Scientific Name: Pimelodus blochii
(Also commonly called One Line Pim Catfish, Bloch’s Catfish, or simply Pim Catfish.)
Maximum Size and Lifespan:
The One Line Pim Catfish can grow to around 10–12 inches (25–30 cm) in length. With proper care, they typically live for 8–12 years, sometimes longer in well-maintained aquariums.
Recommended Aquarium Size, Water Change, and Care:
40 gallon breeder for a single specimen/small group. 50+ gallons preferred for a large group/community setup
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Water Parameters: pH 6.0–7.5, soft to moderately hard water, temperature 74–82°F (23–28°C).
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Aquarium Setup: Provide open swimming areas alongside hiding spots such as driftwood, large caves, or sturdy plants. They are mostly nocturnal and appreciate shaded areas during the day. A secure lid is essential, as they may attempt to jump.
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Water Changes: Perform 30–40% weekly water changes, as they are sensitive to poor water quality and nitrate buildup. Good filtration and moderate current are recommended, mimicking their riverine habitat.
Tankmates:
The One Line Pim Catfish is generally peaceful toward fish too large to be eaten. However, smaller tankmates like small tetras, guppies, or fry may be seen as food. Good companions include:
- Geophagus, Electric Blue Acara, silver dollars, severums, other medium sized catfish, etc.
Diet:
They are omnivorous with a strong preference for meaty foods. A balanced diet should include:
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Sinking carnivore pellets or tablets
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Frozen bloodworms and shrimp pieces
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Occasional vegetable matter or algae wafers for dietary variety
They are opportunistic feeders and will eat most foods offered, but overfeeding should be avoided to prevent obesity and water quality issues.
Overview:
The One Line Pim Catfish is a striking, hardy South American species recognized by its silver-gray body marked with a bold dark lateral line running from snout to tail. Active and somewhat boisterous, especially at night, they bring energy to large community aquariums. Their long whiskers and sleek build make them stand out, but they require ample space, good water quality, and compatible tankmates to thrive.
Natural Environment:
Pimelodus blochii is native to river basins across South America, particularly in the Amazon and Orinoco systems. They inhabit flowing rivers, tributaries, and floodplain waters, where they shelter among submerged roots, driftwood, and rocky structures. They are adapted to moderate currents and are opportunistic feeders in the wild, consuming insects, crustaceans, and small fish.
Breeding:
Breeding in aquariums is extremely rare and not well-documented. In the wild, they spawn seasonally, often during rainy periods when rivers flood and conditions trigger reproductive behavior. They are egg-scattering spawners, with little to no parental care. Due to their size, active nature, and specific environmental triggers, successful captive breeding generally requires very large setups and simulated natural flooding conditions, which are challenging for most aquarists.
