Although the Barreleye fish resembles a submersible, it needs its transparent head to navigate the 2,500-foot-deep seas in which it lives. Scientists have obtained film of a fish with a bulbous, transparent head and green orb-like eyes peering out through its forehead thousands of feet beneath the surface of Monterey Bay off the coast of California.
The half-century-old riddle of a fish with cylindrical eyes and a translucent head was finally solved by researchers at the Monterey Bay Aquarium Research Institute. Marine researchers have known that the Macropinna microstoma’s tube eyes are exceptionally good at collecting sunlight since it was originally described in 1939.
Barreleye Fish is Weird
Researchers originally described the barreleye in 1939 and have been putting together how it thrives ever since. The barreleye fish, known scientifically as Macropinna microstoma, or “spookfish,” is considered by scientists to be one of the “most bizarre and undiscovered fish groups in the deep-sea marine world.”
They favor the Pacific, Indian, and Atlantic seas for their moderate, warm deep-sea waters. They’ve been spotted in North Pacific coastal waters, off the shores of Baja California, the Bering Sea, and Japan, to name a few. It is frequently seen resting still in deep-sea waters with the help of its flat fins. They move their green-capped eyes skyward to see their food as well as jellies, allowing them to feast on the small animals dangling from their tentacles. MBARI’s ROV Ventana was deployed last week, and a team of scientists saw a barreleye fish floating in the sea. Video below.
External fertilization of eggs is used by barreleye fish to reproduce. These organisms’ alpha males and females both discharge sperm and eggs into the ocean, where they fertilize and develop. The parents show no concern for the fertilized eggs or their offspring.
Robison and Reisenbichler plan to conduct more study to see if their findings regarding Macropinna microstoma apply to other tubular-eyed deep-sea fish. For years, oceanographers have been baffled by the barreleyes’ strange physiological adaptations. Only with the development of sophisticated underwater robots have scientists been able to examine these species in their natural habitat, allowing them to fully comprehend how their physical modifications help them survive.