A woman and her dog compete in the Paris Sausage Walk along the banks of the River Seine on Sunday, November 16, 2025. The event raises funds for the well-being and adoption of dachshunds. (Photo by Dimtitar Dilkoff/AFP Photo)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

In this undated photo provided by LittleFriendsPhoto.com via Six Flags Discovery Kingdom, Kai, a 17-year-old male California sea lion at Six Flags Discovery Kingdom in Valejo, Calif. peers into the lens of photographer Seth Casteel, known for his “Underwater Dogs” photo series. ... (Photo by Seth Casteel/AP Photo/LittleFriendsPhoto.com via Six Flags Discovery Kingdom)

Israeli soldiers of the Search and Rescue brigade take part in a training session in Ben Shemen forest, near the city of Modi'in May 23, 2016. (Photo by Amir Cohen/Reuters)

Britain's Queen Elizabeth boards a train at Kings Cross station in London, in this December 17, 2009 file photo. Queen Elizabeth celebrates her 90th birthday on April 21, 2016. (Photo by Stefan Rousseau/Reuters)

Tatyana Abramova, 33, plays with her home fox Plombir at her countryside house outside Siberian city of Novosibirsk on September 12, 2020. The official start of the Soviet experiment to better understand the domestication of animals by humans began in 1959, and was initiated by geneticists Dmitri Beliaiev and Lioudmila Trout on a farm in Akademgorodok, the scientific center of excellence in Siberia. Their primary objective was to domesticate foxes, to understand how the ancestor of wolves, another canine, evolved into a loyal and loving dog. And understand what this domestication tells us about the genetic evolution of species. (Photo by Alexander Nemenov/AFP Photo)

In this image released on November 08, American singer Madison Beer poses at the MTV EMA's 2020 on October 30, 2020 in Los Angeles, California. The MTV EMA's aired on November 08, 2020. (Photo by Rich Fury/Getty Images for MTV)

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)