A hiker walks in the Zillertal Alps during an autumn day near the village of Ginzling, Austria, October 15, 2019. (Photo by Lisi Niesner/Reuters)

Secondary school graduates play in a fountain as they celebrate the last day of school, traditionally called the “last bell” in central Kiev, Ukraine on May 31, 2019. (Photo by Valentyn Ogirenko/Reuters)

A view shows a church in front of a high-rise apartment building in Saint Petersburg, Russia on October 30, 2019. (Photo by Anton Vaganov/Reuters)

A woman holds her inhaler and leans on another person after being sprayed with mace by police officers during a protest near the Minneapolis Police third precinct after a white police officer was caught on a bystander's video pressing his knee into the neck of African-American man George Floyd, who later died at a hospital, in Minneapolis, Minnesota, U.S. May 27, 2020. (Photo by Eric Miller/Reuters)

Greyhounds resume racing behind closed doors on June 01, 2020 in Perry Barr, England. Greyhound racing across England is returning as restrictions on sporting events are relaxed during the coronavirus pandemic. (Photo by Clive Mason/Getty Images)

Revellers shield themselves as they celebrate in the rain near Stonehenge stone circle, despite official Summer Solstice celebrations being cancelled due to the spread of the coronavirus disease (COVID-19), near Amesbury, Britain, June 21, 2020. (Photo by Toby Melville/Reuters)

Freida Pinto as Jas Mitra in Showtime's “Guerrilla”, 2016. (Photo by Sky UK Limited/SHOWTIME)

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)