A man dressed as a demon poses for a picture as he participates in a ceremony known as Los Talciguines, as part of religious activities to mark the start of the Holy Week in Texistepeque, El Salvador, March 26, 2018. (Photo by Jose Cabezas/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 Kurdish girl celebrates Newroz Day, a festival marking spring and the new year, in Akra, Iraq March 20, 2016. Nowruz is the name of the Iranian New Year also referred to as Persian New Year which is celebrated worldwide by Iranian peoples, along with some other ethno-linguistic groups. Nowruz is the day of the vernal equinox, and marks the beginning of spring in the Northern Hemisphere. It usually occurs on March 21 or the previous/following day, depending on where it is observed. Although having Persian and religious Zoroastrian origins, Nowruz has been celebrated by people from diverse ethno-linguistic communities for thousands of years. (Photo by Ari Jalal/Reuters)

Henry Leese drives a 1952 British Rail Ivatt number 46512 at Strathspey Steam Railway on August 27, 2013 in Aviemore,Scotland. This year marks the 150th anniversary of the Highland Main Line built as a transportation link to the South for lairds and landowners living in northern Scotland. (Photo by Jeff J. Mitchell)

It’s a bug’s life for these colorful insects – whose natural markings resemble incredible smiling faces. These dazzling insects, with their colorful patterns and markings, look as if they are living a happy bugs life. But they’re also the spitting image of a whole host of stars from stage and screen from a creeping Charlie Chaplin to Elvis Presley. Photo: Pentomid bug. (Photo by Darlyne Murawsk/National Geographic Creative/Caters News)

The official name for this tiny speck of land – the size of 12 football pitches – is Hashima, but few call it that. In English, its most commonly used name means “Battleship Island” and, viewed from a certain angle offshore, its silhouette is uncannily dreadnought in nature. It was a mining facility until 1974, when it was abandoned to the elements, before partially reopening as a tourist attraction in 2009. Photo: A decades-old television. (Photo by Mark C. O'Flaherty)

Revelers jump on a rainbow painted crosswalk in Church Street, Toronto's LGBT neighbourhood, before “WorldPride”, a gay pride parade, in Toronto, June 29, 2014. Toronto is hosting WorldPride, a week-long event that celebrates the lesbian, gay, bisexual and transgender (LGBT) community. (Photo by Mark Blinch/Reuters)

An India Christian devotee reenacts the sufferings of Jesus Christ on the occasion of Good Friday in Mumbai, India, Friday, March 29, 2013. Christians all over the world are marking Good Friday, the day when Christ was crucified. (Photo by Rajanish Kakade/AP Photo)