Good day, dear readers! Today we will not talk about aquarium fish, plants and other very useful things, since I decided to make this post scientific-informative so that you can plunge into the natural habitat of aquarium fish.
In particular, I would like to introduce you to the great Amazon.
Amazonia got its name due to the mighty and deep river in the world – the Amazon. Although this river takes its beginning deep in the Andes, according to the official version, it takes its source at the confluence of the rivers Ucayali and Maranon.
The width of the river at the confluence exceeds three kilometers, and the channel depth is more than 40 meters. And at the confluence of the Atlantic, the width is altogether cosmic – 300 kilometers and more than 100 meters deep.
And there is nothing surprising in this, since for its very long way the Amazon absorbs the waters of more than five hundred rivers of various sizes.
Thanks to the vast territory, the diversity of the hydrochemical composition of water and the stable high temperature in Amazonia, an amazing diversity of the animal and plant world could develop. According to experts, according to their data, more than 3,000 species of fish inhabit the Amazon, most of which are well known to aquarists.
The waters of the Amazon can rightly be considered the house of catfish: according to the most modest data, there are more than 1,500 species of catfish in this river, starting from 5-cm little babies and ending with multimeter giants.
In view of the wide species diversity of the ichthyofauna in this region, a fairly well-established industry has been organized for the distribution and capture of a huge number of fish that are actively in demand among aquarists of various stripes. The scale of exports can be estimated only by one example: the city of Iquitos (Peru) has a population of about 250 thousand people, and more than 50 firms specializing in catching and exporting ornamental fish have been established in the city. It was found that annually these firms supply millions of fish.
But the first place in the export of aquarium fish is Brazil.
But the high level of capture and export has negative sides, since the fish that are most in demand by aquarists have reduced their numbers and narrowed their habitat, which ultimately will lead to their complete disappearance. Some South American countries impose bans and wildlife protection on capturing endangered ornamental fish.
But, before we start talking about catching fish, we’ll dwell on the hydrochemical characteristics of this region. Conventionally, all the rivers of the Amazonia can be divided into three main groups: with clean, dark and white water. White water has a low transparency and implies the presence in the water of a large number of small suspended particles of bio-organic and physical origin.
Among the major in this group are Madeira and Amazon. In color, their water resembles coffee with milk.
The average annual temperature in them is 27 degrees, and the total hardness from 1 to 1.5 degrees. The active reaction of the medium is near the neutral mark.
The waters of these rivers are inhabited by large and commercial fish species.
But, for aquarists, the inhabitants of rivers with clear and dark water are more important. In this region there are rivers Nanai, Itayo, Napo, Rio Negru, as well as a huge number of other small rivers.
The water in these rivers is famous for its transparency and high content of humic and tannin substances, which give the water a brown tint.
These substances are formed by plants, mainly leaves and bark, and when they die, these substances fall into the water. And since this region is covered with impassable tropical forests, it is not surprising that the water contains a large amount of humic and tannins. These two substances have one major feature – water purification.
Regarding the average annual water temperature, it also amounts to 27 degrees, but in these rivers seasonal fluctuations (3-4 degrees) are more pronounced, the rigidity is 1 degree and the pH is within 5.0 – 5.5.
These rivers are inhabited by all aquarists’ favorite discussions, tetras, small cichlids, loricarids and other very interesting fish. The reproduction of most ornamental fish in natural conditions is associated with the rainy season. If you watched documentaries, then you probably saw more than once what tropical showers are: a solid wall of water falls to the ground, which provokes a rise in the water level in the rivers up to a meter in a day, and during the rainy season the increase can reach 10 – 12 meters
As a result of this spill, boats become the main means of transportation in the Amazon jungle. As a result of showers, water is enriched with oxygen.
The concentration of humic acids increases with a slight decrease in water temperature.
As a result of rising water levels in rivers, some species of ornamental fish are grouped in flocks and gather near their spawning grounds. At this time, the real hunt begins for the most valuable ornamental fish.
Discus is caught as follows:
A small bay is chosen on the shore, preferably a cone-shaped form with a clean bottom. Then this bay is thrown by snags, large branches and trunks of trees. During the day, all kinds of organisms, especially freshwater shrimps, begin to gather in this bay.
Correspondingly, behind the accumulation of food, fish are also pulled up, which also find shelter among the pile of branches and trees.
Then the fishermen block the exit from the bay with a fine-meshed net, take out all the branches and snags from the bay, and then pull the net to the shore and catch fish with nets. Unfortunately, such an activity has a certain amount of risk, since, together with aquarium fish, electric eels and huge catfishes, which you do not want to meet, can enter the bay. The nets, as a rule, are torn up on rags, and the fishermen receive quite serious injuries.
Together with the discus, tsikhlazomy, scalar and other types of fish can be found in the nets.
Fishes that are in demand (and discus is always asked) are delivered to special aqua firms, where they are kept for several weeks in aquariums or adaptation pools, so that they are accustomed to a confined space, and then they are selected. Some species of fish are not caught, but simply collect their large eggs in special breeding grounds.
On aquafirms this caviar is incubated, and then young stock is raised for sale.
By the rivers with crystal water include Xingu, Tigre, Tapajos. The water in these rivers has a high degree of transparency, a weak yellow-green hue and a minimum concentration of calcium, magnesium, nitrate and carbonate salts. The maximum hardness of these rarely exceeds 0.5 degrees, and carbonate hardness tends to zero, the pH varies between 4.5 and 5.0.
The waters of these rivers are inhabited by corridors, American tetras and metinnis.