This pallid octopod is Vulcanoctopus hydrothermalis, a deep-sea species found lurking about hydrothermal vents, where they clamber about among the tube worms, tolerating poisonous clouds of warm sulfides. Hydrothermal vents are rich sources of food with chemosynthesis as the source of energy, as long as you can cope with the occasional scalding hot currents that can boil you alive in seconds, or the toxic chemicals spewing out of them, so Vulcanoctopus can thrive at high densities there.

Here is a photo series taken by the submersible "Alvin" of a Vulcanoctopus feeding frenzy.

The center fields of the photos are murky because they are obscured by dense swarms of amphipods. Another denizen of the hydrothermal vents is Halice hesmonectes, a small crustacean (about 5mm long) that forms thick clouds of arthropods, with a density of thousands per liter. In the photos below, the Vulcanoctopuses are the pale star-shaped creatures clinging to the sulphide spires, covered with white serpulid tube worms.

Images of octopuses of Vulcanoctopus hydrothermalis over a tubeworm mass at the base of the serpulid-covered sulphide spires of Parigo, taken at 20-s intervals by the forward-looking digital still camera on 'Alvin' while sampling is in progress. Amphipods of Halice hesmonectes are visible as particles in the water column. (A) Four octopuses continue to feed from the sulphide spires as the manipulator arm of 'Alvin' begins sampling. The octopus to the left (immediately above the manipulator arm) dangles from a serpulid tube as it pulls its arms together; the centre octopus is beginning to extend its arms in a starburst pattern and the arms of the upper right individual are ballooned. The fourth octopus is advancing from the lower right part of the image; (B) twenty seconds later, as the manipulator arm is lowered, the octopuses largely retain the same positions; the upper right octopus has begun to extend its arms as the lower right individual advances; (C) twenty seconds later, the octopus to the left has ballooned its arms and the centre octopus has maximally extended his arms. The octopuses to the right are in contact; the octopus from the lower right has engulfed the upper individual in its web; (D) after another twenty seconds, the arms of the left octopus remain ballooned, as are the arms of the centre octopus. The octopuses to the right are more readily discernible as the arms of the engulfed individual extend from beneath the upper octopus.

They're clinging to serpulid tubes with one or two arms, and reaching out with the others to scoop up yummy crustaceans spiced with a bit of sulphur and chomping them down. There are so many octopuses here that every once in a while, they'll bump up against one another and one will briefly engulf another in its tentacles.

(Thanks to Steff Zimsen for the paper!)

Voight JR (2005) Hydrothermal vent octopuses of Vulcanoctopus hydrothermalis, feed on bathypelagic amphipods of Halice hesmonectes. J. Mar. Biol. Ass. U.K. 85:985-988.