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)

In this Thursday, April 13, 2017, picture entertainers wearing rabbit costumes speak at a fair in Bucharest, Romania. Ahead of Easter, celebrated by both Orthodox and Catholic believers on April 16 processions of priests clad in golden robes carrying foliage on Palm Sunday in a recreation of Jesus' ride into Jerusalem, mixed with more commercial flavored celebrations like an Easter fair outside the giant palace built by late Communist leader Nicolae Ceausescu where entertainers strutted around wearing giant rabbit heads. (Photo by Vadim Ghirda/AP Photo)

Airmen and their Japanese dates “do” the town together, visiting the local points of interest. Almost every community in Japan has it's famous shrines and parks. Tachikawa boasts beautiful environment. Girls are wearing western dress, May 1952. (Photo by National Archives and Records Administration)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

In this May 1, 2016 photo, a reluctant donkey is alternately pushed and pulled and enticed with carrots toward town hall in order to be dressed for the costume competition at the annual donkey festival in Otumba, Mexico state, Mexico. Otumba was an important donkey market during Spanish colonial times, standing at the crossroads of major roads leading to Mexico City, where the beasts pulled heavy loads and carried travelers. Today, however, farmers use tractors and pickup trucks, and the donkey population is in decline. (Photo by Rebecca Blackwell/AP Photo)

Indonesian tourists take a selfie as Mount Bromo spews volcanic material and ash into the air during an eruption in Probolinggo, East Java, Indonesia, 31 December 2015. Indonesia's Mount Bromo is on the second highest alert level as its activity has increased in the last two months. (Photo by Fully Handoko/EPA)

Jerry Dennehy from Tralee Co Kerry with his horses Mutt and Jeff at the Under 40 Horse Ploughing Class on the first day of the National Ploughing Championships in Ratheniska, Co. Laois on September 20, 2022. (Photo by Tom Honan for The Irish Times)

Workers use the traditional craft of picking waterlilies by hand arranging them into fascinating shapes in Bogor, Indonesia in October 2022. After the waterlilies are harvested and cleaned, they will be sold in the market and are usually used for decoration and bouquets. (Photo by Gatot Herliyanto/Solent News & Photo Agency)