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 stork-billed kingfisher (Pelargopsis capensis) is seen perched on a tree during monsoon rain on July 25, 2016 in Bintan, Indonesia. The stork-billed kingfisher is a tree species which is widely but sparsely distributed in the tropical Indian subcontinent and Southeast Asia, from India to Indonesia. This kingfisher is resident throughout its range. It is very large, measuring 35 to 38 cm (14 to 15 in) in length. The adult has a green back, blue wings and tail, and grey head. (Photo by Sijori Images/Barcroft Images)

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)

Lava erupts from a crater of Mt. Etna, Europe's largest active volcano, behind Santa Maria della Guardia church in Belpasso, near Catania, in southern Italian island of Sicily, early Friday, June 18, 2021. Since Feb. 16, 2021, Mt. Etna has begun a series of spectacular eruptive episodes. (Photo by Salvatore Allegra/AP Photo)

A man holding a pet dog walks past blooming cherry blossoms along the Meguro river in Tokyo, Japan, March 27, 2022. (Photo by Kim Kyung-Hoon/Reuters)

A man looks at the description of a sculpture depicting 17-year-old male chimpanzee Jaska, by Gillie and Mark, in London, Tuesday, September 20, 2022. (Photo by Vadim Ghirda/AP Photo)

A man dressed in the likeness of the Hindu deity Agni Kandakarnan performs during the Theyyam ritualistic dance festival on March 14, 2023 in Somwarpet, India. Theyyam is a colourful socioreligious dance form that is the amalgamation of ritual, vocal and instrumental music, dance, painting, and literature and its genesis can be traced to the coastal regions of the southern Indian states of Kerala and Karnataka. (Photo by Abhishek Chinnappa/Getty Images)

Livestreaming saleswomen sell cars at the Auto Shanghai show, in Shanghai, China on April 19, 2023. (Photo by Aly Song/Reuters)