Medusa Pleco L034 Care Guide
Ancistrus ranunculus (L034) is a flat, tentacled bristlenose from the Xingu and Tocantins that needs warm, fast, oxygen-rich water and a protein-rich diet.
Compiled by Aquairi from published sources · Published · Updated
Overview
Ancistrus ranunculus, the medusa pleco or L034, is a flattened armoured catfish of the family Loricariidae with extensive head tentacles. Seriously Fish gives a size of 100-130 mm standard length; FishBase reports a maximum of about 19.5 cm total length. It is adapted to fast, rocky waters.
Taxonomy
- Family: Loricariidae
- Genus: Ancistrus
- Scientific name: Ancistrus ranunculus
- Order: Siluriformes
- Hobby code: L034
Habitat
Both Seriously Fish and FishBase place the species in the Xingu and Tocantins River basins of Brazil. FishBase notes it lives in clear running water without strong current to about 3 m depth in the dry season, favouring narrow cracks between submerged rocks and the undersides of flat stones.
Tank requirements
- Minimum tank volume: 200 L
- Temperature: 24-28 °C (75-82 °F)
- pH: 5.5-7.0
- GH: 1-10 °dGH
- Lifespan: 8-12 years
- Decor: rocks and caves with strong flow and high oxygenation
Diet
An omnivore. Seriously Fish notes it requires a more protein-rich diet than most Ancistrus, with sinking dried foods supplemented by live and frozen items such as bloodworm, chopped mussel and prawn.
Compatibility
Seriously Fish describes it as generally peaceful but specialised, well suited to biotope tanks alongside certain characins and rheophilic cichlids. Multiple specimens need individual refuges to reduce territorial conflict; small tetras and Corydoras are appropriate companions, while other territorial plecos are best avoided.
Breeding
Seriously Fish reports it is difficult to breed, requiring a dedicated spawning tank with caves, soft acidic water around pH 6.0-6.5, warm temperatures and high oxygenation. It is a cave-spawner in which the male guards the eggs and fry; only males develop full, bushy head tentacles.
Conservation status
IUCN Red List: Near Threatened, assessed 2018 (per FishBase). The species has a restricted range in the Xingu and Tocantins drainages.
Breeding Ancistrus ranunculus (L034)
Overview
Ancistrus ranunculus, known in the hobby as the medusa pleco or L034, is a loricariid catfish native to the Xingu, Trombetas and Tocantins river basins in Brazil, where it inhabits narrow cracks in submerged rocks and spaces below flat rocks. According to Seriously Fish it is a cave spawner that requires a dedicated spawning setup. Wikipedia lists it as Near Threatened on the IUCN Red List.
Sexing
Only males develop the full, bushy growth of tentacles covering the head, and males also possess cheek odontodes (spines on either side of the head). These features make mature males straightforward to distinguish from females.
Conditioning
Condition the breeding fish with plenty of live and frozen foods prior to spawning to bring females into condition.
Breeding Setup
Seriously Fish recommends soft, acidic, very well-oxygenated and turbulent water for spawning, at a temperature of 80-84 F (about 27-29 C) and pH 6.0-6.5. No substrate is required, and caves are provided as spawning sites.
Spawning Behavior & Trigger
Males establish and vigorously defend territories and entice females into a cave. A successful male is briefly ejected from his cave while the female goes inside to lay her eggs, after which the male assumes sole responsibility for defending the cave against intruders.
Egg & Fry Care
The eggs are large and orange and hatch in 4-5 days, with the male providing all parental care. Fry remain in the cave under his protection until their yolk sacs deplete. Once feeding, the fry require heavy feedings of greenstuffs such as blanched spinach, cucumber slices and algae wafers, plus small invertebrates such as microworm and brine shrimp nauplii; food should be available at all times. Seriously Fish reports broods of at least 40-50 fry.
Common Challenges
The species demands clean, highly oxygenated water with strong movement, mirroring its fast-flowing natural habitat, so water quality must be maintained throughout the brood-care period. Heavy fry feeding makes diligent maintenance essential to avoid fouling the tank.