Redfin Cactus Pleco (L024)
Pseudacanthicus pitanga
The Redfin Cactus Pleco (L024 or Pseudacanthicus pitanga) is one of the most aggressive and impressive giant Loricariids in existence. The name "Cactus" derives from its armor literally covered with huge sharp spines all over its body, while "Redfin" refers to the stunning fiery orange and red that ignites its large fins. Reaching 40 cm (16 inches) in length, it is a powerful carnivorous predator that requires monstrous aquariums, extreme filtration, and tankmates capable of withstanding its fierce nature. It is absolutely not a fish for beginners.
Water Temperature
25 - 29 °C
pH Value
6 - 7.5
Water type
Freshwater
Tank level
Bottom
Adult size
40 cm
Minimum tank volume
>= 500 L
Minimum group
>= 1
GH
2 - 15 dGH
KH
1 - 7 dKH
TDS
40 - 295 ppm
Conductivity
63 - 461 uS/cm
Species description
Geographical Origin and Habitat: This species is native to Brazil, endemic to the Rio Tocantins basin. It inhabits deep, turbulent river channels with fast-flowing water and basaltic or volcanic rocky substrates filled with deep cracks and passages.
Taxonomy and Morphology: Commonly known as L024 or Redfin Cactus Pleco, it belongs to the genus Pseudacanthicus. It reaches 40 cm (16 inches) in length and features a heavily armored body covered in sharp, pointed odontodes, giving it the "Cactus" moniker. It has strong jaws and specialized teeth for crushing shelled prey.
Social Behavior: It is the pinnacle of benthic ferocity. It will literally kill and tear to pieces any other pleco or catfish that dares to enter its visual territory. Extremely territorial and aggressive toward conspecifics, it lives a solitary, nocturnal lifestyle.
Coloration and Sexual Dimorphism: The body coloration is dark gray-brown or olive, covered in dark spines. The key feature is the stunning fiery orange-red color on its dorsal and caudal fins. Mature males possess a broader, wider head and significantly longer, denser odontodes on their pectoral fin rays compared to females.
Care, breeding and tankmates
Aquarium Setup: A 2-meter (6-foot) long aquarium of at least 500-600 liters is the basic requirement. The setup must be bare or composed of heavy immovable boulders. This spiny colossus will move any unglued decor. Provide huge thick PVC pipes to act as an impregnable den.
Diet and Feeding: Forget vegetables or scraping. It is a lethal carnivorous scavenger. Feed it with whole tilapia fillets, thawed prawns, and large earthworms. Handle with extreme caution: its spines (odontodes) are actual sharp blades that get tangled in nets; always use rigid plastic containers to move it.
Water Quality: The decomposition of fish-based meals requires giant sumps. Massive weekly water changes are mandatory. Maintain water temperature at 25-29°C (77-84°F), pH between 6.0 and 7.5, and GH between 2 and 15, ensuring high dissolved oxygen levels with strong powerheads.
Compatibility and Cohabitation: Must be kept as the sole bottom dweller. Suitable tankmates are limited to large open-water species (like large predatory Cichlids, Arowanas, large Characins, or large freshwater rays) that will not compete for caves or benthic territory.
Aquarium Breeding: Extremely rare in home aquaria. Requires giant breeding setups with massive caves. Spawning rituals are highly violent and can result in the female's death if inadequate escape routes are available. The male assumes sole care of the egg cluster within the cave.
Risks and Diseases: Due to the high organic load from its protein diet, poor water quality quickly leads to bacterial infections or fin rot. Injuries from territorial fights or violent mating attempts can become infected, requiring immediate water purification or treatment.
Geographic Origin and Distribution
This species is native to Brazil, endemic to the Rio Tocantins basin. It inhabits deep, turbulent river channels with fast-flowing water and basaltic or volcanic rocky substrates filled with deep cracks and passages.
Origin
Amazon, Orinoco, and Guianas
Fish profile
- Temperament
- Aggressive
- Extremely territorial and aggressive towards benthic tankmates. They are heavily armored and possess sharp odontodes. Consider them as a centerpiece bottom fish in a specialized setup.
- Diet
- Carnivore
- Strictly carnivorous. Their diet should consist of high-quality sinking carnivore pellets, shrimp, chopped fish, and bloodworms. They will not survive on an algae-based diet.
- Life expectancy
- 10-15 years
- The Redfin Cactus Pleco is a large, long-lived species that can survive for 10 to 15 years in captivity under optimal care. To support their long lifespan, they require highly stable, clean water parameters and a high-protein diet. Proper aquarium sizing and preventing territorial stress are also crucial factors for their long-term health.
- Adult size
- 40 cm
- The catalog's scalar value is 40 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 30 cm for this species, recorded as standard length (SL). The taxonomic record consulted is Pseudacanthicus pitanga (v25.04); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
- Sex ratio
- Solitary
- Best kept singly. If multiple are kept, ensure a vast tank size with only one male and several females. Males will fight intensely over territory.
- Feeding frequency
- Twice daily
- Feed once daily, ideally at night. They can be shy and may need targeted feeding to ensure they receive enough food. Monitor to ensure they are not outcompeted.
- Bioload
- High
- Heavy bioload characteristic of large carnivorous plecos. They eat heartily and produce a lot of waste. Excellent filtration and regular water changes are mandatory.
- Flow
- Strong
- Prefer moderate to high water flow with excellent aeration. They originate from fast-flowing rivers. Strong current helps maintain water quality and oxygen levels.
- Jump risk
- No
- Reproduction
- Oviparous
- Cave spawners that are difficult to breed in captivity. Requires dedicated breeding setups with large caves and very clean water. The male will fiercely guard the spawn.
- Compatibility & tankmates
- Highly aggressive
- Best kept with medium to large, fast-moving fish that occupy the upper levels of the tank. They are highly intolerant of other bottom dwellers, especially conspecifics. Only mix with other plecos in massive aquariums with broken lines of sight.
- Tank level
- Bottom
- Bottom-dwelling species. They need plenty of hiding spaces formed by rocks and driftwood. They will claim a specific spot and defend it.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Resilience
- Medium (1.4 - 4.4 years)
- Phylogenetic uniqueness (PD50)
- 0.5039
- Bayesian Length-Weight
- a = 0.01549, b = 2.96
- VulnerabilityLow to moderate vulnerability (27 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
Related species
Recommendations grouped by close relatives, companion choices, and similar care.
