Megalancistrus parananus · Loricariidae · detritivore
One of the largest plecos in the Plata basin, covered in short spines that look like pineapple skin. It bites bottom bait and fights hard, trying to dive into a hole.
Also called: cascudo-abacaxi, cascudo, abacaxi
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 large Loricariidae catfish with its body covered in bony plates full of short, rough spines (odontodes), which give a pineapple-skin texture. It lives on the bottom of large rivers and reservoirs in the Paraná, Paraguay and Uruguay basins and can exceed 55 cm standard length. Like other members of the group, it can breathe air when water is low in oxygen. In recreational fishing it turns up on bottom baits and is sought for its flesh. It has a minimum size in Minas Gerais (40 cm), Mato Grosso do Sul and Paraná (30 cm). Older rules cite it as Megalancistrus aculeatus, a name now considered a synonym.
Broad body, flattened underneath, covered in bony plates with many short, rough spines; on the sides of the head, tufts of longer spines that the fish can raise. Sucker-shaped mouth under the head. Dark brown to grey. The other plecos of the basin, such as Hypostomus and Pterygoplichthys, have much smoother plates; the cascudo-preto (Rhinelepis) has smooth plates and uniform dark colour.
Paraná, Paraguay and Uruguay basins, in Brazil, Argentina, Paraguay and Uruguay; common in large rivers and reservoirs of the Paraná.
Habitat: Bottom of large rivers and reservoirs, near rocks, logs and banks.
native to the basins
states
São Paulo, Paraná, Mato Grosso do Sul, Minas Gerais, Goiás, Mato Grosso, Santa Catarina, Rio Grande do Sul
Warm months. The spawning closure shuts fishing for native species in the Paraná basin and in MS from November to February.
Night and twilight. More active at night and at dusk, when it leaves its burrow to scrape the bottom.
Cold reduces activity.
Little effect.
Little known effect.
Little effect.
Stable, clear river makes its burrows easier to find.
Not very sensitive.
Little effect.
Bottom, 2 to 10 m, next to rocks and logs.
natural baits
accessories
Bait on the bottom, near rocks and piles of logs. Hold firmly right after the hookset: it tries to hide in its burrow.
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 of threatened species (Portaria GM/MMA nº 1.667/2026).
In MS, cascudo-abacaxi (cited as Megalancistrus aculeatus) has a minimum size of 30 cm. Remember that amateur fishing in MS is catch-and-release, with only 1 native fish allowed to be carried.
Source: Decreto estadual MS nº 15.166/2019, art. 9º (table as amended by Decreto nº 15.375/2020)
In the inland basins of the Paraná, cascudo-abacaxi has a minimum size of 30 cm total length.
The IEF-MG table sets 40 cm for the cascudo Megalancistrus aculeatus, a synonym of M. parananus.
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
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)
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: 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
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 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
Watch the spines on the pectoral and dorsal fins: hold it with a cloth, behind the head. Release it quickly, supporting the body.
Light flesh; like other plecos, it is often roasted in its own skin over coals.
Length-weight relationship W = a·Lb (a = 0.029, b = 3.03; FishBase (reservatório de Porto Primavera, Brasil)). 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.
