Cryopreservation and hormonal induction of spermic urine in a novel species: The smooth-sided toad (Rhaebo guttatus).


Memphis Zoo, Department of Research and Conservation, 2000 Prentiss Place, Memphis, TN, 38112, USA. Electronic address: [Email]


Global amphibian declines have fueled an increased interest in amphibian assisted reproductive technologies. Within the genus Rhaebo, half of the species are experiencing decreasing population trends; however, insufficient information is available on many of these species' reproductive biology. Using the smooth-sided toad, Rhaebo guttatus, we present effective methods for collecting and cryopreserving an example of Rhaebo sperm. Specifically, our findings show that administering 10 IU/g body weight of hCG (human chorionic gonadotropin) yields the most motile and concentrated sperm and that cryopreserving spermic urine in a solution of 5% DMFA (N,N-Dimethylformamide) and 10% trehalose returns sperm with a 33 ± 3% average post-thaw motility. These findings may represent an important step forward in developing techniques that can be safely applied to other, more vulnerable species within the Rhaebo genus.


Amphibian,Anura,Assisted reproductive technologies,Bufonidae,Human chorionic gonadotropin,Spermatozoa,