Dancers from the Philadelphia Ballet perform for Pope Francis (R) as he attends the Festival of Families rally in Philadelphia, Pennsylvania September 26, 2015. (Photo by Brian Snyder/Reuters)

Youths smeared in coloured powder and dressed as Lord Krishna (L) and deity Radha (R) celebrate with others the Holi festival, the Hindu spring festival of colours, in Kolkata on March 17, 2022. (Photo by Dibyangshu Sarkar/AFP Photo)

American supermodel Bella Hadid (R) holds onto her friend's leg for dear life in the second decade of January 2023. (Photo by bellahadid/Instagram)

Friends (L-R) Katherine Olson, Olivia Carroll and Maron Ross take a memory during the 148th running of the Preakness Stakes at Pimlico Race Course on May 20, 2023. (Photo by Jonathan Newton/The Washington Post)

Cadets prepare to take part in a full dress rehearsal for the upcoming Republic Day parade, in Chennai on January 24, 2024. (Photo by R. Satish Babu/AFP Photo)

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)

Actor and former California Governor Arnold Schwarzenegger (R) and his son Patrick Schwarzenegger (L) attend “Arnold Classic Europe” 2011 Party at “Jardines Cecilio Rodriguez” on October 7, 2011 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)

(L-R) Playmate Victoria Silvstedt, Donald Trump and Melania Knauss at the Playboy 50th Anniversary celebration December 4, 2003 in New York City. (Photo by Peter Kramer/Getty Images)