Jun 25 2015

Why PL12 is the recommended stage for shrimp grow-out?

Photo credit: David Kawahigashi (Thailand – David Kawahigashi – Vannamei101)

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

Whiteleg shrimp PL12

 

 

The inserted photo is for a batch of post-larvae 12 (PL12) of whiteleg shrimp (Litopenaeus vannamei) that are ready for stocking in grow-out facilities. From hatching, it takes about 21 days to reach the PL12.

The stages younger than PL12 do not have sufficient osmoregulatory ability to allow them to acclimate to low salinity water. Therefore, postlarvae held to PL12 in nursery facilities generally show more advanced gill development, which is important to acclimation to farm conditions and hence higher rates of survival which might average >60 percent assuming good environmental conditions.

Because most farming operations for L. vannamei are not furnished with nurseries, they receive the PL12 from shrimp hatcheries and introduce them directly in the grow-out ponds.

 

 

Permanent link to this article: https://fishconsult.org/?p=12739

Jun 24 2015

Commercial fish processing in Zambia

Photos’ credit: Alick Grunnie Mbewe (Zambia)

Review: Alick Grunnie Mbewe and Abdel Rahman El Gamal (Founder of the website)

Zambia processing (01) Zambia processing (02)

 

 

 

The inserted photos show the packaging section of one of the leading companies in Zambia that sells fish and fish fillets. This company was established in 1999 as a privately owned company whose core business is in the wholesale and distribution of fish and seafood products.

The major product lines include tilapia, “Buka Buka” (Lates stapperssii), horse mackerel, red dentex, Tanganyika sardine (kapenta) and assorted seafood.

The types of processing include gutting, filleting, and freezing. In most recently, the establishment commenced a canned Buka Project.

Tilapia required for the establishment is sourced from fish farms on Lake Kariba, Kafue River and from local rivers and lakes. Moreover, tilapia is imported from China, Thailand, India, and also from Lake Harvest, Zimbabwe.  The dry Kapenta is obtained from Lake Kariba and Lake Tanganyika. The horse Mackerel is imported from Namibia, while the seafood is imported from Namibia, Tanzania and South Africa.

 

 

Permanent link to this article: https://fishconsult.org/?p=12735

Jun 19 2015

Feeding caged salmon – Video

Video credit and permitted by: The Scottish Salmon Company

In this 1:30-min video, I would like to draw your attention to the monitoring system which allows the farm management to watch feeding activity in each cage and this would certainly help avoid overfeeding with its economics and environmental consequences.

 

 

Permanent link to this article: https://fishconsult.org/?p=12728

Jun 18 2015

Intensive tilapia aquaculture in Morocco

Photos’ credit: Walid Salah El Din (Egypt)

Review: Walid Salah El Din and Abdel Rahman El Gamal (Founder of the website)

Intensive tilapia culture in Morocco (01) Intensive tilapia culture in Morocco (02) Intensive tilapia culture in Morocco (03)

 

The inserted photos have been taken in a commercial aquaculture project in Tangier region, Morocco. The area dedicated for fish farming is about 28 hectares, on which tilapia and crayfish are farmed. The farm depends on the collection of water from rainfall and wells as the main water sources.

In regard to tilapia, Nile tilapia (Oreochromis niloticus) is the species used in the farm. Because temperature is relatively cold for extended period of time, most of production activities take place under greenhouses using closed system technology. In such intensive and closed system, the production reaches about 50 kg/m3 after a growing season of eight months. Feed used throughout various production stages is produced in the farm. The protein content of produced feed varies from 40%, 32%, 30%, and then 25% and this meets the nutritional requirements of different life stages. The production capacity of feed mill is about 300 tons/year. In one of the photos, the hatchery incubators are seen indicating that tilapia seeds are produced on the farm.

The production of about 600-g tilapia allow the filleting of a portion of the production (the largest), while the remaining harvest are sold as whole after being gutted.

 

 

Permanent link to this article: https://fishconsult.org/?p=12719

Jun 17 2015

Sturgeon nutrition and feeding

Photo credit: Facundo Marquez (Estuario del Plata – Uruguay)

Review: Facundo Marquez and Abdel Rahman El Gamal (Founder of the website)

Sturgeon feed in Uruguay

 

 

 

This photo has been taken in a commercial caviar producing farm in Uruguay. The feed mill shown in the inserted photo belongs to the farm and produced feed and feed ingredients are certified organic.

The followings are additional information related to sturgeon feeding:

The shape of sturgeon’s mouth and their body structure determine their feeding requirements. They are bottom feeders and hence in commercial operation they feed on sinking feed.

Although sturgeons have extremely poor eyesight, but they use their exceptional sensitive barbels and sense of taste and smell to locate and to track down sustenance. Moreover, their lack of teeth is being compensated by their extendible mouth which allows them to suck up their meal.

Depending on the size and nutritional requirements of cultured sturgeon, the feed throughout life phases enjoy protein content of about 40-45% while fat content ranges from 16-18%. The size of feed pellets varies according to fish size. Usually sizes of juvenile feed are 2mm, 3mm, and 4.5mm while pellet size for grow-out are 6 mm and 8 mm. Some feed mills add a known probiotic that is approved by the European Food Safety Authorities to improve survival and overall fish well-being.

 

 

Permanent link to this article: https://fishconsult.org/?p=12713

Jun 16 2015

Female fish farmer while managing her farm in Zambia

Credit: Numel  Phiri  (Zambia)

Review: Numei Phiri and Abdel Rahman El Gamal (Founder of the website)

Female fish farmer while managing her fish farm in Zambia

 

 

The inserted photo is taken in a small-scale fish farm in Zambia. The farm which belongs to a female fish farmer, has a total of 3 ponds; 2 breeding ponds (5mx5m) each and one production pond (20mx25m), the one in the photo.

Three tilapia species are communally cultured in this. These are Red breasted tilapia (Tilapia rendalli), Three spotted tilapia (Oreochromis andersonii),and Green headed breams (Tilapia macrochir). The hatchery is supplying the three species in a mixed form and hence farmers culture the species as received from the hatchery.

Like many fish ponds, the one shown has been dug into the water table thus is not easy to drain it completely. Therefore, the partial cropping is done for particular size. The average marketed fish size ranges from 250g to 300g.

No commercial feed is used in this farm that operates are under extensive management wheras natural food is the only source of nutrition. The production is about 1.4 tons/ha/year.

In general, women do contribute to on farm operations as most of the fish ponds are integrated with vegetable gardens.

 

 

Permanent link to this article: https://fishconsult.org/?p=12708

Jun 12 2015

Construction and management of a typical fish farm in Burundi

Photo credit: Nick James (Rivendell Hatchery – South Africa)

Review: Nick James and Abdel Rahman El Gamal (Founder of the website)

Construction and management of a typical fish farm in Burundi

 

 

 

 

The inserted picture shows an earthen fish pond under construction which is located near Bujumbura, Burundi. The average size of the pond in this private farm is 0.5 ha while water depth is less than a meter. The soil as shown in the picture is heavy clay and so the slope of the dikes is 1:2. The farm receives its surface water through irrigation canals. During operation, the only machinery used in the farm is two portable pumps.

The farmed species in this farm is the all-male of Chitralada strain of Nile tilapia (Oreochromis niloticus) which is commonly known as Thai tilapia.

Fish ponds are usually fertilized with chicken manure to encourage the production of natural food which is supplemented by brewery waste, rice bran, and fish meal (5%). Under the mentioned farming conditions, fish of about 250-300 g average size are harvested after about 5 months after stocking.

 

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12703

Jun 12 2015

Maintenance of cages in Lake Volta, Asuogyaman, (Ghana)

Credit: Patrick Appenteng (Ghana)

Maintenace of cages in Lake Volta

 

 

As cage aquaculture continues to boom in the Asuogyaman District of Ghana, more and more people get employment in diverse fields.

The insert shows a diver in a private cage farm in Lake Volta. His work primarily is to dive into the lake to check the conditions of the cages. This involves inspecting to see if there are thorn nets so they could be repaired immediately or changed as the case may be and inspecting of the cage anchors in the lake. He may occasionally double his work as a feeder too.

 

 

Permanent link to this article: https://fishconsult.org/?p=12699

Jun 09 2015

Dried “dagaa” in Musoma Market (Tanzania)

Photo credit: KIVA-API (build.kiva.org)

Review: KIVA – API and Abdel Rahman El Gamal (Founder of the website)

Dagaa in Musoma fish market (Tanzania)

Musoma is a small town located in the northeastern corner of Tanzania, right on the shores of Lake Victoria. The local market shown in the picture is close to the lake shore, where one can see a pile of small dried fish known as “dagaa” in Tanzania. This fish is the silver cyprinid, (Rastrineobola argentea). Quite often, dagaa is sold in such market by scoop. Dagaa fishing in Lake Victoria is done using light attraction during moonless nights where 10-mm mesh nets is the official size.

Unlike other small fish in Lake Victoria, “dagaa” –being a fast swimmer- was able to withstand the predation pressure caused mainly by the introduced Nile perch, (Lates niloticus). That is why “daaga” is not considered a threatened species by the IUCN.

Captured daaga is sold to traders from and marketed for human consumption, or fish meal production. Dried dagaa is produced by sun-drying which is often done by women. It takes one day or more to complete the sun-drying depending on the weather. The dried fish is marketed in local markets and/or sent to a major wholesale market for dried dagaa is in Mwanza, and from there it is transported all over eastern and southern Africa.

 

KIVA logo

 

Permanent link to this article: https://fishconsult.org/?p=12695

Jun 08 2015

Crab while eating Scallops; its favorite food – Video

This video was filmed in deep sea water in Scotland

Video credit: Grant Campbell (Scot-Hatch Ltd, Scotland)

Review: Abdel Rahman El Gamal (Founder of the video channel)

Crab eating scallop

 

 

Sea stars and crabs are generally thought to have the largest predatory impact on seeded scallops of a variety of species. During sea ranching, a population of seeded scallops may be reduced due to the predation within the sea ranching area. It is believed that the recovery rates of scallop should be at least 25% for scallop sea ranching production to be economically viable. Improving culture practices is usually attempted towards the increase of recovery rates. This issue is pf particular importance when we know that it can take 4-5 years to grow a large scallop (125-140 mm). It is believed that wild scallops may have better escape response than hatchery-produced scallops.

 

 

 

 

Permanent link to this article: https://fishconsult.org/?p=12691

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