blue bobo
Polydactylus approximans
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
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.
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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.
Essential profile: the index uses a general fish model (weather, sun, moon and tide), without a season or time of day specific to this species.
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.
