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Species profile

Blacktop Corydoras

Corydoras acutus

Common names: Blacktop Corydoras, Acutus Corydoras, Longnose Blacktop Cory

Recognized speciesCorydoras
Blacktop Corydoras (Corydoras acutus)

Adult size

Up to 7 cm

Typical adult length 5.5–7 cm.

Up to 7 cm

Countries of origin

  • See all stock from Brazil
  • See all stock from Ecuador
  • See all stock from Peru

Good fit for your tank?

Good fit for

  • A roomy river-style community with a broad sandy floor
  • An experienced keeper seeking a true long-snouted cory
  • A group aquarium with strong filtration and oxygenation

Think carefully if

  • The aquarium has coarse gravel or limited floor space
  • You plan to mix many competing bottom feeders
  • The seller's identification is based on snout shape alone

Blacktop Corydoras is a peaceful South American callichthyid catfish recognised by a long pointed snout, a silvery body, and dark mottling concentrated along the back and dorsal region. It should be kept in a same-species group over fine sand in clean, oxygen-rich freshwater.

Appearance and Identification

A long-snouted cory with a pale body, scattered dark spots and a stronger dark area across the upper head and dorsal region. Its pointed snout and streamlined profile separate it from the rounder, short-snouted community corys.

Identify this profile by the combination of a long pointed snout, a silvery body, and dark mottling concentrated along the back and dorsal region. Colour alone can be unreliable in stressed, juvenile, or poorly conditioned fish, so body shape, snout length, fin pattern, and provenance should also be checked.

Mature females are generally fuller-bodied and broader through the abdomen, while males tend to be slimmer and may show slightly more pointed fins. Sexing young fish remains unreliable.

Tank Requirements

Suggested filter
About 400–500 litres an hour
Suggested heater
About 100–150 W for this tank
Minimum tank volume
100 litres
Minimum tank length
90 cm
Minimum group size
6
Recommended group size
8
Activity level
Moderate
Flow preference
Moderate
Planting preference
Moderately planted
Hiding places
Yes
Lid recommended
Yes
Jumping risk
Low

Provide a larger bottom area than for small short-snouted corys, using fine sand, open foraging lanes, sturdy cover and clean, well-oxygenated water. Long-snouted forms probe deeply into the substrate and should not be kept over sharp or compacted gravel.

Behaviour and Tankmates

A peaceful but active social catfish that benefits from a broad floor and a substantial group. It spends long periods probing the substrate and may be more vigorous at feeding than smaller, round-snouted corys.

Keep at least 6 of the same species or coded population, with 8 or more preferred where space permits. A mixed collection of single corys does not fully replace a proper same-species group.

It is not territorial. Males may briefly chase one another or follow females during courtship, but sustained aggression is unusual when the group has adequate floor space.

Suitable with peaceful community fish and other calm bottom dwellers when the aquarium has ample floor space. Avoid aggressive cichlids, large predators and crowded mixtures of bottom feeders that compete for the same foraging area.

Check tankmates for this species

Water Parameters

Temperature
22–27 °C
pH
5.5–7.5
GH
1–12
KH
0–6
TDS
30–220
Stability importance
Important

Soft to moderately hard, slightly acidic to neutral water is suitable. Provide good oxygenation and keep ammonia and nitrite at zero.

Parameter caveat
Acclimate slowly to changes in temperature, pH, and conductivity. Corydoradine catfish periodically gulp atmospheric air, so the water surface must remain accessible. Warm water holds less oxygen and requires stronger aeration.

Feeding

Diet types
Insectivore, Omnivore, Scavenger
Feeding frequency
Daily
Preferred foods
  • Quality sinking catfish pelletUse a small sinking pellet or wafer as a staple. Feed enough for every fish to reach food after faster midwater fish have eaten.
  • Frozen or live daphnia and cyclopsSmall crustacean prey supports natural foraging and is useful for conditioning breeding groups.
  • Frozen bloodworm, black mosquito larvae, or tubifexOffer clean, appropriately sized portions in rotation rather than as the only food.
  • Soft vegetable-based waferProvides dietary variety, although these catfish are not algae-eating cleanup animals and still require protein-rich food.

Offer substantial sinking pellets or granules plus varied frozen or live invertebrate foods. Long-snouted fish spend much of their time probing for buried food, but the substrate should not be allowed to collect uneaten material.

Feed after faster surface and midwater fish have taken their share, and confirm that every individual reaches food. Use small portions once or twice daily, remove persistent leftovers, and vary prepared and frozen or live foods.

Breeding

Breeding type
Egg Layer
Breeding difficulty
Moderate
Breeding temperature
24 °C
Breeding pH
6.5
Brood or egg count
Usually 60 to 200 adhesive eggs, depending on female size and condition.
Incubation
4 days
Parental care
None
Baby foods
  • Newly hatched brine shrimpA primary growth food after fry have absorbed the yolk sac; feed small rinsed portions several times daily.
  • MicrowormsUseful for newly feeding fry that remain close to the substrate.
  • Vinegar eels or cultured infusoriaHelpful for the smallest species and uneven broods during the first feeding stage.
  • Fine powdered fry foodUse sparingly as a supplement and siphon uneaten material to protect water quality.

Detailed aquarium breeding records are limited. It is expected to use the usual Corydoradinae T-position and attach adhesive eggs to firm surfaces, but triggers, egg output and fry requirements should not be presented as reliably established for this species.

Habitat and Origin

Geographic origin
Amazon Basin, Brazil, Ecuador, Peru, South America
Natural habitat
Freshwater River, Freshwater Stream, Sand/Mud Substrate
Aquarium contexts
Breeding Aquarium, Freshwater Aquarium, Freshwater Community, Planted Aquarium
Audience level
Intermediate

Classification

Profile type
Recognized species
Genus
Corydoras
Family
Callichthyidae
Species group
Corydoras, Fish

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