Medusa Pleco
Ancistrus ranunculus
Parameter dashboard
25-30 °C
6-7
13 cm
8 years
Care guide
The medusa pleco reaches about 13 cm standard length and is easily identified by the long, fleshy tentacles on the snout that give it the namesake jellyfish-like appearance. It comes from the Rio Xingu and Rio Tocantins basins in Brazil, where it inhabits shallow, fast-flowing waters over rocky substrates. A tank with a base of 80 by 30 cm (about 72 L) is sufficient for a couple, but it needs well-oxygenated water with good current — a stream-type setup with rounded stones and sand substrate suits it best. Temperature of 25–30 °C and pH 6.0–7.0 are required; this is a warmer-water pleco that does not do well in standard community temperatures. Unlike most Ancistrus species, the medusa pleco prefers a protein-rich diet with sinking dried foods supplemented by bloodworm, chopped mussel, and prawn. It is generally peaceful but has specialised requirements that make it unsuitable for the general community tank. Ensure each specimen has its own refuge and expect some territorial behaviour between males. Not a beginner fish. When buying, avoid specimens with sunken bellies or eyes. Take care when moving them, as cheek and pectoral spines can snag in nets.
Source
Further reading on identification and aquarium care.
Tankmate compatibility (sample)
Pairwise screening against other species in the database (prioritizing the same family when data is available).
Review first (11)
Caution or avoid from automated rules — confirm before mixing.
| Species | Assessment | Notes |
|---|---|---|
| Giant Whiptail Sturisomatichthys aureus Caution | Caution | the two share only a narrow band of temperature, so one of them sits at the edge of its range Open pair in Compare → |
| Gold Nugget Pleco Baryancistrus xanthellus Caution | Caution | close relatives, and one of them is territorial, so both claim the same kind of space · one is boisterous and the other a much smaller peaceful fish sharing the same floor, where it can be intimidated and outcompeted at feeding time Open pair in Compare → |
| Leopard Frog Pleco Peckoltia compta Caution | Caution | Fish 2x+ larger may eat smaller tankmates · close relatives, and one of them is territorial, so both claim the same kind of space Open pair in Compare → |
| Nannoptopoma Nannoptopoma sternoptychum Caution | Caution | Fish 2x+ larger may eat smaller tankmates Open pair in Compare → |
| Royal Farlowella Sturisomatichthys festivus Caution | Caution | close relatives, and one of them is territorial, so both claim the same kind of space Open pair in Compare → |
| Royal panaque Panaque nigrolineatus Caution | Caution | Fish 2x+ larger may eat smaller tankmates Open pair in Compare → |
| Whiptail Catfish Loricaria simillima Caution | Caution | close relatives, and one of them is territorial, so both claim the same kind of space · one is boisterous and the other a much smaller peaceful fish sharing the same floor, where it can be intimidated and outcompeted at feeding time Open pair in Compare → |
| Zebra pleco Hypancistrus zebra Caution | Caution | close relatives, and one of them is territorial, so both claim the same kind of space Open pair in Compare → |
| Blue-eye panaque Panaque suttonorum Avoid | Avoid | Fish 2x+ larger may eat smaller tankmates · Species with non-overlapping temperature ranges cannot coexist · the two share only a narrow band of temperature, so one of them sits at the edge of its range Open pair in Compare → |
| Common otocinclus Otocinclus vittatus Avoid | Avoid | Fish 2x+ larger may eat smaller tankmates · Species with non-overlapping temperature ranges cannot coexist · the two share only a narrow band of temperature, so one of them sits at the edge of its range Open pair in Compare → |
| Zebra Oto Otocinclus cocama Avoid | Avoid | Fish 2x+ larger may eat smaller tankmates · Species with non-overlapping temperature ranges cannot coexist · the two share only a narrow band of temperature, so one of them sits at the edge of its range Open pair in Compare → |
1 species with compatible assessment in this sampleCollapse to hide the list; use “Open pair in Compare” for the full matrix.
| Species | Assessment | Notes |
|---|---|---|
| Whiptail catfish Farlowella acus Compatible | Compatible | No rule-based conflicts detected for this pair. Open pair in Compare → |
Same rule engine as Compare. Not a substitute for observation, tank size, or acclimation.
Related species
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