Maybe you already know that squids are mollusks that live in the oceans of the whole world. However, if you want to learn more about these creatures, that live either in salty and fresh waters, then this article will be quite useful for you.
The squids are considered one of the fastest marine species. It is even thought, that they possess a certain degree of intelligence, being also very quiet. However, the can adapt to any lifestyle.
Table Of Content
Characteristics Of The Squids
Squids are invertebrate animals which belong to the class of the cephalopods, and they have a wide diversity of properties. There are many mysteries about these creatures that have not been unveiled yet. The giant squid is probably the most fascinating and mysterious individual of this species.
They settle in the depths, taking refuge in unreachable and hidden places in search of protection.
These invertebrates have gills similar to those of fish, and a surprising detail is that they have three hearts. The squids use their 
tails for moving and swim. .
An interesting characteristics of this species, is given by a bag that they have in their bodies, which contains a substance known as squid ink. This fluid is employed by these mollusk as a defense system. We can also mention the particular case ofthe vampire squid, which releases a sticky snot while fleeing its predators.
Squids are also characterized by having eight arms , even ten in the case of the pota ; and the are usually related to the octopus, since they have many properties in common.
These creatures existed since more than five hundred years ago according to different fossil discoveries
The squids have a wide range of characteristics and properties which vary from one species to another. Their sizes ,colors, and behavior are variable, depending on the species. However, what is really clear, is that they are harmless animals, altough they have large tentacles, they do not represent any risk for humans.
There are many researchers carrying out different studies around the world, which make us be optimist that in few time, more information about the squids will be known.
There is wide variety regarding the colors of these mollusks .Their tonalities range from dark red to gray tones, even mixtures some times, that make of them one of the most beautiful especies within the marine environments.
Many of their distinctive characteristics, make them stand out from others invertebrates, such as their tentacles, their long beaks and their mantles which are made up by a series of anatomical properties, that make of this animal a strange and unique species. So,it is quite important to know about every species of squids in order to differentiate them properly.,
These creatures represent a very important source of food both for their predators as for humans.
Unfortunately they are usually eaten by their predators with ease, excepting their elongated peaks which are not digestible.
Another striking feature is that they swim by employing their mantles which allows them to suction water.
In the same way, their bodies are protected by a shell that helps them to perform their movements quietly.
According to all the properties and characteristics afore mentioned, is easy to realize that these are stunning animal, full of 
many surprises.
Regarding their behavior, they tend to be lonely creatures, which only join other groups when they detect some type of danger or a nearby predator. They do so to protect each other and to get their food more easily.
There are three hundred species of squids that have been already identified and classified. However the studies that are being carried out on several invertebrate, could significantly rise this number.
These investigations have not been made so easy, since the species that are being studied, live in the depths of the ocean. The bioluminiscence of their organs, allows them to shine the water at night.
As far as their senses,we must start mentioning that their vision is quite developed, unlike their auditory system which does not work properly.
The squids are also considered as very intelligent creatures, since they are active and cooperate easily during hunting,.
The physical and biological appearanceis determined by the species..
In addition, their size is what gives them the ability to eat large amounts of food, especially meat; and they usually remain actives when they are looking for their prey.
They have a shell inside their bodies, which makes a big difference with other animals.
The squids also possess a syphon, which is an organ that they employ to release water under pressure, and at the same time helps them move quickly.
In terms of alimentation they are mainly carnivorous animals, which eat invertebrates and fish. They trap them by employing their tentacles. The alsohave the ability to swim fast when they are searching for their prey.
Finally, these weird and lovely creatures are also characterized by living in the depths, staying in these locations up to several years without being seen by their predators.
Let´s keep learning about this creatures
Head
This strange invertebrate animal has a head that exceeds the size of its body, it is symmetrical, flattened and bulging. Moreover it doesn´t have any similarity with the head of other marine animals. In general, the shape and size of the head, depends on the species.
Mouth
The mouth of the squids is so small , that sometimes is difficult to be distinguished. It is flattened with a long beak, and they use it to catch and devour their preys.
The radula which is similar to a tongue, is located in their mouth. This is common characteristic for all mollusks except the aplacophores and the bivalves.
Tentacles
The tentacles are those flexible and elongated organs, of which this kind of invertebrate boasts .They have 8 arms and 2 tentacles, which are a sort of sensitive organs, employed by the squids to sustain and to feed themselves. Squids of ten tentacles are also known as potas
Size and Weight
Generally the size of a squid depends on the species. The standard average of this species, when they are already developed , is about twenty centimeters in length, and we must point out the case of the giant squid, which can measure over 13 meters in length.
There is also the case of the colossal squid, that exceeds the giant squid. This species reaches more than 14 meters in lenght, which is why it is considered as the largest invertebrate of all. In addition the colossal squid, has the largest eyes, of any squid species, and its weight oscillates around five hundred kilograms.
Senses
The squid despite its characteristics and strange appearance, has an optimal development of all its senses, being the most prominent the touch, the eyes, the brain that is quite big, and the taste. They have a huge quality in terms of distinguishing flavors much more extensive and effective than human beings.
Life Expectancy
In general terms, the life of the squid is relatively short. They live between three to four years, even one year in some occasions. Not to mention, that they can be captured by a predator, before they even complete one year of life. However, despite all the unfavorable circumstances surrounding this species, specimens of more than fifteen years have been found.
The female squid is characterized by being able to release large proportions of eggs, even exceeding more than 70.000 depending on the species. Then the offspring develop in a period of three to four years.
Habitat
As we have mentioned before , there are more than 300 species of squid, being different each one of them, and with certain peculiarities that make them unique in their style. These invertebrate animals , are distributed throughout the oceans of the entire world, especially in the cold waters of the Antarctica where they find a wide variety of food.
The squids that settle down in the Antarctic eat preferably plankton and krill. In the same way they capture fish to complement their diet, since despite of their small size they can catch and devour big fish.
These mollusk adapt easily to any water regardless of its temperature, they can live either in brackish or sweet waters,surviving any lifestyle.
In general, those who live in great depths of the oceans are the giant squids, they can remain all their life in waters of different temperatures, either salty waters or sweet. The smallest species remain on surfaces.
Alimentation Habits
One of the advantages of the squids is that they can feed on different species. They can adapt to the different options provided by the different habitats where they live.
However, they gather in
immense flocks when they are searching for preys , so they can trap them in an easier way . The squids manage to adapt to the conditions and available food of any habitat, from cold habitats to tropical and subtropical climates.
These mollusk are totally carnivorous, and their diet is based on invertebrates and fish of different sizes. They don´t have any type of inconvenience with any other species, since they have their strong tentacles and a jaw provided with a long and powerful beak, which they use to destroy their prey with great ease.
These tentacles are made up of four rows of spiracles protected by corneas. These spiracles are flexible, long, flattened and wide, and they measure about six centimeters in diameter.
The squids are characterized by being solitaries and quiet hunters , they only group when they find areas of large amounts of invertebrates to support each other, and thus to tear them apart and share the food.
They have a very particular way of getting their prey, they swimm extremely fast and use their tentacles to hold and tear them apart, with their strong beak and with the help of their eight arms. They are animals with a huge ability to adapt to different areas, and to any type of meat-based diet.
Reproduction
The squids reproduce in big amounts due to their fast grow. As a result, there are immense families of these species distributed in all oceans, in spite of their short lives, and their continuous hunt by humans.
When it is time of reproduction to occur, these animals make up large groups of males and females. The process of attracting females begins in the mornings. At dawn they can be seen swimming rapidly in large circles.
The female has certain organs that allow her to make eggs, and she also has ovaries located in her visceral mass. In a different way it is the male who carries a bag containing spermatophores, which are placed in the female during the reproduction process. She usually dies after spawning.
Properties Of The Squids
The squids have a powerful nutritional content rich in proteins, which contain mostly large amounts of amino acids. Likewise they provide a fairly low level of fat, but a certain degree of calories. A single portion of 200 grams of squids, provides 162 grams of calories and 2.4 grams of fat.
The high content of cholesterol, is the only disadvantage of this marine species, thus it is recommended to eat it three times a week, preventing this way any kind of risks. Takes always into account, that this species provides many benefits, and few inconvenience.
These creatures also have a very high nutritional content, which includes minerals such as magnesium, manganese, potassium, zinc iron and phosphorus.
It contains an important part of necessary vitamins for the organism, such as vitamin B12, B3 and A.
Another interesting fact, is that squids don´t contain mercury, even though we know of the serious contamination that is currently found in the different oceans of the world.
Therefore this creature has all the necessary nutrients to maintain a balanced and a complete diet, due to its low fat content . These facts clearly shows, that the squid is a totally healthy food for the human body.
It is considered a perfect food for metabolism, due to its iodine content, which provides energy to the body, as well as the proper functioning of organic cells. It is recommended for diets, strengthening the scalp, nails, and to improve the functioning of the thyroid glands.
Types of Squids
At present about 300 species of squid have been identified, however the different studies that are being developed, will probably result in another 200 hundred species of squids. Following, we will name some of the most important types:
Vampire squids
The Vampire Squids are a little different from the others species, and it is easy to identify them because of their black color. They are characterized by having a black layer that covers their bodies, which makes them resemble the vampires. Their eyes can be blue or red.
Humboldt Squid
Its name is representative of its location, since they are usually established in the different Humboldt currents in the Pacific Ocean areas, the California Coasts, and can even be found in Washington, Oregon and Alaska.
Japanese Flying squid
This small invertebrate has a shape very similar to a projectile. Its upper end is formed by a long and beautiful mantle, with large triangular fins. One of the characteristics that make it different from the others, resides in its eight short arms. Moreover, its eyes are not easy to see at first sight. ( See the Article Flying Squids for Further Information)
Giant Squid
This is one of the largest and strongest squids among the marine animals seen so far. This creature can reach more the 13 meters in lenght ( See: Article Giant Squids for further Information )
Colossal squid
The Colossal squids exceeds in size the squid giant. It feeds on large fish, due to its strength it can easily catch them and eat without any problem.
Believe it or not!
Fishing Squids
Currently about three million squids are fished every year for commercial purposes. This fact is caused by the high consumption of this marine species, but at the same time, it represents a high risk for them.
The technologies that have arisen over the years in terms of their fish and commercialization has made it easier to trap them.
The trade of this species has been difficult to control, due to the large amount of money invested in this business.
It is important to make maximum efforts in favor of these marine animals, since in spite of not being in danger of extinction, their fishing and commercialization, should be ruled by the proper laws.
The squids represent a quite coveted food by humans, and for many species of marine invertebrates, who depend on them for their survival. These facts trigger the enormous concern regarding their preservation.
Take care of the waters, do not contaminate them with waste that harms all the marine species that inhabit the different oceans. A contaminated aquatic environment means, the decay of the squid and many other marine species, who could get sick and die.
Let´s learn about this practice as a hobbie
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Threats
The squids are not threatened, nor in danger of extinction due to their easy reproduction, a fact that really favors this species.
As we explained earlier, this species of invertebrate animals survive at least two or three years in the wild, being the food of many invertebrates in the depths of the oceans.
However, the protective laws that have been developed, for other marine species such as whales or tuna fish , should be also taken into account for this species.
In spite of their small size, the squids are able to face their main predators such as birds, large fish, and pinnipeds, among many other animals. They can even create a battle between their own species. However, the humans beings represent the most dangerous predators for these invertebrate animals.
In spite of not being included in the red list of endangered species, the statistics regarding their fishing are quite disturbing, due to the lack of the proper controls. Thus, it is necessary to develop the proper laws in order to control their trade, preventing this way their disappearance.
Actually the demand of squid is currently quite large, since huge amounts of these creatures are marketed in the course of a year. This fact results in the disappearance of trophic chains of different enviroments.
The pollution of the waters and the global warming, also represent a huge threat for this species. These two factors affect significantly their habitat, causing them to die due to the negative environmental impact .
The hope of counteracting all this problematic factors that affects the survival of the squids, depends on the awareness and concrete decisions,to establish protection parameters for these creatures. In spite of what they represent for the alimentation of other marine species, the proper environmental balance must be maintained, by means of the preservation of every species..
A latent threat for the squids is one of their same species, known as the Humboldt Squid, which in addition to attack sharks, at certain times also fights with other invertebrate animals.
Among the varieties of squid species we have the colossal squid, which is the largest one in the world. On the other hand we find the sepiolid squid, which has a measure of 2.5 centimeters with an approximate weight of seven grams, being the smallest squid of all.
There are still many things to discover about this amazing and strange invertebrate animal, as long as the researches continue. It is real interesting to discover; the wonders that surround this strange invertebrate animal.
The consumption of these mollusks is mostly carried out in countries such as Mexico, Japan and Italy, which are the biggest consumers of this species. Their threat has reached the limit of bringing great concern regarding their preservation within ocean waters, since these are the main sources of food for different species.
Squids and the Human Beings
The squids are very attractive marine creature for humans, especially in terms of consumption. Moreover, many studies are currently being developed about their lives. However, since they inhabit at huge depths, sometimes it is difficult to invetigate about them properly.
After saying so long, we want you to enjoy this video