The strange fish has a penetrating head

An exotic fish that lives in deep water called ocular fish has a clear head and tubular eyes. Since the species was discovered in 1939, biologists have learned that its eyes are very sensitive to light. However the shape of the eyes seems to have made the fish have a tubular market.

The eye fish has a transparent glass-like head

Now scientists have discovered that the eyes can spin, allowing the fish to look directly or to find the object above it through its transparent head.

The empty eye fish (Macropinna microstoma) adapts to the pitch-dark habitat of deep waters where light cannot reach. They used extremely sensitive tubular eyes to search for the faint shadow of prey on its head.

The Macropinna microstoma drum eye has extremely light-sensitive eyes that can be rotated in a shield filled with clear liquid on the head.Its tubular eyes are located deep inside the head covered by bright green lenses . The eyes are pointing upwards (as seen on the picture) when the fish looks for the source of food above it. The eyes are facing down when it is eating. Two points right above the fish's mouth are not its eyes. In fact it is the olfactory organ similar to the human nostril.

However, scientists once thought that the eyes could only be directed upwards. This made it impossible for the fish to see in front of it, and it was difficult for it to catch lips with its tiny pointed mouth.

Bruce Robinson and Kim Reisenbichler of the Monterey Bay Aquarium Research Institute used the tapes obtained from a remote control camera to study empty eye fish in central California. At a depth of 2,000 to 2,600 feet (600 to 800 m), the camera captured images of these fish almost immobile in the water, their eyes emitting vivid green light under the light of the camera. .

Most of the details described and illustrated today about this fish do not show the aforementioned fluid-filled shield component, perhaps because this fragile structure was destroyed when the fish was caught in the net. and was taken ashore.

Robinson and Reisenbichler were fortunate to bring an empty live eye fish to shore after throwing a net. After a few hours for the fish to live in the tank, they were able to confirm that the fish turned its tubular eyes as it changed its body posture from horizontal to upright.

The drumfish is only a few inches long and is thought to eat small fish and jellyfish.The green pigment in their eyes can filter the light coming directly from the sea surface, helping the fish identify the bioluminescent spots of jellyfish or other animals right above its head. When it detects a prey (such as a floating jellyfish), it will turn its eyes forward and swim upwards.

The findings are published in Copeia.