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)

Spanish bullfighter Manuel Jesus “El Cid” is seen through a small window of a door as he performs a pass to a heifer during a “tentadero” (a small bullfight to check the bravery of calves and heifers which are not killed) during the first International Biennial of bullfighting at Reservatauro Ronda cattle ranch in Ronda, near Malaga February 17, 2013. Spain's parliament voted last Tuesday to consider protecting bullfighting as a national pastime, angering animal rights campaigners and politicians in two regions where the sport is banned. (Photo by Jon Nazca/Reuters)

Employees conduct a final check to fix any cavities in the seams of balls inside the soccer ball factory that produces official match balls for the 2014 World Cup in Brazil, in Sialkot, Punjab province May 16, 2014. It was when he felt the roar of the crowd at the 2006 World Cup in Germany that Pakistani factory owner Khawaja Akhtar first dreamt up a goal of his own: to manufacture the ball for the biggest soccer tournament on the planet. Last year he finally got his chance – but only 33 days to make it happen. (Photo by Sara Farid/Reuters)

In this April 12, 2015 photo, Sayed Ahmed Abdoh poles his boat to check his fish traps in the Nile River, near Abu al-Nasr village, about 770 kilometers (480 miles) south of Cairo, Egypt. Abdoh caught some 20 fish this day and gave them to his friend, Salama Osman, a migrant worker in a Cairo apartment building, to celebrate his biannual return to their village. (Photo by Hiro Komae/AP Photo)

A picture taken on August 25, 2021 shows a view of the Aletsch Glacier. After hiking for hours across the mountain and a vast expanse of white, Swiss glaciologist Matthias Huss crouches down near the middle of the massive glacier and checks the measurements. Analysis of the data gathered from Aletsch, the largest glacier in the Alps, paints a dire picture of the toll that climate change is taking on the behemoth. (Photo by Fabrice Coffrini/AFP Photo)

This photo taken on January 30, 2020 shows officials in protective suits checking on an elderly man wearing a facemask who collapsed and died on a street near a hospital in Wuhan. AFP journalists saw the body on January 30, not long before an emergency vehicle arrived carrying police and medical staff in full-body protective suits. The World Health Organization declared a global emergency over the new coronavirus, as China reported on January 31 the death toll had climbed to 213 with nearly 10,000 infections. (Photo by Hector Retamal/AFP Photo)

Police officers with a sniffer dog check a railway as the Soyuz MS spacecraft for the next International Space Station (ISS) crew of Kate Rubins of the U.S., Anatoly Ivanishin of Russia and Takuya Onishi of Japan is ready to be transported from an assembling hangar to the launchpad ahead of its launch scheduled on July 7, at the Baikonur cosmodrome in Kazakhstan July 4, 2016. (Photo by Shamil Zhumatov/Reuters)