Royal Pleco (L190)

The royal pleco, with its striped body and large build, is the best-known member of the genus Panaque. Juveniles of 5–8 cm are sold, but it grows slowly to 35–40 cm and becomes a large, heavy fish. So before buying one, make sure you will be able to set up an aquarium of at least 500 liters in the future.

Panaque species are among the few fish that can eat wood by scraping it with their spoon-shaped teeth. However, research suggests that although they gnaw and swallow wood, they get much of their nutrition from the microorganisms and decaying organic matter on its surface.

It lives in the large rivers of the Orinoco basin, among fallen tree trunks and root tangles. The hollows inside the trunks serve both as shelter and as a food source. The water is usually warm, oxygen-rich and moderately flowing; the fish spend the day inside the hollows of the trunks.

• Volume: at least 500 liters and 150 cm length for one adult.
• Wood: several large, hard roots; the fish will wear them down over the years.
• Filter: the amount of wood shavings and waste is very high; a canister filter or sump, strong mechanical filtration and weekly gravel vacuuming are essential.
• Decor: plants get gnawed or uprooted; hardy species such as Anubias and Java fern hold up better.
• Water: 25–28°C, a 30–40% water change every week.

Gnawing on wood is part of its diet. In addition, it should be given blanched zucchini, cucumber, potato, spinach, peas and vegetable sinking tablets. Protein-rich food should be given rarely, at most once a week.

Calm toward other species. Toward its own kind and plecos of similar size, however, it is territorial and may fight seriously over a cave or root. It is nocturnal, but once settled it is also seen resting on its root during the day.

Good companions: Medium and large peaceful fish: large tetras, silver dollars, Geophagus species, large rainbowfish.

Avoid: Small aquariums, other large plecos (in limited space), slow, flat-bodied fish (risk of slime-coat sucking), delicate planted layouts.

In a home aquarium it is kept as a single fish. More than one Panaque can only be attempted in very large systems with plenty of hiding places.

In the wild it breeds in hollows along riverbanks. Little is known about breeding in the aquarium; the fish sold are mostly wild-caught.

Hardy, but insufficient fiber and dirty water cause problems. As it grows it noticeably increases the bioload of the tank; watch for nitrate rising quickly. Sensitive to copper.

Hard to tell apart externally. In mature males, the odontodes on the rear part of the body and on the pectoral fin spines may be more prominent.