Rio Demini, Upstream area near the community of Tabocal

67th place in Biotope Aquarium Design Contest 2018

russia Greece. Anastasios Fassaris

Volume: 330 L
Dimensions: 150x40x55 cm
List of fishes: Symphysodon discus, Dicrossus filamentosus, Nannostomus eques, Heros efasciatus, Mesonauta festivus, Hemigrammus bleheri, Corydoras adolfoi
List of plants: Eichhornia crassipes
Description of decorations: Combination of Natural Woods found in the natural habitat , fine sand gravel ,similar to that of the biotope , broken branches and leaf litter ,River stones.
Description of equipment: Internal Sump Filter ,1000lph pump, 300w heater, 2x45w T5 tubes lighting , 1x Led spot for moonlight effect.
Water parameters: The temperature at the aquarium ,is set at 29c with small changes that simulate the Rainy periods or the colder streams flowing through. The Ph is 5.2 with 4gh and 2kh.


Description of the area surrounding the biotope: The Rio Demini River originates in the Amazon rainforest of the state of Amazonas, Brazil and is part (tributary) of the river system of Rio negro. The Demini River rises in the Serra do Aracá State Park, a 1,818,700 hectares (4,494,000 acres) conservation unit created in 1990. It flows southwest through the park, then flows south to join the Rio Negro. The Toototobi River is a tributary of the upper part of the Demini near the headwaters of the Orinoco near the border of Venezuela. The Yanomami índios are native to this area. The Rio Demini rises in the Parima Mountains on the border with Venezuela and is 664km long to where it joins the Rio Negro.As was described by scientists there is a link via various waterways between the Demini and Xeruini.Except for its numerous meanders and names it is also noted for its aquarium fishes including dwarf cichlids. Its main tributary on the right hand side is the Araca which is 551km long(to where it joins the demini)and there are discus Habitats ,but mostly upstream to the Parana do Marium and Parana do Calado. The river has sandy beaches and has a rich but little studied Fauna and Flora along its uninhabited tributaries. The habitat of the aquarium simulates a natural Heckel Biotope wich can be found upstream of the River,near the Community of Tabocal.

Description of the underwater landscape of the biotope: Further upstream near its connection with Xeruini and Araca ,the river gets rocky with rapids and waterfalls..Although on its lower region the habitat seems to be more simplistic .
Near the shore ,under the acara-acu(psidium arboreum) roots ,is the home of various kinds of fish.The water flow is slow,plus the bottom is covered in leaf litter,broken branches and nuts fallen from trees which where carried away from the stream.. The coloration of the water is quite dim (tea-like)(except some times of the year that there is white-water) especially at the slow flow regions. The roots of the trees and plants existing at the surrounding ,are spread inside the water ,providing safety for the smaller fish ,and breeding sections..The fish spawn near the canopy of trees and have all the food they want,terrestrial insects, fruits and seeds. Some stones appear sparsely and fine sand covers the bottom.

Description of the parameters of the habitat: The parameters of the habitat are : water,usually tea-coloured ,with Ph range from 5~5.5 ,water temp 29~32 ,conductivity 4-6μS/cm ( max 20μS/cm ).

List of fishes and invertebrates occurring in the nature biotope: Symphysodon discus ,Pterophyllum Altum ,Dicrossus ”rio Negro”, Corydoras Kanai,Corydoras adolfoi Hemmigramus Bleheri , Nannostomus Eques, Heros Efasciatus, Mesonauta Festivus , Taeniacara Candidi,Dicrossus filamentosus Paracheirodon Sp. Hoplarchus Psittacus , Serrasalmus Sp. Demini Tucunare Paca.

List of plants found in the nature biotope: UNDERWATER/FLOATING : Not described ,except some floating plants like used. SHORE: Bertholletia excelsa,Dinizia excelsa,Clarisia racemosa,dilotropis sp, Psidium arboreum ,Euterpe Oleracea, Hevea spruceana, Macrolobium Multijugum.

Sources of information:
rio negro Flora information

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