Brazil, Rio Negro, flooded forest at the source of a small igarapé in Cambeua

25th place in Biotope Aquarium Design Contest 2018

russia Ukraine. Bogdan Oleynik

Volume: 480 L
Dimensions: 160x50x60 cm
List of fishes: Paracheirodon axelrodi, Hemigrammus rhodostomus
List of plants: N/A
Description of decorations: The basis of the decorations is the roots of the vine, resembling flooded trees inherent in the area. The stone heaps are made of rock, which in form, texture and color are similar to boulders from a natural reservoir. The substrate of yellowish sand is identical in color and fraction to the sand of that area. The leaves of the alder cover the bottom of the aquarium, making a similar in appearance foliate litter characteristic for this biotope. Monstera deliciosa is widespread in this part of the continent, the roots of which are located right inside the aquarium, imitating plants that have fallen into the water after a flood during the rain season.
Description of equipment: Aquarium filtration consists of an external filter Fluval FX6, sump 90 L, phytofilter 56 L. Lighting: LED lamp 20W, 3000K, 1900Lm; LED lamp 20W, 4000K, 1900 Lm. Additional equipment: heater 300w, air pump.
Water parameters: The temperature is 26°C; KH is 7; GH is 9; PH is 6.5.

INFORMATION ABOUT BIOTOPE

Description of the area surrounding the biotope: Dense forests and vegetation like the wall hang over above a quiet water, creating an unforgettable impression of a forest that goes deep into the stream, as if hiding it from prying eyes. The ground at the foot of the trees is covered with a thick layer of dry, fallen leaves and branches of various sizes. A characteristic feature of this area that distinguishes it from other bodies of water is a large number of stone heaps, thereby forming blockages from the shores deep into the water. The trees circled with stones force their roots through solid obstacles, wrapping them and becoming one whole object for a long time. In my aquarium, this area is presented during seasonal floods, when the coastline is eroded and the water goes far beyond its borders, changing the landscape suitable for different species of fish. This small piece of nature, living its life and surrounded by picturesque landscapes, fascinates with its tranquility, frozen for a long time in this beautiful place without human intervention.

Description of the underwater landscape of the biotope: Igarape in Cambeua is a creek flowing in Brazil by the Rio Negro River in the state of Amazonas, half way between Manaus and Barcelos. Fish species such as Paracheirodon axelrodi and Hemigrammus rhodostomus are widely distributed in the flooded forests “igapo” and forest streams “igarapes” along the huge “black river” Rio Negro and its tributaries. These reservoirs are characterized by a shallow depth, slow current and a bottom covered with dense cover with the remnants of branches and old trunks. Such conditions allow them to live comfortably in relative safety and with abundant food. The photos shown in the video from the article “Cichlid Heaven in the Lower Rio Negro” were made by the author during the drought. They allowed me to take a look at the drained terrain which, during the seasonal floods, would go under water again. These photos were taken as the basis for my layout, since they allowed me to examine in detail the shore of the reservoir before it was under water. I wanted to show Igarapé in Cambeua during the period of seasonal precipitation, when a tiny and calm stream spreads beyond its boundaries at the foot of the trees surrounding it. Flooded forests, whose mighty roots stretch from the bottom to the surface of the water will become a new home for such species of fish as Paracheirodon axelrodi and Hemigrammus rhodostomus. They are forced to seek refuge in the new territories because of the change in the underwater landscape, which was caused by the current in connection with the arrival of new masses of water. Having lost their habitual way of life at the bottom among a thick layer of foliage and branches, they make school and despite of the danger rise into the water to explore new territories. This leads them to a stony site, made of a large number of boulders and leaves among the trees, whose thick roots pierce the ground deeply making them stand unmoved despite the changes of nature. As a single whole, as if one big fish, shimmering in red and blue hues, dozens of timid eyes search out in the flooded dense forests hiding danger for a quiet retreat for their future existence. The ichthyofauna of this reservoir is very well adapted to different conditions in this area. Paracheirodon axelrodi and Hemigrammus rhodostomus were no exception. Hundreds of years in the struggle for survival. Such harmless and small fishes, despite their peaceful nature, were able to choose their place in the wild.

Description of the parameters of the habitat: Contrasting sharply with the black waters of the Rio Negro and its many tributaries, the water in the Cambeua is not only free of brown hue but also cool: 23°C (75°F).

List of fishes and invertebrates occurring in the nature biotope: Paracheirodon axelrodi, Hemigrammus rhodostomus, Heros cf. efasciatus, Biotodoma cupido, Mesonauta festivus, Crenicichla lenticulata, Crenicichla marmorata, Cichla temensis, Cichla sp., Satanoperca lilith, Hypostomus sp., Leporinus klausewitzi, Leporinus fasciatus, Bryconops humeralis, Potamotrygon wallacei.

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

Threats to the ecology: About 12–15 million Paracheirodon axelrodi are exported annually from the reservoirs of Brazil, which is about 80% of the total volume of the ornamental fish market in this region (Chao 2001). This problem has led to the fear that if this situation is not changed, this species may be doomed to extinction (Bayley and Petrere 1990).

Sources of information:

https://drive.google.com/open?id=11qCTJs-jT_Uhha1zitqSe7YA4X1PlGTM
https://drive.google.com/open?id=18nZDn9AMlKprL52ZEOpUgOtFVf4Pg7kE
http://www.reef2rainforest.com/2016/12/09/biotope-video-cichlid-heaven-in-the-lower-rio-negro/
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672004000100009
https://www.seriouslyfish.com/species/paracheirodon-axelrodi/
https://www.seriouslyfish.com/species/hemigrammus-rhodostomus/

Comments of the members of the jury of Biotope Aquarium Design Contest 2018