Arapaima gigas | |
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Beijing Aquarium, China | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Osteoglossiformes |
Family: | Osteoglossidae |
Genus: | Arapaima |
Species: | A. gigas |
Binomial name | |
Arapaima gigas (Schinz, 1822) | |
Synonyms | |
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Arapaima gigas, also known as pirarucu or simply arapaima, [3] is a species of arapaima native to the basin of the Amazon River. Once believed to be the sole species in the genus, it is among the largest freshwater fish. The species is an obligate air breather, so it needs to come to the surface regularly to breathe air.
Arapaima gigas was originally regarded as the only species in the genus Arapaima , but the subsequent identification of further species, together with the rarity of specimens and the loss of several type specimens, has led to some uncertainty regarding classification within the genus and the identity of described individuals. [4]
The species is among the largest known freshwater fish, commonly measuring 200 cm (79 in) and reportedly exceptionally reaching lengths of up to 450 cm (15 ft). Adults may weigh up to 200 kg (440 lb). [5] A. gigas has a streamlined body with dorsal and anal fins set well back towards the tail. While the body is mainly gray to gray-green, its Brazilian local name pirarucu derives from an indigenous word for "red fish", thought to refer to either the red flecks on the scales towards the tail, or the reddish-orange color of its meat. [3] The fish have "flexible, armor-like scales" made up of "a hard, mineralized outer layer" and "a tough-but-flexible inner layer" that help protect it from attacks by piranhas. [6]
A. gigas is native to freshwater in the basin of the Amazon River; it is known to occur in Bolivia, Brazil, Guyana, and Peru. [5] [1] In Bolivia known as paiche, it is considered an invasive species, affecting local native species and the ecosystem. It was first found in 1976, [7] and presumably introduced from Peru being washed out of a Peruvian fish farm by a flood. [8] The species has been introduced to parts of East Asia, both for fishing purposes and accidentally. [3] The fish are found in flooded forest areas where they reproduce during the wet season; they relocate to lakes after water levels drop. [9]
A 13-million-year-old fossil of arapaima (or very similar species) has been found in Colombia, in the Villavieja Formation, which dates from the Miocene epoch. [10]
Morphology changes occur as A. gigas undergoes the transition from water-breather to air-breather 8–9 days after hatch. [11] During the transition to air-breathing, the structure of the gills changes, making them better adapted for ion absorption, but less able to undergo gas diffusion. Once developmental changes in the gills take place, the lamella is less recognizable. The adult gills are made up of smooth, column-shaped filaments, instead. [12] The kidneys have an important role in nitrogenous waste excretion in this species and are enlarged in adult fish. [11]
Both males and females have a gland-like secretory organ on the head. [13] The secretion is made of 400 substances and consist of hormones, proteins, peptides and likely pheromones. [14]
A. gigas requires breathing surface air to supplement the oxygen it derives from the use of its gills, and as such, is dependent on surfacing every 5–15 minutes to loudly gulp air at the surface. As in other species in the genus, a modified swim bladder that contains lung-like tissue is used for this purpose.
The species primarily feeds on fish, although juveniles prefer insects and fish larvae until fully grown. They also consume birds, mammals, fruits, and seeds on the water surface. [15]
Spawning occurs in lakes and river channels during the time of low water levels (August to March). After the young hatch from eggs laid in a nest constructed by both parents, the male remains to protect them for a period of about three months. The young reach sexual maturity at an age of four to five years; average lifespan in captivity is 15–20 years. [3]
The species has in the past been heavily impacted by overfishing, exacerbated by their easily exploited habit of surfacing regularly for air-gulping. The IUCN is currently not assigning a conservation status to A. gigas due to a lack of detailed information about population developments. [3] Arapaima fishing was banned outright in Brazil from 1996 to 1999, due to declining populations; since then, both subsistence and commercial fishing have been permitted in specially designated areas, and a sophisticated sustainable management strategy has led to massive recovery of stocks, from 2,500 in 1999 to over 170,000 in 2017. [16]
For Bolivia, the paiche as an invasive species is considered a threat to local native species according to reports. Various reports show a correlation between the spreading of paiche and the decline in numbers of native fish species in parts of the Bolivian Amazon. Effects on local fish species populations and on fishing behaviors vary strongly by region. [8] A joint study of the Bolivian government and different research organizations from 2017 points out the necessity to further evaluate the complex environmental and socioeconomic impact of paiche in the country. [17]
Lungfish are freshwater vertebrates belonging to the class Dipnoi. Lungfish are best known for retaining ancestral characteristics within the Osteichthyes, including the ability to breathe air, and ancestral structures within Sarcopterygii, including the presence of lobed fins with a well-developed internal skeleton. Lungfish represent the closest living relatives of the tetrapods. The mouths of lungfish typically bear tooth plates, which are used to crush hard shelled organisms.
The bowfin is a bony fish, native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being one of only two surviving species of the Halecomorphi, a group of fish that first appeared during the Early Triassic, around 250 million years ago. The bowfin is often considered a "primitive fish" because they have retained some morphological characteristics of their early ancestors. It is one of two species in the genus Amia, along with Amia ocellicauda, the eyespot bowfin. The closest living relatives of bowfins are gars, with the two groups being united in the clade Holostei.
An aquatic animal is any animal, whether vertebrate or invertebrate, that lives in water for all or most of its lifetime. Many insects such as mosquitoes, mayflies, dragonflies and caddisflies have aquatic larvae, with winged adults. Aquatic animals may breathe air or extract oxygen from water through specialised organs called gills, or directly through the skin. Natural environments and the animals that live in them can be categorized as aquatic (water) or terrestrial (land). This designation is polyphyletic.
The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about 7,000,000 km2 (2,700,000 sq mi), or about 35.5 percent of the South American continent. It is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela, as well as the territory of French Guiana.
The South American lungfish, also known as the American mud-fish and scaly salamanderfish, is the single species of lungfish found in swamps and slow-moving waters of the Amazon, Paraguay, and lower Paraná River basins in South America. Notable as an obligate air-breather, it is the sole member of its family Lepidosirenidae, although some authors also place Protopterus in the family. In Brazil, it is known by the indigenous language Tupi name piramboia, which means "snake-fish", and synonyms pirarucu-bóia, traíra-bóia, and caramuru.
The arapaima, pirarucu, or paiche is any large species of bonytongue in the genus Arapaima native to the Amazon and Essequibo basins of South America. Arapaima is the type genus of the subfamily Arapaiminae within the family Osteoglossidae. They are among the world's largest freshwater fish, reaching as much as 3 m (9.8 ft) in length. They are an important food fish. They have declined in the native range due to overfishing and habitat loss. In contrast, arapaima have been introduced to several tropical regions outside the native range, where they are sometimes considered invasive species. In Kerala, India, arapaima escaped from aquaculture ponds after floods in 2018. Its Portuguese name, pirarucu, derives from the Tupi language words pira and urucum, meaning "red fish".
Protopterus is the genus of four species of lungfish found in Africa. Protopterus is considered the sole genus in the family Protopteridae, which is grouped with Lepidosiren in the order Lepidosireniformes.
Pseudorinelepis genibarbis is a species of armored catfish native to Brazil, Peru, and Ecuador where it is found in the Amazon basin.
Amphibious fish are fish that are able to leave water for extended periods of time. About 11 distantly related genera of fish are considered amphibious. This suggests that many fish genera independently evolved amphibious traits, a process known as convergent evolution. These fish use a range of terrestrial locomotory modes, such as lateral undulation, tripod-like walking, and jumping. Many of these locomotory modes incorporate multiple combinations of pectoral-, pelvic-, and tail-fin movement.
A fish is an aquatic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits. Fish can be grouped into the more basal jawless fish and the more common jawed fish, the latter including all living cartilaginous and bony fish, as well as the extinct placoderms and acanthodians. Most fish are cold-blooded, their body temperature varying with the surrounding water, though some large active swimmers like white shark and tuna can hold a higher core temperature. Many fish can communicate acoustically with each other, such as during courtship displays.
Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations.
Mimagoniates microlepis, also known as the blue tetra, the croaking tetra, the small-scaled tetra, is a species of tetra in the genus Mimagoniates. First identified by Franz Steindachner in 1876 and named Coelurichthys microlepis, it has also been identified as Coelurichthys iporangae, Coelurichthys lateralis, and Mimagoniates iporangae besides its current taxonomic classification. There is evidence of a variety called M. microlepis 'Joinville' which might be synonymous with Paragoniates microlepis.
Tarpon are fish of the genus Megalops. They are the only members of the family Megalopidae. Of the two species, one is native to the Atlantic, and the other to the Indo-Pacific Oceans.
Polyacanthorhynchidae is a family of parasitic worms from the. It contains a single genus Polyacanthorhynchus.
A. gigas may refer to:
Pterygoplichthys pardalis, the Amazon sailfin catfish, is a freshwater tropical fish in the armored catfish family (Loricariidae). It is one of a number of species commonly referred to as the common pleco or "leopard pleco" by aquarists.It can be called 豹紋翼甲鯰 in Mandarin Chinese.
Fish gills are organs that allow fish to breathe underwater. Most fish exchange gases like oxygen and carbon dioxide using gills that are protected under gill covers (operculum) on both sides of the pharynx (throat). Gills are tissues that are like short threads, protein structures called filaments. These filaments have many functions including the transfer of ions and water, as well as the exchange of oxygen, carbon dioxide, acids and ammonia. Each filament contains a capillary network that provides a large surface area for exchanging oxygen and carbon dioxide.
Arapaiminae is a subfamily of freshwater osteoglossiform (bony-tongued) fishes belonging to the family Osteoglossidae. It includes the South American arapaimas of the Amazon and Essequibo basins and the African arowana from the watersheds of the Sahelo-Sudanese region, Senegal, Gambia, and parts of Eastern Africa. This subfamily is sometimes raised to the rank of family, as Arapaimidae. A commonly used synonym is Heterotidinae, but according to the ICZN, Arapaiminae has priority.
Arapaima leptosoma is a species of freshwater fish endemic to Brazil. It is a member of the arapaimas, a genus of air-breathing fish that contains some of the world's largest freshwater fish. Like other members of the genus Arapaima, this fish can breathe air. It is known only from the confluence of the Solimões and Purus Rivers in Amazonas, Brazil, although due to the lack of obvious geographic barriers, it likely has a larger range.
The Marajó várzea (NT0138) is an ecoregion of seasonally and tidally flooded várzea forest in the Amazon biome. It covers a region of sedimentary islands and floodplains at the mouth of the Amazon that is flooded twice daily as the ocean tides push the river waters onto the land. The flooded forests provide food for a wide variety of fruit-eating fish, aquatic mammals, birds and other fauna. It has no protected areas and is threatened by cattle and water-buffalo ranching, logging and fruit plantations.
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