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)

A suspected Vietcong is kicked by a Vietnamese soldier holding a rifle as another soldier attempts to tie his hands on October 22, 1965. The prisoner was one of 15 captured October 21 near Xom Chua when government troops raided in the plain of reeds area. Troops killed 43 suspected Vietcong and seized some arms. (Photo by Richard Merron/AP Photo)

Meropidae are seen on a rock in Van in Turkey on March 03, 2018. (Photo by Ali Ihsan Ozturk/Anadolu Agency/Getty Images)

The towers of Russky Bridge are seen over the fog covered Vladivostok, Russia on May 26, 2020. The so-called “fog season” on the Pacific coast and in the south of Russia's Primorye Territory lasts from April till September. (Photo by Yuri Smityuk/TASS)

Gina Di Meo, journalist from ANSA sits during a media preview of Summit at One Vanderbilt in New York, October 1, 2021. The Summit viewing deck is spread across the top four floors on One Vanderbilt in Manhattan, the fourth tallest building in the city. (Photo by Timothy A. Clary/AFP Photo)

An a music therapist plays harp during treatment of patients suffering from the coronavirus disease (COVID-19) in the Intensive Care Unit (ICU) at Havelhoehe community hospital in Berlin, Germany, December 6, 2021. (Photo by Fabrizio Bensch/Reuters)

A Brazil supporter kisses a replica of the world cup trophy before the Qatar 2022 World Cup quarter-final football match between Croatia and Brazil at Education City Stadium in Al-Rayyan, west of Doha, on December 9, 2022. (Photo by Adrian Dennis/AFP Photo)

Stardust and Bruno Tonioli at “Britain's Got Talent” TV Show, Series 17, Semi-Final 1, Episode 9 in London, UK on May 27, 2024. (Photo by Dymond/Thames/Rex Features/Shutterstock)