Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

“7584 Fish”. On a windy day right after a Cyclone passed the far northern Great Barrier Reef i took some friends out to the reef. Never before i saw that many glass fish on this particular coral “bommie”. Just when i setup my camera, this Napoleon Wrasse swam right through the school of fish building a living frame. Photo location: Cairns, Great Barrier Reef, Flynn Reef, Australia. (Photo and caption by Christian Miller/National Geographic Photo Contest)

These unique photos capture the moment a boy has his teeth picked clean by amazing underwater shrimp. These fascinating creatures spend their lives diving inside the mouths of fish to remove the parasites that lurk there. Russell Laman imitated the behaviour of the surrounding fish swarm to entice the cleaner shrimp into his mouth whilst snorkelling with his father Tim Laman in Bali, Indonesia. The 13-year-old queued with the waiting fish and then opened his mouth when the shrimps came near. (Photo by Tim Laman/Caters News)

A fisherwoman repairs the fishing nets at a fishing port during the annual summer fishing ban, which covers the Bohai Sea, the Yellow Sea, the East China Sea, and the waters north of 12 degrees north latitude in the South China Sea, on June 8, 2022 in Wenling, Taizhou City, Zhejiang Province of China. (Photo by Liu Zhenqing/VCG via Getty Images)

This little kingfisher clearly didn't read the sign when it landed itself a minnow in a no fishing zone. Taxi driver Paul Bird, 52, from Newmarket, Suffolk, UK, captured this amusing moment whilst out looking to photograph kingfishers in Norfolk, an hour drive from his home. Paul explained: “There are a total of six perches the bird was using from which to fish, one of them being the No Fishing sign”. (Photo by Paul Bird/Solent News & Photo Agency)

Traders lay out their stools in a fishing village of Long Hai commune in Vung Tau province, Vietnam on June 17, 2020 with the market opening at midnight and trading into the early hours of the morning each day. It is the largest wholesale fishing market in the region and market traders can be seen sorting their fish into their different types before putting them into different coloured boxes for sale. (Photo by Pham Huy Trung/Solent News)

In this April 12, 2015 photo, Sayed Ahmed Abdoh poles his boat to check his fish traps in the Nile River, near Abu al-Nasr village, about 770 kilometers (480 miles) south of Cairo, Egypt. Abdoh caught some 20 fish this day and gave them to his friend, Salama Osman, a migrant worker in a Cairo apartment building, to celebrate his biannual return to their village. (Photo by Hiro Komae/AP Photo)

In this November 7, 2016 photo, “El Menor”, a member of “Los Cainos” self-defense group formed by the Marval fishing family, holds a homemade gun before starting a night patrol to help protect fishermen from pirate attacks in Punta de Araya, Sucre state, Venezuela. Pirates are terrorizing the coastal state of Sucre, once home to the world's fourth-largest tuna fleet and a thriving fishing industry. (Photo by Rodrigo Abd/AP Photo)