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 gulf butterfish
how to recognize it
Oval, tall and very compressed body, light blue on the back and silvery below, without spots; the silvery color fades after death. The mouth is small, with a short, rounded snout, and the lower jaw slightly overhangs the upper. The dorsal and anal fins are long, almost the same size, and the pectoral fins are longer than the head and pointed. It has no pelvic fins, and the caudal fin is deeply forked.
Also called: peixe-manteiga-do-golfo, palometa del golfo, gulf butterfish
We don't have tips on season, bait or technique for this species yet.
where found
open on the large mapWhere to look: Sand and mud bottoms of the continental shelf, 2 to 275 m, most abundant between 155 and 225 m.
In Latin America it occurs only in Mexico, in the Gulf of Mexico, in shelf waters.
rules for the gulf butterfish
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.
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 = 0.0138, b = 3.01; FishBase (relação peso-comprimento bayesiana, estimativa da própria espécie)). It's an average: a fat or lean fish can vary by 10% to 20%.
more about the gulf butterfish
Fish of the family Stromateidae, with an oval, tall and very compressed body, reaching 25 cm. It forms loose schools over the continental shelf, on sand and mud bottoms. It stays near the bottom during the day and rises into midwater at night. Adults eat jellyfish, small fish, crustaceans and worms, and juveniles feed on plankton and jellyfish. It occurs in the Gulf of Mexico, from the Tampa region in Florida to Yucatán, Mexico. It is highly valued as food and is mainly caught with trawl nets.
Family: Stromateidae · predator
fun facts
- Juveniles are found under floating algae and alongside jellyfish.
in the kitchen
Highly valued as food, sold fresh and frozen.
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: Peprilus burti (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Peprilus burtiNames 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: