Should I buy it?
Royal pleco
Panaque nigrolineatus
Typical trade / ID note: Panaque nigrolineatus (check L-number vs import)
Also known as: L-191, royal panaque, L190 (trade code)
Fishori provides conservative planning guidance, not guarantees.
Based on typical aquarium care sources; trade names can be ambiguous, so details may vary between setups. Use the numbers here as planning defaults — your room, water, and routine still shape real-world outcomes.
A spectacular pleco that grows to 40 cm. Needs 500L or more at adult size, extensive driftwood, and serious filtration to manage the bioload.
Best for
Dedicated large pleco or South American cichlid setups 500L or more with substantial driftwood and powerful filtration.
Avoid if
You have anything under 300L or want a manageable long-term fish.
Top things that go wrong
- Grows large or needs a very big footprint. Royal pleco is often sold at sizes that hide adult length (~40cm on file) and a published minimum near **500L**. Shop tanks are not adult housing.
- Specialist husbandry. Kept singly or as a paired setup. Check the species profile before doubling up in one tank.
- Shrimp & snails. Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.
Common mistakeBuying a juvenile royal pleco for a 100L community. They outgrow most home tanks within two years and produce waste proportional to their 40 cm adult size.
Common trade-name warning
This fish is often sold under different names or species variants. Care guidance is based on typical aquarium examples rather than a single exact species. Royal and L-191/190 listings may mix Panaque species; wood diet and very large volume still apply, but L-number to Latin name is not always clean in the trade.
What most shops don't tell you
- 1.Large minimum volumes still need real footprint: length and width for turning matter as much as the litre number on a sticker.
- 2.Sold as a 5 cm algae cleaner for a 100L. The adult breaks the tank inside two years.
- 3.Fed protein pellets or wafers only. Without driftwood and vegetable fibre, digestion fails.
- 4.Not a beginner pleco. An adult needs a 150 cm tank or more. Wild imports arrive with parasites, so quarantine and deworming are routine.
- 5.Advanced species — research stable parameters before buying.
About this species
Royal plecos are large South American loricariids that rasp and digest wood. Adults reach 30 to 43 cm. They need multiple driftwood pieces, high oxygen, very large volume, and plant-heavy prepared foods. The waste output is high.
- Common Pleco600L min · same group, comparable tank size
- Clown Pleco110L min · same fish family
- Siamese Algae Eater100L min · same fish family
- Bristlenose Pleco80L min · same fish family
- Otocinclus60L min · same fish family
No close matches on file.
No reverse lookups on file yet.
Plan grid
Key limits are shown above; this section adds planning detail: pH band, swim level, bioload and activity, and the radar.
Swim zones
Planning trait chart
Six indices for comparing species on paper before you spend.
- Beginner ease6
- Peacefulness82
- Community fit73
- Small-tank fit30
- Hardiness36
- Energy24
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Common setup sketches
Conservative patterns from Fishori fields — still run the pair checker for every species you add; sketches are not a stocking guarantee.
Avoid “one of everything” baskets — Royal pleco belongs in a plan built around territory, line-of-sight breaks, and matched water chemistry.
Tank mate intelligence
Use the "Often compatible" lists as a shortlist, not a stocking plan. Always run the pair tool and check the footprint of your actual tank first. Verify behaviour for Royal pleco against your own reading before you buy.
Pair-level compatibility with this fish as anchor.
Read the blocking rule on each pair page before experimenting.
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Royal pleco + Boesemani Rainbowfish
Behaviour, temperament, and what to watch
Prose and lists come from the same record: read temperament first, then glass-level signals so you are not surprised after day three.
Royal pleco is peaceful in mixed company. Holds territory on substrate, in caves, or at the surface film. Break the sight lines with hardscape to keep the resident off the visitor.
Stress / aggression triggers on file
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper, but individuals can still test fins under stress or in a crowded tank.
Predation: Not a predator toward similarly-sized community fish. The usual community caveats about mouth size still apply for very small fry or shrimp.
Territory: Holds territory on substrate, in caves, or at the surface film. Break the line of sight with hardscape, and avoid placing the tank where the fish can see its own reflection.
Planted tanks: good — easy plant ideas
In the glass: typical and warning signs
- Often calm on the glass — bursts of movement around food or tank disturbance.
- Clamped fins, gasping at the surface, hiding non-stop, or refusing food after the first week.
- Rapid breathing when parameters swing — fix ammonia/nitrite first, then reassess mates.
- Corner guarding, flaring, or body-blocking — territory is normal until it becomes relentless.
- Separate or rehome if injuries appear, one fish is pinned, or feeding becomes a daily chase.
- If water is stable but behaviour worsens, reduce stocking or remove the highest-impact species first.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Care parameters: water, food, inverts, grouping
Chemistry and group rules sit here so you are not re-reading the same line from tank mate or temperament blocks. Swim level is in the plan grid above.
Hardness
soft
Diet
herbivore
Vegetable matter, algae, and plant-based prepared foods. Long-term protein-only feeding causes bloat in herbivorous species.
Shrimp & snails
Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.
Kept singly or as a paired setup. Check the species profile before doubling up in one tank.
Breeding behaviour depends on the species. Research before you buy a mixed-sex group of this fish.
- Hold 24 to 30 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6.5 to 7.5 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Footprint: short wide tanks and tall narrow tanks fish differently for the same volume. Match the tank shape to the swim pattern, not just the litre count.
- Tank volume meets or exceeds 500L published minimum for adults.
- Heater can hold 24–30°C without cooking cooler-water tank mates.
- Filter maturity / stable parameters before adding sensitive stock.
Explore and stocking hubs
Same library as the rest of Fishori: tank-mate index for this species, category peers, guides, and litre-based stocking lists where min tank on file is within the hub volume.
Plan with tools
Pair-level rules and multi-fish stocking use the same conservative engine — add this fish in the tank builder only after mates pass pair checks.
Filtration & heating
A 500L minimum tank needs a filter rated for at least 2000L/hr turnover and a heater to hold 24–30°C reliably.
Plant suggestions
Royal pleco does well in planted tanks. Plants compatible with 24–30°C and pH 6.5–7.5:
Profile status: partially verified · Evidence tier: medium · 3 linked source(s). Fishori does not fabricate citations.
Fishori uses conservative planning rules based on these sources.
Confidence is explained in the summary at the top of this page (same tier as here), not repeated below.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- LiveAquaria. Royal (L-191) plecostomus (Panaque-type care sheet)
Primary: retailer care profile for the trade 'royal' / L-191: driftwood, tank size class, and feeding; listing may use Panaque sp. (L-191) as well as nigrolineatus in other lines. Confirm L-number with the seller when dollars matter.
- Planet Catfish. Panaque nigrolineatus (Cat-eLog species sheet)
Primary: community species sheet: wood requirement, import size, and the usual 'royal plec' name confusion across Panaque spp.
- FishBase. Panaque nigrolineatus
Secondary: natural distribution and maximum size; L-number vs museum name is still a moving target in the trade.
Evidence notes
- Royal 'L-191' imports are sometimes filed as Panaque sp. in sales copy while the binomial is P. nigrolineatus; a single public URL rarely carries both the exact L-identity and a peer-reviewed name in one line. LiveAquaria + Planet Catfish cover retailer practice vs hobby log data; FishBase supplies wild length context only.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
- Fishori profiles work from typical aquarium trade sizes and hobby care norms. Specialist site checks and literature review for this species are not yet recorded here, so the ranges on this page are planning numbers rather than guarantees.