Predator of clear and blackwater in the Amazon and the Guianas, which eats almost only fish. It turns up on the line now and then and needs careful handling.
Also called: cachorinho, cachorro, pez zorro, pike characin
The cachorinho is of the family Acestrorhynchidae and reaches 37 cm, weighing up to 230 g. It is common in streams and rivers of blackwater and clearwater, and in lagoons and other side habitats of whitewater rivers. It prefers weak current and a sand or mud bottom. It is a formidable predator, like others of its genus, and only in the dry season does it add insects to its diet. It is caught for commercial sale and also for the aquarium.
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 pike characin (cachorinho); in the meantime, see the similar species.
how to recognize it
identification
Elongated body, with a long snout and a small eye relative to the head. A tiny dark spot sits just behind the gill cover, and the lateral line has many scales. To tell it apart from the peixe-cachorro (Acestrorhynchus lacustris), which has a round black spot behind the head, location helps: the cachorinho is from the waters of the Amazon and the Guianas, and the peixe-cachorro from the Paraná and São Francisco basins.
how pike characin (cachorinho) fishing looks
Loading the next 7 days…
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.
Amazon and Orinoco basins and rivers of Guyana, Suriname and French Guiana, also occurring in Peru and Venezuela.
Habitat: Streams and rivers of blackwater and clearwater, lagoons and side habitats of whitewater rivers, with weak current and a sand or mud bottom.
native to the basins
Amazon
what the law says
rules for the pike characin (cachorinho)
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.
Predator with sharp teeth: use pliers to remove the hook and hold it firmly before releasing it.
calculator
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00794, b = 3.02; 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
—
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.
