Barreleye Fish- the only animal with a transparent head


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Barreleye fish has a transparent head. The green tubes under its transparent head are the eyes. Yes, believe or not. The transparency allows more light to be absorbed in the deep sea. And the transparency allows the barreleye to look upwards towards its prey.  What looks like his eyes are the nostrils. And the small black snout is the mouth.

Written by JY, age 7

Scientific Name: Opisthoproctidae
Where do they live? 2,500 feet (762 meters) below the surface
How big are they? 15 cm (6 inches)
What do they eat: small fish and jellyfish
How long do they live? unknown

  • The Barreleye fish was discovered in 1939 but first seen alive in 2004!
  • The barreleye fish has a transparent (see-through) dome-like head to let in light
  • The barreleye’s name is from the shape of its tubular eyes.
  • The barreleye’s eye usually point upward towards the light to find prey

image credit: National ocean service

The barreleye fish lives in the midnight zone where there is no light.

1.Barreleye fish worksheet

Print out the Barreleye fish worksheets (PDF) here for 3 pages of fun: (1) color and write down fun facts (2) label unusual parts of the fish (3) color with answers

2. Report for Learn about animals

Click on the image or here to download and print out the Animal report PDF

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