The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

Australian performers illuminated with real clocks titled “The Time Minder” attend a media preview of the Night Festival in Singapore on August 23, 2017. Singapore's arts and heritage district will be transformed into Singapore largest outdoor performing arts festival to celebrate its 10th year edition Night Festival from August 24 to 26. (Photo by Roslan Rahman/AFP Photo)

With its huge eyes, comical name and diminutive size, Mark R. Smith’s image of a baby Hawaiian bobtail squid can’t help but raise a smile. A curiously endearing creature, the cephalopod is just 1.5cm across, its mantle cavity bearing more than a passing resemblance to a rather natty shower cap. But it is also a beautiful example of symbiosis – nature’s version of “I’ll scratch your back if you scratch mine” – for on the underside of the squid is a light organ which houses bioluminescent bacteria. The squid offers the bacteria protection and food, while the bacteria emit a glow – a handy trait that the squid uses to offset its silhouette, helping it to evade predators in the depths below. Mark R. Smith’s entry combines several images of a Hawaiian bobtail squid with different focus lengths to create a final picture with greater depth of field than normal. (Photo by Mark R. Smith/Wellcome Images/Macroscopic Solutions)

Jil Belen Teichmann of Switzerland in action against Victoria Azarenka of Belarus in her third round match on Day 6 at Roland Garros on May 27, 2022 in Paris, France. (Photo by Dylan Martinez/Reuters)

Aerial view of a boat working in the green water of Taihu Lake covered by blue-green algae, Wuxi city, Jiangsu province, China on May 23, 2018. (Photo by Imaginechina/Rex Features/Shutterstock)

A five-month-old cheetah seated in the back of a Land Cruiser growls at an outstretched hand after being taken from traffickers in Ethiopia and driven to Harirad, Somaliland, in 2020. This photo is part of the work of more than 100 artists in Why We Photograph Animals, a new collection of wildlife photography that aims to help understand why people have photographed animals at different points in history and what it means in the present. (Photo by Nichole Sobecki/Thames & Hudson)

“Atzeries”, a fire beast sets off his fire crackers during a “Correfocs” in Barcelona's Gracia neighborhood, Spain on May 27, 2023. (Photo by Matthias Oesterle/Alamy Live News)

American model Emily Ratajkowski shows off her new swimwear line in the second decade of March 2022. (Photo by emrata/Instagram)