A woman holds newly designed Indonesia Rupiah banknotes after exchanging her old bills at a Bank Indonesia mobile bank in Jakarta, Indonesia December 19, 2016. (Photo by Fatima El-Kareem/Reuters)

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 miniature model of Chichen Itza in Mexico, part of Gulliver's Gate, a miniature world being recreated in a 49,000-square-foot exhibit space in Times Square, is seen during a preview April 10, 2017 in New York City. (Photo by Timothy A. Clary/AFP Photo)

Andrej Ciesielski dangels his legs off the side of a building overlooking Times Square, New York City. (Photo by Andrej Ciesielski/Caters News Agency)

A reveler dances during the Carmelitas street party in Rio de Janeiro, Brazil, Friday, March 1, 2019. Much of the appeal of Rio street parties is the variety of themes and that people can dress up in costumes or not. (Photo by Leo Correa/AP Photo)

A woman stands on the footbridge over the river Garry near Pitlochry, Scotland, Britain on October 10, 2018. (Photo by Russell Cheyne/Reuters)

Blake Shelton looks “Worse for Wear” after a 5hr dinner with Girlfriend Gwen Stefani and fellow Country star Luke Bryan at “Craigs” Restaurant in West Hollywood, CA on April 15, 2019. (Photo by SPW/Splash News and Pictures)

Kyle Larson (42) flips as he makes contact with Jeffrey Earnhardt (81) on the back stretch during a NASCAR Cup Series auto race at Talladega Superspeedway, Sunday, April 28, 2019, in Talladega, Ala. (Photo by Greg McWilliams/AP Photo)