Strategic biobanking for threatened frogs
51 million frogs are estimated to have been killed or affected by the 2019/20 bushfires according to the WWF interim report: Australia's 2019-2020 Bushfires: The Wildlife Toll.
Zoo-based conservation breeding programs play a critical role in supporting ongoing management and, in some cases, re-establishment of wild populations of threatened frog species.
This project applied established sperm collection methods and developed cryopreservation techniques to capture and store the genetic diversity of four threatened frog breeding programs across two Australian Zoos: The Booroolong Frog (Litoria booroolongensis), Northern Corroboree Frog (Pseudophryne pengilleyi), Southern Corroboree Frog (Pseudophryne corroboree) and Yellow-Spotted Bell Frog (Litoria castanea). The biobanking project aims to support the resilience of frog populations by preventing the loss of genetic diversity through selective breeding using cryopreserved sperm.
Taronga scientists led a collaborative team from the University of Wollongong, Zoos Victoria, the Department of Climate Change, Energy, the Environment and Water, and the University of Newcastle. Together they developed cryopreservation protocols for the threatened frog species with results showing that thawed sperm samples have high fertility potential based on motility and other in vitro quality metrics.
This is the first time that sperm from these species have been cryopreserved, with the work contributing greatly to the collective understanding of biobanking approaches for threatened Australian frogs. It is anticipated that biobanked samples will provide the genetic material to supplement conservation breeding populations for many years.
Ultimately, the project will help to maintain robust genetic diversity, benefiting the long-term fitness of both zoo-based and wild populations.