A woman looks at head of bluefin tuna on display in front of a store at Tsukiji fish market in Tokyo, Monday, February 19, 2018. The large bluefin are particularly valuable in Japan, where they are considered a premium sushi and sashimi fish. A single fish sold for more than $1.75 million at an auction in Japan in 2013. (Photo by Koji Sasahara/AP Photo)

Meropidae are seen on a rock in Van in Turkey on March 03, 2018. (Photo by Ali Ihsan Ozturk/Anadolu Agency/Getty Images)

A Palestinian boy carries dates from palm trees during harvest season in southern Gaza September 25, 2016. (Photo by Ibraheem Abu Mustafa/Reuters)

High-flying photographer Jeffrey Milstein, renowned for his aerial photos of US cities, snaps landmarks through the open door of a helicopter. This month he hired a chopper in London and amazingly he had just an hour to cover all the buildings he wanted to capture including Buckingham Palace, the London Eye, the glass roof of the British Museum and the Gherkin and Walkie Talkie towers in the City. Here: Jeffrey Milstein captured these stunning images through the door of a helicopter hovering over central London. (Photo by Jeffrey Milstein/Rex Features/Shutterstock)

A group of hikers atop Mount St. Helens on July 21, 2016. Mount St. Helens or Louwala-Clough is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is 96 miles south of Seattle, Washington, and 50 miles northeast of Portland, Oregon. (Photo by Raxit Kagalwala)

Trees in a park are illuminated with a red light as a part of an art project in Timmendorfer Strand, northern Germany Wednesday, October 26, 2016. (Photo by Michael Probst/AP Photo)

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)