Image: Glasshead Barreleye from above
The top of the head of a Glasshead Barreleye trawled from a depth of around 1000 m on the abyssal plain in the southern Tasman Sea, between Tasmania and New Zealand. The two round structures are the primary eyes. One guanine crystal-lined mirror-organ is visible below the eye on the right.
- Adrian Flynn
- © Adrian Flynn
The barreleyes are an unusual family of deepsea fishes, most of which have upwardly-directed eyes. The eyes detect the silhouettes of prey swimming above.