Arapaima gigas · Arapaimidae · predator
One of the largest scaled freshwater fish in the world. It breathes air and can only be fished in managed areas across most of the Amazon.
Also called: pirarucu, pirosca (Tocantins), bodeco (jovem)
Choose the place and the species. The index, from 0 to 100, combines weather, sun, moon and tide with each fish's habits. Up to 28 days, with each day's confidence.
Reading the weather across 3 global models and 31 simulations…
Each card shows the day's index (0 to 100) and, below it, a strip with the index for each hour, from 0h to 23h. from poor to excellent.
Choose how many fishing days. We compare each stretch by its average index, discount days with a warning or closed season, and show the 3 best.
Line: the middle value of 31 simulations of the American GEFS model. Band: where 8 out of 10 fall. Narrow, firm trend; wide, high uncertainty.
A scaled giant of the Amazon, the arapaima breathes air and must surface every 10 to 20 minutes, the so-called boiada. It lives in várzea lakes, igapós and still-water eddies, where it hunts fish, shrimp and crabs. Pushed close to collapse by harpoon and gillnet fishing, it has recovered thanks to community management, in which the annual quota depends on counting adult fish in the lakes. Fishing is tightly regulated and, in Amazonas, happens only under authorized management. Outside the Amazon it was released into dams and reservoirs and is treated as an invasive species.
Huge, cylindrical and elongated body, flat bony head, large thick scales. The dorsal and anal fins sit far back, near the tail, forming a paddle. Scales on the rear half with a strong red edge. The arowana is much slimmer and silver, and has barbels on the chin. No other Amazonian fish has that red at the rear at that size.
Várzea and igapó lakes of the Amazon basin and of the Araguaia-Tocantins (Bananal Island). Introduced to dams in the Northeast, in the Baixada Maranhense, to Lake Paranoá (DF), to rivers in Goiás and to the upper Madeira, above Santo Antônio (RO).
Habitat: Várzea lakes, igapós, eddies and still-water channels with vegetation; avoids strong current.
native to the basins
introduced in
states
Amazonas, Pará, Amapá, Acre, Rondônia, Roraima, Tocantins, Mato Grosso, Maranhão, Ceará, Rio Grande do Norte, Paraíba, Goiás, Distrito Federal
In the dry season, from August to November, arapaima are trapped in the lakes, which is when counting and managed fishing take place. Spawning occurs at the start of high water.
Daytime, with peaks at dawn and dusk. Feeds most early in the morning and late in the afternoon, but surfaces to breathe all day. The boiada shows where it is.
Friagem reduces its feeding, but it keeps surfacing.
Moderate effect.
Little effect.
Heavy rain makes the boiada hard to see.
An isolated lake in the dry season concentrates many fish; in high water they spread through the flooded forest.
Extremely wary. A motor, hard paddling or loud talk sends the fish down for a long time.
Strong wind hides the boiada in the chop.
It stays 1 to 5 m deep, but rises to the surface to breathe all the time.
lures
natural baits
accessories
Cast a bit ahead of where it surfaced, in the direction the ripple moved, and wait: it usually feeds right after breathing.
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
Conservation: Not on the national list (Portaria GM/MMA 1.667/2026). Listed in Appendix II of CITES. Populations have recovered where community management exists.
In Amazonas, capture, transport and sale of arapaima are banned year-round (December to May under the federal rule and June to November under the Ibama rule in the state). The only exception is fishing under an approved management plan, with a quota of up to 30% of counted adults, sealed fish and a transport permit. Catch and release also requires authorization from the area.
In the Amazon basin, in the states of Amazonas, Pará, Acre and Amapá, it is banned to catch, sell and transport arapaima from December 1 to May 31. Fish from registered fish farms, with proof of origin, is allowed.
In Rondônia the arapaima closed season runs from November 1 to April 30. Above the Santo Antônio dam, on the upper Madeira, the invasive-species rule applies.
In Roraima, with a different flood regime, the arapaima closed season runs from March 1 to August 31.
Where fishing is allowed, a whole arapaima must be at least 1.50 m in total length. Fresh manta, 1.20 m; dried manta, 1.10 m. It is banned to cut wet manta horizontally.
In the Araguaia-Tocantins basin, arapaima has its own closed season from October 1 to March 31.
In the Araguaia-Tocantins the federal minimum is 1.55 m for a whole fish. In Tocantins the state ordinance sets a 120 to 180 cm window; combining both rules, only fish between 1.55 and 1.80 m may be kept.
Source: Instrução Normativa MMA nº 24/2005; Portaria NATURATINS/GABIN nº 47/2026 (TO)
Until December 31, 2028, arapaima caught in Mato Grosso rivers may not be transported, stored or sold. Amateur anglers may only practice catch and release. The law is being challenged at the STF, but the injunction was denied in 2024.
Source: Lei estadual nº 12.434/2024 (MT), arts. 19-B and 19-C of Lei 9.096/2009
Outside its natural range, including the upper Madeira above the Santo Antônio dam (RO), arapaima is an invasive exotic species. Fishing allowed year-round, with no quota or minimum size. Catch and release is banned: the fish caught must be killed. Sale only within the state of capture.
Arapaima (pirarucu) closed season. Minimum size: 150 cm.
Source: IN IBAMA nº 34/2004
Arapaima (pirarucu) closed season in Rondônia.
Arapaima (pirarucu) closed season in Roraima.
The Ibama table has two entries for Acre: Jun 1 to Nov 30 (IN Ibama-AC 1/2008) and Dec 1 to May 31 (IN IBAMA 34/2004). Together, they cover the whole year. We could not clarify this: treat arapaima (pirarucu) in Acre as prohibited and confirm with Ibama-AC.
Annual arapaima (pirarucu) closed season across the Araguaia-Tocantins basin.
Source: IN MMA nº 24/2005
Transport, storage and sale are fully prohibited for 5 years from Jan 1, 2024 for: cachara, caparari, dorado, jaú, matrinchã (Brycon spp.), pintado/surubim (Pseudoplatystoma spp.), piraíba, piraputanga, pirarara, arapaima (pirarucu), trairão and peacock bass (tucunaré, Cichla spp.). For recreational anglers: catch and release only. These 12 species may not even be eaten on site, since the 2 kg or 1 fish limit excludes the art. 19-B list. The law cites jaú as Zungaro zungaro; we also include the Pantanal jaú (Z. jahu) out of caution. The list may still change: § 2 (exotic and predatory species), § 3 (review through study) and the 3-year assessment planned for 2027. A TJMT news report of Jun 2, 2026 confirms the 12 prohibited species. The STF denied a preliminary injunction in the ADIs against the law in 2024; we found no merits ruling.
In Amazonas, arapaima (pirarucu) fishing is allowed only in authorized managed areas, with a quota. Outside them, it is prohibited year-round. Minimum size: 150 cm.
Source: Portaria Naturatins nº 47/2026, Annex I, as amended by Portaria nº 105/2026
Source: INIs MPA/MMA nº 12/2011 (Araguaia) and 13/2011 (Tocantins), minimum size annexes
Source: Portaria IBAMA nº 8/1996, art. 5º (Amazon basin, except Araguaia-Tocantins)
Allowed: Sport and guided fishing only in reservoirs, catch and release with barbless hooks (no keeping, transporting or eating). Subsistence: up to 5 kg per day, for household consumption only.
Allowed: All fishing modalities are prohibited in rivers, including catch and release (Law 9.096/2009, art. 19-A). Exceptions: subsistence fishing from shore (3 kg or 1 fish, no transport or sale) and scientific fishing. Law 13.159/2025 now allows licensed sport fishing in UHE/PCH hydropower reservoirs, natural lakes and border rivers, subject to a scientific study and a license from the environmental agency. We have not confirmed whether these licenses are already being issued.
Allowed: Recreational fishing only in reservoirs, with handline, rod, or spinning or baitcasting reel. Fish may only be eaten on site, not transported. Competitions prohibited. Subsistence: 3 kg + 1 fish. State rules (GO and TO) may be stricter.
Allowed: Recreational fishing only in reservoirs, with on-site consumption. Subsistence: 5 kg + 1 fish. State rules may be stricter.
Allowed: In 2025/26: catch and release with barbless hooks and recreational fishing card; subsistence fishing on foot or from a rowboat, with simple pole or handline.
Source: Portaria Naturatins nº 244/2025 (2025/26 season); INIs MPA/MMA nº 12 and 13/2011
Allowed: The same recreational-angler exceptions as in Portaria 48/2007 apply (handline or rod, 5 kg + 1 fish), unless a stricter state rule applies.
Source: Portaria IBAMA nº 48/2007
Allowed: Recreational anglers with handline or rod, line and hook are outside the Annex II prohibitions, with a bag limit of 5 kg + 1 fish, unless a stricter state rule applies.
Source: Portaria IBAMA nº 48/2007
Allowed: Subsistence fishing only.
Source: Portaria IBAMA nº 48/2007
Allowed: See the exceptions in Portaria 48/2007 and the state rules for each bank.
Source: Portaria IBAMA nº 48/2007
Don't lift the fish out of the water or by the mouth or gills: the weight injures the spine and organs. Keep it in the water, let it breathe and release it quickly. An exhausted fish needs to be able to surface to breathe air.
White, boneless and highly valued flesh: arapaima de casaca, breaded cutlets, dried and salted like cod. Buy only with the management or fish farm seal.
Length-weight relationship W = a·Lb (a = 0.01096, b = 2.94; FishBase (bayesiano, espécie + forma do corpo da família)). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
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The season weights (months), the time of day and the sensitivities (cold, pressure, moon, wind, rain, tide, strong light, murky water and noise) are the app's editorial estimates, based on the literature below and on the field experience of anglers and guides. They are not official data nor a measurement made for this species, and they may vary by region and year. Closed seasons and legal rules appear in the rules section, with the norm and a link.
The weather comes from three independent global models, cross-checked hour by hour: when they agree, confidence goes up; when they diverge, the band between them shows on the chart. Beyond 16 days, we use the GEFS ensemble of 31 simulations: if 20 of the 31 predict rain, the chance of rain is 65%. Sun and moon are calculated astronomically, with no uncertainty.
The index adds up, weighted for each species: time of day (species curve anchored to real sunrise and sunset), moon (transits, rise and set, phase), pressure (3 h trend and 24 h swing), water temperature (in rivers, estimated from air temperature; at sea, estimated by an ocean model), wind, rain, clouds, tide and the month in the species' cycle.
Accuracy measured in the reference project (4 regions, 93 days, forecast vs. observed): maximum temperature is off by 0.6 °C on average the next day and 1.7 °C at 7 days; rain of 5 mm or more is detected 76% of the time the next day and 57% at 7 days. Detection isn't everything: the false alarm rate isn't published here yet, and 93 days in 4 regions is still a small sample. We now also measure every day, at the app's destinations:
Your location is saved only on this device and feeds the forecast, the map and the "today" on the home page.
