Swirl part upper Sombreiro River, Uppata Vi, Nigeria

_th place in Biotope Aquarium Design Contest 2020

Volume: 400lt
Dimensions: 155x45x60
List of fishes: pelvicachromis pulcher
Brycinus longipinnis
Hymenochirus sp
Polycentropsis abbreviata
Polypterus Senegalus
Xenomystus nigri
Aphyosemion bitaeniatum
List of plants: Anubias Barteri var.Nana
Anubias Barteri var.Barteri
Crinum Natans
Bolbitis Heudelotii
Description of decorations: All the materials used in the aquarium are collected from natural habitat of my region except from the roots which are imported ,(Malaysian driftwood red moorwood)
The layout consists of mixed fine quartz sand substrate with various forms of gravel and pebbles inside it ,lime stones collected from river streams different types and sizes, and also bottom leaf and organic litter collected from lakes and river banks.
Description of equipment: 1x 1500lt Eheim pump classic
1x 300w Eheim Jager heater
3x 30w Coolwhite Led floodlights
2x T5 sylvania grolux bulbs
Water parameters: temp:27c Ph:6.5 hardness: 8°dh
Additional info: the aquarium is well matured and balanced,routine water changes of 30% are planned every week without mixing/cleaning the bottom .The diet plan of the fish consists mostly of frozen foods (bloodworms,Artemia) and also dry foods in granules


Description of the area surrounding the biotope: The Niger delta region is one of the most-biodiverse center of the world that contain significant values of mangroves and diverse fish species in the world. The Sombriero River system is one of the most important river systems in the Niger Delta Basin, providing nursery and breeding grounds for a large variety of fish species. The middle part of the Sombriero River is located between the Degema and Akuku-Toru Local Government Areas of Rivers State. The communities around this river depend on it for their protein source and livelihoods as they are primarily fish food consumers and fishers.

The region which is represented in the aquarium is found on this coordinates :

5.020496, 6.665103

IT extends from the Egbema area of Imo State and meanders through villages and swamps
and empties into the Atlantic Ocean. It has its source from the Niger River, runs downwards into the Southern tip of the Niger Delta basin and empties into the Atlantic ocean. The Middle Reach of the Sombriero River is brackish and appears turbid during the raining season.

The vegetation of this area is made up of red and white mangroves (Rhizophora mangle and Avicenia spp., respectively), Nypa palm (Nypa fruticans), Ipomoea aquatica, Nymphea lotus, Mimosa pigra, Eichhornia natans, among others. This river is economically important as numerous human and economic activities take place within the study area. The area experiences two seasons: wet and dry seasons. The wet or rainy season occur between March to October with annual rainfall between 2,000 and 3,000mm per year. The dry season lasts from October to February with occasional rainfall (Ezekiel, 2002).
It is also worthy of mention , the behaviour of a native fish pelvicachromis pulcher for which this aquarium was set.
They are small sexually dimorphic with color dimorphism. Its sex ratio ranges from 0.75(females) :0.25(males) in the upper part of the sombrero river to 0.5(female):0.5(male) in other locations . The females have intensily colored belly. In the males , there are yellow and red colored morphs. About 50% of the red morphic males are pair forming ,while the other 50%males hold 2-3 females each in their respective harem; The only difference between the haremic and the pairing males is that the former is more aggresive.
The yellow morph develops into pair forming Male or becomes submissive parasitic satellite, when his partner or territory is lost. A few dominant satellites may,however, regain mate and territory. Briefly, the yellow morphic Male, as plastic reversible , can change its status from pair forming to satelite and satellite to pair forming Male.
Description of the underwater landscape of the biotope: At that part of the river there is mixed sandbed among with rocks which the stream spreads among the river..During the dry season and if the water level is too low and the current isnt strong ,regions of black-colored water might appear.
The leaf and branch litter provides an excellent living environment for the p.pulcher among with the hymenocheirus which find hiding spots..Big branches and roots end up ,at the bottom of the river providing lots of hiding spots and safety from predators ,and also place for the fry of the fish to grow.
The plants on the other hand appear as close as shown on the aqua scape…crinum natans with long leaves flowing among the stream and on the river bank
AnUbias species and ferns species (such as bolbitis.) Most of the time the plants are half covered from water dew to the wet and dry season( known as wet season ,it stars from april and lasts about the end of July aproxim.) Anubias and bolbitis are quite adaptive to this climatic changes so they survive in both periods..
Description of the parameters of the habitat: pH < 6.5; TA=10-l5ppm
Temperature :24/27 c
Tds(mg/l) 5.60 / 6.50
List of fishes and invertebrates occurring in the nature biotope: pelvicachromis pulcher
Brycinus longipinnis
Hymenochirus sp
Polypterus Senegalus
Xenomysrus nigiri
Aphyosemion bitaeniatum
Calamoicthys calabaricus
Pantodon bucholzi
Polycentropsis abbreviata
Gnathonemus Petersii
Tilapia Zill
Hepsetus Odoe
Hemichromis Fasciatus
List of plants found in the nature biotope: Rhizophora mangle and Avicenia spp., Nypa palm (Nypa fruticans), Ipomoea aquatica, Nymphea lotus, Mimosa pigra, Eichhornia natans
Threats to the ecology: When it comes in terms of ecology for the Sombreiro River we must take into account the following: Sombreiro river is the major source of drinking water for the natives. Like every other Niger Delta region has gone through devastation and marginalization over the years; a consequent of exploration and its attendant oil spillage, gas flaring and climate changeΟv .er 50% of the people still depend on the river water for their day-to-day activities (2Human activities at the river bank have tremendously increased vis-à-vis the population. The activities ranged from the washing and fermentation of cassava to the washing of clothes, bathing and defecation and the dumping of refuse and abattoir wastes.
There are also the inputs of solid wastes and effluents from the Ahoada Industrial layout. The shortage of water supply and the unreliable sources of drinking water within the
area encourages exploitation of the available source of water (The Sombreiro River) which is increasingly polluted. This study is necessitated by the prevalent occurrences of water borne diseases recently experience such as gastroenteritis, typhoid fever and dysentery. There is fear of the exotic chemical poisoning and gastrointestinal irritations that are associated with a plethora of chemical species from industrial activities and other municipal wastes in the Sombreiro River ecosystem.
Sources of information:

1. https://en.wikipedia.org/wiki/Pelvicachromis_pulcher#:~:text=Distribution%2C%20habitat%20and%20predators,Populations%20of%20P.&text=Other%20fish%20that%20share%20the%20habitat%20of%20P.
2. https://core.ac.uk/reader/11019660
3. https://books.google.gr/books?id=EtfMBQAAQBAJ&pg=PA266&lpg=PA266&dq=River+Sombreiro+Pelvicachromis+pulcher&source=bl&ots=2yPn_JBnMw&sig=ACfU3U18ysFvUZ-XLJ-ASzg2L_ZWrKNvIA&hl=en&sa=X&ved=2ahUKEwiFrfaMh4nqAhUF2KQKHV5wBFYQ6AEwDnoECAsQAQ#v=onepage&q=River%20Sombreiro%20Pelvicachromis%20pulcher&f=false
4. https://www.fishbase.de/summary/7778
5. https://www.academia.edu/19045561/Alternative_male_mating_tactics_in_a_cichlid_Pelvicachromis_pulcher_a_comparison_of_reproductive_effort_and_success
6. https://www.academia.edu/14006318/Water_pH_during_early_development_influences_sex_ratio_and_male_morph_in_a_West_African_cichlid_fish_Pelvicachromis_pulcher
7. https://www.ajol.info/index.php/jasem/article/view/188754
8. https://eol.org/pages/46572797
9. https://www.tfhmagazine.com/articles/freshwater/keeping-kribs-the-culture-of-pelvicachromis-cichlids-full
10. https://journalspress.com/fish-stock-status-of-the-middle-reach-of-the-sombreiro-river-of-the-niger-delta-basin-nigeria
12. https://www.thesprucepets.com/kribensis-1378289
13. https://www.gbif.org/occurrence/1265781795


15. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3201464

16. https://www.ajol.info/index.php/jasem/article/view/187512/176783
17. https://www.ajol.info/index.php/jasr/article/view/166725
19. https://medcraveonline.com/BIJ/BIJ-04-00163.pdf

Comments of the members of the jury of Biotope Aquarium Design Contest 2020