A Hindu holy man, or sadhu, sits beside a fire after smearing his body with ashes at the premises of Pashupatinath Temple, ahead of the Shivaratri festival in Kathmandu, Nepal February 21, 2017. Hindus mark the Maha Shivratri festival by offering special prayers and fasting, with sadhus arriving at Pashupatinath to take part in the event, which takes place on February 24. (Photo by Navesh Chitrakar/Reuters)

Members of the New Orleans Baby Doll Ladies march during the Krewe of Zulu parade at Mardi Gras in New Orleans, Louisiana U.S., February 28, 2017. (Photo by Shannon Stapleton/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)

Miss Universe contestant Carolina Duran of Costa Rica, center, reacts to a TV network's drone as others prepare to pose from the deck of the yacht Happy Life prior to cruising to a beach resort in Batangas province Thursday, January 19, 2017 at the Philippine Navy headquarters in Manila, Philippines. Eighty-six candidates from around the world are vying for the title to succeed Pia Wurtzbach from the Philippines. The competition takes place on Jan. 30. They are, from left, Cherell Williamson of Bahamas, Rebecca Rath of Belize, Hildur Maria of Iceland, and Chanelle de Lau of Curacao. (Photo by Bullit Marquez/AP Photo)

A handout photo made available by the World Press Photo (WPP) organization on 13 February 2017 shows a picture by Rossiya Segodnya photographer Valery Melnikov that won the Long-Term Projects – First Prize award of the 60th annual World Press Photo Contest, it was announced by the WPP Foundation in Amsterdam, The Netherlands on 13 February 2017. Caption: Civilians escape from a fire at a house destroyed by an air attack in the Luhanskaya village. (Photo by Valery Melnikov/EPA/Rossiya Segodnya/World Press Photo)

A woman receives a bouquet made of vegetables and flowers, priced at 238RMB, from a delivery staff of a florist outside an office building on Valentine's Day in Beijing, China, February 14, 2017. (Photo by Jason Lee/Reuters)

A Thai and foreign revelers battle with water guns during the annual Songkran celebration at Khaosan Road, a tourist spot in Bangkok, Thailand, 12 April 2017. The four southeast Asian nations of Myanmar, Thailand, Cambodia and Laos started the Buddhist new year, known as Thingyan in Myanmar and Songkran in Thailand, on April 13. (Photo by Rungroj Yongrit/EPA)

People dressed as ancient Roman reflect on a helmet during a parade to mark the anniversary of the foundation of Rome in 753 BC, on April 23, 2017 in Rome, Italy. (Photo by Alberto Pizzoli/AFP Photo)