the right time
to be on the water
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.
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hour by hour
slide your finger or mouse over the chart to see each hoursee hour-by-hour table
why this index at —?
choose the day
the fishing month at a glance
what's the best window for the crew?
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.
trend for the coming weeks
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.
everything about the pacu-dente
how to recognize it
Deep-bodied, flattened, silvery fish with the strong dentition typical of the Serrasalmidae family. Reaches 20 cm. It can be confused with the piranhas that also live in Guyana, such as the black piranha (Serrasalmus rhombeus) and the red-bellied piranha (Pygocentrus nattereri). Diet is what separates them: the pacu-dente eats plants and seeds and is not a fish predator.
Also called: pacu-dente, pacu
don't confuse with:
We don't have tips on season, bait or technique for this species yet.
where found
open on the large mapWhere to look: Freshwater rivers of the Essequibo basin, with migrations into streams in the rainy season.
Essequibo River basin in Guyana, in tropical freshwater.
rules for the pacu-dente
Rules change; before keeping or transporting fish, check with the state environmental agency.
We found no species-specific rule beyond the region's general rules.
IUCN global: NT · near threatened.
how much it weighs without taking it out of the water
estimated weight
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how we calculate
Length-weight relationship W = a·Lb (a = 0.02399, b = 2.99; FishBase (relação peso-comprimento bayesiana, estimativa)). It's an average: a fat or lean fish can vary by 10% to 20%.
more about the pacu-dente
The pacu-dente is a freshwater serrasalmid of the family Serrasalmidae, reaching 20 cm. It occurs in the Essequibo River basin in Guyana, in tropical water at 22 to 28 °C. Adults feed almost only on rapids plants (Podostemaceae) and, more rarely, on seeds. During the rainy season it makes long migrations into small streams, where it breeds. It is an important food fish, and it has strong teeth that cause serious bites, so handling calls for care.
Family: Serrasalmidae · omnivore
in the kitchen
An important food fish, with commercial fishing and aquarium use.
similar species
sources and references (2)
Essential profile: size, length-weight, depth, countries and conservation come from FishBase and the cited regulations, and the texts were written from those sources. Season, time of day, sensitivities, technique and baits and lures are not included yet, because we did not find a good source for this species.
- scientific FishBase: Myleus pacu (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Myleus pacuNames by country and language.
how we calculatewhere each number comes from
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.
sources for this lookup
how accurate the forecast is
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: