Sep 06 2012
This 2-slide information bite addresses the predation efficiency of Nile perch in relation to its characteristics especially its mouth and gapes. The bite touched the case study of the introduction of Nile perch into Lake Victoria and the impacts of the introduction. The predator-prey relationship has been addressed in this bite which is supported by representing photos.
Predation efficiency of Nile perch
Permanent link to this article: https://fishconsult.org/?p=5506
Sep 04 2012
Credit: Wanna Thawinwan (Thailand)
The three photos address the shrimp feeding in a typical fish farm in Thailand whereas technical and economic issues are considered.
Commercially formulated pelleted feed is used throughout the growing season. The pellet size and so its protein contents vary according to shrimp size as shown in the following Table.
|
Average size of shrimp (g) |
Protein content of feed |
|
0.002 – 0.25 |
50 % |
|
0.25 – 1.0 |
45% |
|
1.0 – 3.0 |
40% |
|
>3.0 |
35% |
The cost of a 25-kg feed sac ranges from 25-30 USD (price in August 2012).
Feeding is usually carried out three times/day whereas a boat is used to distribute the feed.
To avoid over feeding –or underfeeding- the feeding plate (tray) is checked 2 hours after feeding. Based on the level of feed consumption or left over, quantity of feed could be adjusted. Daily feed is used based on shrimp estimated standing crop and the feeding percentage of shrimp weight that declines as shrimp grows.
Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated.
Permanent link to this article: https://fishconsult.org/?p=5499
Sep 03 2012
Credit:Wanna Thawinwan (Thailand)
This photo shows a typical pond for whiteleg shrimp, Liptopenaeus vannamei in Thailand. The pond has a surface area about 16,000 m2 with a water depth of about 1-1.2 m. Shrimp farmer buys the farm requirement of shrimp post larvae (Pl 12) from a shrimp hatchery whereas shrimp are grown for 80-90 days. The paddle wheel aerators shown in the photos are turned on whenever dissolved oxygen is anticipated to drop such as during evenings or rainy days.
Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated. 
Permanent link to this article: https://fishconsult.org/?p=5485
Sep 02 2012
The export of octopus represents a significant portion of total fish export from Egypt. The octopus is harvested from the Mediterranean Sea whereas the export is carried by licensed establishments. A portion of the export is done at fresh form while most of exported octopus is at frozen form. The European markets are the key markets for Egyptian octopus especially Italy, Greece, Cyprus, Spain and Malta.
Note: Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated.
Permanent link to this article: https://fishconsult.org/?p=5476
Aug 28 2012
Rotifers by itself do not possess high nutritional value. However, because of their appropriate sizes to the small larvae such as those of marine fish, rotifers have been successfully used in marine hatcheries after been adequately enriched to meet the nutritional demands of target larvae for proper neural development. Brachionus plicatilis is a common rotifer in marine hatcheries.
Enriching rotifers is done by feeding the rotifers on the food which is required by fish larvae. In other words, the rotifers act as carriers to convey the nutrients from its sources and pass it to the end users (fish larvae). The types of enrichments although vary, it should meet the requirements of fish larvae. Also, the production economics and environmental concerns related to the enrichments should be considered.
The marine microalgae are widely used for enriching rotifers in marine hatchery. Their wide use is based on their richness in essential nutrients such as essential fatty acids, carbohydrates, sterols, protein and vitamins. Moreover, the use of microalgae such as “Nannochloropsis” does not lead to pollution (fouling) in the culture system as compared to the use of powders and emulsions. The nutritional merit of enriched rotifers will depend on the feed they have ingested. This meets the say that tells “rotifers are what they eat”.
Rotifers can be also enriched by feeding on a variety of small micron feeds. In such case, the resulting rotifer will have the nutritional profile of those feeds. It is believed that the last 6-12 hours of rotifer feeding will significantly determine the value of the rotifers.
Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated.
Permanent link to this article: https://fishconsult.org/?p=5464
Aug 27 2012
Credit: Claudia Turra (Uruguay)
This facility is located in Maldonado Department, Uruguay. It´s a company dedicated to the production of Red Claw lobster to gastronomic purposes, ornamental fish like goldfish and Koi carp, and fry production of black catfish (southamerican cathfish), grass carp and Madrecita de agua (Cnesterodon desemmaculatus). The photo shows the earthen ponds dedicated to lobster and fish fattening and fingerlings productions as well as the greenhouses used for lobster reproduction, hatchery and nursery.
Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated
Permanent link to this article: https://fishconsult.org/?p=5458
Aug 27 2012
Credit:Claudia Turra (Uruguay)
Esta ubicada en el Departamento de Maldonado, Uruguay. Es una empresa dedicada a la producción de Langostas Pinzas Rojas (Cherax quadricarinatus) con fines gastronómicos, peces ornamentales: goldfish (Carassius auratus), Carpas Koi (Cyprinus carpio), producción de alevinos y juveniles de Bagre Negro (Rhamdia quelen), Carpa herbívora (Ctenopharyngodon idella) y Madrecitas de agua (Cnesterodon decemmaculatus). Se pueden apreciar en la foto los estanques en tierra dedicados al engorde de langostas y peces y pre engorde de juveniles, además de los invernaderos donde se desarrolla la reproducción, incubación y nursery de langostas entre otros.
Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated.
Permanent link to this article: https://fishconsult.org/?p=5444
Aug 24 2012
These photos were taken in Riyadh fish market in March 2012. One of the photos shows a typical retail shop whereas fish displayed are almost marine and marketed as fresh fish. However, tilapia is sold in some shops as demanded more by foreign residents whether from Arab or South East countries. The main marine species include grouper, blackspot emperor, pomfret, and narrow-barred Spanish mackerel. Also, shrimp and lobster are displayed in these shops (shrimp is seen in the round tray on lower stands). While almost all marine finfish comes from capture fishery, a significant quantity of marine shrimp is locally farmed. Tilapia are locally produced through aquaculture (ponds, cages) and supplemented through importation.
The second photo shows from distance a retail fish shop with preparation facilities and as explained by the banner of the shop, grilling, frying and cooking could be prepared in this shop.
Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated.
Permanent link to this article: https://fishconsult.org/?p=5431
Aug 23 2012
Credit: Gabriel Salvo (Chile) Supplemented text: Abdel Rahman El Gamal
These photos were taken in the Municipal market “La Boquera”, Barcelona, Spain
The variety of seafood displayed in the two photos indicates the high per capita consumption of seafood in Spain.
One of the two photos shows oysters which are often eaten raw with some lemon juice. Oysters are also prepared as breaded or fried.
The second photo shows clams (mesh bag); Lobster (basket); Prawns named “cigala”. Salmon appears in the right bottom corner of the photo. The cigala is also called the Norway Lobster or Dublin Bay Prawn. They are found in the Atlantic Ocean, as well as the North Sea, but are not common in the Mediterranean. They are often prepared by boiling, cooked on a flat grill or fried.
Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated.
Permanent link to this article: https://fishconsult.org/?p=5418
Aug 23 2012
Image credit: D. S. K. Pitigala and Ananda sugathapala (SriLanka) Text: Abdel Rahman El Gamal
Background: the “stilt fishing” or ritipanna is a tradition fishing technique which is practiced especially around the towns of Kathaluwa and Ahangama, Sri Lanka. Historically, stilt fishing in Sri Lanka started after the Second World War when some innovative fishermen used discarded ‘iron poles’ to make stilts by planting them in the reef. Afterwards, timber poles were used and in fact were preferred by fishermen due to its durability and lighter weight especially when made of alstonia. The fishermen sit on a cross bar tied to a 3-4 m vertical pole planted about 0.5-1 m into the coral reef. Hence, the fishermen sit at a height of about 2 m.
Fishing techniques: The movement of the fish is the most important single element in stilt fishing. The fishing season starts when the fish return to the reef with the onset of the monsoon and extends till the end of the monsoon. The fishing periods during the day is related to the in and out movement of the fish during their nocturnal feeding and resting. Line and hook are the only gears in use in stilt fishing. Each fisherman fishes 2-3 times a day ending by the dusk as the fish leave the reef at sunset. The main species targeted are koraburuwa (spotted herring), and bolla (small mackerel).The catch is temporarily stored in a plastic bag tied around the pole or fisherman’s waist. Stilt fishermen realize that if reef fishes get disturbed, the may not come back for years. That is why stilt fishing is quite and very unobtrusive fishing method. The fishermen wait patiently for hours on their stilts for fish to come to their un-baited hooks.
Threats to stilt fishing: tourism carries most of the threat to stilt fishing. Tourists who visit the area get attracted by the sight of the stilt fishermen, stay close by, photograph, bathe in the sea and so breaking the quietness that the fishermen have been trying to maintain for decades. The expansion of tourism and tourists bathing have disturbed fish populations in some areas causing a sharp decline in fishing activity compared to earlier times. There is a concern of shifting this traditional practice into touristic attraction.
Note: We decided not to watermark the photos in order not to upset its clarity. However, we trust you will notify us if you wish to use a picture or more. This is expected and will be appreciated.
Permanent link to this article: https://fishconsult.org/?p=5407
