Deep-Sea Squid With Tentacle Tips That 'Swim' On Their Own

 Many animals in the sea use parts of their body to lure in their prey, such as the anglerfish. It uses something that looks like an antenna that emits light to attract other animals to it. Recently, in a recent paper, researchers, who are affiliated with Monterey Bay Aquarium Research Institute (MBARI), have described a deep-sea squid that uses a different method to lure its prey. The tentacle tips "flap and flutter" as if they were swimming by themselves. Researchers believe that the motion of the tentacles lure the prey close enough for the squid to snag the prey.

Most squids have eight tentacles and two "feeding" tentacles. The feeding tentacles,  known as "clubs", have suction cups or hooks on them, which allows the squid to grasp onto its prey. These squids hunt by swiftly moving their tentacles to grab their prey. 

But, the Grimalditeuthis bonplandi is different. It has a viscid body that is fragile, it is a very slow swimmer, its tentacles do not have any suctions, and it is too weak to capture its prey. Many marine biologists have seen the squid but it was near death or dead and could not examine it alive. Recently, they've had the experience to study the squids using remotely operated vehicles (ROVs) to study the squid in its natural habitat at about a mile below the ocean's surface. They were also able to dissect over a dozen preserved squids.

When the ROVs first approached the squids, the researchers saw the squid motionless with its two long tentacles moving away from its body. What interested the researchers was that the clubs did not seem to move on their own, instead they flapped and fluttered to move around. This squid sends its clubs away from its body by swimming in contrast to other squids who move their tentacles by muscle movements. Whenever the squid felt threatened, instead of retracting its tentacles, the body would swim towards the tentacles and then coil the tentacles and clubs and hide them before swimming away. 

In the dissections that the researchers performed, the researchers found small squids and shrimp in the stomachs of  Grimalditeuthis bonplandi. Because this squid does not glow in the dark and would be hard to see under water, the researchers theorized of other ways how this squid might attract its prey. They believe that the clubs might make vibrations under water which attract the prey to the clubs. They also believe that "the moving clubs could disturb glowing microscopic organisms in the surrounding water, causing the water to glow like a ship's wake during a red-tide bloom." 

http://www.sciencedaily.com/releases/2013/09/130903091606.htm

http://blogs.scientificamerican.com/running-ponies/files/2013/08/Grimalditeuthis-bonplandi.jpg

http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/IMAGES/I-2000.gif