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.
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.
fun facts
The cheek spines can be raised outward as a defense.
The length-weight relationship used here was measured on fish from the Porto Primavera reservoir, on the Paraná River.
how to recognize it
identification
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.
how cascudo-abacaxi 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.
spinning reel 3000 to 4000 or baitcasting reel 200
line
monofilament 0.35 to 0.40 mm or braided line 25 to 30 lb
leader
monofilament 40 lb
hook
#1/0 to 3/0, heavy-duty
natural baits
massa
minhoca
minhocuçu
accessories
thick cloth for holding
alicate
tip from an angler
Bait on the bottom, near rocks and piles of logs. Hold firmly right after the hookset: it tries to hide in its burrow.
what the law says
rules for the cascudo-abacaxi
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).
MS: minimum size for cascudo-abacaxi
30 cmMSParaguay (Pantanal)Paraná
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.
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.
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.
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.
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).
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.
Watch the spines on the pectoral and dorsal fins: hold it with a cloth, behind the head. Release it quickly, supporting the body.
in the kitchen
Light flesh; like other plecos, it is often roasted in its own skin over coals.
calculator
how much it weighs without taking it out of the water
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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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.
scientificFishBase — Megalancistrus parananus (ficha da espécie)Distribution, maximum size (58.8 cm standard length), air breathing in the genus, names and country list. The length-weight relationship is from Porto Primavera reservoir fish (males and females, 18.6 to 55.6 cm); the app's entry maximum weight was estimated with it. Page checked on Oct 13, 2026.