The oxbow of the Khorol River within the city of Mirgorod, Ukraine

_st place in Biotope Aquarium Design Contest 2022

Volume of aquarium: 150

Dimensions of aquarium: 100x50x30см.

List of fishes: Scardinius erythrophthalmus

List of plants: Ácorus cálamus, Scirpus radicans, Cárex aquátilis, Elytrígia répens, Setária víridis

Description of Decorations and Substrate: All filling for registration of competitive work is taken from a reservoir.

Description of Equipment: External hanging filter AQUAEL FZN-3 1200 l/h.
LED Spotlight 30W, 6500К.

Water Parameters: Temperature 5-9 degrees. The aquarium is installed in an unheated room.
Gh 23. Kh 16.

Additional Info: A very difficult aquarium at the start-up stage with low temperatures and a lot of organic matter. Changes every day during the first month at 50%. Thereafter twice a week. Ice placed at the time of shooting (thickness 5cm), lasted three days.

Aquarium video:

Description of the Area Surrounding the Biotope: Description of the river Khorol.
https://ru.wikipedia.org/wiki/%D0%A5%D0%BE%D1%80%D0%BE%D0%BB_(%D1%80%D0%B5%D0%BA%D0%B0)

Description of the Underwater Landscape of the Biotope: As the ice begins to melt in mid-March, the water level rises, flooding the coastal zone, making room for areas of ice-free water. In such places where there is a rapid saturation with oxygen and warming up of water, intensive reproduction of vegetation, plankton and protozoa begins. Which leads to a large accumulation of most types of small fish: roach, perch, rudd. The fish begin to stray into flocks for pre-spawning food. Coordinates 49.969757,33.596055

Description of the Habitat Parameters: The average water temperature is 3-5 degrees. A lot of last year’s withered plants fall into the spill area, which, having caught the spring warming, begin to release the first green leaves. The river is fed mainly by melting snow, so in the spring the water becomes much softer.

List of Fishes and Invertebrates Occurring in the Nature Biotope: Окунь речной ( Perca fluviatilis)
Плотва ( Rutilus rutilus)
Карась ((Carassius)

List of Plants Found in the Nature Biotope: Камыш (Scírpus)
Тростник ( Phragmítes)
Водная лилия (Nymphaea alba)
Кувшинка желтая ( Núphar lútea)

Threats to the Ecology of the Biotope: The threat at the moment for the river is global warming, lowering the level of groundwater, clogging of the riverbed and the inept use of chemistry in farms.

Sources of Information:
Own observations.
https://www.aquaforum.ua/showthread.php?t=286677