The madalena belongs to the family Characidae, the same as the lambaris, and has a characin body, compressed from side to side. Reaches 22 centimeters and up to 116 grams. It occurs in the Amazon, Orinoco and Parnaíba basins, in Brazil, Peru and Venezuela. It lives between the bottom and midwater. The Spanish names denton and dientón refer to its large teeth, a trait of the genus Roeboides. In fishing it has commercial use, but it hardly ever shows up on the line of a sport angler.
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 madalena.
how to recognize it
identification
Body compressed from side to side, with the adipose fin typical of characins, a small fleshy fin between the dorsal and caudal fins. Reaches 22 centimeters. The names denton and dientón, used in Peru and Ecuador, point to the large teeth in its mouth. It occurs in the Amazon, the Orinoco and the Parnaíba.
how madalena 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.
It occurs in the Amazon, Orinoco and Parnaíba basins, in Brazil, Peru and Venezuela.
Habitat: Freshwater, from the bottom to midwater.
native to the basins
AmazonParnaíba
what the law says
rules for the madalena
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.
Spawning closure (piracema) in the Parnaíba River basin
15/11 to 16/03PIMACE
Allowed: Recreational fishing from a boat or from shore with handline, rod, spinning or baitcasting reel, up to 5 kg + 1 fish per day. Prohibited within 1,500 m of dams, waterfalls and rapids. Competitions prohibited.
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.
It has no spines or venom. Be careful with its teeth when removing the hook from its mouth.
calculator
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.01259, b = 3.08; 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.
