Dorado is one of the favorite fish among residents for its high palatability. And due to the ease of its artificial cultivation, in recent decades, more and more of this fish is exported, so it has begun to be actively consumed in other countries. Dorado is also well known in Russia.
Origin of the species and description
Photo: Dorado
The closest ancestor of fish is over 500 million years old. This is a pikaya – a few centimeters long, she did not have fins, so she had to bend her body in order to swim. The most ancient fish were also similar to it: only after 100 million years did ray-finned ones appear – dorado also belongs to them. Since the time of their appearance, these fish have changed very much, and the oldest species have long since died out, moreover, their closest descendants have already died out. The first bony fish arose 200 million years ago, but the species inhabiting the Earth now occurred much later, most of them after the Cretaceous period.
Video: Dorado
It was then that the evolution of fish went much faster than before, and speciation became more active. Fish became the masters of the seas and oceans. Although a significant part of them also died out – the species that live in the water column mostly survived, and when conditions improved, they began to expand back to the surface. Dorado arose one of the first in the Spar family – perhaps even the very first. But by the standards of fish, this happened not so long ago, at the very beginning of the Eocene, that is, a little more than 55 million years ago – the family as a whole is relatively young, and new species continued to form in it until the very Quaternary period.
Scientific the description of the dorado species was made by Carl Linnaeus in 1758, the name in Latin is Sparus aurata. It is from him that two other names come from, by which this fish is known: golden spar – nothing more than a translation from Latin, and aura.
Appearance and features
Photo: What a dorado looks like
The type of fish is memorable: it has a flat body, and its length is three times its height – that is, the proportions are similar to crucian carp. The head has a sharply sloping profile with eyes in the middle and a mouth with a slanted downward slit. Because of this, the fish always looks like they are dissatisfied with something. It grows up to 60-70 cm in length, and the weight can reach 14-17 kg. But this rarely happens, only in those cases when the dorado lives up to 8-11 years. The usual weight of an adult fish is 1.5-3 kg.
The color of the dorado is light gray, the scales are shiny. The back is darker than the rest of the body. The belly, on the contrary, is lighter, almost white. There is a thin lateral line, it is clearly visible near the head, but then it gradually becomes less and less visible, and is barely visible towards the tail. Sometimes you can see other dark lines running along the body of the fish. On a dark head, a golden spot stands out, located between the eyes. In juveniles, it may be poorly visible, or even not visible at all, but with age it appears clearly.
Dorado has several rows of teeth, in front it has rather powerful fangs, which speak of a predatory lifestyle. The back teeth are smaller than the front teeth. The jaws are slightly protruding, the lower one is shorter than the upper one. The caudal fin is forked, with dark lobes; an even darker border runs in its middle. A noticeable pink tint in the color is noteworthy.
Where does the dorado live?
Photo: Dorado in the sea
This fish inhabits:
- Mediterranean Sea;
- adjacent region of the Atlantic;
- Bay of Biscay;
- Irish Sea;
- North Sea.
Most of all, dorado lives in the Mediterranean Sea – they can be found in almost any part of it, from the very west to the eastern coast. The waters of this sea are ideal for golden spar. The waters of the Atlantic Ocean lying on the other side of the Iberian Peninsula are less suitable for him – they are colder, but a significant population also lives in them. The same applies to the other listed seas and bays – the waters of the North or Irish Sea are not as favorable for the life of dorado as in the Mediterranean, because far from such large populations live in them. Previously, dorado was not found in the Black Sea, but in recent decades they have been found off the Crimean coast.
Most often they live sedentary, but there are exceptions: some dorado huddle in flocks and make seasonal migrations from the depths of the sea to the shores of France and Britain, and then back. Young fish prefer to live in river mouths or shallow and low-salt lagoons, adults move to the open sea. The same with depth: young dorado swim near the surface, and after growing up they prefer to live at a depth of 20-30 meters. During the breeding season, they dive much deeper, at 80-150 meters. In addition to the wild dorado, there are also captive-bred dorado, and they are becoming more and more.
This fish was bred in the Roman Empire, for which ponds were specially built, but real industrial breeding began in the 1980s. Dorado is now bred in all the Mediterranean countries of Europe, and Greece is the leader in terms of production. Fish can be grown in lagoons, floating cages and pools, and every year there are more and more fish farms.
Now you know where the dorado fish is found. Let's see what she eats.
What does a dorado eat?
Photo: Dorado fish
Most often in the stomach of a dorado hit:
- molluscs;
- crustaceans;
- other fish;
- roe;
- insects ;
- algae.
Aurata is a predator that preys on other living creatures. Thanks to a large set of specialized teeth for various occasions, it can grab and hold prey, cut its meat, crush strong shells. With hunting adult fish eats also caviar – both other fishes, and congeners. It can swallow insects and various small crustaceans and fry that have fallen into the water. The diet of young dorado is similar to adults, the only difference is that they still cannot fully hunt serious prey, as well as split shells, and therefore eat insects, caviar, small crustaceans and fry more.
It is necessary to eat dorado algae if it was not possible to catch anyone – animal food is still preferable for it. You need to eat a lot of algae, so it is often easier to hunt and eat for a long time than to constantly eat algae. Nevertheless, they are also a source of important vitamins and minerals for fish. When artificially grown, dorado give granular feed. It includes meat waste, fishmeal and soybeans. They grow very quickly on such food.
Interesting fact: If there is another fish, also called dorado, which sometimes causes confusion. Moreover, it even belongs to another family (haracin). This is a species of Salminus brasiliensis, and it lives in the rivers of South America.
Character and lifestyle features
Photo: Dorado sea fish
Aurats differ from dolphins in that they usually live alone. Most of the time they spend hunting: they lie in wait for a careless fish to then suddenly grab it, or swim to the surface and collect insects that have fallen into the water. But most often they carefully examine the bottom of the sea, looking for edible crustaceans and molluscs. As fish hunters, golden spars are not so successful, and therefore the main source of their food is the benthic fauna, which cannot escape from them.
Often she has a different defense – strong shells, but dorado rarely manages to resist against the teeth. Therefore, they live mainly in areas of the sea with a shallow depth – so where they can explore the bottom. They move to deeper waters if there are large schools of fish that are easier to hunt. Dorado love calm, sunny weather – it is in this that they hunt and are caught most often. If the weather has changed dramatically or it has started to rain, then it is unlikely that they will be able to catch them. They are also much less active and if the summer is cold, they can generally swim away to another place where the weather is better, because they love warm water very much.
Interesting fact: When buying a dorado, you should check for freshness. The eyes of the fish should be transparent, and after light pressure on the abdomen, there should not be a dent. If the eyes are cloudy or there is a dent, then it has been caught too long ago or stored in improper conditions.
Social Structure and Reproduction
Photo: Dorado looks like
If a young fish usually lives in flocks near the shore, then after growing up it blurs, after which it already lives alone. An exception is sometimes those dorado that live in areas of seasonal migration – they swim from place to place immediately in flocks. Awrata is extremely remarkable in that it is a protandric hermaphrodite. Still young fish, usually not older than two years – without exception males. Growing up, they all become females: if earlier their gonad was a testis, then after this rebirth it begins to work like an ovary.
Sex change is useful for dorado: the fact is that the larger the female, the more caviar she will be able to sweep, and the caviar itself will be larger – which means that the offspring will have a higher chance of survival. But nothing depends on the size of the male. It spawns for the last three months of the year, and practically stops sleeping at this time. In total, the female can lay from 20 to 80 thousand eggs. They are very small, less than 1 mm, and therefore few survive – especially since many other fish want to eat dorado caviar, and it takes a long time to develop: 50-55 days.
If the caviar managed to stay intact for such a long time, fry are born. When hatched, they are quite small – about 7 mm, at first they do not look like adult fish and are almost helpless. Nobody guards them, so most of them die in the jaws of predators, mainly fish. After the fry grow up a little and take on a dorado-like appearance, they swim to the coast, where they spend the first months of life. Young, but grown up fish can already stand up for themselves and become predators themselves.
In artificial breeding, there are two approaches to growing fry: they are bred either in small tanks or in large pools. The first method is more productive – one and a half to two hundred fry hatch for each liter of water, because its quality can be very accurately controlled and made ideal for their breeding. In large pools, productivity is an order of magnitude lower – there are 8-15 fry per liter of water, but the process itself is similar to what happens in the natural environment, and resistant fish appears, which can later be released into the reservoir.
For the first few days, the fry feed on stocks, and on the fourth or fifth day they begin to be fed with rotifers. Ten days later, their diet can be diversified with brine shrimp, then vitamins, fatty acids are gradually introduced into it, microalgae are added to the water, and they begin to feed crustaceans. By one and a half months, they grow enough to be transferred to another body of water and feed on pelleted food, or to be released into a backwater or other environment close to natural.
Natural enemies of dorado
Photo: Dorado
This fish is large enough to interest large aquatic predators such as sharks, but small enough to fight them. Therefore, the main threat to dorado is they. Many types of sharks live in the Mediterranean Sea and the Atlantic: sand, tiger, blacktip, lemon and others. A shark of almost any species is not averse to having a bite of a dorado – they are generally not particularly picky about food, but they are clearly attracted to dorado more than other prey, and if they see this fish, they tend to catch it first of all. Probably, for them, dorado is the same delicacy as for people.
People themselves can also be written down among the enemies of dorado – despite the fact that a large number of this fish are bred on fish farms, the catch is also active. The only thing that hinders him is that the dorado live alone, so it is difficult to purposefully catch them, and usually this happens along with other species. But an adult fish is large enough not to be afraid of most of the predators living in sea waters. Much more dangers threaten caviar and fry. Caviar is actively eaten by other fish, including small ones, the same applies to fry – they, moreover, can be caught by birds of prey. Especially large of them also hunt for young dorado weighing up to a kilogram – after all, birds of prey, in general, cannot cope with already adult, large individuals.
Interesting fact: Dorado may be gray or royal – the second species has a more delicate fillet, colored in a slightly pinkish color.
Population and species status
Photo: Dorado fish
Dorado is considered to be the species with the least number of threats. This is one of the most common fish of this size in the Mediterranean, so its population is very large, and even active fishing has not undermined it. In other habitats, there are fewer dorado, but also a significant number. No reduction in range or decline in the number of golden spars has been noted, their population in the wild is stable, perhaps even growing. So, in recent decades, they have been increasingly noticed in waters adjacent to their usual habitat, but not previously visited. And in captivity, more and more of these fish are bred every year.
There are three main breeding methods:
- intensive – in various ground containers;
- extensive – practically free growing in lagoons and backwaters.
semi-intensive – in cages and feeders set up near the shore;
The difference between these methods is important, since the last of them is comparable with conventional fishing – although it is believed that the fish is artificially bred, in fact it lives under normal conditions and forms part of the natural environment. The fish kept in this way can even be counted as a normal population, unlike those bred in cramped cages. With a free content, often artificial feeding is not even carried out. Sometimes juveniles are reared under supervision and then released – as a result, the loss of fish due to predators is significantly reduced.
Dorado — an inhabitant of the warm waters of the Atlantic – a fish that is demanding on the weather, but otherwise quite unpretentious. This allows you to grow it in special farms in large quantities. But dorado living in natural conditions have to be caught one at a time, since they almost never stray into shoals.
