Transcript for Strange fish with see-through head

Macropinna is a small, dark fish with large fins, a tiny mouth and a remarkable pair of eyes.

The two green spheres in these video shots are the lenses of its tubular eyes.

Behind the eyes is a set of large scales.

The eyes are enclosed within a transparent shield, sort of like the canopy of a jet fighter.

In front of the eyes are two dark capsules containing the fish's olfactory organs.

Typically, Macropinna sits quietly in the water, using its big fins for stability...

while it scans the water above for food.

When it spots food, it can rotate its eyes to look forward, to include its mouth in the field of view.

We speculate that Macropinna steals food from siphonophores,

elongate animals with tentacles that capture prey that swims into them,

and we think that Macropinna swims into the tentacles and steals the food from the siphonophores.

The shield over its eyes protects those sensitive structures from...

...the stinging cells on the siphonophore's tentacles.

It can also rotate its eyes to avoid predators...

...or to avoid being captured by scientists...

This is Bruce Robison at the Monterey Bay Aquarium Research Institute.