Local snake helps zoo in efforts to conserve endangered species

By Kelli Mattson and Jonathan Aaltonen

Researchers at Omaha’s Henry Doorly Zoo are developing reproductive technologies in snakes to improve breeding conditions and enhance the genetic diversity of endangered snake species. Scientists gain insight into snake reproductive physiology by using a species common to the Midwest, the corn snake (Elaphe gutatta), as a research model. Corn snakes are easy to maintain, help keep the rodent populations down, tend to have a docile nature and are easily bred in captivity. For these reasons, they are the perfect candidate for developing reproductive techniques such as artificial insemination. 

Reproduction in snakes differs from mammalian reproduction in many ways. Some species are known to store sperm in the female reproductive tract for months, if not years, before fertilization. Snake sperm are also shaped differently than mammalian sperm and respond to cryoprotective solutions in a unique manner which makes sperm freezing more difficult. For these reasons, assisted reproductive techniques in snakes have generally been unsuccessful and have been ignored for many years by breeders. 

Captive breeding programs involving some snakes, particularly rare species, are often limited due to complications in inducing successful copulation or conception. Most often, unsuccessful breeding attempts are a consequence of a lack of knowledge or inability to provide proper environmental conditions. Environmental cues play a large role; yet these poorly understood factors that promote proper sexual stimulation are often difficult, or impossible, to control under captive conditions. In some species or individuals, males and/or females need to undergo certain behavioral rituals (e.g., aggressive interactions) in order to achieve mate selection and stimulate copulation. Artificial insemination can potentially reduce the risk of injury or death posed by aggressive social interactions.

Omaha’s Henry Doorly Zoo is the first institution to produce genetically proven corn snake offspring as a result of artificial insemination using either freshly collected semen, or semen stored in a refrigerator for three days. Researchers at the Omaha zoo are currently performing experiments to cryopreserve (freeze) snake semen. As of yet, there is no reliable technique developed for the long-term preservation of snake semen by freezing; however, their preliminary results show some promise. The development of a successful method for sperm freezing would insure the long-term survival of many species of threatened or endangered snakes by maintaining genetic diversity for future generations.

Bookmark/Search this post with:

Delicious  •   Digg  •   StumbleUpon  •   Facebook  •   Yahoo