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 flood-affected couple sits along a flooded roadside under a picture of Jayalalithaa Jayaram, chief minister of the southern Indian state of Tamil Nadu, in Chennai, India, December 6, 2015. (Photo by Anindito Mukherjee/Reuters)

An Indian man, Kalpesh Modi, performs stunts with his motorcycle during the rehearsal for the forthcoming Lord Jagannath Rath Yatra, an annual Hindi festival, in Ahmedabad on June 23, 2019. The 142nd Lord Jagannath Rath Yatra festival in Ahmedabad is scheduled for July 4. (Photo by Sam Panthaky/AFP Photo)

U.S. President Donald Trump gestures during his visit to a section of the U.S.-Mexico border wall in Otay Mesa, California, U.S. September 18, 2019. Trump threatened to do “dastardly things” to Iran in response to the drone attacks on the world’s largest oil plant in Saudi Arabia. The US President indicated he is wary of involving America in another war in the Middle East – but he did not rule out a military attack. (Photo by Tom Brenner/Reuters)

Women compare their bikini marks after sunbathing on a terrace to have the perfect bikini line (“marquinha” in Portuguese), at the Erika Bronze spa in Rio de Janeiro, Brazil, November 17, 2016. Women start arriving at the spa between 7am and 8am and will tan for approximately 3 hours. (Photo by Pilar Olivares/Reuters)

The buildings of the banking district are seen through thousands of rain drops on a glass railing in central Frankfurt, Germany, Wednesday, January 11, 2017. (Photo by Michael Probst/AP Photo)

A former Gurkha (special forces soldier), Nirmal Purja, takes a selfie at the start of his attempt to scale the world’s 14 highest peaks in seven months to break a 31-year-old record. Nirmal Purja, known as Nims, aims to smash the current record – which stands at seven years, 11 months and 14 days – set by Polish climber Jerzy Kukuczka. On the way, he also plans to defeat at least seven speed world records on mountains over 8,000m high. (Photo by Nirmal Purja/PA Wire Press Association)

Aerial view of a giant sinkhole on June 09, 2021 in Santa María Zacatepec, Mexico. The giant sinkhole is located 20 kilometers northwest from the capital city Puebla, the hole now measures 110 meters across its widest point, covering around 11,000 square meters and damaging a house built near the place where it appeared. Farmers of the surroundings have been affected since they are not allowed to enter their fields due to the warning perimeter set up by the authorities. (Photo by Hector Vivas/Getty Images)