A slender piau of fast-flowing streams, with records in the Guaporé and Negro rivers in Brazil, and in the Orinoco basin. It has commercial and aquarium use.
The slender piau belongs to the family Anostomidae and reaches 18 cm, with a common size of 14 cm. It lives in streams with strong current, in shallow water up to 1 m deep. Adults stay in crevices. It occurs in the Guaporé and Negro rivers in Brazil, and in the Orinoco basin in Venezuela. Pairs breed in places with dense vegetation. It has commercial use and is also sold for aquariums, but it rarely turns up on the line of 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 piau-esguio; in the meantime, see the similar species.
how to recognize it
identification
A spindle-shaped, slender body, with 12 soft rays in the dorsal fin and 11 to 12 in the anal fin. It lacks a dark spot at the center of the scales, which sets it apart from some specimens of the three-spot piau (Pseudanos trimaculatus), a close relative. It is also told apart by habitat: the slender piau lives in fast streams, among crevices, while the other forms schools in deeper water.
how piau-esguio fishing looks
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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.
Guaporé and Negro rivers, in the Brazilian Amazon, and the Orinoco basin, in Venezuela.
Habitat: Streams with strong current, in rock crevices and shallow water up to 1 m deep.
native to the basins
Amazon
what the law says
rules for the piau-esguio
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency. Conservation: Not on the Brazilian national list (Ministerial Ordinance GM/MMA No. 1.667/2026).
We found no species-specific rule beyond the region's general rules.
piracema closures in the basins where the species lives
Spawning closure (piracema) in Mato Grosso (all basins)
01/10 to 31/01MT
Allowed: All fishing modalities are prohibited in rivers, including catch and release (Law 9.096/2009, art. 19-A). Exceptions: subsistence fishing from shore (3 kg or 1 fish, no transport or sale) and scientific fishing. Law 13.159/2025 now allows licensed sport fishing in UHE/PCH hydropower reservoirs, natural lakes and border rivers, subject to a scientific study and a license from the environmental agency. We have not confirmed whether these licenses are already being issued.
Allowed: Recreational anglers with handline or rod, line and hook are outside the Annex II prohibitions, with a bag limit of 5 kg + 1 fish, unless a stricter state rule applies.
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.
A small fish: remove the hook in the water carefully and release it promptly.
calculator
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.01072, b = 3.04; FishBase (relação peso-comprimento bayesiana, estimativa)). 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.
