Shallow stream of Gorgulho da Rita in dry season, Rio Xingu, Para, Brazil

_ place in Biotope Aquarium Design Contest 2019

Volume: 100 L
Dimensions: 100x50x20 cm
List of fishes: Scobinancistrus aureatus, Ancistomus sabaji, Baryancistrus sp, Moenkhausia heikoi
List of plants: There are no aquatic plants except for the plants that are submerged during the rainy season.
Description of decorations: The pebbles, rocks and sands were all collected in the river. The shape and color of the selected pebbles, rocks and sands are basically the same as the habitat. At the same time, some fallen leaves and branches were found at the bottom of the river. The driftwood is very common in the Rio Xingu River. Loricariidae Family fish feed on this. I used rocks and sands of different sizes to imitate the hidden places in the habitat for Loricariidae Family fish to live. In addition to these fish, I also put some Moenkhausia heikoi as middle-layer fish to enrich the species in the aquarium. In my aquarium, different fish can find almost the same environment as in the habitat. Scobinancistrus aureatus, Ancistomus sabaji and Baryancistrus sp. live in the shelter area, while Moenkhausia heikoi swim in the open area. There is occasional intersection between them, just like going to the house as a guest, lively and interesting.
Description of equipment: EHEIM compact+ 3000 pump (3000L/h)
Kessil 360x Tuna Sun 90w (6000k-9000K color spectrum)
Laoyujiang CX-W3 55w Natural Wave Pump (20000L/h)

The color spectrum of Kessil 360x Tuna Sun spotlight is closer to the sun. The shining light can more prominently show the relationship between the ripples of the water surface and the underwater objects.

I carefully designed an annular water flow system for these fast-flowing stream fishes. The bottom of the aquarium is vacuum. A natural wave pump is placed on the one side of the bottom. Under the thrust of the wave pump, the water flows out from the other side of the bottom of the aquarium and enters the top of the tank, returning to the starting point under the action of the water flow, which forms a water circulation inside the cylinder. Since, the flow rate in the tank is very fast, just like the habitat I described, these fish can live in my aquarium in the same way as they do in the nature.
Water parameters: The temperature of the water is about 28 ℃. pH=6.3 to 6.7 and GH=3.
Additional info: No


Description of the area surrounding the biotope: The Rio Xingu River is in Para State in the central part of Brazil. It is formed by the source of several rivers. The river generally flows northward and is injected into the Amazon River just south of the island of Ilha Grande de Gurupa, which is about 2,100 kilometers long. The upper course of the Rio Xingu River is gentle, with a rapid stream at the north of the 10° south latitude; the downstream river is wide and deep. The Rio Xingu River is a large tributary on the right bank of the Amazon River, flowing through the states of Barato and Mato Grosso state, Brazil.

From Sao Felix to Altamira, the length of the river is 500 kilometers, with a total drop of 95 meters. From the 16km long section of the Altamira, it is a very sharp corner. For the Volta Grande corner, the total drop is 85 meters, with an average of 0.53 meters / km. The number of plant species in the basin is the highest in the world.

Many large trees are more than 60 meters high and cover the sky. Therefore, the ground of the dry forest is bare and there is only one layer of decaying foliage. The forests in the depression are very different, and the shrubs and trees have slab-like roots that help to survive. Kudzu, orchids, and bromeliad plants compete for high growth, with monkeys, sloths, hummingbirds, diamonds, parrots, giant butterflies, and countless bats. The water is home to caiman, freshwater turtles, and aquatic mammals such as manatees and freshwater dolphins. Lands are home to jaguars, western, lynx, capybara, and crickets. There are also 2,500 species of fish.

Description of the underwater landscape of the biotope: Rio Xingu, located in the states of Pará and Masto Grosso, Brazil, is not only a treasure trove of tropical fish in South America, but also a rich species of fish (especially the Loricariidae Family fish), which is the most famous origin of freshwater fish in the world. During the dry season, the underwater roots are exposed, and underwater stones are common here. The color of the stone varies from black to blue to purple, depending on the condition of the sun. Many fish will gather behind the stones, avoid the water, and still eat all the food that passes. Loricariidae Family fish also often hide in the cracks of the stone.

Description of the parameters of the habitat: Water parameters in dry season: pH: 6.0-6.7, GH: 1-3, temperature: 26.3-34.6 ° C, measured at a depth of 30-100 cm.

List of fishes and invertebrates occurring in the nature biotope: Hypancistrus zebra, Baryancistrus sp, Ancistomus sabaji, Scobinancistrus aureatus, Moenkhausia heikoi, Geophagus argyrostictus, Leporinus friderici, Hemiodus vorderwinkleri

List of plants found in the nature biotope: There are no aquatic plants except for the plants that are submerged during the rainy season. Podostemaceae grows in those small waterfalls. They bloom and develop fruit in the dry season and even self-pollinate. Seeds attach to the rock through the biofilm of the bacteria. They are important to the ecosystem here. There is almost no aquatic plant in this rushing river.

Threats to the ecology: Deforestation As in many other parts of the world, habitat destruction is sad. As the population grows, the demand for land is also greater. The construction of the Belo Monte dam also destroys the large natural environment. Once the habitat was submerged, the river’s direction has also changed. Only the future will explain how this affects all animals living here. The area on the other side of the Belo Monte dam no longer exists. This area is now being flooded. It has now become a large static reservoir. This fast-moving part of the river is home to many endemic fish, which happens to be one of the worst-affected areas after the dam started. I hope that such a place will continue to exist in the future.

Sources of information:

Comments of the members of the jury of Biotope Aquarium Design Contest 2019