Mar 06 2017

Diving the Blue Hole (Dahab – Egypt) and this marvelous octopus specimen (Video)

Video credit: Patricia Martin Cabrera

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

This video was filmed during a dive at the Blue Hole, Dahab (Egypt).

Blue Hole and octopus

 

 

One should look carefully to identify this beautiful specimen of common octopus (Octopus vulgaris) with its marvelous green color that makes the animal blends with its surroundings. Using camouflage is considered among the unique traits which the animal adapts in order either to not to be detected or not to be seen at all. If interested, more information on the biology and habits of this animal could be accessed on: (http://fishconsult.org/?p=9100) on this website.

The “Blue Hole” diving location is located a few Kilometers north of Dahab, Egypt on the coast of the Red Sea. This area has a rich and unique marine life and reef. The “Blue Hole” itself is a submarine sort of cave, around 130m deep. There is a shallow opening around 6m deep, opening out to the sea and a 26-m tunnel, known as the arch, the top of which is 52m. The Blue Hole itself and its surrounding area have an abundance of coral and reef fish.

The Blue Hole is known for the number of diving fatalities. Accidents are frequently caused when divers attempt to find the tunnel through the reef (Arch) connecting the Blue Hole and open water at about 52m depth. 

Even though, the Blue Hole in Dahab is considered a challenging and maybe a dangerous diving site, it attracts divers who seek adventures. Divers who decide to experience the famous Blue Hole need to be well informed, and well prepared especially The bottom of the hole lies at 100+ meters and you will need great buoyancy skills and enough experience to decent in a controlled manner and to stay within the limits divers are trained to.

 

 

Permanent link to this article: https://fishconsult.org/?p=13885

Mar 03 2017

Sabalo fishing in Pilcomayo River (Bolivia)

 

Photo credit: Rory Felix Mamani (Bolivia)

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

Sabalo fishing in Bolivia

 

 

 

The inserted photo shows indigenous people from the Weenhayek population during the fishing of  “sabalo” in Pilcomayo River using “cabbage nets”.

In Bolivia, Sábalo is the common name of an Amazonian fish that enjoys a good cultural acceptance and means so much as for a part of the local diet and income generation.

It worth mentioning that sabalo was formerly abundant in the Pilcomayo River and its fishing used to be a major importance for the fishermen as well as for the indigenous communities such as the Guarani and Weenhayek. However, the sabalo fishery experienced major events and practices which negatively affected the abundance and the fishery of the species.

The decline in sabalo catch has been mainly attributed to overexploitation and contamination of the river by mining activities in the upper course of the river. It is also believed that the 1990-1995 El Nino events contributed to the collapse of the sabalo in Bolivia. Moreover, the 17-kilometer drying stretch of the Pilcomayo River located in Argentine prevented the sabalo from swimming upstream and led to the trapping of huge quantities of the fish in water pools where they die.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=13880

Mar 02 2017

Fish Culture Development training course (2003)

EICA 2003 (01)

 

Even though each of the training courses which I organized is very important especially in knowing new friends, some courses including this one have something to add. This course has been annually hosted by the Egyptian International Centre for Agriculture (EICA) since 1989 and I have been teaching in this course since beginning until now. Upon establishing the regional center of ICLARM in Egypt, we thought to host a part of the practical training of EICA course on our facility at Abbassa in a win-win situation. The idea was never implemented before 2003 where we hosted the program initially for five days during November 2003. Afterwards and based on the feedbacks from the course participants and EICA organizers and of course the World Fish Center management, the practical training of EICA courses on WorldFish facility turned to be a key component of the course reaching of about three weeks spread over the 70-day training course. The names of participants who joined the 2003 course are: Eleni Loni Lilaj (Albania), Jaime Vidal Claros (Bolivia), Kamugisha Marie France (Burundi), Magne Berthe (Cameroon), Ousman Hissein (Chad), Silvia Garcia Serrano (Colombia), Juan Carlos Salinas Vargas (Colombia), Abdou Mohamed Saleh (Comoros), Locko Christin (Congo), Jescitan Tetteh Sanakey (Ghana), Kondo Timite Mariama (Mali), Soonil Kumar Ramsaha (Mauritus), Myint Thein (Myanmar), Martin Chang Rojas (Peru), Michael Barbe (Seychelles), Onita Grace Farma (Sierra Leone), Samart Detsathit (Thailand), Santiwat Pithakpol (Thailand), Mayusa Joseph (Uganda), and Andrea Sylvia Croci Reyes (Uruguay).

Since the speaking languages of the course participants are English, French and Spanish, we had to furnish our auditorium at Abbassa with a simultaneous interpretation facility for the first time. The slide show presents the flavor of training provided throughout the course including presentations, field and laboratory training and having some social activities during the very last evening the ending with a good-bye ceremony.

Note: during 2003, the emailing system was not common and facebook was not existing and hence I lost contacts with most of the course participants except some email addresses I was able to find through regular search.

[gview file=”http://fishconsult.org/wp-content/uploads/2017/03/EICA-2003-slide-show.pps”]

 

 

 

Permanent link to this article: https://fishconsult.org/?p=13874

Feb 28 2017

Climate change in Malaysia

A permission from the report owners has been granted to publish the report on this website

cover-climate-change-malaysia

http://fishconsult.org/wp-content/uploads/2016/12/Climate-Change-Malaysia.pdf

Permanent link to this article: https://fishconsult.org/?p=13750

Feb 26 2017

Outcomes of the in-captivity reproduction initiative of octopus (Octopus tetricus) in Australia

Photos’ credit: Dr sagiv Kolkovski (Australia)

Review: Sagiv Kolkovski and Abdel Rahman El Gamal (Founder of this website)

Octopus project (Sagiv with the juvenile) Octopus project (clutch of eggs)

 

 

 

 

 

 

This work has been conducted at the Western Australian Fisheries and Marine Research Laboratories (WAFMRL) based at Hillarys Boat Harbor, north of Perth.

The document of this project covers in details the all of the reproduction stages of octopus (Octopus tetricus) starting with the acquisition of octopus broodstock of between 1.5 – 3 kg, transportation of collected broodstock and then placing them in holding tanks whereas stocking density, sea water flow, and filtering has beed described. The project investigated also the broodstock feeding in regard to timing and frequency (once/day) and feed diet which mainly was fresh Pilchards, Prawns, Lobster, Abalone or Crab.  

The mating system has been shared including key information about instant mating or induced mating if natural mating was delayed using temperature as a triggering factor whether through raising or lowering water temperature by 2-3°C. The fecundity has been estimated by 100,000 to 200,000 of very small eggs for each female of the mentioned size range whereas egg clutch -as shown in the inserted picture- is guarded by the female during incubation period that lasts 35-40 days at the experimental temperature keeping in mind that raising water temperature to 21-23 °C the incubation period is reduced to 25-30 days, while lower temperatures (16-18 °C) can increase incubation time up to 45-50 days.

The embryonic development of hatched octopus has been addressed highlighting the significant bottleneck in the breeding system as represented in the almost mass mortality of “paralarvae” produced during the course of the study ending with only an individual who could reach juvenile octopus that was nicknamed “Bob” (Shown in the picture) which represented to the team a rare and exciting event which deserved to held a birthday party in Bob’s honor.

The research team is confident that the knowledge gained related to the closing of the life cycle of O. tetricus in areas of broodstock management and natural induced spawning as well as handling of eggs and paralarvae and required environmental factors and nutrition will assist in accomplishing a commercial octopus breeding program in the future.

This study has been a part of a larger project that aimed to close the life cycle of the octopus and produce juveniles to be used in aquaculture especially wild-capture octopus is unable to keep up with demand by Australian consumers. The tank-based production system has been another part of this project in which relied on wild-caught juveniles, the bycatch of adult harvest and this part will be addressed in a separate post.

 

For whoever interested in this subject matter, you may visit the full story on the link below:

http://frdc.com.au/stories/Pages/16_octopus-farming.aspx

Permanent link to this article: https://fishconsult.org/?p=13854

Feb 19 2017

A small-to-medium aquaponic project in California (USA) – Video

I filmed this video during my visit to this facility that took place on the 6th of January, 2015.
Description: Paul Trudeau (owner of the this project) and Abdel Rahman El Gamal (Founder of the video channel)

small to medium aquaponics

 

 

The operation is established in a greenhouse with the dimensions of 3.7m x 3m x 2.4m. The fish component consists of a fish tank that has a volume of about 380 liters (100 gallons). The greenhouse is thermally insulated solely by the plastic coverage. However, the video shows a “solar batch heater” located outside the greenhouse which helped to raise the temperature in the fish tank by 3-5 degrees C during the two cold months of the year when ambient temperature turns very low. By the way, this type of heater is made mostly of used and scavenged materials and designed by the owner of the operation. The heat generated in the solar heater was transferred to the fish tank by way of a closed-loop pipe arrangement with a heat exchange coil in the fish tank.

Adding iron to the water is a typical practice in aquaponics in order to maintain healthy plant growth whereas frequency is based on personal experience as well as observations. In iron-deficit water, the plant leaves develop chlorosis – yellowing between the veins. One can see the dates of adding iron is hand written on the cover of iron container.

It may of interest to know that the mound of leaves of about 1m high x 1m wide shown around the circumference of the greenhouse is a way to insulate the greenhouse. In addition to its insulation role, the leaves also serve a source of heat when large quantities of vegetable scraps are mixed into the leaf mounds, turning it into a row of compost. The microbial action in the compost generates a significant amount of heat.

It worth mentioning that blue gill (Lepomis macrochirus) is the fish species in the current system as the introduction of tilapia is banned in Sacramento, California. In regard to plants, Red Russian kale, Mibuna, Swiss chard, arugula, collard green and shiso.

Permanent link to this article: https://fishconsult.org/?p=13850

Feb 17 2017

Durability and water stability of fish feed pellets

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

One of the inserted photos shows feed fines while the second shows the initial signs of pellet disintegration in water.

Water stability of fish feed and production economics Pellets and fines in fish feed

 

 

 

 

High quality animal feed is always essential for enhancing productivity and for improving the production economics.

In addition to nutritive merit of animal feed, the durability of feed pellets is highly considered parameter in the quality of animal feed indicating how pellets have been able to withstand repeated handling during bagging, transportation, and storage without excessive breakage or generation of fine particles.

In aquaculture, the durability of pellets would be of utmost importance since pellet fines –if excessive- will be wasted when pellets are thrown in water and will be out of fish reach and hence subsequently could negatively affect feed conversion. Moreover, such washed-out broken feed and fines may turn into pollutants and contribute to the eutrophication process and subsequent disturbance in the dynamics of dissolved oxygen.

Water stability is another quality factor that is of significant important if aquaculture feed as feed pellets should be consumed before being disintegration in water into water. Because fish in their feeding habits vary considerably, water stability of feed pellets may vary accordingly. For example, trout, salmon and channel catfish are quick eaters and can consume their daily meals in matters of minutes while other species such as tilapia may require about two hours for consuming their meal. Shrimp, are known by their slow feeding habits as they chew their feed pellets whereas several hours are often required for consuming their meal. Therefore, pellets of good quality should remain intact and retain its physical integrity with minimal disintegration and nutrient leaching while in the water until consumed by target fish otherwise leaching of nutrients occurs, lost and negatively affecting productivity and economics.

Pellet quality can be influenced by several factors, including the ingredients, diet formulation, processing and binding agents.

There are quality tests designed to measure the durability, water stability and leaching rate throughout all of the stages from manufacturing till consumption by target fish and shrimp.

 

 

Permanent link to this article: https://fishconsult.org/?p=13847

Feb 05 2017

Reducing Cannibalism among African catfish fry by grading- Video

 

Video credit: Charles Bernard Makuya (Malawi)

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

grading of African catfish fry

 

 

 

Cannibalism is a common phenomenon which starts early in the life of African catfish (Clarias gariepinus) and usually causes significant losses. The phenomenon of cannibalism is encouraged by some environmental factors such as insufficient food, high stocking density and others. The situation becomes worse along with the spotting of few individuals of exceptionally large sizes (shooters). In order to minimize the losses due to cannibalism, periodic grading should be carried out as an essential practice in catfish hatcheries. As the cannibalistic behavior has been observed among catfish fry upon their first feeding, the grading is usually performed periodically during the nursing of fry to juveniles with higher frequency in case of fry (could be weekly) to bi-weekly grading in case of advanced fingerlings and in regard to juveniles, a monthly grading would be sufficient.

Catfish fry and fingerlings are usually graded into 2 or 3 sizes using proper graders which could be made of nets with varying mesh sizes and/or bar graders. In fact, hand sorting could be performed especially for the exceptional large size specimens (shooters).

The relative uniformity of graded fry does not only minimize the occurrence of cannibalism, but is also in their management especially in regard to feeding whether in ratios or frequency.

The 5-min video has been filmed as a part of training program carried out in Egypt. The grading targets three size grades whereas the medium size represents the largest portion (retained above), the smallest size which passes through the mesh of the grader –along with debris- are retained by the underneath net of small mesh in addition to few specimens of largest size which were picked by hand and placed in the red bucket. Of course, as fish grows, nets with larger mesh would be in use.

 

 

Permanent link to this article: https://fishconsult.org/?p=13838

Feb 04 2017

Country report – Pakistan (2015)

A permission from the report owner has been granted to publish the report on this website

cover-country-report-pakistan-2015

http://fishconsult.org/wp-content/uploads/2016/12/Country-report-Pakistan-2015.pdf

Permanent link to this article: https://fishconsult.org/?p=13732

Feb 03 2017

Crayfish – the unwanted invasive species in Egypt

Photo credit: Willy Oviedo Pereira (Uruguay)

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

Crayfish in pond harvest (01) Crayfish grabing tilapia in pond harvest (02)

 

 

The inserted photos were taken in a fish farm located in Sharkia, Egypt. One of the photos shows the contribution of crayfish (Procambarus clarkii) to the pond harvest while the second photo shows how a specimen of crayfish while grabbing a tilapia fingerling using its claws.

Red swamp crayfish has been accidently introduced into Egypt by a private operation during late 1980s to early 1990s. Upon realizing that the species has no farming potential coinciding with the zero consumption as fishermen and consumers could not accept this weird animals; in fact artisanal fishermen developed negative attitude against crayfish and blaming them for the damage that occurs to their nets. Under such situation of almost zero consumption, the crayfish repopulated freely and were able to spread over larger bodies of water including fish ponds that seemed optimum for their well-beings. Only several years ago, some initiatives came from abroad attempting to process the catch of crayfish towards converting such unwanted guest into a useful product. Whether these attempts are partially or fully successful, some consumers began to try the crayfish even slowly but could improve in the future. This minor change in crayfish consumption led to place some value on the catch instead of throwing it away as was done in the past.

 

Permanent link to this article: https://fishconsult.org/?p=13835

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