The common name for the fish is “barreleyes.” Monterey Bay Aquarium Research Institute investigators recently figured out why this species has such an unusual head. Its eyes can actually rotate within its “skull,” so the transparency allows the wary swimmer to keep a literal eye on happenings above it, as well as to the sides and directly in front.
Using video cameras, MBARI researchers Bruce Robison and Kim Reisenbichler revealed the fish’s eye movements. When remotely operated vehicles approached the fish, its eyes glowed a vivid green shade in the bright lights of the ROVs. Usually the fish were just hanging out motionless under the deep waters offshore California’s central coast.
Here’s a “face-on” view showing the green glow.