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 U.S. Marine leads training on a shooting range in France in an undated photo taken during the First World War. (Photo by Reuters/Courtesy Library of Congress)

An Iraqi military vehicle passes displaced Iraqi boys returning to their homes in West Mosul's Oreibi neighbourhood after government forces retook control of the area from the Islamic State (IS) group during the ongoing offensive against the jihadists on May 21, 2017. (Photo by Ahmad Al-Rubaye/AFP Photo)

Thomas Shelby makes a fire as he prepares to stay the night by the rubble of his home to protect from potential looters in Dawson Springs, Kentucky, on Saturday, December 11, 2021. One or more tornados tore through Dawson Springs late last night. (Photo by Austin Anthony/The Washington Post)

Russian cosmonaut Alexander Skvortsov, Expedition 40 flight engineer, attired in a Russian Orlan spacesuit, participates in a session of extravehicular activity (EVA) in support of science and maintenance on the International Space Station on August 18, 2014. During the five-hour, 11-minute spacewalk, Skvortsov and cosmonaut Oleg Artemyev (out of frame) deployed a small science satellite, retrieved and installed experiment packages and inspected components on the exterior of the orbital laboratory. (Photo by NASA)

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)

People take a walk among cherry blossoms at a park in Seoul, South Korea on April 6, 2022. (Photo by Kim Hong-Ji/Reuters)

A preserved Sumatran Tiger (Panthera tigris sumatrae) that was collected by the Natural Resources Conservation Board (BKSDA) as evidence is burnt in Palembang, Indonesia on March 18, 2022. (Photo by Novaa Wahyudi/Antara Foto via Reuters)