Lima Shovelnose Catfish (Sorubim lima)

What is a Lima Shovelnose Catfish?

The Lima Shovelnose Catfish (Sorubim lima), also called the Duckbill Catfish, is a striking South American predator in the family Pimelodidae. Its most distinctive feature is the long, dramatically flattened snout — broad enough to justify the “duckbill” nickname — which it uses to ambush fish and invertebrates along the river bottom. The body is torpedo-shaped and strongly counter-shaded: dark olive to brown above, brilliant white on the belly, with a pale lateral stripe from snout to tail.

Adults reach 40–50 cm (16–20 in), placing S. lima firmly in the specimen-fish category. It is not a beginner’s catfish — it demands a very large tank, powerful filtration, and a reliable meaty diet — but in the right hands it is one of the most dramatic and long-lived freshwater fish available, with a lifespan of 10–15 years.

Nocturnal by nature, S. lima shelters beneath driftwood overhangs by day and becomes bold and active after lights-out. That nocturnal rhythm, combined with its arrow-like silhouette and predatory presence, makes it a rewarding centrepiece for experienced keepers with the infrastructure to support it.

Where do Lima Shovelnose Catfish come from in the wild?

Wild Sorubim lima range across the Amazon and Orinoco basins — Peru, Brazil, Colombia, and Venezuela. They prefer main channels and larger tributaries with moderate current, sandy or silty substrate, and submerged wood tangles that provide daytime refuge. Water is warm (23–30 °C / 73–86 °F), soft to moderately soft (1–15 dGH), and slightly acidic to neutral (pH 6.0–7.5). Unlike blackwater specialists, S. lima is a large-river fish built for open, flowing, well-oxygenated conditions.

Most specimens in the trade are wild-caught imports; commercial captive breeding is uncommon. That wild origin makes stable water quality and robust oxygenation essential rather than optional.

What tank size and setup does a Lima Shovelnose Catfish need?

The minimum tank size is 760 litres (200 gallons) — a 50 cm (20 in) carnivore needs genuine swimming room and enough water volume to buffer its heavy waste load. Prioritise a long footprint (180–240 cm / 6–8 ft) over height; S. lima works the bottom and mid-water, rarely using the upper third.

Use fine sand or smooth rounded gravel to protect the barbels and belly. Provide large driftwood overhangs or PVC pipe hides that the fish can fully enter; open swimming lanes between hides are equally important. Filtration should turn over 6–10× the tank volume per hour across multiple canisters or a sump. Add a powerhead for supplementary flow. Fit a secure, weighted lid — S. lima is a strong jumper, especially at night.

What water parameters does a Lima Shovelnose Catfish need?

• Temperature: 23–30 °C (73–86 °F); a stable mid-range of 25–27 °C (77–81 °F) suits most captive specimens well.
• pH: 6.0–7.5; slightly acidic to neutral is ideal.
• Hardness: 1–15 dGH; soft to moderately hard water is acceptable, but very hard tap water should be softened.
• Ammonia / Nitrite: 0 at all times — a fully cycled tank is mandatory before any fish is added.
• Nitrate: keep below 20 ppm with regular large water changes (30–40% weekly is typical for a heavily fed large predator).

Oxygenation deserves special mention. S. lima has a high metabolic demand and does not tolerate low dissolved oxygen well. Ensure strong surface agitation and do not allow temperatures to creep above 28 °C (82 °F) for extended periods.

What do Lima Shovelnose Catfish eat?

Sorubim lima is an obligate carnivore in the wild, feeding primarily on fish and large invertebrates. In captivity the diet should reflect that:

• Meaty frozen foods — whole prawns (shell on), market shrimp, mussels, squid rings, and large earthworms are nutritionally superior to feeder fish and carry lower disease risk.
• Feeder fish — a useful supplement to stimulate hunting behaviour; use quarantined, gut-loaded fish rather than unknown-source feeders.
• Prepared foods — large carnivore sinking pellets (Hikari Massivore, Northfin Monster, etc.) make a convenient staple once the fish is trained; offer at lights-out.

Feed every 2–3 days in the early evening, remove uneaten food within a few hours, and avoid gorging — consistent moderate portions keep water quality stable.

How does the Lima Shovelnose Catfish behave — and what can live with it?

S. lima is semi-aggressive in a purely predatory sense — it will not harass or nip companions, but any fish small enough to fit in its large upturned mouth will be eaten. Any tankmate under roughly two-thirds of the catfish’s body length is at risk, particularly at night.

Suitable companions include large characins (silver dollars, pacu), robust cichlids (severums, Geophagus), sailfin plecos, large Doradidae catfish, and tinfoil barbs. Avoid all small or slender fish and any invertebrates. Multiple S. lima can coexist in very large systems; monitor feeding-time competition.

For a full breakdown of tested pairings, see Lima Shovelnose Catfish tank mates.

How do you tell a male Lima Shovelnose Catfish from a female?

External sexing is unreliable in home aquaria. The most useful indicator is body profile viewed from above: females tend to be noticeably broader across the abdomen, particularly when gravid, while males are slimmer and more elongated. No consistent colour or fin differences exist. Because hobbyist breeding is not practically achievable, sex ratio rarely matters in most setups; if you do intend to attempt it, growing out a group of four to six juveniles together gives the best chance of having both sexes represented.

Can Lima Shovelnose Catfish be bred in captivity?

Breeding is rated Very Hard and has not been reliably achieved in home aquaria. In the wild, S. lima is a migratory spawner cued by seasonal flooding — changes in temperature, barometric pressure, water chemistry, and photoperiod that are essentially impossible to replicate in a tank. Commercial production relies on hormone injection (hypophysation) under hatchery conditions.

For hobbyists, S. lima is best treated as a long-lived display fish. Excellent husbandry — stable water, varied diet, adequate tank dimensions — is the goal; breeding should not be the expectation.

What diseases are Lima Shovelnose Catfish prone to?

Like most large pimelodid catfish, S. lima is sensitive to the following:

• Ich (white spot disease) — often triggered by temperature swings or stress; the white cysts are visible on the body and fins. Prevention: stable temperature, quarantine all new fish and plants.
• Bacterial infections and ulcers — abrasions from sharp decor or rough handling can become infected. Prevention: smooth substrate, careful netting technique, pristine water quality.
• Hole-in-the-head (HITH) — associated with poor water quality, high nitrates, and nutritional deficiencies. Prevention: consistent large water changes, varied diet, keeping nitrates below 20 ppm.
• Barbel erosion — a common and often underappreciated indicator of poor water quality or coarse substrate; barbels thin and shorten progressively. Prevention: sand substrate, ammonia and nitrite at zero.

Like many pimelodid catfish, S. lima can be sensitive to standard medication doses — copper-based treatments in particular. Always research catfish-safe dosing and remove chemical filtration before treating.

Health note: medication dosing and disease diagnosis are beyond the scope of a care profile. For a sick fish, cross-reference symptoms against a reputable fish-health resource before treating.

How long does a Lima Shovelnose Catfish live?

A well-maintained Sorubim lima lives 10–15 years in captivity. That longevity is both a selling point and a serious commitment — buying a juvenile is a decision measured in over a decade, through potential house moves and tank upgrades.

Growth is rapid initially — a juvenile of 10 cm (4 in) can reach 30+ cm (12 in) within two to three years — then slows near adult size. Consistent diet variety, stable water in the 25–27 °C (77–81 °F) range, and low chronic nitrates are the variables most associated with long captive lives in large pimelodids.