Canada's Marissa Papaconstantinou makes her way to the finish line after falling in the Women's 200m T44 Final during day ten of the IPC World ParaAthletics Championships 2017 at London Stadium on July 23, 2017 in London, England. (Photo by Peter Cziborra/Reuters)

Cosplay fans (R) take selfies as comic book and gaming fans attend the annual Ani-Com and Games Fair in Hong Kong on July 28, 2017. Tens of thousands were expected to attend the annual event on animation, comics and games, from July 28 to August 1. (Photo by Isaac Lawrence/AFP Photo)

A member of Team Chez Victor falls in the water while competing during the Ice Canoe race at the Quebec Winter Carnival in Quebec City, February 5, 2017. (Photo by Mathieu Belanger/Reuters)

Models walk the runway at the Yandy Swim Show during February 2017 New York Fashion Week at Pier 59 on February 14, 2017 in New York City. (Photo by Noam Galai/Getty Images)

A masked reveller poses during the Venice Carnival in Venice, Italy February 17, 2017. (Photo by Alessandro Bianchi/Reuters)

A Hindu holy man, or sadhu, sits beside a fire after smearing his body with ashes at the premises of Pashupatinath Temple, ahead of the Shivaratri festival in Kathmandu, Nepal February 21, 2017. Hindus mark the Maha Shivratri festival by offering special prayers and fasting, with sadhus arriving at Pashupatinath to take part in the event, which takes place on February 24. (Photo by Navesh Chitrakar/Reuters)

Members of the New Orleans Baby Doll Ladies march during the Krewe of Zulu parade at Mardi Gras in New Orleans, Louisiana U.S., February 28, 2017. (Photo by Shannon Stapleton/Reuters)

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)