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 Friday, January 9, 2015 photo, bathhouse worker Omid Riahi, 39, scrubs a man to remove dead skin, at the Ghebleh public bathhouse, in Tehran, Iran. The steamy air and curved tiled walls of Iran's famed public bathhouses, some rinsing and massaging patrons for hundreds of years, slowly may wash away as interest in them wanes. The bathhouses, known as “hammams” in Persian, find themselves in rough financial times as modern conveniences now allow showers and baths in most homes across the Islamic Republic. (Photo by Ebrahim Noroozi/AP Photo)

People release floating lanterns during the festival of Yee Peng in the northern capital of Chiang Mai, Thailand November 14, 2016. Yi Peng refers to the full moon day in the second month according to the Lanna lunar calendar (the twelfth month according to the Thai lunar calendar). Swarms of Lanna-style sky lanterns are launched into the air where they resemble large shoals of giant fluorescent jellyfish gracefully floating through the sky. The festival is meant as a time for tham bun, to make merit. Khom loi are made from a thin fabric, such as rice paper, stretched over a bamboo or wire frame, to which a candle or fuel cell is attached. When the fuel cell is lit, the resulting hot air is trapped inside the lantern and creates enough lift for the khom loi to float up into the sky. (Photo by Athit Perawongmetha/Reuters)

This picture taken on November 11, 2016 shows participants releasing a hot- air balloon during the Tazaungdaing Lighting Festival at Taunggyi in Myanmar' s northeastern Shan State. The skies of central Myanmar were set ablaze this week with the beginning of the Taunggyi fire balloon festival, one of the most beautiful and dangerous celebrations in Asia. Brightly coloured balloons with hundreds of homemade fireworks woven into their frames are sent soaring into the night sky, showering down cascades of sparks onto adoring crowds. (Photo by Ye Aung Thu/AFP Photo)

A jockey falls from his buffalos during Barapan Kebo or buffalo races as part of the Moyo festival on September 30, 2014 in Sumbawa Island, West Nusa Tenggara, Indonesia. The traditional Buffalo races, known as Barapan Kebo, are held by Samawa tribes in muddy rice fields to celebrate and provide entertainment ahead of the annual planting season. Jockeys secure themselves on a wooden structure attached to the buffalo, and maneuver across the mud in a race to the finish line. The jockeys weild long sticks, in a similar style to jousting, and direct them towards targets called “Saka”. (Photo by Ulet Ifansasti/Getty Images)

Girls of the Long Horn Miao ethnic minority group wear headdresses as they prepare gather for Tiaohua or Flower Festival as part of the Lunar New Year on February 6, 2017 in Longga village, Guizhou province, southern China. (Photo by Kevin Frayer/Getty Images)

Supporters of Venezuela's President Nicolas Maduro take part in a rally in support of the government in Caracas, Venezuela on May 20, 2019. (Photo by Ivan Alvarado/Reuters)

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)