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)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)

Festival-goers take photo inside of Spectra, a seven-story spiral walkway up to a viewing deck, at the Coachella Valley Music and Arts Festival in Indio, California, on April 17, 2022. (Photo by Valerie Macon/AFP Photo)

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)

People socialising in Soho, central London on July 11, 2020, after the lifting of further coronavirus lockdown restrictions in England. Revellers are urged to remember the importance of social distancing as pubs gear up for the second weekend of trade since the lifting of lockdown measures. (Photo by Stefan Rousseau/PA Images via Getty Images)

An actor dressed as Santa Claus and wearing a face mask to protect against coronavirus infection speaks with a boy during the New Year celebration in a shopping mall in St.Petersburg, Russia, Saturday, January 2, 2021. (Photo by Dmitri Lovetsky/AP Photo)

A Capetonian watches the sun rise from the top of Signal Hill as smoke engulfs the city of Cape Town, South Africa, Tuesday April 20, 2021. A massive fire spreading on the slopes of the city's famed Table Mountain, at right, is kept under control as firemen and helicopters take advantage of the low winds to contain the blaze. (Photo by Jerome Delay/AP Photo)