Because they live at depths of around 2,500ft (762m) down, there is very little light. It is speculated that the Barreleye fish use their large, flat fines to remain motionless in the water, and fix their eyes upward. The green pigments in their eyes might help them to filter out any sunlight that reaches down into the water, allowing them to more easily locate the bioluminescent glows of various jellyfish and other creatures. When prey has been found they then swim upwards, moving their eyes into a forward position.
There is still much to learn about the Barreleye and many other deep sea denizens. Just image what else is down there, new things are discovered all the time!
IUCN Status : Not Listed
Location : Deep Sea Oceans
Classification : Phylum : Chordata -- Class : Actinopterygii -- Order : Osmeriformes
Family : Opisthoproctidae -- Genus : Macropinna -- Species : M. microstoma