Vampyroteuthis infernalis (Vampire squid). The squid has large fins at the to of its body that resemble large ears. It is very gelatinous in form, resembling a jellyfish more than the common squid. The vampire squid has the largest eyes of any animal. It is a small animal, growing to a length of about six inches, bit it has globular eyeballs as large as the eyes of a large dog. The vampire squid's body is covered with light-producing organs called photophores. This gives the squid the unique ability to "turn itself on or off" at will. When the photophores are off, the squid is completely invisible in the dark waters where it lives. These squid live as deep as 3000 feet. Unlike other squid and octopi, the vampire squid has no ink sack. The vampire squid's arms are covered with sharp tooth-like spikes. This gives the animal its name. One pair of arms has been modified into retractile filaments that can extend to twice the body length of the animal. The squid may use these arms to capture its prey. When threatened, the squid can draw its arms up over itself and form a defensive web that covers its body. The vampire squid can swim extremely fast for a gelatinous animal. It can reach a speed of 2 body lengths per second and can accelerate to this speed in only 5 seconds. If danger is present, it can make several quick turns in an attempt to escape its enemies. The vampire squid is found throughout the world in most tropical and temperate regions.