COMMERCIAL APPEAL (Memphis, Tennessee) 25 October 10 Memphis Zoo shares the fine art of wooing frogs (Linda A. Moore)
There are 1,400 Mississippi gopher frog tadpoles swimming around at the Henry Doorly Zoo in Omaha, Neb., who owe their very existence to experts in Memphis.
Techniques developed at the Memphis Zoo have resulted in successful in vitro fertilization of these endangered frogs, including the successful transport of frog sperm to Omaha to help them get it done.
"For the first time, amphibian sperm can be shipped between institutions for in vitro fertilization," said Andy Kouba, director of research and conservation at the Memphis Zoo. "It's a conservation milestone."
Animals are regularly transported for breeding purposes, but it's stressful for them and requires a month of quarantine, Kouba said.
Regardless, it wouldn't have worked with these frogs.
U.S. zoos have had the Mississippi gopher frogs (also known as dusky gopher frogs) in captivity since 2001.
And although they've tried everything short of candlelight and Barry White, the frogs won't mate.
"We tried all the traditional methods: hibernating, artificial rain. We would actually play the frog call," said Jessi Krebs, curator of reptiles and amphibians at the Henry Doorly Zoo. "We just couldn't get them to exhibit any interest in each other."
After years of experimentation, Kouba and the Memphis team have devised a method to get the females to drop the eggs and the male to release sperm, allowing for fertilization in a petri dish.
"We're able to use hormones to noninvasively collect the sperm," said Jen Germano of the Memphis Zoo's conservation and research department.
She recently traveled to the Omaha zoo to teach the staff there the techniques, successfully producing the massive number of tadpoles.
Loss of habitat and disease have left amphibians endangered on every continent in the world except Antarctica (where there are none), Germano said.
Newfound techniques to breed in captivity are significant.
"The implications are broad," said Steve Reichling, curator of reptiles, aquarium and small animals in Memphis. "There are hundreds of species worldwide that are technically endangered and this technique or tweaks of it can probably be applied to all manner of endangered frogs."
At about a month old, the tadpoles in Omaha are doing well, Krebs said.
"The next challenge is how do you raise 1,400 tadpoles?" he said. "We're using people on the animal keeper side and the reproductive side. We've got five people continually cleaning water, feeding animals, caring for them and it's working out really well right now."
They're also lining up zoos to take the frogs when they're older, Reichling said.
To date, there is no place to release the frogs into the wild and no reintroduction programs under way.
"We're ready now," Reichling said. "When the U.S. Fish and Wildlife Service taps on our door and says we need frogs for reintroduction, we can say when and how many."
Memphis Zoo shares the fine art of wooing frogs