The giant pangasius, paroon shark, pangasid-catfish or Chao Phraya giant catfish (''Pangasius sanitwongsei'') is a species of freshwater fish in the

shark catfish The shark catfishes form the family Pangasiidae. They are found in fresh and brackish waters across southern Asia, from Pakistan to Borneo. Among the 30-odd members of this family is the plant-eating, endangered Mekong giant catfish ''Pangasian ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

(Pangasiidae) of order

Siluriformes Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

, found in the

Chao Phraya The Chao Phraya ( or ; th, แม่น้ำเจ้าพระยา, , or ) is the major river in Thailand, with its low alluvial plain forming the centre of the country. It flows through Bangkok and then into the Gulf of Thailand. E ...

and

Mekong The Mekong or Mekong River is a trans-boundary river in East Asia and Southeast Asia. It is the world's twelfth longest river and the third longest in Asia. Its estimated length is , and it drains an area of , discharging of water annual ...

basins in

Indochina Mainland Southeast Asia, also known as the Indochinese Peninsula or Indochina, is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to the west an ...

. Its populations have declined drastically, mainly due to overfishing, and it is now considered Critically Endangered.

Etymology

The specific name ''sanitwongsei'' was chosen to honor M. R. Suwaphan Sanitwong ( th, ม.ร.ว.สุวพรรณ สนิทวงศ์) for his support of fisheries in Thailand.

Geographic range

The species is native to the

and

rivers. It has been introduced to central

Anatolia Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

, and

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

Habitat

The ''Pangasius sanitwongsei'' is tolerant in poor quality water and prefers to live in the bottom of deep depressions in freshwater rivers. The fish live in rivers but are experiencing endangerment due to dams being built, causing the fish to be trapped and unable to migrate.

Physical characteristics

The giant pangasius is pigmented with dusky

melanophore Chromatophores are cells that produce color, of which many types are pigment-containing cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopods. Mammals and birds, in cont ...

s. It has a wide, flat, whiskerless head. Its body is compressed and elongate, with a depressed head. It has a continuous and uninterrupted single vomero-palatine teeth patch which is curved. The anal fin has 26 rays and the pectoral spine is similar in size to the dorsal spine and also shows serrations. It has a silver, curved underside and a dark brown back. Its dorsal, pectoral and pelvic fins are dark gray and the first soft ray is extended into a filament. Its dorsal, adipose, pectoral, and caudal fins are a dark grey to black coloring, with its anal fin and pelvic fins a white to grey coloring. Full-grown adults can reach SL in length and weigh up to . More commonly the fish's length is around 2 meters.

Development

This species reproduces sexually, and the eggs and sperm are usually released in a muddier area to prevent eggs from sticking to each other. The number of eggs per each spawning is around 600 (with a diameter of 2-2.5mm) and the brood shows low genetic variation. There is no parental care after spawning.

Behavior

The giant pangasius is a

benthopelagic The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

and migratory species. Juveniles and adults feed on

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

s and

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

es. These fish typically spawn just prior to the

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal osci ...

season. It is believed that the ''P. sanitwongsei'' prey on shrimp, crabs, and fish and hideout in deep areas in rivers. The ''P. sanitwongsei'' have a seasonal migration but the fish does not leave the river during its migration, it only stays within the river during the seasonal migration.

Food habits

The ''P. sanitwongsei'' is a carnivorous fish, whose prey consist of shrimp, crabs, and fish. Since the fish lives on the bottom, it is also known to feed on larger animal's carcasses.

Predation

There are no known natural predators of the ''P. sanitwongsei,'' besides humans due to overfishing which is leading to a decline in population.

Reproduction

Little is known of the reproduction of ''P. sanitwongsei,'' but the time of spawning happens in the months of April and May. It is predicted that spawning happens in the rivers that they are found and are not believed to be migrating from outside the river when getting ready to spawn.

Longevity

This fish's lifespan isn't known, but it is known that it grows fast and usually the trend is when it grows fast, it dies quickly. The possible reasoning for this could be the fact that there is over-fishing of the species.

Ecosystem roles

The ''P. sanitwongsei's'' role in the ecosystem is the top predator, or also known as the "umbrella" species for the other species that live in the habitat. Due to overharvesting, the native fish population may increase since the ''P. sanitwongsei'' population is declining.

Economic importance

This fish is important to humans due to the lack of knowledge we have about it, and this fish can show us migratory pathways and spawning habits. This fish also has an important role in fisheries since they are fast growing and can live in poor water environments, plus they bring in good prices for a fish of this fish

Relationship to humans

Fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment, but may also be caught from stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques inclu ...

of this species used to be accompanied by religious ceremonies and

rite Rite may refer to: * Ritual, an established ceremonious act * Rite of passage, a ceremonious act associated with social transition Religion * Rite (Christianity), a sacred ritual or liturgical tradition in various Christian denominations * Cath ...

s. It is often mentioned in textbooks, news media, and popular press. This fish is a popular food fish and marketed fresh, They are introduced to

for both food and ornamental fish. These fish sometimes appear in the aquarium fish hobby. Most specimens do not reach their full size without an extremely large aquarium or pond. There is even a "balloon" form of this fish where the fish has an unusually short and stocky body.

Conservation status

This fish is highly protected and has a high conservation value and is banned from being fished through all seasons. The fish is being threatened by overharvesting, damming rivers, and pollution. A known breeding practice, to try and help the population, is being practiced by the Thai's government, and recommendations about the conservation of this fish is to halt harvesting until the ''P. sanitwongsei's'' population can rise to a safe level.

References

{{Taxonbar, from=Q133444 Pangasiidae Freshwater fish of Southeast Asia Fish of Thailand Fish described in 1931