Biologists reported this week that they had unlocked secrets about the vampire squid, a mysterious creature known as a "phylogenetic relic," that combines features of octopuses and squids in a unique evolutionary formula that has survived for millions of years.
A team of scientists in California report in in the journal Proceedings of the Royal Society B on 30 years of chance encounters with vampire squids by robot submarine explorers, laborary experiments and dissections. Unlike its latter-day cousins, the vampire squad does not tuck into living prey, they say. Instead, examination of the squid's digestive tract, faeces and regurgitations suggest it is a "detritivore"—it tucks into the corpses (or what remains of them) of larvae, crustaceans and zooplankton that sink gently to the ocean floor.
The most amazing feature is the vampire squid's mouth, which opens up like a black umbrella, comprising a web that encompasses eight octopus-like arms, studded with suckers and finger-like spines called cirri. It also has a second pair of arms called retractile filaments that can reach out to lengths that are far bigger than that of the squid itself, and can then be withdrawn into pockets within the web.
These sticky filaments, Unique to the vampire squid, were long thought to be sensors to detect living prey and predators.The evidence suggests that they are used to reach out and snare morsels of food, say Hendrik Joving and Bruce Robison at the Monterey Bay Aquarium Research Institute. The scraps are then glued together into a little ball using mucus from secretory tissue in the suckers, and then transported to the squid's jaws by the cirri.
According to the study, "Vampyroteuthis' feeding behavior is unlike any other cephalopod, revealing a unique adaptation that allows these animals to spend most of their life at depths where oxygen concentrations are very low, but where predators are few and typical cephalopod food is scarce.
The Daily Galaxy via Proceedings of the Royal Society B and AFP