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)

Soldiers with the Afghan National Army (ANA) at an outpost in the Momand Valley on July 16, 2017 in Achin District, Afghanistan. The building was previously used as of a jail by the Islamic State of Iraq and Syria – Khorasan (ISIS-K) and was taken by Afghan Commandos nine days prior. Operations are currently underway to remove ISIS fighters from Nangarhar Province in Eastern Afghanistan. (Photo by Andrew Renneisen/Getty Images)

A woman shoots her rifle at a forest shooting range near the village of Visnova, Czech Republic, June 9, 2016. (Photo by David W. Cerny/Reuters)

Firefighters of the Texas Canyon Hotshot crew fight the Sand Fire on July 23 2016 near Santa Clarita, California. Fueled by temperatures reaching about 108 degrees fahrenheit, the wildfire began yesterday has grown to 11,000 acres. (Photo by David McNew/AFP Photo)

A member of the 324 Squadron during the Anzac Day dawn service at Coogee Beach in Sydney, Australia on 23 April 2019. Anzac Day, held annually on 25 April, is a national day of remembrance across Australia and New Zealand, which commemorates the people who lost their lives or served in wars and conflicts. The day coincides with the first landing of the Anzacs at Gallipoli, Turkey, in World War One. (Photo by Steven Saphore/Australian Associated Press)

A gorilla cube named Pepe eats frozen fruit to fight high temperatures at the Bioparc zoo in Valencia, eastern Spain, 28 June 2019. Spanish peninsula is suffering a heat wave with temperatures reaching up to 45 degrees. (Photo by Kai Foersterling/EPA/EFE/Rex Features/Shutterstock)

This year’s World Nomad Games, a celebration of nomadic heritage, took place in the Issyk-Kul province of Kyrgyzstan. Eleanor Moseman photographed female competitors who had travelled from all over central Asia and eastern Europe, and explored the difficulties and challenges they face as competitors. (Photo by Eleanor Moseman/The Guardian)

A woman carrying a child on her back looks at wigs on sale at the Baragwanath Taxi Rank in Soweto, South Africa, Wednesday, September 16, 2020. South African president Cyril Ramaphosa is scheduled to address the nation later in the day, as case numbers and death from COVID-19 hit the lowest in months. (Photo by Jerome Delay/AP Photo)