Cactus plecos (Pseudacanthicus) (Pseudacanthicus spp.) care guide

Group
Freshwater fish
Other names
Cactus plecos, Scarlet cactus pleco (L025), Slender cactus pleco (L079), Leopard cactus pleco, Titanic pleco (L273)
Family
Loricariidae (suckermouth armoured catfishes)
Origin
South America: rocky rivers of Brazil (Xingu, Tocantins and others), the Guianas and the Orinoco basin.
Water
freshwater
Maximum size
30 cm
Temperature
26–30°C
pH
6–7.5
Hardness
Soft to medium
Minimum tank
500 litres
Care level
intermediate
Temperament
semi_aggressive

Care

Genus overview. Pseudacanthicus are the cactus plecos, heavily armoured fish with rows of spiny keels along the body and bristly snouts. Adults are typically around 20-30 cm SL (PlanetCatfish gives 30 cm for L079), and some forms, such as L025 and L273, can grow larger still. Figures in this entry vary by species, so check the species or L-number before buying. Popular fish sold under this genus include L025 (scarlet cactus pleco, P. pirarara), L065, L079 (slender cactus pleco), L097, L114 (leopard cactus pleco), L185, L273 (titanic pleco), L282, L380, L406 and P. histrix. The 500-litre minimum is our estimate for a single adult of the bigger types. Tank: bogwood and pipes or caves sized for the adult fish; plants usually get damaged even though they are not eaten. Strong flow and high oxygen levels are important. Each fish is territorial from a young age, so keep one per tank unless the tank is very large. Water: warm (about 26-30 °C), soft to medium and slightly acid to neutral. Sexing: males grow far more odontodes on the fin rays, especially the pectoral spines, and are slimmer; females are noticeably fuller in the body. Names: the genus name means "false Acanthicus". Several L-numbers are still undescribed and some are wild-caught from threatened habitats. Selling: our policies require the adult size and long-term tank needs to be stated clearly in the listing. Large fish must travel by a specialist live-animal courier (see the Livestock shipping guide). Sources: PlanetCatfish (planetcatfish.com/common/species.php?speciesid=848). Checked October 2026.

Diet

Mainly carnivorous. Prawns and chopped mussel are favourites; also sinking pellets, tablets, shrimp, bloodworm and other frozen foods, with some vegetables for balance. They produce less waste than similar-sized Panaque or common plecos.

Breeding

Cave or pipe spawners; the male guards the eggs. A few forms have been bred in the hobby, but many L-numbers have no confirmed spawning; PlanetCatfish lists none for L079. A large tank, big caves, very clean warm water and rich, meaty conditioning foods are needed.

Compatibility and tank mates

Generally peaceful with mid-water fish, but territorial towards other bottom-dwellers. Larger adults can be aggressive towards other large nocturnal fish and plecos. Avoid fast, pushy tankmates of a similar size, which can bully them at feeding time despite their armour.

Last updated 5 October 2026. Community-edited care guide on Aquatic-Auctions.

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