Pimelodus blochii · Pimelodidae · omnivore
The mandi of the Amazon and Araguaia-Tocantins. Travels in schools, eats almost anything and stings anyone who handles it carelessly.
Also called: mandi, mandi-prata, mandi-cabeça-de-ferro, mandi-pintado, mandijuba
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…
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.
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.
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.
A small, gregarious catfish common in the lower reaches of the big Amazon rivers and in the Tocantins-Araguaia. It eats fruit, seeds, insects, small fish and detritus, and helps spread seeds of the flooded forest. It is active by day and night and shelters under logs. It runs upriver to spawn, and the female releases tens of thousands of eggs. It is sold in quantity at markets in the region and is a favorite of anyone fishing from the bank with a cane pole. The serrated spines of the dorsal and pectoral fins cause painful stings.
Silver to grey body, sometimes with dark spots on the flank. Three pairs of long barbels. Strong, serrated spines on the dorsal and pectoral fins. Forked tail. The yellow mandi (Pimelodus maculatus), from the South and São Francisco, is yellowish with large spots.
Amazon basin and Tocantins-Araguaia, especially in the lower stretches of large rivers.
Habitat: Cut banks, eddies, submerged logs and beaches; sand and mud bottoms.
native to the basins
states
Amazonas, Pará, Amapá, Acre, Rondônia, Roraima, Mato Grosso, Tocantins, Goiás, Maranhão
All year; best during falling water and the dry season, with the school concentrated along the cut banks.
Night and twilight. Feeds day and night; bites best in late afternoon and early evening.
Cold spells reduce biting.
Little effect.
Dark nights produce a little more.
When the water starts to cloud, it often activates the school.
A falling river concentrates mandi along the cut banks.
Not very sensitive.
Little effect.
Bottom, 1 to 5 m.
natural baits
accessories
Bait on the bottom at the foot of the bank late in the afternoon. Hold it behind the spines, with a cloth or pliers.
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 national list (Portaria GM/MMA 1.667/2026).
In Goiás the silver mandi (Pimelodus blochii) may only be killed between 15 and 20 cm, and only for consumption on site.
Source: IN Semad-GO nº 17/2026, Annex I (in force May 28, 2026; on-site consumption only, zero transport)
Above 20 cm the silver mandi must be returned to the water in Goiás.
Source: IN Semad-GO nº 17/2026, Annex I (in force May 28, 2026; on-site consumption only, zero transport)
In Tocantins the iron-head mandi (Pimelodus blochii) may only be kept between 15 and 35 cm. In TO recreational anglers may not transport fish until Feb 28, 2029, except one native fish; they may eat up to 3 kg on site (Portaria Naturatins 44/2026).
Source: Portaria Naturatins nº 47/2026, Annex I, as amended by Portaria nº 105/2026
Above 35 cm the mandi must be returned to the water in Tocantins.
Source: Portaria Naturatins nº 47/2026, Annex I, as amended by Portaria nº 105/2026
Allowed: Sport and guided fishing only in reservoirs, catch and release with barbless hooks (no keeping, transporting or eating). Subsistence: up to 5 kg per day, for household consumption only.
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 fishing only in reservoirs, with handline, rod, or spinning or baitcasting reel. Fish may only be eaten on site, not transported. Competitions prohibited. Subsistence: 3 kg + 1 fish. State rules (GO and TO) may be stricter.
Allowed: Recreational fishing only in reservoirs, with on-site consumption. Subsistence: 5 kg + 1 fish. State rules may be stricter.
Allowed: In 2025/26: catch and release with barbless hooks and recreational fishing card; subsistence fishing on foot or from a rowboat, with simple pole or handline.
Source: Portaria Naturatins nº 244/2025 (2025/26 season); INIs MPA/MMA nº 12 and 13/2011
Allowed: The same recreational-angler exceptions as in Portaria 48/2007 apply (handline or rod, 5 kg + 1 fish), unless a stricter state rule applies.
Source: Portaria IBAMA nº 48/2007
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.
Source: Portaria IBAMA nº 48/2007
Allowed: Subsistence fishing only.
Source: Portaria IBAMA nº 48/2007
Allowed: See the exceptions in Portaria 48/2007 and the state rules for each bank.
Source: Portaria IBAMA nº 48/2007
Hold it behind the spines, with a cloth or pliers, and release it quickly.
White, tasty meat; fried whole or in broth.
Length-weight relationship W = a·Lb (a = 0.00912, b = 3.03; FishBase). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
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The season weights (months), the time of day and the sensitivities (cold, pressure, moon, wind, rain, tide, strong light, murky water and noise) are the app's editorial estimates, based on the literature below and on the field experience of anglers and guides. They are not official data nor a measurement made for this species, and they may vary by region and year. Closed seasons and legal rules appear in the rules section, with the norm and a link.
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.
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:
Your location is saved only on this device and feeds the forecast, the map and the "today" on the home page.
