Baryancistrus chrysolomus L-047

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The Magnum, known scientifically as Baryancistrus chrysolomus L-047, is a large loricariid catfish from the Rio Xingu in Brazil. This bottom-dwelling fish draws attention with its substantial size, robust body and dark coloration marked with yellowish patterns. It inhabits rocky areas with strong current, which explains its need for highly oxygenated water and a mature aquarium. The specimens offered are wild-collected; availability is therefore irregular, and the species is considered uncommon in the aquarium trade.

General species description

Baryancistrus chrysolomus L-047 is a large armored catfish in the family Loricariidae. It differs from the smaller plecos commonly sold in its considerable adult size, broad head and mainly nocturnal habits. The L-047 code belongs to the aquarium numbering system used to identify loricariids before scientific descriptions are available. In captivity, this fish becomes a substantial bottom resident requiring ample floor space, hiding places and efficient filtration. It is usually peaceful with similarly sized tankmates, although adults may defend a cave or feeding area. It is best suited to experienced aquarists who can provide stable, clean and highly oxygenated water.

Geographic origin and biotope

The species comes from Brazil, in the Rio Xingu basin, particularly around the Volta Grande area near Altamira, Pará. Its habitat includes fast-flowing water, rocky slabs, boulders and crevices used as shelter. The water is generally clear to slightly stained, warm and rich in oxygen. Aquatic vegetation is often sparse in the most exposed current zones, while the banks may be bordered by tropical forest and dense riparian growth. In an aquarium, the functional features of this environment should be reproduced: strong water movement, stable rocks, hiding places and shaded areas.

Precise location and local name

Aquarium references associate Baryancistrus chrysolomus L-047 with the Rio Xingu in Pará State, especially around the Volta Grande and Altamira region. In Brazil, it may be referred to by the broad regional term acari, while the aquarium trade mainly uses Magnum or L-047. Magnum is not a scientific name; it is primarily used in the hobby to distinguish this large Baryancistrus type. Geographic origin matters because Xingu fishes are adapted to warm, clear and strongly circulated water rather than stagnant conditions or low oxygen levels.

Appearance and physical characteristics

Baryancistrus chrysolomus L-047 has a stocky, ventrally flattened body protected by bony plates. Its base coloration ranges from dark brown to black, with variable golden-yellow markings on the body and fins. The head is broad, the inferior mouth forms an effective sucker and the pectoral and dorsal fins are well developed. The fins may show lighter margins, especially in healthy specimens. Like other rheophilic loricariids, it often rests on rocks or aquarium walls before moving to graze or search for food. It may reach about 30 cm as an adult and needs a stable layout without loose or sharp decorations.

General diet

Baryancistrus chrysolomus L-047 is primarily herbivorous with an omnivorous tendency. Its diet should be based on quality loricariid wafers, vegetable tablets and vegetables such as zucchini, cucumber or blanched spinach. It also benefits from the natural biofilm growing on rocks and wood, although grazing alone may not be enough for a large adult. Protein-rich foods can be offered occasionally but should not become the main part of the diet. Evening feeding is preferable because activity increases at that time, and leftovers should be removed to protect water quality. A varied diet supports proper growth and body condition.

Essential data

• Name of origin river: Rio Xingu
• Local name used: Acari; Magnum and L-047 in the aquarium trade
• Origin of the scientific name: Baryancistrus is formed from Greek roots suggesting a robust hook; chrysolomus refers to a golden mouth
• Etymology of the full name: Baryancistrus means approximately fish with a robust hook; chrysolomus means golden mouth
• Common/vernacular names: Magnum, L-047, acari
• Family: Loricariidae
• Subfamily: Hypostominae
• Name pronunciation: ba-ree-an-SIS-trus kry-so-LO-mus
• Discovery: Lúcia Helena Rapp Py-Daniel, 1989
• Maximum adult size: About 30 cm
• Water temperature and pH: 26 to 30 °C; pH 6.0 to 7.5
• Appearance of the watercourse and surrounding vegetation: Warm, clear and highly oxygenated water; rocks, rapids and tropical riparian forest
• Typical tankmates: Krobia xinguensis, Hypancistrus zebra L-046, Scobinancistrus aureatus L-014, Baryancistrus xanthellus L-018, Panaque armbrusteri L-027
• Temperament and behavior: Generally peaceful, territorial around shelters; mainly crepuscular and nocturnal
• Water depth: Shallow to moderately deep areas, usually near rocks and shelter
• Sexual dimorphism: Mature males generally develop a broader head and more pronounced odontodes
• Bottom structure and flow: Rocky bottom with crevices and boulders; moderate to strong current

In your aquarium

To succeed with this large Xingu fish, provide a spacious aquarium, a firmly secured layout of rocks and wood, and vigorous circulation. Warm water, excellent cleanliness and strong oxygenation are essential. Offer several shelters to reduce conflict, then feed after the lights have been partly dimmed. Because these fish are wild-collected, careful acclimation and quarantine are especially advisable. Stable parameters and regular vegetable-based feeding remain the keys to long-term success.