the right time
to be on the water
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.
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hour by hour
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why this index at —?
choose the day
the fishing month at a glance
what's the best window for the crew?
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.
trend for the coming weeks
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.
everything about the catfish (focinho-de-porco)
how to recognize it
Grayish-brown to dark brown body, lighter on the belly, covered in bony plates that form the 'armado', with a small head relative to the body and a snout that resembles a pig's, hence the name. Strong spines on the pectoral and dorsal fins. It is confused with the common armado (Pterodoras granulosus), which Santa Fe species accounts give as about 70 cm and 4.5 kg, while the pig-snouted fish reaches 9 kg. When in doubt, treat both as armado.
Also called: focinho-de-porco, armão, botoado
don't confuse with:
where found
open on the large mapWhere to look: Channels and backwaters of large rivers, over stone and sand bottoms, where it stirs up the substrate looking for food.
Plata basin: Paraná, Paraguay and Uruguay rivers and the Río de la Plata. In Brazil, in parts of the Paraná, Paraguay and Uruguay basins; outside Brazil, Argentina, Paraguay, Uruguay and Bolivia.
native to the basins
when to fish
best season
The spawning season has not been confirmed. In the Plata basin, bottom catfish fishing tends to be better with warm water, from September to February.
best time of day
Any time. Little studied. It searches for food on the bottom, with no clearly defined schedule; bottom fishing usually produces from late afternoon into early evening.
what affects the catfish (focinho-de-porco)
cold and cold fronts
It cools and becomes less active in winter; fishing improves with lukewarm water.
atmospheric pressure
Little effect.
moon
Small effect.
rain
Heavy rain and high water cloud the water and scatter the fish.
water level
A stable or falling river concentrates fish in the channels and backwaters.
noise
Moderate: avoid knocking the hull.
wind
Little effect on the bottom.
depth
Bottom of backwaters and channels, 3 to 10 m.
how to fish
natural baits
- minhoca
- ripe fruit
- fish pieces
- caramujo
tip from an angler
Enough sinker to hold the bait on the bottom in the current, and strong-smelling bait such as worm or ripe fruit. Set the hook when the line tightens, and wear gloves when removing the hook.
- rod
- 6'6" to 7', medium-heavy action, 20 to 40 lb
- spinning / baitcasting reel
- 5000 to 6000 spinning reel or low-profile baitcaster 300
- line
- braid 30 to 50 lb
- leader
- heavy 0.60 to 0.80 mm monofilament, 60 cm, to withstand rubbing from the plates
- hook
- 2/0 to 5/0, forged
accessories
- thick gloves
- long-nose pliers
- boga-grip
catch and release
Wear thick gloves and watch the pectoral and dorsal spines and the lateral plates. Hold the fish firmly by the body, remove the hook with long pliers, and release it slowly, facing the current.
rules for the catfish (focinho-de-porco)
Rules change; before keeping or transporting fish, check with the state environmental agency.
Santa Fe (AR): minimum size 45 cm
45 cm total lengthconfirm with the agency details
Santa Fe Provincial Law 12.212, art. 10, sets 45 cm for the armado chancho (Oxydoras kneri) in the commercial fishing table in the alluvial valley of the Paraná River; for sport fishing in environments and species not listed, the measures are left to the enforcement authority. According to the press, sport fishing in Santa Fe has its own rules (resolutions of the Environment Ministry, with mandatory release and on-site consumption within size and quota limits). We did not check these texts or the rules of Corrientes, Entre Ríos, Misiones and Chaco.
Source: Ley provincial de Santa Fe nº 12.212, art. 10 (copy published by the press)
Paraguay: annual closed season for fishing in shared rivers
in 2025/26: November 2 to December 20 (waters shared with Argentina) and until January 31, 2026 (waters shared with Brazil); boat fishing, sport or commercial, transport and sale prohibitedconfirm with the agency details
Paraguay's Ministry of the Environment (MADES) sets the closed season each year, by resolution, for rivers shared with Argentina and Brazil. In 2025/26 it began on November 2, 2025 and ended on December 20 in waters shared with Argentina and on January 31, 2026 in waters shared with Brazil. All boat fishing, sport or commercial, the use of gear, transport and sale of fish, and the sale of live bait are prohibited; licensed farmed fish are excluded. Dates for 2026/27 have not yet been published. The resolution number has not been confirmed.
Source: MADES (Paraguay) Resolution on the 2025/26 fishing closed season, per Prensa Mercosur
piracema and closed seasons
Each bar is the period when fishing is prohibited or restricted. The green line is today. Tap the name to see what is still allowed.
Spawning closure (piracema) in the Paraná River basin
Allowed: Recreational fishing only for non-native species and hybrids (peacock bass, tilapia, black bass, carp, croaker, etc.; piauçu remains prohibited), with handline, simple pole, or rod with spinning or baitcasting reel, up to 10 kg + 1 fish. In rivers, from shore only; in reservoirs, from a boat or from shore. Prohibited: floodplain lakes, aquatic-animal bait, within 1,500 m of dams and waterfalls, and within 500 m of confluences. Tournaments only in reservoirs and only with non-native species.
Source: IN IBAMA nº 25/2009
Spawning closure (piracema) in Minas Gerais (state rule)
Allowed: Only exotic or hybrid species, 3 kg + 1 fish per day, with handline, rod, simple pole, or spinning or baitcasting reel. Nets prohibited. Keep the minimum distances from dams and reservoirs.
Source: Portarias IEF nº 154/2011 (São Francisco), 155/2011 (East) and 156/2011 (Grande/Paranaíba)
Closed season in Goiás (state rule)
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.
Spawning closure (piracema) in the Pantanal of Mato Grosso do Sul
Allowed: Subsistence fishing by riverside residents and authorized scientific fishing. Decree 15.166/2019 (art. 11, §5) allows catch and release only in February and only in the channels of the Paraguay and Paraná rivers. For the rest of the period, not even catch and release is allowed. Check the Imasul portaria for each season.
Source: Decreto estadual MS nº 15.166/2019, art. 11; IN IBAMA nº 201/2008
Spawning closure (piracema) in Mato Grosso (all basins)
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 Uruguay River basin
Allowed: Recreational fishing from shore, or from a boat without motor. Only handline or rod, line and hook, one gear per angler, up to 5 kg. Prohibited in floodplain lakes, within 1,500 m of dams, within 500 m of confluences, and in stretches listed in the rule (e.g., Turvo River).
Source: IN IBAMA nº 193/2008
Conservation: Not on the Brazilian national list (Ministerial Ordinance GM/MMA No. 1.667/2026).
how much it weighs without taking it out of the water
estimated weight
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how we calculate
Length-weight relationship W = a·Lb (a = 0.01479, b = 2.99; FishBase (relação peso-comprimento bayesiana, estimativa)). It's an average: a fat or lean fish can vary by 10% to 20%.
more about the catfish (focinho-de-porco)
A doradid catfish of the Plata basin (Argentina, Bolivia, Brazil, Paraguay and Uruguay), with bony plates along its body that give it the name armado. It reaches 70 cm and 9 kg according to FishBase; Argentine species accounts cite up to 80 cm. It is demersal and omnivorous: it eats insects, crustaceans, mollusks and other invertebrates, as well as plant material, and its mouth lets it search for food among stones and sand. It is oviparous with external fertilization, and there are no reports of captive breeding. In Argentina it is caught with longlines, gillnets and trawls and sold on the domestic market. For sport anglers it is an occasional bottom fish, caught in large rivers with natural bait.
Family: Doradidae · omnivore
fun facts
- Out of the water, it makes sounds.
- The shape of its mouth lets it search for food among stones and sand.
- In Argentina it is known as armado chancho ('chancho' means pig in Spanish).
in the kitchen
It turns up in commercial fishing on the Paraná and is sold on the Argentine domestic market. The thick skin and plates call for careful cleaning; it is usually served fried, roasted or in a stew (caldeirada).
similar species
sources and references (7)
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.
- scientific FishBase: Oxydoras kneri (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology and IUCN status. Page checked on October 13, 2026. The typical size and depth range are editorial estimates for sport fish; the typical weight comes from the length-weight relationship. The maximum length of 70 cm and weight of 9 kg are the published values; Santa Fe species accounts cite 80 cm total length. We found no Brazilian rule that names this species: the armado in the Paraná and Paraguay rules is Pterodoras granulosus.
- scientific FishBase: nomes populares de Oxydoras kneriNames by country and language.
- official Portaria GM/MMA nº 1.667, de 27 de abril de 2026: Lista Nacional Oficial de Espécies da Fauna Ameaçadas de Extinção (peixes e invertebrados aquáticos)The species is not on the list. Checked in the DOU of April 28, 2026.
- official Acuario del Río Paraná (Santa Fe, Argentina): ficha do armado chancho (Oxydoras kneri)Size up to 70 cm, bony plates, small head, coloration, omnivorous diet, oviparous reproduction, sounds out of water, and a mouth for searching for food among stones and sand. Species account checked on October 13, 2026.
- official Província de Santa Fe: Características biológicas (material do Guarda Pesca Honorário), fichas da SAGPyAArmado chancho: distribution in the Plata basin, omnivorous diet, up to 80 cm total length and 9 kg, caught with longline, gillnet and trawl. Document checked on October 13, 2026.
- press Ley provincial de Santa Fe nº 12.212 (pesca)Art. 10: table of minimum sizes, with the armado chancho (Oxydoras kneri) at 45 cm. Copy of the text published by a newspaper; the official text is on the Province's portal. Checked on October 13, 2026.
- press Prensa Mercosur: inicia veda pesquera y MADES refuerza tareas de concienciación y control (02/11/2025)Dates of the 2025/26 closed season in waters shared with Argentina and Brazil, and what is prohibited. The MADES resolution number does not appear in the article. Checked on October 13, 2026.
how we calculatewhere each number comes from
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.
sources for this lookup
how accurate the forecast is
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: