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)

This week's full Moon as photographed from on board the International Space Station by NASA astronaut Jeff Williams on August 19, 2016. Jeff is currently Commander of the Space Station for the Expedition 48 crew. (Photo by Jeff Williams/NASA)

Indian Students of Rabindra Bharati University at the BT Road Campuses Celebrates the Holi, Color Festival on March 09, 2017 in Kolkata.Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 13 this year. (Photo by Debajyoti Chakraborty/NurPhoto)

Ratana Das, 40, a female vendor, carries sacks full of clothes at a second-hand clothing market early morning in Kolkata, India, March 10, 2016. Das said she was born and brought up in Kolkata and feels proud being a resident of the city that gives her he opportunity to be financially independent. (Photo by Rupak De Chowdhuri/Reuters)

This picture taken on March 21, 2015 shows a couple kissing in front of blooming cherry blossoms in Wuhan in central China's Hubei province. The cherry blossoms, now in full bloom, attracted tens of thousands of visitors, local media reported. (Photo by AFP Photo/Stringer)

In this April 16, 2015 photo, costume jewelry is on display for sale at al-Aqeeliya open-air auction market in Riyadh, Saudi Arabia. A man came with the suitcase full of beaded jewelry and sold the whole bag to the auction winner, who had just a few moments to inspect its contents before buying. (Photo by Hasan Jamali/AP Photo)

A purebred Spanish horse is pictured during the Sicab International Pre Horse Fair which is dedicated in full and exclusively to the purebred Spanish horse in the Andalusian capital of Seville, southern Spain November 17, 2015. (Photo by Marcelo del Pozo/Reuters)

A college girl takes part in the Holi festival celebrations in Bhopal, India, 19 March 2019. Holi is celebrated on the full moon day and marks the beginning of the spring season. Holi will be celebrated as the Hindu spring festival of colors across the country on 21 March. (Photo by Sanjeev Gupta/EPA/EFE)