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)

People walk along the Neva River at sunset in St.Petersburg, Russia, Tuesday, December 6, 2016. The temperature in St.Petersburg is –9C ( 15.8 °F). (Photo by Dmitri Lovetsky/AP Photo)

People wearing protective face masks amid the coronavirus disease (COVID-19) outbreak are seen near foodstuffs, which are displayed for sale on a car in Omsk, Russia on December 4, 2020. (Photo by Alexey Malgavko/Reuters)

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

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)

American singer-songwriter Olivia Rodrigo shows off her excitement ahead of her San Diego show in the second decade of May 2022. (Photo by oliviarodrigo/Instagram)

Residents wearing masks rest in the shade near a graffiti of a dragon, Friday, May 27, 2022, in Beijing. (Photo by Ng Han Guan/AP Photo)

A student of the Sri Lankan ancient martial art “Angampora” performs during a practice session at the angam maduwa or fighting field, in Korathota, a suburb of Colombo, Sri Lanka, 07 September 2022. Sri Lanka's ancient martial art, Angampora, is thought to be thousands of years old. Anga translates to “body parts” and Angampora is a fighting art that uses body parts. Martial arts practitioners in Angampora were mostly in the king's service, and they were tasked with protecting the king and his kingdom. Angampora was practiced in secret for most centuries because the British, who colonized Sri Lanka, banned it in 1818 after seeing it as a threat. (Photo by Chamila Karunarathne/EPA/EFE)