Paraná River, Brasil

_st place in Biotope Aquarium Design Contest 2022

Volume of aquarium: 240

Dimensions of aquarium: 150x40x40

List of fishes: Serrasalmus marginatus

List of plants: individual branches and leaves of trees

Description of Decorations and Substrate: have tried to maximize the design as in nature. The stones lie on the ground between leaves and branches. Also a large branch takes care of the water parameters. The substrate is a mixed substrate mixed with sand and small stones, just like in nature.

Description of Equipment: The aquarium water is filtered using a specially designed cassette filter with various fine-pored and coarse-pored sponges as well as biological filtration using large bio belle. A Jebao DCP 2500 pump is installed in the filter because it ensures there is enough movement of the water surface and in the event of a power failure Installed air lifter with diaphragm pump that comes on at regular intervals throughout the day. This keeps the bacteria cultures alive in the filter and thus prevents the filter from tipping over in an emergency of a power failure.

The built-in TUNZE NANOSTREAM 6055 flow pump also ensures circulation.

The water temperature is taken care of by a 250W heater built into the cassette filter.

A specially designed Led 2 zone lamp provides lighting on one
Aluminum profile 1100x160x20.
Equipped with PowerLed 1W only 6 pieces.
Colors used from 4500 and 6500 Kelvin.

Complete day simulation with sunrise and sunset including bad weather clouds etc.

Water Parameters: Ph 6
Gh 7
Kh 7
Temperature 24-28

Additional Info: The aquarium water is changed at 30% in a 7-day interval.

The water is taken from the pool by a pump system with approx. 13-15 watts and returned to the desired upper water level by a Gardena system with level control.
This avoids overflowing.

Aquarium video:

Description of the Area Surrounding the Biotope: The Paraná (Guaraní Parana) is a river in South America. It begins at the confluence of the Paranaíba and the Rio Grande at the point where the Brazilian states of Minas Gerais, São Paulo and Mato Grosso do Sul also form a triangle. After about 3200 kilometers to the south, it flows together with the Río Uruguay to the 290km long and up to 220km wide estuary of the Río de la Plata.

The catchment area of ​​the Paraná covers an area of ​​around 2.8 million square kilometers up to its influence in the Rio de la Plata. For the course of the Paraná together with the longer of the two source tributaries, the 1360 km long Rio Grande, a total length of 4880 kilometers is given.

Description of the Underwater Landscape of the Biotope: The river Ivaí is dark brown during the dry season. During the rainy season, the river turns into a torrent that regularly flooded parts of its catchment area. The riparian areas are thus flooded generously, so that large branches protrude into the water and thus offer the unique fauna a natural protection. For the competition, the water parameters were attenuated in terms of turbidity. Since the riparian area is heavily vegetated, branches, fruits and many leaves regularly fall to the ground, accumulate and form a thick layer and offer so many animals a wide food supply. Since the riparian area is exposed to strong changes due to different weather conditions, there are hardly any significant aquatic plants there.

Description of the Habitat Parameters: The water is medium brown to dark brown impermeable and slightly muddy, the normal temperature varies between 24 and 28 degrees Celsius. The pH values are between 7.0 and 7.8. The water depth is 0.3 m to 15 m.

List of Fishes and Invertebrates Occurring in the Nature Biotope: Known fish species are:

– Perch

– Piranhas or Pirañas (from Guaraní: Pirá=fish and aña=evil/devil)

– Surubi, a edible fish up to 1.5m long and weighing 50kg (see photo)

– Dorado, a large food fish

List of Plants Found in the Nature Biotope: In the place of the biotope, which I have described, there are no aquatic plants, except the forest-flooded plants.

Threats to the Ecology of the Biotope: As in almost all countries of the world, in Paraguay there is a stark contrast between culture and nature. Not so long ago, the systematic deforestation and slash-and-burn of the jungle began. Today, the largest area of the country is used for agriculture and there are almost no pristine jungles and other natural landscapes. For some years, however, even the government of the country has recognized that it is important to protect the remaining areas and to create “new primeval landscapes”. The nature reserves distributed throughout the country are a first step in the right direction.

Sources of Information: