MS: minimum 35 cm
35 cmMS
Minimum size for armado in MS.
Source: Decreto estadual MS nº 15.375/2020 (amends Decreto nº 15.166/2019), art. 9º - Semadesc/Imasul
catalog
Doradidae · omnivore
granulated catfish
Pterodoras granulosus
Freshwater
Plated, spiny catfish, very common in the Paraná and the Pantanal. Heavy, stubborn on the bottom and dangerous to handle.
Also called: armado, abotoado, armal
- common size
- 35–55 cm
- maximum
- 90 cm
- common weight
- 1–4 kg
- record/max.
- 7.5 kg
- depth
- 2–15 m
- ideal water
- 23–29 °C
overview
who is the granulated catfish
Armored catfish from the family of the "snoring fish." It has a row of bony plates with spines along the body and strong spines in the fins. Eats just about anything: fruit, seeds, mollusks, shrimp and scraps. In the upper Paraná it spread after Itaipu flooded Sete Quedas, and today it is one of the most-caught fish from cutbanks and dams. It also eats the golden mussel, an invasive mollusk. Pulls hard and sticks to the bottom. The biggest difficulty is getting it off the hook without getting hurt. Use gloves and pliers.
fun facts
- Makes an audible snoring sound out of the water, produced by its swim bladder.
- Eats the golden mussel, an invasive mollusk that clogs power plant pipes.
how to recognize it
identification
Row of bony plates, each with a curved spine, along the lateral line. Thick, serrated dorsal and pectoral spines. Dark grey to brown body, head with rough plates, three pairs of short barbels. No other fish on this list has those lateral plates.
how granulated catfish 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.
distribution
open on the large map where found
Pantanal, Paraná River channel and upper Paraná reservoirs (where it spread after Itaipu), Uruguay River and the Amazon.
Habitat: Bottom of big rivers and reservoirs, near rocks, cutbanks and dam bases.
native to the basins
Paraguay (Pantanal)ParanáUruguayAmazon
states
Mato Grosso do Sul, Mato Grosso, São Paulo, Paraná, Goiás, Minas Gerais, Rio Grande do Sul, Amazonas, Pará
when to fish
best season
time of yearbest: Mar
JanFebSeaAprMayJunJulAugSepOctNovDec
Warm months are the best. The bite drops in winter.
best time of day
Night and twilight. Feeds mostly at night and at dusk, but bites on the bottom during the day.
what affects the granulated catfish
sensitivity The little bars show how much each factor affects this species. Five full: it feels it a lot.
sensitivity The little bars show how much each factor affects this species. Five full: it feels it a lot.
cold and cold fronts
Strong cold keeps the armado still.
atmospheric pressure
Little effect.
moon
Little effect.
rain
Little effect.
water level
In a reservoir, rocky spots and dam bases produce all year.
noise
Tolerant.
wind
Almost no effect.
depth
Bottom, 3 to 12 m.
how to fish
- rod
- 6' to 7', medium action, 15 to 30 lb
- spinning / baitcasting reel
- spinning reel 3000 to 4000
- line
- monofilament 0.35 to 0.40 mm or braided 30 lb
- leader
- monofilament 40 to 50 lb
- hook
- 1/0 to 4/0 heavy; sinker 30 to 80 g
natural baits
- minhocuçu
- minhoca
- massa
- caranguejo
- piece of fish
- boiled corn
accessories
- long-nose pliers
- thick gloves
- cloth to grip
tip from an angler
Set the hook and pull hard right away: if it reaches the bottom, its spines lock and it won't come loose. To release it, use pliers and a cloth.
rules for the granulated catfish
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
MT: minimum 35 cm
35 cmMTParaguay (Pantanal)
Minimum size for armado in the Alto Paraguay basin, in MT and MS.
Source: Portaria Ibama nº 03/2008 (fishing in the Paraguay River basin), per the official Sema-MT table
Paraná basin: minimum 40 cm
40 cmSPPRMGGOParaná
Federal minimum size for armado in the Paraná basin.
Source: Instrução Normativa Ibama nº 26/2009 (fishing rules for the Paraná River basin), Annex
Minimum size: 35 cm
MSParaguay (Pantanal)Paraná
Source: Decreto estadual MS nº 15.166/2019, art. 9º (as amended by Decreto nº 15.375/2020)
Minimum size: 40 cm
SPPRMGGOMSDFParaná
Source: IN IBAMA nº 26/2009, Annex (Paraná River basin; stricter state rules prevail)
Minimum size: 40 cm
PRParanáSoutheast Atlantic
Source: Portaria IAT nº 650/2025, Annex I (interior basins of PR, except Iguazu and coastal)
piracema closures in the basins where the species lives
Spawning closure (piracema) in the Paraná River basin
01/11 to 28/02SPPRMGGOMSDF
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)
01/11 to 28/02MG
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)
01/11 to 28/02GO
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
05/11 to 28/02MS
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)
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 Uruguay River basin
01/10 to 31/01RSSC
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
Closed season in the rivers of Marajó Island (PA)
01/01 to 30/04PA
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
Closed season in the Amazon basin in Amapá
15/11 to 15/03AP
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
Closed season in Roraima
01/03 to 30/06RR
Allowed: Subsistence fishing only.
Source: Portaria IBAMA nº 48/2007
Border rivers MT/RO and MT/PA
05/11 to 28/02MTROPA
Allowed: See the exceptions in Portaria 48/2007 and the state rules for each bank.
Source: Portaria IBAMA nº 48/2007
catch and release
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.
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.
Never hold it with your bare hand: the spines pierce and inflame. Use a cloth or glove and pliers, and release it without throwing it.
in the kitchen
Fatty, tasty meat; in broth or stew. Cleaning is laborious because of the plates.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.011775, b = 2.97; FishBase; coeficiente a ajustado ao porte máximo registrado). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
—
sources and references
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 — Pterodoras granulosus (ficha da espécie)Names, distribution, biology, length-weight relationship and references. Page checked on October 13, 2026.
- 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)Most recent national list. The species is not on it (search by scientific name in the text published in the DOU, checked on October 13, 2026).
- official ICMBio/SALVE — Ficha de Pterodoras granulosus (avaliação nacional do risco de extinção)National assessment by ICMBio, published in 2024. DOI verified on Crossref.
- scientific IUCN Red List — Pterodoras granulosus (avaliação global: Pouco Preocupante, LC, 05/08/2020)Global assessment. Link given on the FishBase entry (Red List, version 2025-2).
- scientific Sabaj, M. H.; Ferraris Jr., C. J. (2003). Doradidae (thorny catfishes). In: Reis, R. E.; Kullander, S. O.; Ferraris Jr., C. J. (orgs.). Check List of the Freshwater Fishes of South and Central America. Porto Alegre: EDIPUCRS, p. 456–469.Printed book chapter; the URL is the bibliographic record on FishBase, which cites the chapter for the species.
- scientific Ota, R. R.; Deprá, G. C.; Graça, W. J.; Pavanelli, C. S. (2018). Peixes da planície de inundação do alto rio Paraná e áreas adjacentes: revised, annotated and updated. Neotropical Ichthyology 16(2): e170094.Annotated list of species of the upper Paraná River, indicating native and non-native ones. Open access; species name checked in the text.
