A small clearwater forest brook emptying into igarapé Yavuari, Brazil

32nd place in Biotope Aquarium Design Contest 2018

croatia Belgium. Vern Van de Weyer

Volume: 200 L
Dimensions: 125x49x35 cm
List of fishes: Tucanoichthys tucano, Ivanacara adoketa
List of plants: N/A
Description of decorations: Driftwood to replicate the tree trunks and flooded tree. The bottom is coverd with a thick layer of leaf litter, I only used oak leaves to replace the ficus leaves from the biotope description. Also the small branches are from the oak tree. For the palm leaves i used the leaves of a dypsis lutescens beauces they look almost similar to the leopoldina palm. Underneat this al we got Jbl sansibar riversand.
Description of equipment: Eheim 2213 external pump with a spraybar, 120cm long for creating a lowflow of water. Lightning is from easyled.
Water parameters: Temperature is 25°C, pH is 6, KH is 1, GH is 3.


Description of the area surrounding the biotope: The Igarapé Yavuari is the first lefthand tributary of the Rio Uaupés down stream of the Tucano settlement of Açai, Amazonas, Brazil.
The Biotope loacality is approximately 300m above the mouth, approximately 300m SW from the camp site called locally “Yavuary”, on the right bank ca. 20 km above the mouth of the Igarapé Yavuari. The brook runs through a dense forest with ficus trees and leopoldina palms. Coordinates : 0° 14’ 31”N 68° 03’ 48” W.

Description of the underwater landscape of the biotope: The brook, 80-200cm wide, 50-120cm deep near the end of the dry season, runs rather swiftly in a through dense forest with Ficus (probably ficus Americana) trees en leopoldina palm, lies in the water as dominant plants. Dead wood mostly prickly trunks of palm are lying in the water, usually covered with ficus leaves, which also cover the bottom with a layer 50 to 100cm thick. No submerse plants only the branches and roots from emerse plants provide shelter for aquatic organisms near the surface. Probably to the rarity of predators the tucanoichthys tucano is able to swim in the shallow open water, and only hides in the ficus roots in the event of danger or spawning.

Description of the parameters of the habitat: Clear water with black water influence, extremely acid. End of february (ending of dryseason). Current 0.5-1m/sec. Temp air 29°C, temp water 26°C at the surface and 25.5°C at a depth of 30 cm, 24°C at a depth of more than 50 cm. Conductivity : 24 µS/cm. Ph 4.09. Oxygen 6.3mg/l.

List of fishes and invertebrates occurring in the nature biotope: The fish fauna seems quite poor in species. Only 6 species were collected in the brook. Tucanoichthys tucano, Ivanacara adoketa, Crenicichla sp., Amblydoras sp., Rivulus sp., Poecilocharax weitzmani.

List of plants found in the nature biotope: N/A

Threats to the ecology: Despite intense collecting in the area. Tucanoichthys tucano was found only along 200m of the brook, and nowhere else. If the area is someday populated and polluted, the species might be greatly endangered. Tucano Indians living in the upper Rio Negro and the Rio Uaupés area are already endangered. Less than 5000 members of their tribes survive nowadays along the bank of the Rio Uaupés, and their future is in doubt.

Sources of information:
