Aug 16 2012

Integrating large animals in a small-scale fish farm in Nyagasambu, Rwanda

Credit: Emmanuel Hahirwabasenga and Rwigiriza Augustin Kanimba (Rwanda)

These photos show the integration of large animals as source of fertilizer in a small-scale fish farm owned by cooperative farmers in Nyagasambu site. The number of animals is sufficient to produce enough manure as required by the fish farm.

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=5195

Aug 15 2012

Blackfooted Penguins, Spheniscus demersus (Breeding, climatic adaptation, threats and conservation measures) – Video

This video was taken at Monterey Bay Aquarium, California, USA in June 2012

Breeding: The African Penguin reaches breeding maturity in about four years.  They form nesting colonies, with pairs returning to the breeding site year after year. The breeding nests are usually found on coastal islands, where pairs construct their nests from their hardened excrements (guano) in a form of dug burrows in the guano or scrapes in the sand under boulders or bushes whereas some protection from the sun is provided. Black-footed penguins are monogamous as the breeding takes place with the same mate.

Two or three greenish eggs are laid each time in the breeding nest whereas egg incubation provided by both parents in shifts. The bare batch of skin on the lower abdomen allows the transfer the heat to the eggs as required during the incubation that lasts 40 days. The parents continue to guard their chicks that stay in the nest until they reach about 30 days old. Also, the adults -that continue to carry out foraging trips- feed their chicks with food which is brought up from their stomachs. This continues until the chicks fledge which occurs when they reach 70-80 days old. Afterwards, the immature penguins leave the land and go to the sea on their own where they remain for 12-24 months. Then they usually return to the land site where they hatched and molt into the familiar penguin adults.

Climatic adaptations: In cool climates, penguins have evolved behavioral and morphological features that help them retain heat. This includes the thick layer of fat under the skin and the densely packed feathers compared to other birds. In warmer climates, the pink glands above their eyes of the birds are believed to have a thermoregulation role to aid the bird in losing heat especially when the bird is out of the water for prolonged periods. Limiting their time at the nesting site to dusk and dawn is a behavioral pattern to protect themselves from solar radiation.

Threats and conservation measures

Threats: As a result of the collapse of Black-footed Penguin populations, the species is classified as Vulnerable (VU) on the IUCN Red List 2007.

Several threat sources contribute to the collapse of the black-footed penguins. These include human activities as represented in the previous practice of egg collection for human consumption, overfishing of penguins’ food of sardines and anchovies; oil pollution; removal and use of guano as organic fertilizer. The use of Penguin skins in leather goods has contributed to the over hunting of the bird.

The black-footed penguin’s predators contribute to the collapse of the penguin’s populations. Ocean predators include sharks and fur seals while land-based predators include mongooses, genets, and feral cats.

Conservation measures: The mediation measures include the establishment of nature reserves on locations or islands on which the species breeds. The egg collection and bird slaughtering are widely prohibited. Similarly, the collection of guano is no longer allowed.

The positive mitigation measures include the recovery of rescued oiled birds, hand-rearing and releasing abandoned chicks, and setting up artificial nests.

References: The Encyclopedia of Earth, Wikipedia, Mac Como Zoo

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Permanent link to this article: https://fishconsult.org/?p=5184

Aug 14 2012

Black-footed penguins, Spheniscus demersus (Description, distribution and feeding habits) – Video

This video was taken at Monterey Bay Aquarium, California, USA in June 2012

The black-footed penguins or African penguins, Spheniscus demersus are water birds which belong to the family Spheniscidae

Description: Black-footed penguins when fully developed grow to 60-70 centimeters tall and weigh between 2 and 5 kilograms. These penguins have black backs, faces, wings, feet and beaks. They have a black stripe and black spots on the chest. White stripes run around their faces to above their eyes. The color pattern of the bird (black above and white below) is a form of camouflage against underwater predators and predators looking down onto the dark water. Males are slightly larger than females. The average lifespan of the black-footed penguin is 10-11 years.

Distribution and habitats: Black-footed penguins are found exclusively in Africa. They live mainly on the south-western coast between Namibia and Algoa Bay, near Port Elizabeth, South Africa where they live and breed. When not breeding, the birds can be found across Africa’s southern shore, from Gabon to Mozambique, generally within 40 kilometers of the ocean shore.

Feeding habits: It is estimated that about 40% of the black-footed penguin’s diet is composed of small pelagic fish such as anchovies (Engraulis capensis) and sardines (Sardinops sagax), horse mackerel and small fish. The bird forages also on marine invertebrates such as squid, small crustaceans and polychaete worm. Birds are capable to swim for long distance after their food (30-70 km from the coast. In regard to food quantities, it is claimed that the birds eat about 14% of their body weight each day. When penguins molt, they fast over the molting period (about 20 days) as their new feathers are not waterproof and hence birds would not be able to forage.

References: The Encyclopedia of Earth, Wikipedia, Mac Como Zoo, Monterey Bay Aquarium

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Permanent link to this article: https://fishconsult.org/?p=5177

Aug 12 2012

Feeding tilapia fingerlings in Kigembe research station (Video)

Credit of the video: Emmanuel Hahirwabasenga and Rwigiriza Augustin Kanimba (Rwanda) – Description: Abdel Rahman El Gamal

This video shows the feeding of tilapia fingerlings in earthen ponds at the research facility of Kigembe, Rwanda. As shown in the video, the feed looks like a ration-type feed and is spread in a feeding ring which keeps the feed in a limited space where tilapia approach and feed.

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Permanent link to this article: https://fishconsult.org/?p=5170

Aug 11 2012

Monkfish, Lophius sp. (Description, distribution and consumption) – Sweden

Credit for the photo: Gabriel Salvo (Chile)      Description: Abdel Rahman El Gamal

This photo was taken in the fish market at Gotemburg, Sweden

Monkfish and goosefish are the most common English names for the genus Lophius.  Angler fish and all-mouth are also used for the monkfish.

Atlantic monkfish, Lophius americanus, does exist in the Atlantic Ocean while the European monkfish, Lophius piscatorius, can be found in northern European waters. Even though, the monkfish is a bottom-dwelling species that may occur to a depth of about 1800 m, it also occurs in shallow waters close to water surface. However, the stock of monkfish migrates to deeper water to spawn.

The body of this bottom-dwelling fish is composed mainly of huge mouth with sharp teeth attached to a muscular tail. It grows to a length of about 1 m are common. The sharp teeth and huge mouth imply the predation behavior of this species.

Although monkfish is often described as an ugly fish, its edible portions especially its tail meat is delicious and comparable to lobster tail meat. Also, its liver enjoys high demand for special dishes.

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=5158

Aug 07 2012

Commercial salt extraction from Lake Qarun, Egypt (Video)

Credit for the video: Albert Mugabe(Uganda); Description: Abdel Rahman El Gamal

Since the disconnection of Nile water reaching Lake Qarun (21,800 ha), Fayoum (Egypt), the lake has been facing the consequences of the rising of water salinity. This results of the evaporation of lake water that originates from agricultural draining water. The threating of salinity increase to the lake fishery called for mitigation approaches especially when we know that the total build-up of salt in the lake is estimated by about 600,000 tons annually. The salt extraction proved to be the realistic and effective approaches so far.

This video has been taken in unit of much larger salt extraction factory (Emisal). The infrastructure and so the technologies in practice allow the extraction of about 300,000 tons of salt/year composed of sodium chloride, sodium sulfate and magnesium sulfate.

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Permanent link to this article: https://fishconsult.org/?p=5150

Aug 05 2012

Construction of artisanal fish pond for rainbow trout, Oncorhynchus mykiss in Peru (in Spanish)

Credit: Claudio Alvarez (Peru)

Construcción de estanques artesanales.para el cultivo de truchas arco iris Oncorhynchus mykiss, en la ciudad de Carhuaz-Huaraz.

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=5133

Aug 05 2012

Construction of artisanal cages for rainbow trout, Oncorhynchus mykiss in Peru (in Spanish)

Credit: Claudio Alvarez (Peru)

Construcción de jaulas artesanales para cultivo de truchas arco iris  Oncorhynchus mykiss, en la ciudad de Puno, con participación mayoritaria de mujeres campesinas.

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=5138

Aug 02 2012

Flamingo Birds, Phoenicopterus sp. (Introduction, distribution, description, feeding and reproduction) – Video

The video was taken in Sea World, California, USA in June 2012

Introduction: Flamingos are a type of wading birds in the genus Phoenicopterus, which hosts six recognized species in the world; four species of which in the Americas and two species in the Old World. The Old World flamingos were considered by the Ancient Egyptians to be the living representation of the God Ra. The Moche people of ancient Peru who placed emphasis on animals often depicted flamingos in their art. Flamingos are the national bird in Bahamas. On the other hand, Roman emperors were fond of dishes made of flamingo tongues for which flamingos were slaughtered. Also, the birds were slaughtered in other regions under the belief of curing some diseases. Flamingos are very social birds that live in colonies that can number in the thousands. These large colonies are believed to serve predator avoidance, maximizing food intake, and exploiting suitable nesting sites.

Distribution and habitats: The home of four species in the new world includes South America (Peru, Chile, Bolivia and Argentine), Caribbean and Galapagos islands. The two remaining flamingo species are found in the old world that includes parts of Africa, South of Europe, and Great Rift Valley. These famous pink birds can be found in warm, watery regions on many continents. They favor environments like estuaries and saline or alkaline lakes.

Description: Flamingos (Phoeniconaias sp.) are gregarious, tall, pink wading birds with thick downturned bills. Flamingos have slender, long legs and large wings. They have long, lean and curved necks which allow for maximum movement and twisting. Flamingos have black-tipped beaks with a distinctive downward bend. Their size (according to species) ranges from about 90 to 150 cm tall (standing) and with an average weight of about 4 kg. The flocks of flamingos like to wade –in large groups- in shallow saline waters. It is claimed that in East Africa’s large lakes, flamingo groups may be as big as two million individuals during the breeding season. The ability of the bird to stand on one leg may allow the birds to conserve more of their body heat which will be highly required as birds spend a significant amount of time wading in cold water.

Feeding habits: Flamingos are omnivore birds. Their filter feeding ability allows them to trap plankton, crustaceans (e.g. artemia), mollusks, and tiny fish larvae & insects. Using their long legs and feet, flamingos stir the bottom of the shallow water and use their bent beaks to access their target food. The bird organs are well adapted to filter feeding as reflected in the shape of organs and feeding actions. A flamingo’s beak has a filter-like structure to strain food items from the water before the liquid is expelled. A part of the flamingo’s filter feeding is done through swinging the head back and forth and letting the water flow through the beak whereas the efficiency is enhanced by the large, fleshy tongue is covered with bristle-like projections that help filter water and food particles. The pink or reddish color of flamingos comes from beta carotene-rich food such as artemia. A white or pale flamingo indicates unhealthy or malnourished flamingos. This has been noticed in captive flamingos and in order to maintain the desired pink color, zoos are adding prawns and other carotene-rich supplements to the diets of flamingos.

Reproduction: The pair relationship (one male and one female) is the basic social unit of flamingos although some mate changes may occur in large colonies. The pair formation is done through performing displays among the breeding groups of flamingos ending by forming the pairs. Most likely the female flamingo chooses a suitable spot on the mudflat to build a nest. Both the male and the female contribute to building the nest which is a cone of mud. Parents defend the nesting territories. The copulation takes place during nest building. Flamingos will defend their one or two eggs and continue to defend their young.  The parental care is represented in feeding hatched chicks by crop milk produced by parents. Chick nursing is carried out by both parents. At about 7-12 days, the chicks begin to move and explore their surroundings and two weeks after, the chicks join groups of the same age and at this stage their parents leave them in these groups which come together to form larger groups which contain thousands of chicks representing a means against predation.
The chicks will reach adult size in about 21 months. After two more years, they will begin their own mating.

Source: Encyclopedia Britanica, National Geographic, http://www.stanford.edu, Wikipedia, http://animaltrial.com, Sea World

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Permanent link to this article: https://fishconsult.org/?p=5123

Aug 01 2012

Shrimp harvesting in a shrimp farm in Egypt (Video)

Tracing the caption of this video, I was able to find out that this video was taken in a shrimp farm in Suez (Egypt) and shared with me unlabeled. The credit of the video should go to a friend who I do not remember

This video shows the harvesting of shrimp in a shrimp farm in Egypt. In this farm which is located in Suez, the post larvae used in this farm are collected from the wild. Green tiger shrimp, Penaeus semisulcatus and Penaeus japonicus are the main shrimp species in the farm. The harvesting as shown in the video is carried out during dark nights (moonless nights). In such harvesting method, a source of light is placed in a proper position to attract shrimp which are dragged by water current towards the light and enter a netting structure where they are scooped and processed.

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Permanent link to this article: https://fishconsult.org/?p=5111

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