blue bobo
Polydactylus approximans · Polynemidae · omnivore
Grey threadfin of bays, estuaries and beaches in the eastern Pacific, from Mexico to Peru. It is a highly prized food fish where it occurs.
Also called: barbudo-azul, barbudo azul, barbudo seis barbas, guapuro azul, Blue bobo
- maximum
- 37 cm
- depth
- 10–60 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
tap or drag on the chart to read each hour · on a keyboard, arrow keyssee 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 blue bobo
who is the blue bobo
The blue threadfin is a fish of the family Polynemidae, found in shallow waters near the coast, in bays, tidal channels and estuaries of the eastern Pacific, from Mexico to Peru. It lives on sand or mud bottoms, from 10 to 60 m, and reaches 36.8 cm, with a common size of 20 cm. It feeds on worms, shrimp, sand crabs and mollusks, and sometimes eats small fish. It is a highly prized food fish where it occurs, and it has long filaments below the pectoral fins.
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 blue bobo; in the meantime, see the similar species.
fun facts
- Larvae and small juveniles are pelagic and sometimes occur hundreds of kilometers from the coast.
identification
Grey fish with no stripes or spots and a well-developed lower lip. The filaments of the pectoral fins do not reach past the end of the anal fin base. The lateral line splits on the tail membranes. It has a swim bladder. Unlike the yellow threadfin (Polydactylus opercularis), which is yellowish and has no bladder, this species is grey.
where found
In Latin America it ranges from Mexico to Peru, with records in the Galápagos. The record in Chile still needs to be confirmed.
Habitat: Shallow waters near the coast, in bays, tidal channels and estuaries, over sand or mud bottoms, from 10 to 60 m.
rules for the blue bobo
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.
Not dangerous. Release it carefully, with wet hands, since it is a bay and estuary fish.
in the kitchen
Highly prized as a food fish where it occurs.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00661, b = 3.06; 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: Polydactylus approximans (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Polydactylus approximansNames 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: