Cockatoo Squid (Galiteuthis phyllura)
The Cockatoo Squid is a species of glass squid. Rather than squirting ink when agitated, it changes the color of its body from transparent to colored by expressing pigment-filled cells called chromatophores. It can grow up to a length of three m. It is able to hold itself motionless in the water column by regulating the ratio of ammonium chloride to seawater that it holds in an internal cavity. They are thought to inhabit depths of 300 m to 1000 m. Cockatoo Squid have been seen at the Oregon Offshore Site at 586 m, floating in the water column, where we witnessed its skin change from dark red to transparent. It was also spotted swimming around ROCLS at Southern Hydrate Ridge at 786 m in depth.
References:
Marine Life Field Guide (Neptune Canada)
http://eol.org/pages/488004/details
http://www.mbari.org/news/homepage/2010/youtube-squids.html