The bluefin tuna has the scientific name Thunnus, or as it can be known in other parts of the world bluefin tuna, bighorn or bigeye as they usually call it in some islands of Spain; It comes from the shores of the Atlantic Ocean both western and eastern, and sometimes you can find it in the Mediterranean Sea.
Characteristics of bluefin tuna.
Bluefin tuna is considered one of the largest fish in the world, what differentiates it from other tuna species are its fins; since it has two dorsal fins that can be yellowish or blue, and a second dark brown or red.
This type of fish can tolerate various changes in temperature, since corporally due to the skills that the pawns themselves can raise the temperature of their blood and endure very cold waters, which does not mean that this is precisely hot blood, can reach to submerge until about 900 meters deep to hunt their prey.
It can reach three meters in length and weigh at least 600 kg, its longevity can reach 20 years of life. Its anatomical structure is given by a robust body in its frontal part, very small eyes with respect to other species, its jaw contains small teeth formed in a single row.
In its dorsal part the bluefin tuna presents bluish colorations almost black with gray or greenish flashes that are completely eliminated after dying, it is a very active fish in terms of its swift and swift, it can reach up to 30 km / h, which makes it very capable of making migrations at large scales; in spring you can get to take refuge in warm Mediterranean waters to be able to reproduce, being in these times the most suitable for fishing.
Its longevity is varied and depends on the waters where it can develop most, many studies show that it can live between 20 and 30 years respectively, that is because it reaches adulthood very slowly; the same can vary there are species that are captured and bred in captivity and only able to live one 8 years barely manage to reach the stage where they can reproduce.
Other studies show that under normal natural conditions are able to exceed 30 years of age, which have coincided with several species that have 32 years of life, although even this type of events have not been fully confirmed. All this, as we mentioned before, will depend on the waters where it is most developed, since it is said that when it coexists in western waters it can survive for a longer time.
The behavior of bluefin tuna is based mainly on their constant migrations, which they carry out in order to search for their food and swim at a greater distance when they need to reproduce. In terms of feeding, they can form groups together with other tuna species and swim through the Pacific Ocean.
When the reproduction time ends, the male red tuna usually returns to the seas where they were born, to be able to conceive their young during the same territory, a single tuna can make several migrations swimming from the Atlantic Ocean and crossing all the Pacific in so Only 1 year.
The bluefin tuna is considered a powerful carnivore, because among its known migrations it can feed on a great diversity of fish and shellfish throughout the oceans that it travels like other types of tuna; among its most prized species are sardines, shrimp, mackerels, anchovies, herring, eels, octopus and jellyfish.
All of them caught in different areas where they look for food, do not consume them daily if we know something is that the bluefin tuna is very specific in what they will consume for their food, preferably they prefer to feed on small fish since they are easier and more practical to capture .
As for hunting big fish like eels, octopus and jellyfish; the bluefin tuna usually consume them when they are in their non-mature stage, since they can take better advantage of the size of these and it is easier to hunt them.
The maturity of bluefin tuna is reached between 4 and 8 years of longevity of the same, although not yet fully verified that specifically at that age begin to reproduce, many consider that this occurs a little earlier but has not been fully tested.
The reproduction of the tuna and of these in particular is usually done in the same places where the females then come after a time to release their eggs, even when they have to travel many kilometers for this, the bluefin tuna particularly always returns to the place where he considers his house .
There is no distinction between males and females, both can produce the same amount of sperm and eggs between them; so many have the ability to reproduce at the same time.
The female has the possibility of reproducing at least 10 million eggs which fertilize them two or three days after reproduction. The larvae that remain deposited in the water run with great risk because they are considered as food for other fish and even birds.
Although it is known that the female can produce a significant amount of these eggs, the few that manage to survive their home take the form of larvae and raise themselves until they reach their maturity stage, these young can weighing about 80 kilos and can move away from the area where they grew up grouping with other species of fish, which may vary according to the size they have, all this far from the care of their mothers.
The habitat where red tuna is commonly developed is mainly temperate waters, these range from the north Atlantic, crossing the Mediterranean Sea and reaching the Mexican coasts.
The temperate waters that this species prefers are of great help, since like other species of tuna and some sharks they must swim constantly to generate enough heat to keep all the organs of their body in perfect condition.
Its complexity in terms of the circulatory system of bluefin tuna we refer, is that it needs your body to reach temperatures above the waters where it walks, not to say that it is a warm-blooded fish, just do this to keep in better conditions your vital organs at the same time has the ability to immediately minimize the body temperature you have at the time and adapt to the waters in which it transits.
He likes more than everything to roam in the depths of these seas that are greater than 100 meters since according to previous studies they are better developed and can manage to capture their prey more easily, although in certain occasions this type of species manages to get closer eventually on the shore of said coasts.
Today a total number of the amount of bluefin tuna is unknown, we can only say that since 1996 approximately, the few statistics that were obtained were decreasing considerably. Prolonged hunting of this species mostly in Japan has increased, since the number of tonnes caught from bluefin tuna ranges from 15,000 to 30,000 tonnes per month.
Although it is a plan agreed by the foundations that preserve the habitat of the same does not prevent these figures may increase, the loss of large quantities of bluefin tuna is so significant that they have led to being on the red list of species found in Danger of extinction.
One of the solutions of many of the conservatives, is to take a certain number of offspring that are not yet in the adult stage and take them to captivity, with this implementation they have managed to conserve more than 15,000 species and many of the conservatives seek to increase these little figures little by little over the years, what they predict that in 10 years they can triple these numbers.
Although this type of practice only predicts a longevity of the tuna of 5 years many consider that adapting their conditions can be extended to a few years, since what is sought is that they can reach the adult stage and reproduce to make way to the greatest number of species.
The advantage of this type of captivity for bluefin tuna hatchlings is that they are not exposed to any type of danger, and the amount of eggs that the female expels will be approximately the same as that which survives under such conditions.