Artificial reproduction of Pacu in Paraguay – Egg incubation

Photo credit: Ariel Montiel Benitez (Paraguay) Review: Ariel Montiel Benitez and Abdel Rahman El Gamal (Founder of the website)

Pacu (Piaractus mesopotamicus) is an important fish species with high commercial value in Paraguay. The availability of its fingerlings in a sufficient number would be essential towards the expansion of pacu aquaculture in Paraguay.

The inserted picture was taken at the Laboratory of Pacu in the National Center of Production of Alevines of Paraguay. The center is located in the city of Eusebio Ayala.

The picture shows a part of pacu reproduction as fertilized eggs are placed in netting incubators hanged in a rectangular tank. Tanks receive appropriate water flow sufficient to take waste metabolites out. Incubators are aerated in order to secure sufficient oxygen as required for developing embryos.

Under optimum water temperature of about 25C, hatching occurs after about 23 days whereas newly hatched larvae are nursed towards the production of fingerlings.


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In-pond raceway in Egyptian aquaculture (Video)

Video credit: Marcel Adaveleo (Madagascar) and Danial Osiyoye (Nigeria) Review: Abdel Rahman El Gamal (Founder of the video channel)

Historic information: As reported, the “In-pond raceway technology – IPR” was first developed in 2007 on a channel catfish farm in West Alabama, USA. Afterward, the technology was transferred to China in 2013 and then to more Asian countries including Vietnam, and India. Currently, the technology has been introduced to more countries around the globe. This video was filmed at the WorldFish Center in Egypt whereas Nile tilapia (Oreochromis niloticus) is the cultured species.

System description: The system relies on the creation of water circulation within the raceway units located in earthen ponds as well as on the removal of the organic wastes. The water circulation is done using paddlewheel aerators and/or air blowers. The use of low-speed paddlewheels provides a constant water current through the raceways. The aerators should be of capacity sufficient to create water flow of enough volume with particular velocity in the raceway cells which ultimately determines the frequency of water renewal within the raceway that in turn is a function of several parameters including the species, stocking density, and fish biomass.

In regard to the waste removal, the water and sludge are moved from the raceways into a waste-settling zone in the open pond from where the water is filtered before re-circulation, while the organic wastes are periodically collected using mechanical collectors. The organic waste products in the open pond are carried into the open pond area where they are processed naturally and at the same time stimulate the growth of natural organisms that in-turn becomes good food for other fish species especially in the open pond.

Typically, the raceways are constructed in parallel in a chosen corner of a traditional earthen pond with a center baffle to provide for a continuous circulation pattern around the pond and through the raceways. 

Advantages: The IPR as mentioned ultimately targets higher production of high-quality fishery products that result from the healthy environment that ensures higher growth rate and survival, efficient feed conversion ratio, and other production traits.

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Use of cribs in the organic manuring of fish ponds in Togo

Photo credit: Sabi Asma (Togo) Description: Sabi Asma and Abdel Rahman El Gamal (Founder of the website)

The structure shown in the corner of a fish pond in the inserted picture is typically used in the organic manuring in Togo as well as in other African countries. Instead of spreading the organic materials over the entire water surface, it is placed within the crib whereas the decomposition takes place and the nutrients are filtered between the bars of the crib and with the water current in the pond, the whole pond is fertilized.

This simple system is usually adopted in small-scale fish farms where farmers rely on organic manure. While only the nutrients dissolve into the water and used for the fertilization, the undissolved bulk of the manure remains within the crib and hence could be easily moved without disturbing the entire pond water.

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Shrimp culture in Guatemala – Video

Video credit: Alejandro Joachin (Guatemala) Review: Alejandro Joachin and Abdel Rahman El Gamal (Founder of the video channel)

The inserted video was filmed in a shrimp farm in Aldea El cebollito, Monterrico (Guatemala). The farm consists of three ponds of 1-ha each. The white leg shrimp Litopenaues vanammei is the species farmed in the farm.

The stocking density in this project is 250 shrimp PL/m3. As shown in the video, the shrimp ponds are furnished by paddle wheel aerators sufficient to maintain optimum dissolved oxygen throughout the growing season. The salinity of the farm water is 15 gram/liter. As the temperature in the region throughout the year suits the growth of this species of shrimp, four production cycles are practiced every year of a 12-week each. The biggest shrimp harvest is targeted in the month of April (Eastern week) whereas the maximum demand on shrimp occurs and so the highest market value. The average size of harvested shrimp is about 14 g.

According to FAO statistics, the total production of shrimp from aquaculture in Guatemala amounted 17,273 tons in 2018.

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Pit fish smoking in Chad

Photo credit: Saleh Abakar Oumar (Chad) Review: Saleh Abakar Oumar  and Abdel Rahman El Gamal (Founder of the website)

The inserted picture shows a simple traditional smoking facility in Chad that is made of a pit (hole) dug in the ground. The soil selected for the pit digging should be stable to help the pit keep its shape and prevent the pit from caving in. A metal mesh is placed over the pit above which the fish is placed.

The logs and so the fire are produced in the bottom of the pit. Bearing in mind the simplicity of such smoking pits, and the escape of generated smoke, the cooking time ranges from 12 to 24 hours depending on fish type and size.

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Promoting aquaculture in Namibia – Video

Video credit: Kaulo Salushando (Namibia) Description: Kaulo Salushando and Abdel Rahman El Gamal (Founder of the video channel)

This video was filmed during an official harvesting that took place in Fonteintjie fish farm which is a governmental farm. The harvest was covered by media and attended by the minister and top officials as well as invitees from the community including a number of school children who witnessed the harvest. The event targeted to promote aquaculture especially in the southern part of Namibia.

We can see that tilapia is the main species cultured in the farm along with some common carp.

The national strategy strongly advocates for aquaculture in that it empowers people, provides employment opportunities and provides food security for communities. It may worth noting that aquaculture in Namibia still in its infancy stage as according to FAO statistics, aquaculture in Namibia amounted 647, 626, 605, 587 and 472 tons during the years from 2014 to 2018 respectively.

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Small-scale aquaculture in rural development (2020 updated version)

I delivered this lecture in a regional short-term training courses held in Egypt during March 2020 and organized by the Egyptian International Centre for Agriculture (EICA) and titled “Small-scale aquaculture”. The course hosted 25 participants from 21 African countries.

The lecture starts with an overview on the features of rural communities focusing whenever applicable on fish consumption. The items needed for the promotion has been addressed including appropriate technologies, selected species, labor, credit when required and others. The introductory part has been followed by examples of small-scale projects especially those integrated with other agricultural crops or livestock.

The adoption curve in rural community has been addressed. Moreover, a proposed criterion of small-scale aquaculture has been discussed. The lecture addressed the promotion strategy and the importance of initial success as well as the sustainability beyond the promotion program. The Special issues have been emphasized in the lecture including extension service, project planning, environmental concerns, subsidies and others.

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Role of women in seaweed farming in Zanzibar (Tanzania)

Photo credit: Farida Mlaponi Mohamed (Tanzania) Review: Abdel Rahman El Gamal (Founder of the website)

Commercial seaweed farming started on Zanzibar (Unguja) Island in 1989 and expanded to Pemba Island and mainland Tanzania around 1994.  The seaweed strains of Kappaphycus were imported from the Philippines.

Tanzania Seaweed farming in Tanzania started commercially in 1989 and is mostly performed on the Zanzibar Islands (i.e. Unguja and Pemba) whereas the seaweed farming is currently the third largest industry that brings in foreign revenue (after tourism and the clove trade).

The available gender data revealed that 78% of seaweed farmers in Zanzibar are woman. The same trend occurs in the mainland Tanzania where about 90% of seaweed farmers are women.

It may be of interest to know that when the farming of seaweed started, almost equal numbers of men and women were engaged in different activities of seaweed farming. Afterwards, a gradual decrease in men engagement in the seaweed farming as the overall activities were believed to suit women more who showed enough patience and persistence with such new farming technology including seeding lines, tending lines, harvesting, drying, selling, etc.   Based on the success of women in seaweed farming, they are able to generate a stable income for themselves and their households. From social point of view, this work opportunity gave women elevated and more respected status in their households and communities.

Main reference: Flower E. Msuya & Anicia Q. Hurtado (2017) The role of women in seaweed aquaculture in the Western Indian Ocean and South-East Asia, European Journal of Phycology, 52:4, 482-494

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Pond culture of African catfish in Togo

Photos’ credit: Sabi Asma (Togo)     Description: Sabi Asma and Abdel Rahman El Gamal (Founder of the website)

According to a conducted survey, two production systems do exist in Togo with extensive system (about 88%) that is carried out in earthen ponds and reservoirs, while the semi intensive system (about 12%) is practiced in tanks and ponds.  The pond shown in the inserted pictures covers about 600 m2.

Among the eight fish species that are farmed in Togo, Nile tilapia (Oreochromis niloticus) and the African catfish (Clarias gariepinus) combined represent about 80% of farmed fish production in Togo. In fact, the consumption of catfish is moderately appreciated in Togo because there are certain populations which do not consume it. However, it is much more appreciated by Nigerians residing in Togo.

Catfish fingerlings are obtained from fingerling farms in Togo. They are stocked at a density that ranges from 3 to 5 fingerlings/m2. The feed provided is extruded compound feed. The grow-out period lasts about 6 to 7 months depending on the stocking dates and market availability. The average weight upon harvesting is about 750g/specimen.

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Machinery use in the construction of Egyptian fish ponds (Video)

Video credit: Herman Hennig (Argentina) Review: Abdel Rahman El Gamal (Founder of the video channel)

This video was filmed in 2015 during the construction of a fish farm in Egypt.

Typically, fish ponds in Egypt are constructed using different types of machinery that are required for excavation, compacting, levelling and dyke construction; bulldozers, rollers, tractors and may be others are used.

The average size of fish farms and so fish ponds justify the use of machinery in the construction and maintenance of fish farms. In fact, the gained experience over years encouraged the establishment of private enterprises capable to carry out the construction of fish ponds. In line with that and according to the official statistics by GAFRD, the land-based fish farms cover around 127,000 ha in 2017. This includes the governmental, private owned, private leased, and temporarily fish farms.

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