Saudi Arabia - March 04, 2025 Red Sea, Saudi Arabia – Astonishing discoveries lurk in the shadowy, oxygen-starved depths of the Red Sea, where an exploratory expedition has uncovered thriving ecosystems teeming with unexpected fish. Two deep-sea zones, probed by Shannon Klein and her team during the 2022 Red Sea Decade Expedition, reveal a hidden world beneath the vibrant coral reefs. Using remotely operated vehicles and crewed submersibles, the researchers dived into the Amq Deep, plunging 619 meters below the surface. There, in warm waters of 22ºC with scant oxygen levels between 2 and 10.958 μmol O2 kg⁻¹, they spotted lace corals and a trio of fish species—lightfish, soldierfish, and vast schools of lanternfish. These lanternfish, dawdling at a pace five times slower than their cousins in oxygen-rich waters, may sneak upward at night to gulp air and snatch a meal. Then there’s the Farasan Deep, a 491-meter plunge where near-anoxic conditions below 2 μmol O2 kg⁻¹ should spell doom for air-breathing creatures. Yet, defying all odds, unidentified fish were caught gliding along the sediment’s surface. Persistent low-oxygen zones like these are familiar in temperate seas, but the tropics have kept their secrets—until now. The Red Sea’s warm, salty embrace and deep, enclosed pockets stifle oxygen flow, crafting these strange habitats. Experts reckon similar spots dot tropical coasts worldwide, each potentially hiding its own quirky cast of underwater survivors.