Production of all-male tilapia through hybridization – Video

Author: Abdel Rahman El Gamal (Founder of the website and video channel)

This 8-min presentation addresses one specific topic which is the use of hybridization in the production of all-male tilapia fingerlings. The presentation highlighted to role of tilapia in global aquaculture as well as the necessity of producing all-male tilapia. Hybridization among tilapia species being one of practices adopted for all-male tilapia production has been focused on starting with the sex-determining systems in tilapia ending by the outcomes and explaining why there are usually some tilapia females which could occur within the male progeny. A special part on the risk of hybridization in Africa has been presented. The presentation has been supported by related pictures and a diagram.

 

 

Permanent link to this article: https://fishconsult.org/?p=12238

On-going Cobia research in CENIACUA, Colombia

Photo credit: Andres Delgado (Colombia)

Review: Andres Delgado and Abdel Rahman El Gamal (Founder of the website)

On-going cobia research in Colombia

The tanks in the inserted photo are a part of the facilities that belong to the Colombian Aquaculture Research Center (CENIACUA), Punta Canoa, Department of Bolívar, Colombia. These particular tanks have been used for the captive breeding research on tropical and marine species; “Cobia”, (Rachycentron canadum).

The culture of cobia  which began in 2007 in Colombia, has gained popularity over time and hence called for the searching as well as staff training on areas of importance including diseases (especially during larviculture stage), broodstock management, live feed culture, and larviculture and grow-out at offshore sites.

A pioneering project on cobia aquaculture has been carried out in CENIACUA in collaboration with CEINER and the University of Miami in Florida (USA). This project is considered the first experience in mariculture in Colombia.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12234

California two-spot Octopus, Octopus bimaculoides (Description, feeding, reproduction, camouflage) – Video

This video was filmed at the Sea World, San Diego, USA

Source: www.fishconsult.org

 

Introduction: The California two-spot octopus (Octopus bimaculoides), also known as the “bimac” octopus, is an octopus species found off the coast of California (from central California to northern Baja California).

The species is normally found in the shallow areas of about 20-m depth so they can reach their preferred sandy bottoms with rocks and crevices for hiding. Although they may tolerate a wide temperature range (about 16 -26°C), their preferred temperatures would go from 18 to 22°C. One the average, these octopuses live for about one to two years old. They are considered the best pet octopus.

Description: The animal gets its name from its distinct appearance for having a dark ovoid deep-blue false eyespot under each real eye on each side of its head. This may be tricky to predators.The animal is not usually heavily textured and can grow up to meter long, including its mantle and outstretched arms.

Feeding behavior:Adults of the two-spot octopus usually feed on clams, mussels, abalones, small crabs, crayfish, and snails. They may also eat small fish when opportunities arise. The hatchlings feed on amphipods or mysid shrimp. This octopus is easily able to remove the shells from most of their prey. They can also circle and grab their victims using their tentacles and then immediately releases their toxic saliva into or near the victim.  This saliva instantly paralyzes the victim allowing the octopus to handle them easily.

On the other hand, the common predators of the two-spot octopus are California moray eels, California Sea Lion and several of large fish such as cabezon and leopard sharks.

Reproduction: Upon mating, a male octopus mates with as many females as possible. Few weeks after mating, the males die. Mature female lays strings of white eggs (in thousands) andfertilize their eggs with the sperm that the male has deposited into their body cavity. The female continuously tends their fertilized eggs for two to four months until they hatch. Throughout this period, females stop eating and while watching over their eggs, they got exhausted and die after the eggs hatch.

Camouflage: The common color of the two-spotted octopus is grayish with yellow spots on them. However, these animals are commonly is equipped with high developed color changing systems which are structures of their skin. They are also capable to eject out a cloud of ink when got threatened. Their outstanding ability to change colors and/or hiding enable the animals to blend with their environments, confuse and avoid their enemies. Being nocturnal with their sensitive eyes will enable the animal to benefit from the darkness cover.

 

Permanent link to this article: https://fishconsult.org/?p=12232

Fish smoking facility in Bambalang, Cameroon

Credit: Innocent Zambou (Cameroon)

 

Fish smokers in Cameroon (02) Fish smokers in Cameroon (01)

 

 

 

 

 

 

 

 

 

The photos show fish smokers that belong to the same operation.  These represent double oven Chorkor type with dimensions of 2m by 1m. The ovens are separated by an inner wall so that in case of less quantity of fish, only one oven can be used. This particular smoking facility is located near a lake in a locality called “Bambalang” in the North West region of Cameroon. The facility has been built by the government and managed by fishermen.

Fish caught from the lake are transformed to the smokers and then after the smoked fish are sold to whole sellers who carry it to different localities, in particular to the fish market which is held once a week. The commonly smoked fish are tilapia and catfish.

Consumers especially in village areas prefer smoked tilapia because of its affordable prices. In addition, smoked fish can be consumed over at least a week before the next market day. The type of wood used is mostly eucalyptus and other hard wood.

 

 

Permanent link to this article: https://fishconsult.org/?p=12227

Fishery co-management approach of Lake Victoria in Uganda

Photos’ Credit: Stella Nabayunga Walugembe (Uganda)

Review: Stella Nabayunga Walugembe (Uganda) and Abdel Rahman El Gamal (Founder of the website)

BMUs and enforcing fishery regulations in Uganda (02) BMUs and enforcing fishery regulations in Uganda (01)

 

 

 

 

 

 

 

 

 

The lake shown in the background whether is a part of Lake Victoria, Uganda. The photo shows the burning the confiscated fishing gears which belong to fishing violators. The burning of illegal gears which is the most common type of punishment is performed –in this particular case- by “Kasenyi” Beach Management Unit (BMU). However, other actions could be taken based on the BMU decision. Culprits may be sent to police, charged by fines or sent to court.

The Beach Management Units (BMUs) are legally empowered communities that serve as the foundation of fisheries co-management system that brings together all stakeholders working in fisheries at a given beach within fishing communities including boat owners, traders, processors, and boat builders & repairers as well as the traditionally marginalized communities within fishing communities which are namely women and boat crew.

The implementation of the BMU responsibility on fisheries management is done in partnership with the Central and Local Government Department responsible for fisheries regulations. In addition to enforcing fisheries regulations, BMUs have been also involved in the planning and data collection.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12221

Launching aquaponics in Egypt – Video

Video credit: Manuel Cano (Guatemala)

Credit for inserted photos and project details: Ashraf Goda (Egypt)
Review: Abdel Rahman El Gamal (Founder of the video channel)

This 7-min video skims the features of first aquaponic project in Egypt. The filmed project is affiliated to the National Institute of Oceanography and Fishery (NIOF). This project is located at about 25 km from Cairo at the Barrage (Kanater). The facility includes five earthen ponds for fish and greenhouse facility for the main aquaponic components (fish and plants). The project is furnished by a renewable energy system (photovoltaic) that is used to run the water pumps with a discharge capacity of 16 m3/hour. As shown in the video, plastic materials (tubing) act as a biological filter. During the first year of the project, more fish and plant species have been explored as candidates for aquaponic system under the project conditions. There are several aquaponic projects which have evolved during 2013.

Permanent link to this article: https://fishconsult.org/?p=12216

Sustainability of “subienda” fish stocks in Colombia – Video

Credit: Andres Delgado (Colombia)

Source: www.fishconsult.org

Sabaleta in ColombiaThe video was made during November 2013 in the municipality of Ricaurte, Nariño Department, Colombia. The day was the day of “subienda”, (Brycon henni) that belongs to the Characidae family. This benthopelagic/pelagic species is endemic to Colombia and found in Trans-Andean river basins of Colombia. During the spawning season, fish go upstream to spawn. During the spawning migration of the species, the residents (especially the youth) head to the nearest river for the easy catching of the spawners using sheets, nets or even with their bare hands. The event shown in the video was an educational event designed to educate people about the harm which their practice can cause against the sustainability of this fishery resource which has economic value when caught using fishing rod and bait. This species has also an economic value for aquaculture in Colombia.

 

 

Permanent link to this article: https://fishconsult.org/?p=12208

Cage culture of Asian seabass (Lates Calcarifer) in Thailand

Credit: Narin Songseechan (Thailand)

Cage culture of Asian seabass in Thailand (02)

Cage culture of Asian seabass in Thailand (01)The photos show small to medium-size cage farming of Asian seabass (Lates Calcarifer) in Thailand. The shown cages are placed in Khlong Koh Kui; Phuket province. The cage dimensions are 3×3.5 m with a depth of 1.5 m. Fish fingerlings are obtained from fish hatcheries (governmental). Fish are mainly fed on trash fish. Typically, the growing season lasts about 6-8 months allowing the fish to reach an average size of about 500-1000 g.  Produced fish could be marketed by the cage farmers or via fish traders. One of the photos shows an active role of women in cage management.

 

Permanent link to this article: https://fishconsult.org/?p=12203

Visiting some fishing activities in San Diego region

San Diego fish market (01) San Diego fish market (02)

That was nice to have some fishing activities in San Diego region. The information obtained will be developed into useful posts. The photo was taken in a Tuna Harbor fish market. Thanks to everyone who welcomed my questions and provided enough information. Andrea (who is in grade 4 and Ken in grade 8) are not only selling fish but they go in fishing trips with their father. In the second photo, Mr. Kawika who is a fisherman and I joined  in the fishery. Technical information will follow on series activities which are namely whale watching, marine fish farm, sea world and open fish market. Thanks. Abdel Rahman El Gamal

 

Permanent link to this article: https://fishconsult.org/?p=12197

Providing extension services to a fishermen community in Volta Lake (Ghana)

Credit: Patrick Appenteng (Ghana)

Fishery extension service in GhanaThis picture shows a boy operating a 12-15 m motorized canoe. Beckoning him at the other side of the Lake is a fisherman.  The extension officer who is the owner of the photo is on the seen boat on his way to disseminate extension services to a fishermen community across a portion of the Volta lake in the Asuogyaman District of Ghana.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12194

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