Visitors look at the blue-green damselfish at the Unseen Oceans exhibition held in the American Museum of Natural History in New York, the United States, March 14, 2018. The exhibition highlights the latest advances in ocean exploration, the researchers and technologies behind them and the mysteries that remain. Visitors can join scientists on their high-tech, high-adventure, and high-impact fieldwork to see and discover beautiful, diverse, and important creatures living at previously unseen ocean layers. (Xinhua/Wang Ying)