Mysterious, fish-like creature with transparent skull and vibrant green eyes dwells in the abyssal Ocean.

Deep-Sea Wonders: The Barreleye Fish and its Transparent Companions

In the depths of the North Pacific, a peculiar fish named the barreleye (Macropinna microstoma) has been captivating marine biologists with its unique features. First described in 1939, this fascinating creature has adapted to its dark and sunless environment in intriguing ways.

The barreleye fish's most striking feature is its transparent head, which houses tubular eyes that look upwards. This design allows the fish to block sunlight and blend in with its surroundings, aiding in its camouflage. Its eyes are equipped with green pigments that further help in concealment when viewed from above, a strategy particularly effective when the fish rests on the green leaves of the deep-sea landscape.

But the barreleye is not the only creature to employ transparency as a survival tactic. Glass squids, found in the deep sea, are almost completely transparent, using this quality to avoid being seen by both prey and predators. Meanwhile, glass frogs in tropical Central and South America have translucent bellies, allowing onlookers to see their internal organs and providing excellent camouflage among their leafy surroundings.

The behavior of the barreleye fish has been observed by researchers from the Monterey Bay Aquarium Research Institute (MBARI) through footage gathered by remotely operated subs off the coast of Central California at a depth of 600 to 800 meters. In this footage, the fish can be seen sitting motionless in the dark waters, waiting for its prey to come within sight. Its unusual visual system allows it to detect the silhouettes of prey above, a tactic that keeps it well-fed on tiny crustaceans and other small animals swept up by jellies.

In 2009, MBARI researchers were successful in catching a live barreleye fish that survived for several hours in a pressurized aquarium. The fish was able to rotate its tubular eyes forward to focus on food in front of it, a fascinating adaptation that aids in its hunting strategy.

Despite its captivating nature, the barreleye fish typically remains hidden in the deep, dark waters of the North Pacific. Its transparent head, combined with its unusual visual system, helps it keep an eye on its prey while avoiding the stinging cells of jelly tentacles. This elusive deep-sea creature continues to fascinate scientists and the public alike, offering a glimpse into the strange and wondrous world beneath the waves.

Mysterious, fish-like creature with transparent skull and vibrant green eyes dwells in the abyssal Ocean.