fantail flounder
Xystreurys liolepis · Paralichthyidae · predator
Eastern Pacific flounder with a fan-shaped tail that buries itself in mud and sand. It is sold fresh and also attracts sport anglers.
Also called: linguado-cauda-de-leque, linguado, fantail flounder
- maximum
- 64 cm
- record/max.
- 4.0 kg
- depth
- 5–79 m
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.
Reading the weather across 3 global models and 31 simulations…
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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
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.
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 fantail flounder
who is the fantail flounder
The fantail flounder is a fish of the family Paralichthyidae that lives in the eastern Pacific, from Monterey Bay, United States, to the Gulf of California, Mexico. It occurs on mud and sand bottoms, from 5 to 79 m, where it usually lies buried. It feeds almost only on crustaceans. It reaches 63.5 cm and 4 kg, and its common size is 25 cm. It has little commercial importance and is sold fresh, but it is also targeted by rod anglers.
Essential profile. Identification, where it occurs and rules, with data from FishBase and the cited regulations. Season, time of day, technique and bait are added once we have a good source for the fantail flounder; in the meantime, see the similar species.
fun facts
- It feeds almost only on crustaceans.
- It usually lies buried in the mud and sand bottom.
identification
Flatfish with a short, deep body and a wide tail that fans out, which gives it its Portuguese name. It usually lies buried in mud and sand. On the same coast, the California halibut (Paralichthys californicus) is much larger: it reaches 152 cm, against 63.5 cm for this species. Size is enough to tell the two apart.
where found
In Latin America, it occurs in Mexico, as far as the Gulf of California. Farther north, it reaches Monterey Bay, United States.
Habitat: Mud and sand bottoms, from 5 to 79 m, usually buried.
rules for the fantail flounder
Summary of the regulations we found, with the source for each. 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.
catch and release
catch and release Releasing the fish alive, quickly and with a wet hand. During a closed season it isn't always allowed: what the regulation says applies.
It has no spines or venom and is not dangerous. Release it carefully and remove the hook with pliers.
in the kitchen
It is sold fresh and has little commercial importance.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00741, b = 3.22; FishBase (relação peso-comprimento bayesiana, estimativa da própria espécie)). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
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sources and references
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: Xystreurys liolepis (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Xystreurys liolepisNames by country and language.
similar species
where 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: