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)

Rascal, and her brother Petey, were abandoned as pups near the railroad tracks in Union County, Arkansas. She is a pit bull cross and approximately 6 months old, in Arkansas, United States. These canine portraits will make any dog lover's day – and they're helping to get sheltered pups adopted at the same time. Kind-hearted photographer Tammy Swarek came up with the idea of dressing up rescue dogs to draw attention to their stories and help potential owners personally connect with them. (Photo by Tammy Swarek/Barcroft Images)

An indigenous man of Mahmeri tribe wearing a costume of Puteri Gunung Ledang character receives a dose of the vaccine against Covid-19 in Banting, near Kuala Lumpur, Malaysia,15 August 2021. Malaysia recorded another 20,670 new Covid-19 cases on 14 August, bringing the cumulative total to 1,384,353 cases. (Photo by Ahmad Yusni/EPA/EFE)

An Iranian woman wearing a face mask walks on a street in Tehran, Iran, 19 October 2020. According to the Iranian Health ministry, Iran reported its highest daily COVID-19 death toll of 337 and 4,251 new infections in past 24 hours as it appears that Iran is in a third wave of COVID-19 outbreak. (Photo by Abedin Taherkenareh/EPA/EFE)

Indian people bang utensils and clap from the balconies of a residential building in Mumbai, India, 22 March 2020. Prime Minister Narendra Modi asks citizens to impose self-curfew to fight Coronavirus COVID-19 and also ask them to clap, bang the bells and utensils at 5pm Indian time to mark of respect and to thank the medical staff and others working 24 hours, during Covid-19 outbreak to keeping the Indians safe. (Photo by Divyakant Solanki/EPA/EFE)

A Thai Buddhist monk prepares to take part in a televised anti-plague prayer at Wat Traimit Temple (Temple of the Golden Buddha) amid lockdown restrictions to contain the spread of the COVID-19 coronavirus in Bangkok on March 25, 2020. The monks at Buddhist temples nationwide chanted the Rattanasoot (Seven Legends) Prayer in unison in a bid to boost public morale amid the epidemic of COVID-19 coronavirus. (Photo by Mladen Antonov/AFP Photo)

A woman wears a scuba mask and a surgical mask as a precaution against the spread of the new coronavirus, while buying food in a popular market in Lima, Peru, Monday, March 23, 2020. The vast majority of people recover from the COVID-19 disease. (Photo by Rodrigo Abd/AP Photo)

Journalists practice social distancing outside a meeting to wrap up work on coronavirus economic aid legislation to prevent the spread of coronavirus disease (COVID-19) in Washington, U.S., March 21, 2020. (Photo by Mary F. Calvert/Reuters)