Cuban soldiers receive combat training at the Cadets School “Antonio Maceo” November 28, 2001, 30 kilometers East of Havana. (Photo by Jorge Rey/Getty Images)

In this handout GOES satellite image provided by the National Oceanic and Atmospheric Administration (NOAA), Irene reaches hurricane strength as it moves across Puerto Rico towards Hispaniola August 22, 2011 in the Caribbean Sea. Irene, the first hurricane of the Atlantic storm season, brought torrential rains and winds to Puerto Rico, downing trees and powerlines and flooding streets. The expected path will bring Irene through the Bahamas and is likely to hit Florida and up the east coast of the U.S. (Photo by NOAA via Getty Images)

Open jaws of a Great White Shark Carcharodon Carcharias, South Africa. (Photo by Stephen Frink Collection/Alamy Stock Photo)

A great crested grebe feeds a chick sitting on its mother’s back on a lake in Cáceres, Spain. (Photo by Jose Luis Ruiz/Solent News & Photo Agency)

A visitor feeds a food pellet to a giraffe in the Giraffe Centre in Nairobi, Kenya January 15, 2017. (Photo by Goran Tomasevic/Reuters)

A red deer stag in Bushy Park, southwest London, pulls a comical face for the camera in the second decade of November 2023. (Photo by Andrew Wood/Caters News Agency)

A fox pounces on a mouse in the snowy hills on the border of the Czech Republic and Slovakia. (Photo by Johnny Krüger/Mediadrumimages)

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)