Vampyroteuthis infernalis, the vampire squid, which technically isn’t a squid at all, is a cephalopod that lives 3,000 feet deep in warm waters. In the deep pelagic zone, there is little oxygen and V. infernalis reaches a size of just 30 cm in adulthood.
V. infernalis feeds on corpses, feces and its own mucus and has characteristics of both octopi and squids. The scientists published their findings in the journal Proceedings of the Royal Society B.
V. infernalis feeds unlike any other cephalopod. It has a unique adaptation that allows it to remain at depths where the oxygen concentrations are very low, but where predators are few. It feeds solely on marine snow, the debris that falls to the ocean floor. Marine biologists have never been able to prove this, since necropsies have proven to be inconclusive.
The specimens were filmed in their natural habitat by using remotely operated vehicles and studied in tanks at the lab. Once debris of animal particles was sunk into the tanks, the cephalopod extended a fine, long filament from its umbrella-like mouth, which contains a web of eight arms covered in suckers and spines. The filament extends to eight times its body length and sticks to the debris, drawing it back through the web of arms where edible particles are cleaned off the filament.
Reference: “Vampire squid: detritivores in the oxygen minimum zone” by Hendrik J. T. Hoving and Bruce H. Robison, 26 September 2012, Proceedings of the Royal Society B.