Igarapé do Daracua, shallow blackwater habitat, Rio Negro river, Brazil

_ place in Biotope Aquarium Design Contest 2019

Volume: 330 L
Dimensions: 120x50x55 cm
List of fishes: Uaru amphiacanthoides, Hemigrammus rhodostomus
List of plants: Rhizophora mangle
Description of decorations: The main driftwood used is red mangroves , the redish colour merges well with the tealike water and form a natural look , also i used live red mangroves (Rhizophora mangle) to replicate the little vegetation that is seen in the underwater footage and for the carpet of leaves i used catappa leaves which serve both for decoration but also as food (for the uaru) and source of tannins, the branches stretching from the surface of the water are dryed peach wood chosen cause it also has a reddish colour and adds a little diversity as seen in the wild. The substrate i used is 1-2mm aquarium light aquarium gravel.
Description of equipment: For filtration i use a 70Liter sump with 3 JBL Filter Foam(sponges) and aquarium cotton(for mechanical filtration), 4liters of Siporax and 2 liters of Eheim Substrat Pro(for biochemical filtration) , the lighting is provided by a DIY RGBW LED strip attached to the aquarium lid and a led lamp for the main area of the aquarium ilumination. 2 heaters are used one in the sump and one in the aquarium.
Water parameters: The Temperature is 28°C, pH varies between 5-6 , in the wild it can go even as low as 3-4
Additional info: I do 20-30% waterchanges weekly. And add water to compensate the for the evaporation daily if needed in the summer time. As for the decoration , i replace or add more leaves once a month.

INFORMATION ABOUT BIOTOPE

Description of the area surrounding the biotope: Rio Negro is the largest blackwater river in the world, its waters are similar in color to strong tea colour given by the decomposing vegetation. Igarapé do Daracua is a inaccessible place of the rainforest and it is located near Barcelos ,its name is given by the village near it “Daracua” accessible only by boat.

Description of the underwater landscape of the biotope: As the water rises during rainy season ,the large amount of leaf and plant litter forms a dense carpet, thiese along with the tree trunks and branches form a perfect habitat for fish to spawn , take shelter , feed and prosper. In my biotope im showing a group of jouvenile Uaru amphiacanthoides a couple of months old taking advantage of their camouflage( they look like a dead leaf ) and the surrounding crevaces made by the wood. Also the Hemigrammus rhodostomus are used by them as a warning mechanism against predators , since the Uaru are a “peacefull” fish, their diet being omnivore but mostly herbivore they get along very well with small fish and complement eachother.

Description of the parameters of the habitat: The water temperature ranges between 23 to 30 degrees C depending on the time of the year (rainy or dry season).The water is a dark tea-ish colour because of the tannins and the pH can go as low as 3-4.

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

List of plants found in the nature biotope: N/A The only plants present are flooded terestrial plants that i imitate with Rhizophora mangle.

Threats to the ecology: As for recent news people start throwing trash in the Amazon river and its tributarys , the materials that are not decomposing (plastic&others) endangers the unique biotopes and species of the Amazon , this along side with masive clearings of rainforest are a danger to the planet and us all.

Sources of information:
article: https://www.seriouslyfish.com/species/uaru-amphiacanthoides/
https://www.fishkeepingworld.com/rummy-nose-tetra/
https://weatherspark.com/y/28529/Average-Weather-in-Barcelos-Brazil-Year-Round
http://www.reef2rainforest.com/2017/01/09/biotope-video-blackwater-shallows-in-the-middle-rio-negro/

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