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)

An environmental activist adjusts his mask while taking part in “The Dead Sea Swim Challenge”, swimming from the Jordanian to Israeli shore, to draw attention to the ecological threats facing the Dead Sea, in Kibbutz Ein Gedi, Israel November 15, 2016. Swimmers from around the world plunged into the salty waters of the Dead Sea on Tuesday to attempt a seven-hour swim across the fabled lake in a bid to draw attention to its environmental degradation. Wearing protective masks and snorkels, 25 swimmers paddled through the muddy water to attempt the 9-mile (15-kilometer) swim from Jordan to Israel. (Photo by Nir Elias/Reuters)

People take pictures of deer in the Phoenix Park in Dublin, Ireland December 5, 2016. (Photo by Clodagh Kilcoyne/Reuters)

Student of Meiji University Yuki Hou licks a screen of Taste the TV (TTTV), a prototype lickable TV screen that can imitate the flavours of various foods, during its demonstration at the university in Tokyo, Japan, December 22, 2021. (Photo by Kim Kyung-Hoon/Reuters)

A male green anole lizard flares his throat fan in a backyard in Cary, North Carolina on April 27, 2021. This pink section is actually a thin flap of skin that hangs down below the green anole's throat. Anoles are renowned for their displays in which they do pushups, bob their heads up and down, and unfurl their colorful dewlaps. The male anole uses it for two primary purposes: to protect his territory and attract a mate. (Photo by Bob Karp/ZUMA Press Wire/Alamy Live News)

A woman poses for photographs after Gucci Cruise 2024 collection fashion show at the Gyeongbok Palace in Seoul, South Korea on May 16, 2023. (Photo by Kim Soo-Hyeon/Reuters)

A white yak sits on the lakeside of Namtso on May 19, 2024 in Lhasa, Xizang Autonomous Region of China. As temperature rises and ice melts, Lake Namtso is entering its tourism season. An event celebrating the melting of frozen water of Lake Namtso is held on May 19. (Photo by Jin Wei/VCG via Getty Images)

Hisao Mitani walks with an African tortoise, which he named Bon-Chan, on the street on September 16, 2022 in Tokyo, Japan. Bon-chan, the 26-year-old tortoise who is cared for by 69-year-old funeral director Mitani, has become an internet sensation after starring in a viral tiktok video that has gained over seven million views since it was released, making both Mitani and Bon-chan tiktok celebrities. (Photo by Tomohiro Ohsumi/Getty Images)