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)

Gisele Marie, a Muslim woman and professional heavy metal musician, plays her Gibson Flying V electric guitar during a concert in Sao Paulo December 16, 2014. Based in Sao Paulo, Marie, 42, is the granddaughter of German Catholics, and converted to Islam several months after her father passed away in 2009. Marie, who wears the Burka, has been fronting her brothers' heavy metal band “Spectrus” since 2012. (Photo by Nacho Doce/Reuters)

A woman smokes a cigarette next to man wearing a mask during lunch hour at the central business district in Singapore September 29, 2015. The 3-hour haze Pollutant Standards Index (PSI) reached a high of 173 at 8am on Tuesday, according to the National Environment Agency. Slash-and-burn agriculture in neighboring Indonesia has blanketed Singapore in a choking haze for weeks. (Photo by Edgar Su/Reuters)

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)

Cuban migrant Yamilen Arbelo, 40, walks down a hill as she crosses the border from Colombia through the jungle into La Miel, in the province of Guna Yala, Panama November 29, 2015. According to local authorities in La Miel, some 100 to 150 Cubans have been entering Panama from Colombia every day for the last three months. Scores of Cubans have come to Panama as they seek overland passage towards the United States fearing a recent detente between Washington and Havana could end their preferential treatment. (Photo by Carlos Jasso/Reuters)

A model is seen backstage before the Rochas Spring/Summer 2019 women's ready-to-wear collection show during Paris Fashion Week in Paris, France, September 26, 2018. (Photo by Gonzalo Fuentes/Reuters)

A general view of the ghost town of a former Soviet military radar station near Skrunda, Latvia, April 9, 2016. (Photo by Ints Kalnins/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)