Confluence between Jhuoshuei River and its major tributary Qingshui River near Ershui and Zhushan Township, Taiwan

28th place in Biotope Aquarium Design Contest 2018

russia Taiwan. Jun-Xiu Chen

Volume: 110 L
Dimensions: 80x48x38 cm
List of fishes: Opsariichthys pachycephalus, Rhinogobius candidianus, Caridina multidentata , Neocaridina denticulata
List of plants: N/A
Description of decorations: This biotope is close to my hometown, the raining season at here usually is continuous few showers, when the rain has stopped, I observed the biota in the still water shoal and smooth flow of water, I used different size of rocks, pebbles, small gravels, black grey mud and “Clay soil” “Calcareous soils”, keep sludge and “filamentous algae”, “Phaeophyceae” in substrate, and those branches, roots, driftwood and rotting plants are collected on nearby shoal or stone seams.
Description of equipment: External filter MA-650 650L/H *1 , POWER FILTER 720L/H*1 , PL 55W*1 6500k.
Water parameters: Temperature is 28-29°C, pH is 8.

INFORMATION ABOUT BIOTOPE

Description of the area surrounding the biotope: Jhoshuei River as known as the Black River, with the total length of 186.6 km. Its flow source from Hehuan Mountain Main peak and East peak, with many river tributaries and it passes by the erodible rock which is slate, shale, sandstone, so it carries lots of sand. The middle reaches is located at the confluence between Jhoshuei River and Qingshui River which near Ershui and Zhushan Township, full of small river terraces and shoal.

Description of the underwater landscape of the biotope: I mainly observed the biotope on shoal, during the raining season the water level will reduce if the rain has stopped for few days, in order to avoid the predators those small fish and young fish will move to shallower area, few were carried by the heavy rain, so far there are “Spinibarbus hollandi Oshima”, “Zacco sp.(Opsariichthys pachycephalus).” and few unknown fresh water snail with caridina inhabited at this area, Alien Species is “Tilapia sp” and Native invasive species is “Spinibarbus hollandi Oshima”,There are large of amount of “Rhinogobius candidianus” biocoenosis inhabit at shallower layer of rapids. It provides food like “Insecta” “detritus” “filamentous algae” “Cladocera” “fish eggs” for them. Under the water you can see sandy soil with rocks, branches, water color is normal with highly mineral content and some sand, organic material. There are some driftwood and lots of wetland plants near the shoal.

Description of the parameters of the habitat: Dry season (October to March) when the water level reduced there are many rotten wetland plants and driftwoods in the shoals, water is clear only with small among of sand. Wet season (April to September). Upper river brings lots of water and driftwood to the middle and lower reach of river, water level rise up to submerge the shoal and small tributaries, watercolor becomes dark grey and highly full of sand, and due to the slate weathering and content of “Calcareous soils” from the upsteam of Jhoshuei River, the water PH is about 7-8ph.

List of fishes and invertebrates occurring in the nature biotope: Zacco sp., Rhinogobius brunneus, Rhinogobius candidianus, Misgurnus anguillicaudatus, Acrossocheilus formosanus, Gobiobotia cheni, Abbottina brevirostris, Hemimyzon formosanus, Carassius auratusauratus, Cyprinus carpio carpio, Paracheilognathus himantegus, Rhodeusocellatus, Caridina multidentata, Neocaridina denticulata, Alien Species is Tilapia sp. and Native invasive species is Spinibarbus hollandi Oshima.

List of plants found in the nature biotope: No plant underwater, there are Typha orientalis, Phragmites australis, Equisetum ramosissimum, Schoenoplectus wallichii (Nees) T. Koyama wetland plants, etc.

Threats to the ecology: Jhuoshuei River is the largest River in Taiwan, the construction of dam in upstream, flood control and bridge project, and due to the river brings clay soils which contain organic matter to middle and lower reach cause the river’s dry land has been cultivating around 24 % for agriculture purpose in years. import of Alien Species Tilapia sp. and Native invasive species Spinibarbus hollandi Oshima, those reasons all cause serious threat and change to Jhuoshuei River, Native species are becoming increasingly rare, I hope my biotope aquarium can help these issues get attention.

Sources of information:
https://tesri.tesri.gov.tw/show_report.php?id=611
https://www.wra04.gov.tw/12188/12189/12264/16104/16126/16129/
https://tesri.tesri.gov.tw/files/tesri_protect/tesri_queen_20101018122631/4.pdf
http://fishdb.sinica.edu.tw/
http://www.wracb.gov.tw/public/Data/6971157671.pdf

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