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
Giant squid by greatly stretching the two tentacles like elastic bands. Based on the examination of 130 specimens and of beaks found inside sperm whales, giant squids' mantles are not known to exceed . Including the head and arms, but excluding the tentacles, the length very rarely exceeds . Maximum total length, when measured relaxed "post mortem", is estimated at for females and for males from the posterior fins to the tip of the two long tentacles. Giant squid exhibit sexual dimorphism. Maximum weight is estimated at for females and for males. Little is known about the reproductive cycle of giant squid.