Tuesday, April 24, 2012

Presentation on Vampire Squids


The vampire squid is an impressive animal of the deep sea. They have over enlarged eyes that are a result of the dark environment in which they live in. They are considered to be living fossils because they have been around for such a long time. The animal lives at around 300 meters deep. They are found in the tropical and temperate regions of the world’s oceans. They are not very large; they grow to around 13 cm long. They have 8 arms and a long curly strand that acts as a sensory filament. They are technically not squids. It is thought to be an ancestral line between squids and the octopi. They do not produce in nor do they have the ability to change their coloration in order to blend into their surroundings.
       They have a unique defense mechanism that makes them very interesting. They have the ability to turn themselves inside out. Their tentacles come up over their body, giving them their name the “Vampire squid.” The one characteristic that they are known for is their defense mechanism that is to turn themselves inside out. 
The study that I particularly looked at for my presentation was done at Monterey Bay, California. The study was done in order to observe the luminescent clouds. They looked at 57 individuals in situ and they looked at 18 individuals in the laboratory aquarium. The vampire squids that were in the aquarium were recorded in complete darkness and under red light by the use of low light video cameras.    
       In particular, the study looked at the arm tips of the squid. They are known to hold the particles that glow. Then when the arms are put over the head and the mantle of the squid the particles are released. This puts the squid into what is known as a luminous cloud. The squid releases a few hundred to several thousand particles each time it makes the luminous clouds.  The glowing particles last between 2-3 minutes. Some trials happened to last as long at 9 minutes. In this study there was no way to measure the intensity of the luminescence. They could only record the amount of time that the particles were luminescent.

       The  light has been found to be emitted from the 2 fin- based photophores. The photophores are a light emitting organ that are found on deep water organisms. It is hypothesized that they use light to get away from predators. The light is thought to distract the predator long enough for the vampire squid to get away.
       Later on in the study they found that the luminous fluid was sticky, therefore when the squid released it into the surrounding water some of it stuck to the predator. This is interesting fact, because it leaves the predator glowing and it is more vulnerable to secondary predators.

The bright blue lights usually appeared as a tight chain of 4 to 6 small discs, tapering in size distally along the oral surface of each arm tip. Occasionally there were different patterns, in which the light appeared as two parallel lines separated by a dark gap. The green areas next to the arrows are where the particles are ejected from. They are less than 1mm wide.
To test for the presence of coelenterazine, they homogenized individual arm tips in 500 μl of methanol. The graph A above shows the light produced by methanolic extracts upon addition of Oplophorus luciferase, this indicated the presence of the luciferin coelenterazine. The graph B above shows the addition of coelenterazine to aqueous  extracts, it shows high luciferase activity. As the two graphs show the amount of light over a given period of time, graph B showed that the coelenterazine resulted in a more solid glow in comparison to sample A. This is represented by the linear line on the graph. It was also concluded that the Calcium chloride did not emit light, indicating that the calcium-activated photoprotein was not involved in making the particles glow.
It was concluded that the lights are used for intraspecific communication, attracting prey, and also to get away from predators. The arm tips glowed every time after the animal was handled. The luminous ejecta was never observed without the tip lights glowing as well. The light that was produced by the methanolic extracts upon the addition of Oplophorus luciferase indicates the presence of the luciferin coelenterazine.

2 comments:

  1. What a bizarre creature and intriguing study. There really must be no end to the adaptations of creatures types of defense mechanisms used. Cool post Shawn!!

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  2. I gree with Lydia, this is one of the most bizarre creatures I have ever seen! It makes me wonder about what interesting organisms can be found in the deep sea since such a vast amount of it is undiscovered. Very interesting post Shawn.

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