Bank of flooded Morichal creek, Maripa, lower Caura River, Venezuela, 630 L

Bank of flooded Morichal creek, Maripa, lower Caura River, Venezuela

65th place in Biotope Aquarium Design Contest 2017

Indonesia. Andy Basuki

Volume: 630 L
Dimensions: 150x60x70 cm
List of fishes: Myloplus rubripinnis, Geophagus taeniopareius, Ancistrus sp (as a substitute for Ancistrus tenmickii), Agamyxis pectinifrons, Pterygoplichthys gibbiceps, Hyphessobrycon eques (as a substitute for Hyphessobrycon cf. serpae), Moenkhausia sanctaefilomenae (as as substitute for Moenkhausia oligolepis), Melanoides tuberculata (introduced/non-native species)
List of plants: Eichhornia crassipes
Description of decorations: A mixture of JBL River Sand and smooth silica sand as well as ADA Amazonia Soil was used to simulate the sand/mud combination that occurs in the Morichals. The mixture of different kinds of driftwood is used to simulate the roots and tangles of the riparian trees that are submerged during the high water period of the morichal creek. The different palm leaves that mostly belong to Chamaedorea sinensis are to simulate the fallen palm leaves of the palms that line the Morichal creeks, while the assorted leaves that are found on the substrate are to simulate the fallen leaves of Campsiandra laurifolia and Ocotea cymbarum that are found as riparian trees along the lower Caura river and the morichals that are in that area.
Description of equipment: External Filter ATMAN AT-3337 900 lph, bottom sump filter with flow pump rated 2400 lph. DIY LED lights (16 warm white @ 5W 10000K , 1 yellow @ 5W 8500K , 7 blue @ 5W 8500K , 7 green @ 5W 8500K, 4 red@ 5W 8500K ), Resun CL-260 chiller.
Water parameters: Temperature is 27oC, pH is 7.2, gH is 6, kH is 8. My natural tap/well water is naturally hard, so I use a mixture of distilled water and tap water and the addition of leaf litter, cattapa leaves, Sera Super Peat to try and reduce the pH but 7.2 is all I can manage. For achieving the water color, the Super Peat, Cattapa leaves and the assorted dried leaf litter and the use of AZOO Triple Strength black water extract as well as the addition of some ADA Aquasoil helps me to achieve the look I want. A Resun CL-260 Chiller is used to keep the temperature stable at 27oC as without it the temperature would normally be around 29-30oC.

Description of the area surrounding the biotope: The Caura River is a tributary of the Orinoco River, located in the State of Bolivar in Venezuela. Its flow is second to the Caroni River among the affluent of the Rio Orinoco with almost 3000 cubic meters per second (11.000 cu ft/s). The river drains the Guayanan Highlands moist forests ecoregion. The Caura River is about 723 kilometres (449 miles) long. Its major tributary is the Erebato. Both rivers emerge from the Jaua-Sarisariñama Plateau, more than 2,000 metres (6,600 feet) above sea level). The Caura is navigable up to Para Falls (Salto Pará), an impressive waterfall formed by two branches of the river with an island in the middle 6.310521°N 64.523735°W. Both branches have some rapids and join in one of the most remarkable waterfalls in the Orinoco basin, not because of its height, but because of the impressive flow of water. The Caura is a Blackwater river, like the Caroní, the Ventuari River and the upper Orinoco. The Caura is 1,500 metres (4,900 feet) wide at Musinacio (Musiú Ignacio), the point where it joins the Orinoco, 5.6 kilometres (3.5 miles) wide at this point. It is also one of the best conserved river drainages in all the tropics.
The lower region of the Caura River flows 270 km from the Para Falls (Salto Para) which acts as a natural boundary to river traffic and thus separates the fish faunas between the Upper Caura and the Lower Caura to its mouth at the Orinoco. The Lower river channel runs through rolling hills below the falls that give way to extensive lowland floodplains with numerous annual floodplain lagoons that flank the main channel of the Caura. Precipitation (rainfall) in the Lower Caura region is unimodal and the temperature is isothermic. According to Vargas and Rangel, a climactic gradient exists from North to South. In the Maripa region, it is dryer and hotter with a precipitation value of 1980 mm, temperatures of 27.7 degrees Celsius and a humidity of 75%. Forests are present in the lower Caura region, mostly consisting of Dry Tropical Forests but Humid and Very Humid Tropical Forests are also present as well. During the rainy season in June and July, the water depths of the morichal creeks including those near the Maripa increased moderately and some of the roots of not only the morichal palms but other trees nearby are submerged underwater as well providing shelter and refuge to many different fish species.

Description of the underwater landscape of the biotope: The flooded waters of the morichales contain some small rocks, though they are rare. The fallen leaves of the Morichal palms are often found in the rivers which are fallen from the trees and during this time, roots and fallen branches and leaves from the trees that are submersed during the rainy season are found as well. The substrate is of a mud/sand combination.

Description of the parameters of the habitat: The water in the Morichals of the Lower Caura is not your usual blackwater habitat unlike the Amazon and other areas. Suspended sediments are relatively low at 2 ∞ 106. The water is of a dark reddish-tea color which is of an average pH of 6.5 which is much more alkaline than the general blackwater habitats of the Amazon. Clarity of the water is high with an average transparency of 1.2 meters. Temperatures at this area average around 27.7 degrees Celsius.

List of fishes: Astynax bimaculatus, Ctenobrycon spilurus, Cyphocharax spilurus, Bryconamericus deuterodonoides, Charax gibbosus, Moenkhausia copei, Mylossoma duriventre, Poptella compressa, Roeboides affinis, Steindacheria argentea, Gymnotus carapo, Panaque nigrolineatus, Cochliodon plecostomoides, Pimelodus blochii, Andinoacara pulcher, Cichla orinocoensis, Astynax anteroides, Bryconamericanus hypheson, Iguanodectes geisleri, Microschemobrycon casiquiare, Microschemobrycon callops, Moenkhausia oligolepis, Moenkhausia browni, Melanocharacidium dispilomma, Lebiasina uruyensis, Caenotropus labyrinthicus, Hoplias macrophthalmus, Semaprochilodus knerri, Anchoviella guinanensis, Steatogenys duidae, Brachyrhamdia imitator, Heptaretus aff. tapaboiensis, Rinelocaria formosa, Megalonema platycephalum, Vandellia plazaii, Fluviphylax obscurum, Potamorrhapis guianensis, Geophagus taeniopaerius, Hypselecara coryphaenoides, Dicrossus filamentosus Microphilypus macrostoma, Monocirrhus polyacanthus, Hyphessobrycon cf serpae, Ancistrus tenmickii, Pterygoplichthys gibbiceps, Agamyxis pectinifrons, Aphyocharax alburnus, Brycon bicolor, Moenkhausia lepidura, Bryconamericanus sp ‘linea’, Hemigrammus schmardae, Melanoides tuberculata (introduced species)

List of plants: None, but many terrestrial palms and trees are present in the lower Caura River and especially near the Morichals. Palms such as Euterpe precatoria, Attalia maripa, Socratea exhorizza, Bactris brongniartii as well as the tree species Campsiandra laurifolia and Ocotea cymbarum are present in the banks of the lower Caura river morichals.

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