Imagine living in the sea where it is permanently dark, cold, and food is hard to find. For many animals at depth, it may be weeks to months between meals. If you find something to eat, you have to hang on to it. This is why so many deep-sea fishes have lots of big teeth. This dragonfish, spotted off the coast of Australia, even has teeth on its tongue. They would be terrifying animals ... if they weren’t the size of a banana. (Photo by Julian Finn/Museum Victoria)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

Opossums on their mothers back at a game reserve in Central Minnesota, USA, on September 2, 2013. (Photo by Caters News Agency)

People participate in a Zombie Walk in Sao Paulo, Brazil, November 2, 2016. (Photo by Nacho Doce/Reuters)

The Perseid Meteor Shower seen over The Scorhill Stone Circle in Dartmoor, Devon on August 2, 2016. (Photo by John Baker/SWNS.com)

A man sleeps at Beirut's Corniche, a seaside promenade, in Lebanon May 2, 2016. (Photo by Alia Haju/Reuters)

The Lamb National takes place for the racegoers at Ascot Racecourse on April 2, 2017 in Ascot, England. (Photo by Alan Crowhurst/Getty Images)

Sheep stand on a dyke as clouds cover the sky over Tossens, northern Germany, on September 2, 2019. (Photo by Mohssen Assanimoghaddam/dpa/AFP Photo)