and geographically discontinuous species like L. hochstetteri, every population may be an important component of total biogeographic diversity, since each isolate may represent an emergent historical entity. Variation in supernumerary chromosome number between populations and, particularly, the morphology of the sex chromosome, in conjunction with isozyme evidence, enable the identification of important subdivisions within L. hochstetteri. The population on Great Barrier Island is cytogenetically distinct since its members have no univalent, sex-specific chromosome such as is present in all females from the North Island. Frogs from Mt Ranginui in the Rangitoto Range are the most chromosomally and biochemically distinctive of the North Island populations. Identification of geographic subdivisions in Hochstetter’s frog indicates that conservation management practice should focus upon populations rather than the species as a whole. © 1994 Taylor & Francis Group, LLC.