Wednesday, November 10, 2010

Calamari anyone?

Dr. Vladimir Laptikhovsky and Amy Taylor have been examining the Cephalopods (squids) collected during the seamounts cruise in 2009. There are around 300 species of squid that live in the open ocean and larger individuals tend to inhabit progressively deeper waters. Squid are considered the most highly developed of all invertebrates due to their sophisticated nervous and circulatory system, and the fact that they continue to survive in the absence of a hard outer shell. By squirting water out through their siphons, they dart through the water column and catch fish with their tentacles. Using this jet propulsion, they are capable of extreme speeds and some even launch out of the water to ‘fly’ for considerable distances. Their skins are covered in chromatophores which enable them to instantly change color to suite their surroundings and effectively become invisible when they need to. Some species are also able to eject dark ink into the surrounding water to temporarily confuse attacking predators.

In these first three days of the workshop, Vladimir and Amy have already identified approximately 30 different species… two of which have not been collected before in the Indian Ocean!

Picture 1: Dr. Laptikhovsky and Amy Taylor.

Picture 2: Some interesting examples of squid species: A) Onychoteuthis sp: This species is known for its elaborate hooks at the ends of its tentacles which aid it in grasping its prey more securely. B) Pyroteuthis margarititera: Being less streamline, this squid probably relies more on camouflage than speed. C) Pterygioteuthis giardi: The smallest species known to man! D) Cranchia scabra: Although probably quite slow, this squid has some elaborate defense mechanisms. Firstly, it can suck its head and tentacles into its mantel cavity! Next, it injects ink into the cavity and because the mantel is translucent, it is able to match the color of the surrounding water and become invisible. In case all this fails, it sports tiny spikes all along its outside which may irritate the alimentary canals of some predators.

No comments:

Post a Comment