Pirarucu

Its Portuguese name, pirarucu, derives from the Tupi language words pira and urucum, meaning "red fish".

The pirarucu is among the largest known freshwater fish, commonly measuring 200 cm (79 in) and reportedly reaching lengths of up to 450 cm (15 ft). Adults may weigh up to 200 kg (440 lb). Of the total body weight, head weight is typically 10.3% to 12.8%. The scales of pirarucu, which are typically 5-7 cm but can reach 10 cm in larger individuals, are built from collagen fibers in a layered structure. On the body, they overlap each other to form the armor-like characteristic.

It is an ancient fish, belonging to a group of primitive carnivorous bony-tongued fishes. The pirarucu 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. Red coloration of pirarucu typically shows up in males after sexual maturation, with up to 70% of the total body plan in males having red coloration.

Once believed to be the sole species in the genus Arapaima, it is among the largest freshwater fish. The pirarucu was originally regarded as the only species in the genus Arapaima (monotypic), 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.

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.

Having "a tough-but-flexible inner layer" and "a hard, mineralized outer layer," their "flexible, armor-like scales" help protect the pirarucus against piranha attacks. The species must frequently surface to breathe air because it is an obligate air breather. The arapaima's primary source of oxygen is surface air. It can draw oxygen from the air thanks to its enlarged and modified swim bladder, which is made of tissue that resembles lungs, in addition to its gills.

In South America, its tongue is believed to have therapeutic properties. After being dried, it is blended with grated guarana bark and water. Intestinal worms are killed with doses. The bony scales are used as nail files, while the arapaima's bony tongue is used to scrape cylinders of dry guarana, a component of some drinks.

• Overgrowth (Low) - Fish poop, or fish waste, can be effectively used as a natural fertilizer for plants. Fish waste is rich in essential nutrients like nitrogen, phosphorus, and potassium, which are vital for plant growth. It can be incorporated into the soil or used as a foliar spray, improving soil health and boosting plant development. 

• Controlling Population - Any species of bony fish regulate populations of other marine life, preventing any one species from becoming dominant and disrupting the ecosystem. Their presence also contributes to nutrient cycling and the overall health of the waters.

During the rainy season, the arapaima migrate to floodplains to take advantage of rising waters and new food sources. During the dry season, they return to lacustrine habitats for protection from environmental changes. The arapaimas are carnivorous and eat fish, crustaceans, fruits, seeds, insects, and small land animals. The species are specialized carnivores, feeding primarily on fish. The invertebrates are also part of their diet. Juveniles prefer insects and fish larvae until fully grown. Seasonal growth is observed due food selectivity and strong seasonal changes in food availability. They also consume birds, mammals, fruits, and seeds on the water surface. The prey fish families include Callichthyidae, Loricariidae, Pimelodidae, and Heptapteridae.

In the Araguaia wetlands, the arapaimas are the top predator in lakes during low-water season, except for caimans, jaguars, cougars, river dolphins, otters, condors, harpy eagles, and humans.

The pirarucus are very aggressive, even toward species of their own kind. The pirarucu follows what is coined as the "Biodiversity Conservation Paradox", where a species has become endangered in its native habitat yet becoming growingly invasive in nonnative home ranges. Previously discussed in the "Distribution" section of this page, aquaculture for both fish meat and ornamental markets has caused the spread of the fish where it has become invasive and threaten the integrity of ecosystems.

The pirarucu is native to freshwater in the basin of the Amazon River and Tocantins-Araguaia (Brazil) river basins; it is known to occur in Brazil and Peru. In Bolivia and Peru known as paiche, it is considered an invasive species in most parts, affecting local native species and the ecosystem. Other small populations have been found in the Iquitos region of Peru, four distinct rivers in Ecuador, Colombia, and Guyana.

The arapaima have been introduced to China, Cuba, Mexico, Indonesia, the Philippines, Singapore, and Thailand, there are subsequent consequences that can be followed in the future, as populations are not yet established enough to significantly affect native species. However, it can be assumed that risks would be similar to events observed in Bolivia and Brazil such as decrease in native populations and fishing stock. Some fishermen even say that these large bony-tongued fish damage their nets, therefore causing socio-economic losses.

How the dead arapaima got to the Caloosahatchee River remains a mystery. There's a chance someone had it as a pet and released it into the wild.

• Movement Pattern: Random

• Individual Type: Solo

• Population Trend: Unspecific

• Population: ugh

• Locomotion: Aquatic

• Habitat: Warm River; Cold River; Lukewarm River; Warm Pond; Cold Pond.

• Earth: 

  • Extant (Resident): Brazil; Guyana; Peru

• Berbania/Hirawhassa: 

  • Extant & Introduced (Resident): none

• Reinachos/Ityosel: 

  • Extant & Introduced (Resident): none

• Thatrollwa/Delphia: 

  • Extant & Introduced (Resident): none

• Sawintir/Everrealm: 

  • Extant & Introduced (Resident): none

Coming soon

13,000,000 BCE

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.

Past and Present Incidents - Individuals

• Terran/Gaian

  • n/a

• Berbanian/Hirawhassan

  • n/a

• Reinachos/Ityoselese

  • n/a

• Delphian/Thatrollwan

  • n/a

• Sawintiran

  • n/a 

• Jotunheim

  • n/a

The Recollections of Queen Arianna - Individuals

• Terran/Gaian

  • n/a

• Berbanian/Hirawhassan

  • n/a

• Reinachos/Ityoselese

  • n/a

• Delphian/Thatrollwan

  • n/a

• Sawintiran

  • n/a

• Jotunheim

  • n/a

See also: none

• Coming soon

• Deutsch: Arapaima, piraruku

• English: Arapaima, pirarucu

• Español: Paiche, arapaima, pirarucu

• Eesti: Arapaima, piraruku

• Magyar: Arapaima, piraruku

• Bahasa Indonesia: Arapaima, piraruku

• Italiano: Pirarucu, arapaima

• Hebrew: פיררוקו

• Nihongo: ピラルクー (Pirarukuu)

• Maori: Arapaima, piraruku

• Melayu: Arapaima, piraruku, paiche

• Português: Pirarucu, arapaima

• Tagalog: Arapayma, piraruku

• Thai: ปลาช่อนยักษ์อเมซอน

• Türkçe: Arapayma, piraruko

• 中文: 巨骨舌鱼

• Coming soon

• https://en.wikipedia.org/wiki/Arapaima_gigas

• https://en.m.wikipedia.org/wiki/Arapaima_gigas

• https://species.wikimedia.org/wiki/Arapaima_gigas

• https://www.iucnredlist.org/species/1991/9110195

• https://www.cbsnews.com/news/florida-arapaima-new-invasive-species/

• https://www.britannica.com/animal/pirarucu

• https://materialdistrict.com/material/pirarucu-arapaima-gigas-fish-leather/

• https://animaldiversity.org/accounts/Arapaima_gigas/

• https://www.fishbase.org/summary/2076

• https://www.deviantart.com/ognimdo2002/art/Pirarucu-1098500582