Vampire squid a human's inner ear) and ammonium-rich gelatinous tissues closely matching the density of the surrounding seawater. Like many deep-sea cephalopods, the vampire squid lacks ink sacs. If disturbed, it will curl its arms up outwards and wrap them around its body, turning itself inside-out in a way, exposing spiny projections. If highly agitated, it may eject a sticky cloud of bioluminescent mucus containing innumerable orbs of blue light from the arm tips. This luminous barrage, which may last nearly 10 minutes, would presumably serve to daze would-be predators and allow the vampire squid to disappear into the blackness without the
Colossal squid whales and sleeper sharks), while the other predators only eat juveniles or young adults. The species was first discovered in the form of two tentacles found in the stomach of a sperm whale in 1925. In 1981, a Russian trawler in the Ross Sea, off the coast of Antarctica, caught a large squid with a total length of over , which was later identified as an immature female of "M. hamiltoni". In 2003 a complete specimen of a subadult female was found near the surface with a total length of and a mantle length of . This specimen shows that