A Deep-Sea Discovery
Macropinna microstoma, also known as the barreleye fish, was first described in 1939, but for decades, little was known about it. This deep-sea fish lives at depths of 600 to 800 meters (2,000 to 2,600 feet) in the Pacific Ocean, where sunlight barely reaches.
A Head Like No Other
Its most striking feature is its transparent head, which allows researchers to see its barrel-shaped eyes inside. Unlike most fish, its eyes can rotate within its head, enabling it to look forward or straight up to spot prey while remaining motionless.
Adapted for Darkness
Macropinna microstoma’s eyes are extremely sensitive to light, helping it detect the bioluminescent glow of jellyfish and other deep-sea organisms. It uses specialized fins to remain nearly motionless while scanning for food drifting in the current.
First Footage Captured
For decades, scientists only studied dead specimens. In 2004, researchers at the Monterey Bay Aquarium Research Institute (MBARI) captured the first live footage, revealing how it moves and hunts in the deep sea.
Macropinna microstoma, also known as the barreleye fish, was first described in 1939, but for decades, little was known about it. This deep-sea fish lives at depths of 600 to 800 meters (2,000 to 2,600 feet) in the Pacific Ocean, where sunlight barely reaches.🧵👇 pic.twitter.com/Kn7NHuBxgi
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