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)

In this Thursday, April 13, 2017, picture entertainers wearing rabbit costumes speak at a fair in Bucharest, Romania. Ahead of Easter, celebrated by both Orthodox and Catholic believers on April 16 processions of priests clad in golden robes carrying foliage on Palm Sunday in a recreation of Jesus' ride into Jerusalem, mixed with more commercial flavored celebrations like an Easter fair outside the giant palace built by late Communist leader Nicolae Ceausescu where entertainers strutted around wearing giant rabbit heads. (Photo by Vadim Ghirda/AP Photo)

A supercell thunderstorm develops, May 8, 2017 in Elbert County outside of Limon, Colorado. With funding from the National Science Foundation and other government grants, scientists and meteorologists from the Center for Severe Weather Research try to get close to supercell storms and tornadoes trying to better understand tornado structure and strength, how low-level winds affect and damage buildings, and to learn more about tornado formation and prediction. (Photo by Drew Angerer/Getty Images)

The Soyuz TMA-18M spacecraft is transported from an assembling hangar to its launch pad at the Baikonur cosmodrome, Kazakhstan, August 31, 2015. The Soyuz is scheduled to blast off with Aidyn Aimbetov of Kazakhstan, Sergei Volkov of Russia and Andreas Mogensen of Denmark to the International Space Station (ISS) on September 2, 2015. (Photo by Shamil Zhumatov/Reuters)

Trees in a park are illuminated with a red light as a part of an art project in Timmendorfer Strand, northern Germany Wednesday, October 26, 2016. (Photo by Michael Probst/AP Photo)

Fishermen collect their catch from a net at Dojran Lake, Macedonia, January 4, 2017. Fish from the lake is a traditional food for locals for orthodox Christmas eve, which falls on January 6. The lake faced sustainability issues during the 1990s due to drought and excessive use of its water but has since recovered after measures were taken to replenish and sustain water levels, according to local media. Dojran Lake is one of the three natural lakes in Macedonia, and also the warmest. It is said it is also the richest lake in fish in Europe. (Photo by Ognen Teofilovski/Reuters)

Firefighters of the Texas Canyon Hotshot crew fight the Sand Fire on July 23 2016 near Santa Clarita, California. Fueled by temperatures reaching about 108 degrees fahrenheit, the wildfire began yesterday has grown to 11,000 acres. (Photo by David McNew/AFP Photo)

Nepalese Hindu priests perform rituals during Janai Purnima festival at Pashupatinath temple in Kathmandu, Nepal, Thursday, August 18, 2016. During this festival Hindus take holy baths and perform annual change of the Janai, a sacred cotton string worn around their chest or tied on the wrist, in the belief that it will protect and purify them. (Photo by Niranjan Shrestha/AP Photo)