Remote-controlled vehicle captures rare sighting of the barrel-eye fish, a creature with green eyes that can see through its forehead to hunt for prey.
Barrel-Eye Fish – The “Ghostly” Creature of the Ocean
The Monterey Bay Aquarium Research Institute (MBARI) has released a new video featuring a peculiar fish with glowing green eyes and a transparent head. This is the barrel-eye fish (Macropinna microstoma), captured by a remote-controlled vehicle during an expedition aboard the research vessel Rachel Carson in Monterey Bay, off the coast of California.
The barrel-eye fish can see through its forehead to observe above it and search for prey. Scientists need to use remote-controlled vehicles to capture footage because they typically live at depths of 600 to 800 meters, far beyond human reach.
The barrel-eye fish can see through its forehead to observe above and search for prey.
Sightings of the barrel-eye fish are incredibly rare. “Ventana and Doc Ricketts, MBARI’s remote-controlled vehicles, have made over 5,600 dives and recorded over 27,600 hours of footage, yet we have only seen this species 9 times,” MBARI stated.
The barrel-eye fish is accustomed to operating in darkness, and its unusual eyes help it find food in such conditions. Experts at MBARI have observed that they feed on jellyfish and can grow up to 15 cm in length. The two small indentations on their face are actually olfactory organs, resembling nostrils.
The Ability to Rotate Vision
For many years, scientists believed that the barrel-eye fish’s eyes could only look straight up – a reasonable feature for spotting the silhouette of prey against a dimly lit background. However, a 2008 study by the Monterey Bay Aquarium Research Institute (MBARI) revealed a surprising fact: Macropinna microstoma can rotate its eyes from above to in front of its face. This allows them to accurately target prey while resolving the long-standing mystery of this fish’s feeding abilities.
The “Helmet” That Protects Its Transparent Head
Not only does the transparent head optimize light, but it also serves as a protective layer. When studying this creature, scientists discovered traces of siphonophores, a complex marine organism with long tentacles that contain venom. Researchers believe that barrel-eye fish often steal prey from siphonophores, and the transparent head acts like a “helmet” to shield their eyes from harmful stings.
Other Barrel-Eye Fish and Their Limitless Oddities
The barrel-eye fish family is not limited to Macropinna microstoma, as it also includes species such as Opisthoproctus barreleyes and Dolichopteryx, which possess unique characteristics. Opisthoproctus barreleyes features upward-facing tubular eyes but lacks a transparent head. Instead, they utilize their keen eyesight to detect faint light, enhancing their hunting efficiency in the dark.
