Minoan Sea Culture

The story of a Cuttlefish
There are over 650 different species of cephalopod, some of which are benthic (living on the seabed), and others pelagic (living near the surface). Cuttlefish, octopuses, squid and nautiluses all belong to the class of cephalpods.Cuttlefish have eight arms lined with rows of suction pads, and two additional appendages (prehensile tentacles), which only have suckers and hooks at their ends. The prehensile tentacles are fired out at extremely high speed, grabbing prey in less than 15 milliseconds, while the remaining eight arms help to immobilize prey. Cuttlefish produce toxins that can paralyze their victims in a matter of seconds. They feed on crabs, shrimp and fish.

Cuttlefish do not use their arms for swimming in the way that other creatures such as octopuses do. Locomotion is achieved by drawing water into the body cavity and then forcing it out via an opening known as the siphon or funnel, so as to move at high speed in the opposite direction. Cuttlefish have an internal shell (cuttlebone) which varies in size and shape from one species to the other. The cuttlebone is porous and assists in maintaining buoyancy. Air drawn into the pores helps the animal to rise to the surface, whereas when the pores fill with water it sinks. Cuttlebone is used by gold and silversmiths to make moulds for jewellery; as a source of calcium it is also a favourite treat for parrots and other birds.Cuttlefish eyes are considered to be among the best developed in the animal kingdom. This lends them a significant edge when hunting for food, especially at night. Though colour blind, their perception of contrast is extremely good. Light-sensitive receptors are concentrated at two points on the retina, one of which is used to look forward and the other backward. In order to focus the entire eye changes shape, rather than the lens alone, creating a high definition image of objects close up or far distant.  

Cuttlefish spend a considerable part of the day buried in the sand, hiding from their enemies. They also have a sac of ink that can be ejected whenever they are at risk, to confuse the enemy and buy time to escape. As well as reducing the predator’s visibility, the ink contains chemical agents that paralyze the senses. The cuttlefish’s main predators are dolphins, sharks, seals and fish.In common with other cephalopods, cuttlefish have a number of specialised cells in their skin called chromatophores, by means of which they can constantly change colour. This means that they can mimic their environment perfectly, for total protection against their enemies. Furthermore, they can lure prey, communicate with other cuttlefish or send alarm signals when in danger. There are approximately fifty chromatophores in every square millimeter of the cuttlefish’s outer skin, which contain yellow, red and brown or black pigments. Other specialized cells contributing to colouring are leucophores, which create white spots, and iridophores, which make green, blue, silver and gold. All of these cells can be used in combination to create the variegated colouring on a cuttlefish.  

Male cuttlefish use their chromatophores to create a typical zebra pattern when courting females. The same pattern in reply indicates another male, but no reaction is taken as meaning that the other cuttlefish is a female, and so courting begins in earnest. Female cuttlefish lay their eggs in bunches of about 100 hundred a time, and attach them to seaweed or other elongated objects suspended in the water. More than one female may lay eggs at the same place. The fertilized eggs contain a developing embryo and are full of ink, for protection against predators. Females stay by the eggs in the initial phase, spraying them with water to enrich them in oxygen and keeping predators at bay. Eventually, any females that do not leave their eggs for any reason, even for food, die from exhaustion brought about by starvation. Depending on water temperature, the young cuttlefish hatch and begin foraging one to three months later. They live for one to two years.

 

 

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