Schizodon fasciatus · Anostomidae · omnivore
The striped piau of the Amazon várzea. A schooling herbivore, widely sold in Manaus and Santarém and a good fighter on light tackle.
Also called: aracu-comum, aracu, araçu, aracu-pinima, aracu-pintado, piau
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 relative of the southern piaus, the common aracu eats plant debris, leaves and algae in várzea lakes. It lives in schools and migrates with the water cycle. During the rise and the flood it stores fat, which it uses to mature its gonads; it grows faster in falling water. Males mature from about 18 cm and females from 22 cm. It is a regular at markets in Amazonas and Pará. On the hook it takes dough, corn and fruit over groundbait, and it is a challenge on a light rod.
Elongated, rounded body, silver to yellowish, with three to four dark vertical bands on the flank and a dark spot at the base of the tail. Small mouth at the tip of the snout, with incisor-like teeth. Piaus of the genus Leporinus have different spots or bands; the piau-três-pintas has three round spots, not bands.
Várzea lakes and whitewater rivers of the Amazon, especially the middle and lower Amazon (Manaus, Santarém). FishBase also records coastal rivers of French Guiana.
Habitat: Várzea lakes, paranás, grassy banks and aquatic vegetation; flooded forest in the flood.
native to the basins
states
Amazonas, Pará, Amapá, Acre, Rondônia
famous destinations
Best in falling water and the dry season (July to November), with the school concentrated. There is a closed season from Nov 15 to Mar 15 in Pará and Amapá.
Daytime, with peaks at dawn and dusk. Active by day, with peaks early and late in the afternoon.
Cold snaps (friagem) keep the school still.
A bad-weather front shuts down the bite for a day or two.
Little effect.
Light rain doesn't bother it.
A falling lake concentrates the fish at the mouths and channels.
Staying quiet on the bank pays off more.
Little effect.
Shallow, 0.5 to 3 m.
natural baits
accessories
Nibbles like the piaus: small hook, groundbait, and a quick strike at the first touch.
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).
In PA and AP the aracu (Schizodon spp.) is in Annex II of the ordinance, with fishing prohibited from Nov 15 to Mar 15. Under art. 2 of the ordinance, anglers fishing with a handline or pole, line and hook are exempt from this ban, unless a stricter state rule applies; during the period the angler's limit is 5 kg + 1 fish.
In the rivers of Marajó Island the aracu (Schizodon spp.) is on the fishing ban list from Jan 1 to Apr 30. Under art. 2 of the ordinance, anglers fishing with a handline or pole, line and hook are exempt from this ban, unless a stricter state rule applies; during the period the angler's limit is 5 kg + 1 fish.
The MT law lists the 'piau-cabeça-gorda (Schizodon fasciatum)' with a minimum of 30 cm in the Araguaia stretch from the headwaters (GO) to Antônio Rosa (MT), including the Araguaia National Park. In MT, anglers may only kill for consumption on site (up to 2 kg or 1 fish, art. 19-C); the rule applies to that kill.
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: 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
Hardy: remove the hook in the water and release it.
White, fatty meat in season. Fried in steaks with fine cuts or grilled over coals.
Length-weight relationship W = a·Lb (a = 0.01259, b = 3.06; FishBase). 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.
