Artists perform during the opening show directed by German director Volker Hesse, on the opening day of the Gotthard rail tunnel, at the fairground Rynaecht at the northern portal in Erstfeld, Switzerland, Wednesday, June 1, 2016. The construction of the 57 kilometer long tunnel began in 1999, the breakthrough was in 2010. After the official opening on June 1, the commercial operation will start in December 2016. (Photo by Ruben Sprich\Pool Photo via AP Photo)

Revellers head out in Leeds city centre, which has one of the country's highest infection rates on October 11, 2020. Cities in northern England and other areas suffering a surge in Covid-19 cases may have pubs and restaurants temporarily closed to combat the spread of the virus. (Photo by NB PRESS LTD/The Sun)

Muslim pilgrims pray around the holy Kaaba at the Grand Mosque, during the annual haj pilgrimage in Mecca September 30, 2014. (Photo by Muhammad Hamed/Reuters)

Actress and model Rosie Huntington-Whiteley during an evening out and about in London, England on January 23, 2020. (Photo by Stephen Coke/Rex Features/Shutterstock)

Alex Sun, left, Peter Simplicio and Matt Connelly jump through a hole in the ice into Lake Andrews on the Bates College campus, Friday, February 9, 2024, in Lewiston, Maine. The annual Bates College Puddle jump started 50 years ago as a Winter Carnival tradition. (Photo by Andree Kehn/AP Photo)

Models present creations during the Richard Quinn catwalk show during London Fashion Week in London, Britain on February 18, 2023. (Photo by Henry Nicholls/Reuters)

Two working girls entertaining themselves in the absence of customers at the Moonlite Bunny Ranch, a legal brothel owned by Dennis Hof, in Lyon County, one of the fews counties in the USA which permits legalized prostitution. (Photo by Stephan Gladieu/Getty Images)

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)