There are only three of these turtles left

This is the Yangtze giant softshell turtle, one of the most endangered species on Earth. There are two at China's Suzhou Zoo and one in the wild in Vietnam's lake Dong Mo. Conservationists really need to find a fourth to aid their efforts to rebuild the species. National Geographic spoke with Aimin Wang, director of the China division of the Wildlife Conservation Society, about the group's efforts to find another elusive Yangtze turtle:

What would it mean for the species if one were to be found?

It increases our opportunity [for successful breeding] quite a bit. The male in China is quite old, but the female is young. The turtles are bred using artificial insemination. The last four attempts with the breeding pair in China were unsuccessful. We just tried for a fifth time and got high-quality sperm. We won't know for another month if our results were successful.

Why are these turtles so important to save?

This is a flagship species, and for biodiversity, they're quite important. They serve as an important [indicator of environmental health]. If we can help them survive, that means our ecological system is quite good. If they disappear, that means our ecological system is quite bad.