As Photo Ark turns 20, Joel Sartore photographs 18,000 animal species

Photographer Joel Sartore marked the 20th anniversary of his Photo Ark project this year by photographing its 18,000th animal species, though he isn't certain which creature actually crossed the threshold — he credits a critically endangered red handfish.

The project, born after Sartore came home to be near his wife during her cancer treatment, has taken him to zoos, aquariums, pet shops, a Kenyan cave, and his own porch, where he recently photographed an unidentified moth.

Sartore says publicity from the project has helped species like the Florida grasshopper sparrow, while other subjects he's photographed, including a northern white rhino and a since-extinct tree frog, are now functionally or entirely gone.

The full dispatch is available from the source below.