Glass Octopus
A deep-sea octopus so transparent that only its digestive gland and optic nerves are visible — everything else is see-through
No photo available for Glass Octopus
Superpower
The glass octopus (Vitreledonella richardi) is nearly completely transparent — its mantle, fins, and arms are all optically clear. Only its cylindrical optic nerves and small digestive gland cast any shadow. In the midwater ocean where bioluminescence is the only light, transparency is the ultimate camouflage: there's nothing to reflect a flash or cast a silhouette. Its eyes are tubular rather than spherical, pointing upward to maximize detection of prey silhouetted against whatever faint light filters down from above.
Overview
Glass octopuses live in the open midwater ocean worldwide at approximately 200–1,000 meters depth — rarely encountered enough that most behavioral knowledge comes from ROV footage captured since the 2000s. A major Schmidt Ocean Institute survey in 2021 around the Pacific Remote Islands captured some of the clearest footage to date, revealing behaviors not previously observed. They're solitary hunters thought to eat small crustaceans and fish.
Found in
Open ocean midwater worldwide at depths of approximately 200–1,000m. Found in tropical and subtropical regions of all major ocean basins. Most observations come from equatorial Pacific waters.
Things worth knowing
- 1
The glass octopus's tubular eyes can rotate to always point upward regardless of the animal's body orientation — maintaining upward visual vigilance for silhouettes even when the animal is swimming sideways or inverted.
- 2
Transparency in the open ocean midwater has evolved independently in many unrelated groups — salps, comb jellies, certain shrimp, and the glass octopus all use the same principle. The convergence suggests it's one of the most effective strategies available at those depths.
- 3
The digestive gland — the only opaque organ — is positioned and oriented to minimize its shadow in downwelling light, reducing its detectability even though it cannot be made transparent.
- 4
Glass octopuses have been observed by ROVs appearing to 'vanish' when they orient their bodies perpendicular to a camera's light source, as the transparent tissue becomes impossible to distinguish from the surrounding water.
- 5
Almost nothing is known about glass octopus reproduction, diet, or population size. They represent one of the largest gaps in knowledge about any cephalopod species despite being found in all major oceans.