Video credit: Charles Bernard Makuya Description: Abdel Rahman El Gamal (Founder of the video channel)
the superiority of tilapia males over females in regard to growth rate, several
scenarios are adopted towards the culture of all-male tilapia. Whether the use
of male hormone (17-alpha methyl testosterone) is permitted or banned, its use
is widely practiced in the sex reversal process.
In order for the hormonal treatment
to be highly effective, the treated fry should be at a very young age and hence
the hormonal treatment covers the period of sexual un-differentiation that
lasts 22 days for tilapia ending by all-male tilapia seeds that are targeted
for the use in farming operations.
While controlled reproduction through
the collection and incubation of fertilized eggs allows knowing the age of
hatched fry, and so the hormonal treatment is applied to known age of tilapia
fry and so, if all elements of the sex reversal process are properly applied, a
very high ratio of produced males is expected.
In regard to the mass spawning that depends on
the collection of fry, the age of fry cannot guarantee to be the optimum.
Instead, the size of fry is used to indicate its age. Based on the scientific
findings, the fry with a total length of 11-12 mm are suitable for the
sex-reversal process. On the other hand, the effectiveness of the hormonal
treatment on larger sizes produces questionable results. In order to have the
optimum results of the grading of collected tilapia fry, a grader with a 2.5 mm
opening (mesh) is recommended; the passed fry undergoes the hormonal treatment while
retained fry could be used in different farming systems.
Photos’ credit: Hassan Shettima Modu (Nigeria) Description: Hassan Shettima Modu and Abdel Rahman El Gamal (Founder of the website)
The photos show a type of fish smokers used to produced tilapia and African catfish. The consumer preference for smoked fish is high due to its taste, color and texture.
The smoker shown in the pictures is made of aluminum with insulator sheet. The bottom pot is used for loading the charcoals required for the smoking process. The smoker compromises of five to seven trays depending on its size. The capacity of shown smoker is about 50 kg of fish. Typically, a period of seven to eight hours is produced high quality smoked product.
Photo credit: Armando Romero (El Salvador) Description: Armando Romero and Abdel Rahman El Gamal (Founder of the website)
As shown in the photos, the tanks are above ground and constructed
using locally available materials especially the wooden materials. The tanks
are lined with plastic materials.
These aquaculture structures are used to grow
tilapia and act to train families on aquaculture. There is a governmental
program supporting this initiative.
Photo credit: Asma Sabi (Togo) Description: Asma Sabi and Abdel Rahman El Gamal (Founder of the website)
The inserted photo shows a cage
farming operation in Lake Nangbeto in Togo. The lake
is a man-made lake for hydro-electric power generation with a size of 18,000 ha.
farming was introduced in Lake Nangbeto by private investors. It is
believed that cage aquaculture in lakes such as Lake Nangbeto can contribute to
aquaculture production in Togo once found economically feasible especially in
regard to the high cost of fish feed.
Even though aquaculture in Togo
is still in its infancy stage with a production of about 25, 58 and 98 tons in 2014,
2015 and 2016, Nile tilapia (Oreochromis niloticus) is the leading
species representing 76, 69 and 54% of total aquaculture in the three mentioned
In the cage operation shown in
the picture, the fingerlings of tilapia are either produced in Togo or imported
from Ghana. The feed used is imported extruded pelleted feed.
The cages in this farm are square with 5 meters
for length and width while the depth is also 5 meters.
Video credit: Patricia Martin Cabrera (United Arab Emirates)
Review: Abdel Rahman El Gamal (Founder of the video channel)
The video was filmed is the premise of the British navy shipwreck
“Thistlegorm” located on the west coast of the Sinai Peninsula and 40 km from
Sharm El Sheikh. This 125-meter
steamship was built in 1940 and was launched in June 1940 and got sunk by two German
bombers on 6 October 1941 during the World War II.
Being well-preserved, the wreck is considered the most popular wreck in the world. It is estimated that more than one million people have dived the Thistlegorm that acts as a giant underwater museum whereas divers enjoy watching the amazing sea life especially this wreck is in a good visibility. Even though, the focus has been placed more on Crocodile fish, many fish species are present on and around the wreck including barracuda, scorpionfish, moray eels, lionfish, turtles and other aquatic life. In addition to the living organisms, the wreck hosts variety of its original shipment of motorbikes, automobiles, trucks, trailers, armored cars and others. Because the Thistlegorm was classified as an armed freighter, it is considered as a war grave that must be treated with diver’s respect.
credit: Marx Perfecto C. Garcia
Description: Marx Perfecto C. Garcia and Abdel Rahman El
Gamal (Founder of the website)
These fish cage modules are
a part of the Magat Dam Aqua-Park Project of the Bureau Resources of
& Aquatic Fisheries/ Cordillera Administrative Region (BFAR-CAR). The project is composed of the cage modules and a
floating house. Out of the 10 cage modules, nine have been established to
provide areas for the fisherfolk to conduct their aquaculture activities
towards improving their nutritional status as well as increasing their income.
It is used for grow-out of tilapia and carp species. The fish cage modules are
located within the Baligatan area of the reservoir. The fish cages are also
designed to withstand typhoons.
Each of the nine modules
has four cages, plus mooring
system, and service boats. Each cage has been stocked with 2,500 fish fingerlings. The tenth module has six cages
intended to be used as technology demonstration project of BFAR.
In order to
ensure the friendly nature of the operation, the alternate-day feeding strategy
has been recommended (skip feeding) which implies less feed provided and hence
reduced possible pollution. In addition to the environmental safety of such
approach, its economic feasibility has been reported.
Magat Dam, which was completed in 1982, is one of the largest dams in the
Philippines located in Ifugao. The Magat Dam and reservoir has a total water area
of 4,500 hectares. By law, about 10% of the area can be used for aquaculture.
Video credit: Marx Perfecto C. Garcia (Philippines)
Description: 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. Afterwards, the technology was transferred
to China in 2013 and then after to more Asian countries including Vietnam, and
India). Currently, the technology has been introduced to more countries
around the global.
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.
This video was filmed in the Freshwater
Fisheries Research Center (FFRC), Wuxi, China.
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 in the same time stimulate the growth of
natural organisms that in-turn become a 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.
The application of the IPR technology has been promoted as a means to enhance
aquaculture production of good quality fish and in the same time achieve a best
utilization of water resources. That is why the technology has been encouraged in
situations of water scarcity or high cost of natural resources such as land and
water especially when the intensification of farming practices is targeted.
Several species have been grown
in the IPR systems including and not limited to carps, channel catfish, paddlefish
and others. Because of the cost involved in the establishment and operation of
this system, high market value fish are often targeted.
IPR as mentioned ultimately targets higher production of high quality fishery
products that result from healthy environment that ensures higher growth rate
and survival, efficient feed conversion ratio and other productive traits.
Depending on the overall conditions
and practices, the increase of the system productivity has varied significantly
and ranged from as low as low as 50% to as high as 300%. Moreover, the
environmentally nature of the system, the no water discharge from production
ponds to outside eliminates the possible negative impacts to the environment.
The sustainable utilization of water resources is considered a key advantage
for the IPR system especially when compared to the traditional raceway system
depends on high-flow rate of incoming water with no reuse of discharged water.
The choice of the
raceway fish and the co-cultured species would vary depending on the production
target. An example for that is culture of channel catfish (Ictalurus punctatus) in the raceway
facility, while the paddlefish (Polyodon
grown as a co-cultured species in the open pond. In a production arrangement as
such, the main cultured species which is channel catfish enjoys the best water
quality in the raceway. Also, the open pond system provides a safe and
stress-free environment to the paddlefish (co-cultured species).
Description: Abdel Rahman El Gamal (Founder of the website/FB
Because the testes of the males of African catfish (Clarias
gariepinus) are situated in the dorsal part of the abdominal
cavity, and because of the anatomy of the species and the presence of the seminal
vesicle and internal organs block the flow of milt and prevent its release under
abdominal massage from live males in captivity. Thus, in order to obtain milt
for artificially fertilizing eggs, males are generally sacrificed before testes
are removed and squeezed to release the milt.
Losing a male catfish after another could limit their numbers
along with the possible production problems. Added to that, sacrificing catfish
males hinder particular genetic applications that require the repeated use of
the same male especially in the absence of cryopreservation facilities.
In order to avoid sacrificing the catfish males, surgical
operations have been successfully practiced. The operation begins with the
selection of sexually mature males based on their genital papilla.
Afterwards, the chosen fish is anesthetized usually in bath treatment to the
level that allows the surgical operation.Even though severalanesthetics
have been used, the Tranquil (Tricaine) MS-222 is the only anesthetic approved
by FDA for use in food fish.
Once the fish are totally anesthetized, the ventral side of
fish abdomen should be disinfected using a proper substance such as methylated
spirit (40% alcohol). Immediately after, an incision is made on the ventral
side of the abdomen using surgical scissors and the testes are exposed for
ablation whereas about three quarter of the testes were removed for the use in
the fertilization of catfish eggs.
The incisions are typically sutured in a way similar to
surgical operations. On the average, the surgical operation lasts about 10-15
min. An antiseptic medicine is used to treat the wound and skin infection. Afterwards,
fish are to be placed in anesthetic-free, aerated water for recovery which is
expected to take place within few minutes.
For a relatively long-term treatment, operated fish may be
placed in a tank containing water with antibiotics such as Oxtetracycline at proper
dosage for recommended period of time; 50mg/L for 5 days.
Operated fish should be fed high quality feed as
required for speeding the regeneration process of ablated testes which is usually
reached after a period ranging from as short as 30 days to as long as 120 days
from post the ablation. On the average, the operated male may be used again
after about 90 days and so on.
Photo credit: Franck Aristide (Gabon) – Description: Abdel Rahman El Gamal (Founder of the video channel)
The inserted picture shows floating cages located in Lake Mbolet in Gabon where Nile tilapia (Oreochromis niloticus) is the species cultured in these cages. The authorities in Gabon are encouraging the development of cage fish farming. It is believed that the new fish station that was inaugurated in July, 2013 and located few miles away from Lake Mbolet would support the development of cage fish farming in the lake. The station with its hatchery, food storage room, research laboratory and others has been constructed as a result of a partnership with the government of Japan.
Nathan Chama and Abdel Rahman El Gamal (Founder of the website)
The inserted picture shows a
woman while drying some Tanganyika sardine Stolothrissa miodon which is known in
Zambia as “kapenta”. The sardine drying takes place on the beaches of
Lake Tanganyika in Nsumbu area (Zambia). Dried kapenta fetches a good market price
in the mentioned area.
These sardines are freshwater species that belong to the family Clupeidae. They are planktivorous,pelagic and characterized by their small size with average length of about 7cm. The species experienced high level of overfishing in the last two decades.The dried kapenta being made from whole fish was found to be a good source for minerals and trace elements such as calcium, iron and zinc. Added to that, the dried kapenta is rich in vitamin B12 and other bioactive substances. The overall nutritive merit of the dried sardines makes it a recommended supplement for the improvement of maize-based diets.