Early in the rainy season, forest creeks near Barcelus, tributaries of the Negro River, Brazil

16th place in Biotope Aquarium Design Contest 2019

China. Wang Peng

Volume: 276 L
Dimensions: 200×60×50 cm (depth of water 23 cm)
List of fishes: Nannostomus eques, Paracheirodon axelrodi, Hemigrammus bleheri, Dicrossus filamentosus
List of plants: No aquatic plants were found in the habitats I described, only some land plants that were flooded.
Description of decorations: The materials I chose were collected in rivers, riverbanks and forest parks. Some of them were purchased in China. Material includes drifting trees, branches, dried leaves (oak leaves), natural river sand, peat and coconut soil mixtures to simulate the soil on the forest floor. There are also streamstones of different sizes to simulate the riverbank scene.
Description of equipment: Filter equipment: ATMAN-CF1200 External Filter ×3 / Pre-filter ×3. Degreasing Film Filter ×2. Lamps: Netlea/Nitley LED 6500K 50W×5 / Spotlight 5W×2. Heating device: EHEIM IHAN heating rod 200W *3 (2 with 1 spare, no heating device used in summer). Others: oxygen pumps×1.
Water parameters: PH: 6.6, GH: 5, TDS: 7, Temperature: 25 ±1. PH: 6.6, GH: 5, TDS: 7.
Additional info: In my aquarium, I used a lot of driftwood, branches, dead leaves and a lot of soil to simulate the water and underwater environment of forest streams in the rainy season. I used three larger external filters and two pre-filters for both physical filtration and nitrifying bacteria culture. I use pure water and a small amount of domestic water to mix to ensure the balance of GH/TDS values, because there are a lot of driftwood and dead leaves in the tank, they can control the fluctuation of PH values very well. It’s easy for me to control algae growth by changing water and controlling light time. In daily maintenance, only changing water and cleaning the glass of fish tank. In the photos and videos, you can see that the fish are in excellent condition. They like the ecological environment I simulate very much, and I am very happy about it.


Description of the area surrounding the biotope: The Negro River, which means the Black River, is the largest tributary on the North Bank of the Amazon. Its source is the watershed between the Orinoco River and the Amazon River. It is connected with the Orinoco River by the Cassikiahre River. The Negro River is named the Guyana River in Colombia, its source, and its largest tributary is the Vopes River. The Negro River has a total length of 2252.6 km, a basin area of 620,000 square kilometers, an average annual discharge of 30,000 cubic meters per second, an average annual runoff depth of 1,600 mm and suspended mass concentration of 0.007/cubic meters. The largest tributary of the lower Negro River is the Broncou River, which originates from the Rofuma River at the junction of Brazil and Guyana, Brazil and Venezuela. Mountains (Roraima, 2772 m above sea level), the upstream is called Cotingo River, and the downstream is called Surumu River. There are two main tributaries in the upper reaches of the Broncou River: the Takatu River, a tributary of the Ireng River, which is the boundary between Brazil and Guyana, and the Uraricoera River, which originates from the eastern slope of the Parima Mountains on the border between Brazil and Venezuela, and its tributaries are the Auari River and the Paris River. Parima River, Uraricaa River and Majari River. The middle and lower tributaries are Mucajai River, Ajarani River, Anaua River and Catrimani River. From the Urariquilla River, the Broncou River is 1470 km long. It flows through northwest Brazil and southeast, accepting tributaries such as the Broncou River and pouring into the Amazon River 17 kilometers below Manaus. It’s about 2000 kilometers long. The river is winding and winding. The lower reaches of the river are sandy bars with a width of 30-50 kilometers, similar to long lakes. It is navigable below Taproquala. Through the Negro and Cassikiares rivers, the Amazon and Orinoco rivers are interconnected. The watershed is hot and rainy with few people. Because of the humus in the marshes along the coast, the river is dark.
One of the small tributaries is Igarap do Daracua, located near Barcelona in the depths of the Amazon rainforest. It is covered by rain and needs to be entered by boats. A large number of interlaced drifting trees and fallen leaves (close to dense trees) are accumulated underwater, and some mud flows into the river with the arrival of the rainy season.

Description of the underwater landscape of the biotope: The habitat I describe is at the beginning of the rainy season, when the water level rises and floods into the surrounding forests. Some of the trees are underwater, and fish swim in large numbers to parts of their native River habitats, completely covered by the canopy of the rainforest. Here, fish produce a lot of aggregation. There, abundant food sources were found and began to breed. Forests are the main source of natural food for juvenile and adult fish. The underwater environment also provides them with perfect habitats and shadows on the water surface to prevent overheating or even excessive drying during the dry season. The bottom bed is sandy, with a lot of drifting trees and fallen leaves and soil at the roots of flooded forests. Many branches are inserted into the water from the surface of the water, providing a good shelter for fish. No water plants were found in the environment I described, only some terrestrial plants submerged in the rainy season. Water carries a large amount of debris, which contains decomposed organic matter.

Description of the parameters of the habitat: The rainy season begins in September and ends in May. The temperature of water is about 22-24 degrees C and the pH value of water is about 6ph. In the dry season, the water level decreases and the temperature rises from May to September, and the water temperature is about 28-30 degree C. Because of the low water level, there are a lot of leaves and branches on the bottom of the river. The water contains a lot of tannins and dyes the water.

List of fishes and invertebrates occurring in the nature biotope: Crenuchus spilurus, Nanostomus eques, Poecilocharax weitzmani, Liosomadoras oncinus, Dicrossus filamentosus, Crenicichla notophthalmus, Mesonauta festivus, Acarichthys heckelii, Crenicichla marmorata, Heros notatus.

List of plants found in the nature biotope: At the location of the biotope I have described there are no water plants, except the forest flooded plants. The water plants that can be found in the nearby area are Echinodorus horizontalis, Echinodorus tenellus, Eleocharis sp.

Threats to the ecology: Because it was a dense forest stream, people could only reach it by boat, so he was not cut down and mined. But when it rains in the Amazon tropics closer to where humans live, their fate is unfortunate. The annual deforestation of forests has affected the lungs of the Earth. Global warming, deterioration of air quality, abnormal climate and frequent natural disasters. God is warning humans that if it continues, we may be slowly heading for destruction in the absence of winter or summer in many years. Please put down the logging tools in your hands, stop cutting down the Amazon tropical rain, and protect my natural environment.

Sources of information:

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