Photo Ark reaches 18,000th subject with the endangered red handfish

The Photo Ark, a two-decade visual catalog of the world’s wildlife, has logged its 18,000th species - the critically endangered red handfish - according to a National Geographic announcement. Joel Sartore photographed the thumb-sized fish, which propels itself with its fins like a walk, inside a small tank set up at the University of Tasmania’s Institute of Marine and Antarctic Studies. The project began in 2006 with a naked mole-rat and has since amassed images of fish, birds, mammals, insects and even corals, often captured in zoos, aquariums and research facilities.

Sartore’s portraits use plain backgrounds to highlight each animal’s unique form and to inspire public concern for habitats under threat. The initiative also funds on-the-ground conservation, exemplified by grants supporting Florida’s Pine Rocklands and amphibian rescue work in Ecuador. At 64, Sartore plans to continue photographing the roughly 25,000 species held in human care, with his son Cole slated to carry the work forward.