Nature Blows My Mind! The Bobtail Squid and Its Amazing Invisibility Cloak

CC BY-NC 3.0. Nick Hobgood

This mind-blowing squid makes a home for bioluminescent bacteria inside its body, using the glowing bacteria as camouflage against predators at night in a brilliant symbiotic relationship.

bobtail squid photo

Hans Hillewaert/CC BY 3.0

The bobtail squid is a tiny creature (only about two inches long) that can be found in shallow coastal waters of the Pacific Ocean, some parts of the Indian Ocean, and on the west coast of the Cape Peninsula off South Africa. Hidden in the sand by day, it comes out at night to hunt. To avoid detection by predators from below, it harbors glowing bacteria on its underbelly to mimic the moonlight and essentially eliminate its shadow.

The bacteria are housed in a special light organ in the squid's mantle, where the squid provides food in the form of sugar and amino acid solution. The squid uses filters in this organ to adjust the brightness of the bacteria to match that of the moon, essentially using the light as an invisibility cloak or, as one researcher put it, a Klingon cloaking device.

bobtail squid photo

Nick Hobgood/CC BY-NC 3.0

The way that the bobtail squid and bacteria interact to activate the glowing is called quorum sensing. If we can figure out just how it works and use it ourselves, we might be able to come up with better ways to fight illnesses or perhaps even new camouflage techniques. Bobtail squid have even been part of experiments in space to help figure out ways to keep astronauts healthy.

Here is a great little video explaining a little more about quorum sensing and the amazingness that is the bobtail squid:

And here is another informative video about researchers studying this fantastic creature: