May 08 2013

Banggai cardinal fish (Distribution — biology — conservation) – Video

Video and text ownership: Abdel Rahman El Gamal
Source: www.fishconsult.org
This video was taken at the Sea World – California – USA

Introduction: Ichthyologist Dr. Frederick Petrus Koumans he is the one who described the species and erected a new genus, Pterapogon (cardinalfish with long fins), and assigned the species name of kauderni in honor of the Swedish zoologist Walter A. Kaudern who was the first to collect this species in 1920. It is among the relatively few marine fish to have been bred regularly in captivity, but significant numbers are still captured in the wild and it is now a threatened species. The Banggai cardinalfish is the only representative of the family that is diurnal.

Description: The Banggai cardinalfish (Pterapogon kauderni) is a small tropical cardinalfish that belongs to the family, Apogonidae. This attractive fish is popular in the aquarium trade. The Banggai Cardinal has a distinctive pattern of color with a remarkable arrangement of vertical bars and white spots. The beautiful color along with elongated fins in addition to its small sizes (a maximum total length of about 8 cm), explain the popularity of the Banggai cardinalfish in the aquarium trade. Although there is no distinct difference in color pattern between male and female, males have enlarged buccal cavity during the incubation of fertilized eggs till hatching.

Distribution and habitats: This species has an extremely limited geographic range and is originally found only at select sites around the coasts of 33 islands in the Banggai Archipelago of Indonesia. It is estimated that the total suitable habitat available within the Banggai cardinalfish’s range amounts to a mere 34 square kilometers.
The Banggai cardinalfish are more common in shallow waters at 1.5–2.5 m depth inhabiting various habitats such as seagrass beds, coral reefs in association with the seagrass Enhalus acoroidesand and long spined Sea Urchins, Diadema setosum.

Feeding habits: In nature, the Banggai cardinalfish are an opportunistic species that feeds principally upon tiny planktonic crustaceans whereas Copepods constitute a bulk of their diet. They feed also on variety of small organisms from the water column and the seabed, including marine worms, molluscs and fish larvae as well as preying on the larval stages of coral reef fishes’ parasites. Males carrying eggs do not eat throughout the incubation period.
In aquariums, the wild caught Banggai cardinalfish are fed meaty foods, including chopped seafood, adult brine shrimp, and Mysis shrimp. Feed is provided just before lights out, leaving a dim light. Enriching the artemia may be practiced several hours before they are fed to the cardinalfish.
On the other hand, the Banggai cardinalfish in nature is preyed upon by various species, such as the crocodile fish, various lion fish species, moray eel, stonefish, sea snake, and grouper.

Reproduction: The reproduction of the Banggai cardinalfish in nature is considered an easy process. The female begins the courtship before choosing a male partner and then after the pair, separates from the group and establishes and defend their own territory.
The Banggai Cardinalfish reaches their sexual maturity in about 10 months of age. The female spawns about 50-90 eggs with an average of about 75 eggs of about 2.5 mm in diameter. Eggs are quickly swallowed by the male, fertilized and incubated in a special pouch inside the male’s mouth whereas the male takes care about the embryos till hatching. The incubation lasts about 20 days. Hatched embryos continue for additional 10 days in the male’s mouth pouch till the reach 5-6 mm in length and develop into miniature versions of the adults. By then, young are released into, and hide among the spines of the long-spined sea urchin. During the 30-day brooding period the male does not eat.

Threats and conservation status: The first international trade of the species as an aquarium fish was in 1995–1996. The growing demand on the species as well as its premium prices led to the overfishing throughout the archipelago as well as attempting to raise it in captivity. Over few years of collection, the populations of the Banggai cardinalfish showed a drastic decline reaching close to extinction in some of home islands. This situation necessitated the reproduction of the species in captivity that which was done successfully. However, it appears that the demand on the species exceeds the available fry whether collected from the wild or produced in captivity.
According to the IUCN standards, the Banggai cardinalfish was listed as Endangered on the IUCN Red List of Threatened Species in 2007.

References: Wikipedia, Fish Channel.com, Fishlore (Aquarium Fish Information), ARKIVE, Aquarium Explorer, IUCN Red List of Threatened Species, Banggai Rescue, Acebook

Permanent link to this article: https://fishconsult.org/?p=7784

May 08 2013

Lake Nangbéto freshwater fishery (Togo)

Credit: Pham Beigue Alfa (Togo)

The two photos show a sample of fish catch from the artificial Nangbeto Lake in Togo. The principal fishery of the lake is attributed to the African butter catfish (Schibe mystus), Tilapia guineensis and Nile tilapia (Oreochromis niloticus). The annual fish catch from the lake ranges from 1500-2000 tons. Fishermen usually sell their catch to women fishers.

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.

Lake Nangbeto fishery 02 (Togo) Lake Nangbeto fishery 01 (Togo)

 

Permanent link to this article: https://fishconsult.org/?p=7768

May 08 2013

Seahorse, Hippocampus sp. (Distribution, biology and conservation) – Video

Source: www.fishconsult.org
This video was taken in Monterey Aquarium, California, USA

Video ownership and review: Abdel Rahman El Gamal (Founder of the website and video channel)

Introduction: the name of seahorses is given to about 40 species of marine fish that occur worldwide. This group belongs to the family: Syngnathidae and the genus Hippocampus. The genus name comes from the Ancient Greek whereas Hippo means horse and Kampos means sea monster. The name in other Greek translation means bent horse. The size of this unique fish may reach up to 35 cm with an estimated lifespan of about 5 years.

Distribution range: Seahorses are mainly found in tropical and temperate waters throughout the world. Several seahorse species are found in Pacific waters from North America to South America as well as in the Atlantic. Seahorses also occur in Bahamas, some European waters and in the Mediterranean Sea. A given body of water may host seahorse species different from those in another water body.
Habitat: Typically Seahorses are found in shallow waters with abundant vegetation. They are well camouflaged among the relatively tall eelgrasses, seaweeds and coral branches.

Physical description: Seahorses are unique animals whether is their shape, behavior or reproduction. Even though, seahorses might not look like traditional fishes, they are true fishes of the class Actinopterygii (ray-finned fishes).
Seahorses are elongate with their bodies covered with bony rings and ridges. They have a flexible, well-defined neck. They swim upright. Because of their body shape, seahorses are poor swimmers and can easily die of exhaustion in unfavorable conditions. They are often found resting around stationary objects.
While seahorses have pectoral fins and a small dorsal fin, they do not have caudal fins. They have long snouts, which they use to suck up food, and eyes that can move independently of each other.

Feeding habits: They have small mouths located at the end of its tube-like snouts. Seahorses have no teeth and no stomach. They use their elongated snouts to suck in their food that drifts by. While the small shrimp-like crustacean, mysid is their most favorite food, Seahorses feed also on plankton, small crustaceans, and fish larvae which may float or crawl on the bottom within striking range. Their excellent camouflage helps catching their prey. Because of the make-up of their digestive system, eaten food passes through their digestive systems quickly, and hence they must eat almost constantly to stay alive.

Reproduction: In general, Seahorses are monogamy animals in which –with some exceptions- and depending on species, mating partners remain as such for life time or at least during the breeding season. Among the unique reproductive features, the male seahorse bears the unborn young till birth.
It is believed that the lengthy courtship that may last days helps seahorse partners to synchronize the timing for the deposit/receive of mature eggs which is done upon the insertion of female’s ovipositor into the male’s brood pouch which is located on their ventral, or front-facing, side. The number of deposited eggs could range from tens to several thousands. Afterwards, the female swim away while the male releases his sperm directly into seawater where it fertilizes the eggs. In the same time, the male supplies the eggs with prolactin, the same hormone responsible for milk production in pregnant mammals. The pouch provides oxygen as well as a controlled environment incubator.
Upon the completion of incubation which lasts 2-6 weeks depending on the species, eggs hatch and remain in the pouch for 2-4 weeks. During this period the newborns develop and get prepared for sea life. By the end of this phase, male seahorse gives birth to the tiny seahorses of about 1 cm long. The number of born depends on the species and could range from as low as 5 for the smaller species to as high as 1500. The mating could be repeated between the same couple throughout the breeding season. There is no parental care provided after birth. It is believed that less than 0.5% of born seahorses survive to adulthood.
Several species of sea horse are now bred in aquariums and hence reducing the pressure on wild-caught seahorse stocks.

Threats and conservation: It is believed that the information on seahorse population dynamics is not sufficient in general. However, loss of habitats, pollution, and over fishing must have negative impacts on seahorse populations. Harvesting of seahorse is mainly done for the trade of ornamental fish or for the use in Asian traditional medicine.
According to IUCN and CITES, many of sea horse species are either endangered or vulnerable and at a significant risk. That is why some countries have issued the policies to regulate and trade for endangered seahorse species.

References: Wikipedia, National Geographic, fun facts, Animals and Aquatic community

Permanent link to this article: https://fishconsult.org/?p=7763

May 08 2013

Introductions and catch of soles (Solea vulgaris) in Lake Qarun, Egypt

Photo credit: Amal Mogga (South Sudan) and Lury Garcia Nunez (Colombia)
Description: Abdel Rahman El Gamal

These photos show the soles (Solea vulgaris) which represents a key species of Lake Qarun especially when considering the increasing levels of the salinity of the lake.

Sole was first introduced to the lake in 1938, and followed by subsequent introductions in 1943, 1945 and 1948. The species established itself in the lake and propagates naturally and hence no further introduction of the species was carried out.

Soles are considered a luxury fish species especially when caught at large size. The catch of the species has witnessed considerable fluctuations over years as mainly affected by over fishing practices. In 2009, the catch of Lake Qarun soles amounted 581 tons that represented 16% of the total catch of the lake in that year.

Sole fishery in Lake Qarun (Egypt) 02 Sole fishery in Lake Qarun (Egypt) 01

 

 

Permanent link to this article: https://fishconsult.org/?p=7757

May 08 2013

Indonesian Fishery sector (capture fishery – aquaculture – processing – trade) – 33 min-video

The owner of this video is “Directorate General of Culture Fishery – Department of Marine Affairs and Fisheries”

Credit: Solah Ahmad (Indonesia)Indonesian fishery sector

This relatively long video covers the fishery sector in Indonesia starting by capture fishery and then aquaculture, processing and export. Aquaculture system is being covered in more details whereas key farmed species were highlighted including: grouper, marine shrimp, milk fish, red seabass, white seabass, pearl culture, freshwater prawn, GIFT tilapia, local catfish, green muscle, Gracilaria and others. Aquaculture facilities include earthen ponds, tanks and cages. Artificial reproduction for key species is included. Several research stations and their activities have been brought in the video including Kenipa Macan, Unit Pengembangan Buoidaya Air Tawar UPPAT, Kerapu Babak, Pembudidayaan Rumput Laut, and others.

Permanent link to this article: https://fishconsult.org/?p=7753

May 08 2013

Farming and processing of catfish and shrimp in Vietnam – 15-min Video

Credit: Nguyen Van Hoa (Vietnam)

Source: www.fishconsult.org

This video presents farming of catfish and shrimp in Vietnam. Farming husbandry such as feeding and sampling is covered. Fish processing is covered in this video.

Continue reading

Permanent link to this article: https://fishconsult.org/?p=7727

May 08 2013

Chlorination and dechlorination in aquaculture operations

http://fishconsult.org/wp-content/uploads/2013/05/Chlorination-in-aquaculture-operations.pdf

Permanent link to this article: https://fishconsult.org/?p=7742

Dec 18 2012

Fish gene banks (features and technologies)

This three-slide bite addresses the role of gene banks in the conservation of genetic conservation for fish. The rationality of gene banks have been addressed. Also, the main gene banking technologies are covered, namely; cryopreserved (in vitro) and live (in vivo) gene banks. The features of fish gene banks are addressed. Examples of fish gene banks are included.

Fish gene banks

Permanent link to this article: https://fishconsult.org/?p=7733

Dec 16 2012

Chinese style incubators for the production of Chinese carp and common carp fingerlings (in Spanish)

Credit: Gerardo Ontiveros Lopez (Mexico)
La foto muestra el sistema chino de circulación incubadoras usadas para la producción de carpa herbívora (Ctenopharyngodon idella) alevines y también la carpa común (Cyprinus carpio).
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=7716

Dec 16 2012

Collection of armoured catfish (Auchenoglanis occidentalis) for research in Zambia

Credit: Lumbwe Kalumba (Zambia)

This photo shows a fisheries Officer doing collection of armoured catfish (Auchenoglanis occidentalis) from the wild. This species is still being studied at a Government aquaculture Research station in Luapula Province, for possible induced reproduction in captivity. This expensive fish species is favored by many people in Zambia.

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=7706

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