Jul 27 2014

Flying fish (Description – fights – feeding – reproduction – flying- utilization)

The photo of this model was taken in Sea World, San Diego, USA

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

Introduction: Flying fish is the common term for about 50 species within the family Exocoetidae. Flying fish has captured the imagination of people throughout the world for centuries because of its ability to glide in the air before returning into the water. It may be of interest to know that the Greek word “Exococetidae” means to ‘lie down outside’. Also, the Latin word “Exocoetus” means “sleeping outside”, so named as flying fish were believed to leave the water to sleep on the shore. The average lifespan of flying fish is around 5 years.

Habitats: Flying fish live in all of the oceans, particularly in tropical and warm subtropical waters of Atlantic, Pacific, and Indian Oceans.  They are abundant in the Caribbean Sea as well.

Description: For most of flying fish species, their size ranges from 7 to 12 inches with some individuals which can reach up to 45 cm. Flying fish are ray-finned fish. Their ability to leap out of the water and fly is supported by their streamlined torpedo shape and their pectoral fins which are unusually large. Pectoral fins of flying fish can be spread out like a bird’s wing. Flying fish has deeply forked tail with its lower end longer than the upper end.

Flights: Flying fish are distinguished by their ability to glide upward out of water in a natural defense mechanism when threatened by predators. They launch themselves into the air by beating their tail very fast (about 50-70 times/second) and with the help of their streamlined torpedo shape they accelerates toward the surface of the water with the speed of about 60 kilometers per hour enabling them to break the water surface spreading their large, wing-like pectoral fins for gliding through the air above water’s surface for considerable distances.

According to studies and observations, flying fish can spend up to 45 seconds in flight, in which they glide a distance of about 100-200 meters and at a height of about 1-1.2 m above water surface. The gliding speed is estimated to be about 60-70 km/h.

Feeding habits: Flying fish usually feeds during night whereas their diet is mainly composed of plankton, bacteria and other tiny marine creatures.

Reproduction and life cycle: The mating of flying fish takes place in the open ocean when the ocean currents are the weakest. Flying fish spawn in large group of a number that can reach or exceed one million individuals. A Female flying fish deposits large number of eggs near the surface of the water, usually attached to floating debris by sticky filaments. Newly hatched flying fish have long whiskers around the mouth making the hatchling look like the flower produced by plants and this ensures their survival their early life stage during which the newly hatched fry are most vulnerable to predators.

Predation: It is thought that flying fish evolved a flying mechanism to escape their predators such as tuna, mackerel, swordfish, and marlin. Once in the air, flying fish sometimes are exposed to fish-eating birds.

Flying fish fishery: Flying fish are easily attracted to the light and so fishermen operate well-lit boats using luring light during night to guide flying fish toward their ships with good results. Hence, fishing of flying fish is done mainly during nights and only when no moonlight is available.

The tendency of flying fish to swim in large schools makes them an easy target to fishermen who could catch number of fish as they come across a large school.

Flying fish are commercially fished in some places using variety of fishing gears.  For example, gillnetting is used in Japan, Vietnam, and China while dip netting is used in Indonesia and India. 

Flying fish are also fished by small-scale fisheries with dip nets, seines, gillnets, and hook-and-line, sometimes at night with the aid of lights.

In the Solomon Islands, the flying fish are caught during their flying, using nets held from outrigger canoes.

Consumption of flying fish: The flying fish is consumed in some societies, but it is considered a delicacy whether the whole fish or its roe.  The species is widely consumed in Taiwan and is an important part of main national dish of Barbados. The common preservation method of flying fish is drying.

Flying fish and Barbados: The flying fish is the national fish of Barbados that was once known as “the land of the flying fish”. The flying fish appears on coins, and there are several sculptures of the flying fish in Barbados. Flying fish appear also in artwork, and as part of the official logo of the Barbados Tourism Authority. The disputes between Barbados, Trinidad and Tobago over the flying fish stocks which reached the council of United Nations Convention indicates the importance of flying fish to Barbados culture.

References: Sea World Display, the National Marine Fisheries Service (NOAA Fisheries), Wikipedia, National Wildlife Federation, BBC Nature Wild Life, National Geographic

Flying fish

Permanent link to this article: https://fishconsult.org/?p=11208

Jul 24 2014

Parrotfish (Description, habitats, feeding, life cycle, utilization)

This model photo was taken in the Sea World, San Diego, USA

Introduction: Parrotfishes are a group of about 80- 90 identified species of fishes which are now often considered a subfamily (Scarinae) of the wrasses to which they are close relatives. Parrot fish are abundant in and around the tropical reefs of all the world’s oceans. The average life span of parrot fish is about 7 years.

Distribution and habitats: Parrot fish are mostly tropical and are found in relatively shallow tropical and subtropical waters throughout the world, displaying their largest species richness in the Indo-Pacific. They are found on tropical reefs, rocky coasts, and seagrass beds.

Description: Parrotfish are named for their powerful, parrot-like beak formed by the fused teeth which is adopted for grasping algae from corals and rocky substrates as well as for crushing and chewing chunks of living corals. Parrot fishes are often well known for their bright colors. Depending on species, the sizes of parrot fish vary with the majority of species reaching 30–50 cm in length. However, a few species reach lengths in excess of 1 m. They use their paired set of pectoral fins primarily to swim, with an occasional flick of the tail fin for a burst of speed.

Mucus: At night, a number of parrotfish species envelope themselves in a transparent cocoon made of thick coat of mucous secreted from an organ on their head.  This is a means of hiding from potential predators especially the nocturnal ones which hunt by smell such as moray eels and lemon shark. This cocoon protects the sleeping parrotfish from bloodsucking parasites.

Feeding: Although parrot fish are considered to be herbivores, they eat a wide variety of reef organisms. Their beaks are specialized for scraping algae and invertebrates from coral and rock surfaces. Also, their pharyngeal teeth crush the ingested materials during feeding. While parrotfish digest the edible portions, they excrete the undigested portions as sand. On the average, it is estimated that a specimen of parrotfish excretes about 90-100 kg of sand/year.

Life cycle: Almost all parrotfish species are sequential hermaphrodites, starting as females (known as the initial phase) and then changing to males (the terminal phase). There are some exceptions in some species in which individuals develop directly to males while females in other species do not change sex. In most parrotfish species, several females are presided over by a single male who defends them from any challenge. If the dominant male dies, the group’s largest female will change gender and color and become the dominant male. Parrotfish are oviparous; they lay many tiny, buoyant eggs into the water. The eggs float freely, settling into the coral until hatching.

Utilization: In the Indo-Pacific, a commercial fishery of larger species of parrotfish does exist. Parrotfish are not consumed in some counties while considered a delicacy in other parts of the world. In Polynesia, it was once considered “royal food,” only eaten by the king. Despite their striking colors, they are not suitable for most marine aquaria due to their feeding behavior.

References: Sea World Display, Hanauma Bay, Sea World, Encyclopaedia Britannica, Sport Diver, National Geography, Wikipedia

 Parrot fish

 

Permanent link to this article: https://fishconsult.org/?p=11204

Jul 23 2014

Research facilities at the National Aquaculture Research and Development Centre (NARDC), Zambia

Credit: Majorie Mbambara (Zambia)

The National Aquaculture Research and Development Centre (NARDC), is located in Kitwe district, Copperbelt Province, Zambia. The first photo shows hapas set in an earthen pond in preparation for a research experiment. The second photo shows experimental units which are sometimes used as holding ponds for fingerlings before selling. The building shown in the photo is the hatchery of NARDC.

Zambia - NARDC facility (02) Zambia - NARDC facility (01)

 

 

 

Permanent link to this article: https://fishconsult.org/?p=11199

Jul 23 2014

Water analysis prior to the construction of Merowe Dam, Sudan

Credit: Mamoun Obeida (Sudan)

Merowe Dam was constructed in North State, Sudan. The photo was taken during the pre-construction of the dam whereas the physical and chemical properties of water were periodically analyzed including (pH, water conductivity, temperature and Dissolved Oxygen. This work was funded by Dams Implementation Unit. This analysis was stopped after the completion of the dam.

Sudan - Water analysis in Merowe Dam

 

 

Permanent link to this article: https://fishconsult.org/?p=11195

Jul 23 2014

Rescue efforts on endangered fish species in Guatemala (in Spanish)

Credit: Manuel Francisco Cano Alfaro (Guatemala)

Como parte del plan de trabajo incluida en el gobierno de la República de Guatemala, el día 29 de septiembre del año 2006 se realizó la primera liberación de alevines de blanco (Petenia splendida) con el fin de contribuir a la protección de esta especie que es objeto de pesca y goza de gran importancia a nivel alimenticia en el departamento del Petén.

El Gobierno de Guatemala a través del Ministerio de Agricultura del Petén y de la Unidad de Manejo de la Pesca y Acuicultura, han desarrollado la reproducción en cautiverio de esta especie nativa desde el año 2003 en las instalaciones del Centro de Producción y Capacitación Acuícola ubicado en El Remate, Flores.

Como inicio del trabajo de repoblamiento se sembraron 30,000 alevines de blanco y se tiene considerado continuar con el trabajo de reproducción en cautiverio y liberación en el Lago Petén Itzá.

Guatemala - rescure of endagered fish species (01) Guatemala - rescure of endagered fish species (02)

 

 

 

 

 

 

Permanent link to this article: https://fishconsult.org/?p=11190

Jul 21 2014

A little home for fishery/aquaculture-related videos

Dear Visitor,

So far the video channel has attracted more than a quarter million visits paid by friends from 217 countries and islands who spent more than 7700 hours on the channel. There are 379 subscribers so far.  If you have a look, you will notice there is technical information which goes with each of the 157 videos at the present. Until now, videos cover fishery and aquaculture related topics in 17 countries: (Benin, Burundi, Colombia, Egypt, Ghana, Guatemala, India, Indonesia, Italy, Malawi, Oman, Rwanda, Sao Tome, Turkey, Uganda, USA, and Vietnam). You are welcome to visit, subscribe or contribute if you wish to share your genuine fishery/aquaculture related videos. If you like to tour the channel, here is the link:

http://www.youtube.com/user/fishconsultgroup?feature=results_main

It will be nice if you can share the link with friends and colleagues who might be interested in. Thanks

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

21 July, 2014

Permanent link to this article: https://fishconsult.org/?p=11186

Jul 21 2014

Nile tilapia males (coloration during the breeding season) – Video

Video credit: Ivan Venkonwine Kaleo and Patrick Appenteng (Ghana)

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

This video was filmed during July, 2014 in a private fish farm in Kafr El Sheikh, Egypt

The video shows a sexually mature male of Nile tilapia (Oreochromis niloticus) during the spawning season in which the throat region as well as the pectoral, dorsal and caudal fins turns reddish. The vertical bars on the caudal fin are also obvious.

 

 

 

Permanent link to this article: https://fishconsult.org/?p=11183

Jul 19 2014

Inception of cage aquaculture in the Asuogyaman District, Ghana

Credit: Patrick Appenteng (Ghana)

The fisheries sector in Ghana provides employment for for about 2 million people (2% of the total population); these include aquaculture as well as those engaged in its ancillary work.

The inception of cage aquaculture in the Asuogyaman District had also provided employment for other ancillary workers such as electrical welders.

The first picture shows a local electrical welder who had won a contract to manufacture the frames for more than one hundred cages. He is happy because, the returns far outweigh what he gets from his main work. The second picture shows the manufactured frames being sent to be assembled into a cage for sinking in the water body for aquaculture practices.

The socioeconomic impact of cage aquaculture in the Asuogyaman District of Ghana is worth emulating.

Cage frame (01) Ghana Cage frame (02) Ghana

 

 

Permanent link to this article: https://fishconsult.org/?p=11181

Jul 18 2014

Rural cage aquaculture in Volta Lake (Ghana)

Credit: Patrick Appenteng (Ghana)

The adoption of the cage aquaculture technology in Ghana comes along with different materials from different farmers. The picture shows a group of rural farmers working on their cages on the Volta Lake.

Apart from the conventional galvanized pipes usually used for the frames although some had tried using bamboo’s and some water resistant timber species, different farmers also use different materials as floats.

Over here, these small scale rural farmers have resorted to the use of metallic drums as floats which they will later on stop because they will find it as not sustainable and environmentally friendly. The picture shows farmers standing on the catwalk trying to fix their cage nets.

Rural cage aquaculture in Lake Volta (Ghana)

 

 

Permanent link to this article: https://fishconsult.org/?p=11175

Jul 15 2014

Catching mud crab (Scylla serrata) in Mannar District, SriLanka

Credit: Ajith Kumara (SriLanka)

This photograph was taken in Mannar area, North province in 2009 (Mannar District is one of the 25 districts of SriLanka). The water body is a part of lagoon (tidal flat) during low tide. People shown in the photo dig holes to catch Scylla serrata  (mud crab or mangrove crab). According to outer opening of the tunnel fishermen get a good idea on the size of the crab.

Catch of mud crab in Mannar (SriLanka)

 

 

 

Permanent link to this article: https://fishconsult.org/?p=11172

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