Squids are cephalopods belonging to the order Teuthoidea. They live in both coastal and oceanic waters. They can be found in all climatic zones. Outwardly, they look like aliens who have taken over our oceans. Some of them are well known and widely eaten by humans, while others have not been studied at all. There are deep-sea species of these molluscs that live where there is no sunlight, and very little reliable information is still known about them. As a rule, the greater the depth, the larger the squid.
Habitat: mostly Atlantic, Indian and Pacific Ocean
Lifespan: up to 3 years
Size: 1/2 inch to 20 feet (6 meters)
Weight: up to 900 pounds (400 kg)
Diet: zooplankton, small fish and other squid
Predators: Big Fish & Humans
Top Speed: 55 kph (35 mph)
Facts about squid
The habitat of squids is wide. They live in any sea salty waters, ranging from the mainland Arctic to the hot subtropics.
The habitat of the mollusk affects its color. The colder the water, the less bright the color of the animal. Colorless squids live in northern waters.
Some squids live close to the surface of the water, others deep (up to 2 km) at the bottom of the sea. The closer to the surface, the smaller the body size of the mollusk.
Scientists know more than 200 species of squid, of which only 30 species have been described and classified.
Squids are close relatives of cuttlefish and octopuses.
Description of squid facts
Mollusks have blue blood, because instead of the usual hemoglobin, the blood contains copper and hemocyanin.
The squid has three hearts attached to its tentacles. The two hearts are called gill hearts, they saturate the blood with oxygen, and the main heart pumps oxygenated blood throughout the body.
The body of the animal has no bones, the hard parts of the mollusk are the chitinous beak, as well as the cartilage of the head.
Squids have large eyes and excellent vision underwater.
The nerve fibers of an animal are much thicker than a human, which helps to instantly respond to a change in the situation.
In its class, the squid has the most developed brain and even has a cartilaginous likeness of the skull. The brain provides the complex behavior of the squid. The animal is capable of cunning, deceit and other intellectual tricks.
The animal has a specific tube in its body, which, like a siphon, pushes a high-pressure jet of water out of the body, which makes the mollusk extremely mobile and an excellent swimmer.
On the tentacles of mollusks there are many suckers. Each tentacle is controlled by the nervous system and deals with different problems. Some feel the stones, others send food into the mouth, and others are responsible for the cleanliness in the hole. All squids have 10 tentacles, of which 2 are dexterous (catching prey), and the rest act as auxiliary arms.
Despite the absence of teeth, squids have a beak that easily pierces the backbone of fish and even the shell of crabs. The process of digestion in the stomach takes about 4 hours.
The body size of female mollusks is much larger than the size of males.
Like representatives of the fish class, squids have gills, which are their respiratory organs.
In the body of small planktonic squids there is a special bag containing ammonia, due to which they do not drown, since ammonium chloride is lighter than water.
The life expectancy of an animal is from 1 year to 3 years.
Facts about squid behavior
Some species of squid, escaping from enemies, can jump out of the water and at the same time fly more than 10 meters above the sea surface. Birds of prey are not averse to eating such “flyers”.
During the spawning season, squid reach speeds of up to 55 kph (35 mph), swimming several thousand kilometers away. Squids do not have their own territory. The mollusk swims backwards, showing sharp turns.
Squids have the unique ability to change color. Seeing the enemy, the molluscs can turn black, secrete a dark liquid and become completely colorless. At the same time, the released ink resembles the animal itself in shape and the enemy attacks the ghost, and the squid successfully leaves the dangerous place.
The process of mating animals is quite complicated. The male attaches a special bag of sperm to the female’s body. Upon contact with salt water, the sac breaks and activates an internal spring that ejects the contents into the body of the female. Sperm cells are in the body for up to 3 months, until the favorable time for the spawning of mollusks comes. The female squid lays more than 1 thousand eggs and then dies.
In the depths of the ocean there is a species of glass squid, whose body is transparent. The exceptions are his eyes and digestive organs. It either runs away from the enemy, or, collecting a large amount of water, swells into a transparent ball.
Squid is a swimming champion. Only dolphins and swordfish can catch up with him.
Squids hunt with two tentacles, with which they capture food. The tentacles can be up to 10 meters (30 ft) long. Having captured the victim, the mollusk injects a poisonous liquid into it, the victim is immobilized. The squid begins to slowly tear off pieces from the victim and move them into the oral cavity.
In the ocean, squids are hunted by sperm whales, dolphins and sharks. In humans, squids are also in demand because of their taste.
The Kraken is a giant sea monster about which Scandinavian and German sailors tell legends. The real source of these legends seems to be the huge deep-sea squid, which are sometimes found in the stomachs of sperm whales or washed up dead on the surface of the sea.