Blacktop Corydoras
Corydoras acutus
A long-snouted Corydoras species, known for the large and striking black saddle on the upper half of its dorsal fin. An excellent sand sifter with an extremely peaceful nature.
Temperatura da água
22 - 26 °C
Valor de pH
6 - 7.2
Tipo de água
Água doce
Nível do tanque
Parte inferior
Tamanho adulto
5,5 cm
Volume mínimo do tanque
>= 60 L
Grupo mínimo
>= 6
GH
2 - 12 dGH
KH
1 - 6 dKH
TDS
40 - 240 ppm
Condutividade
63 - 375 uS/cm
Descrição da espécie
Geographical Origin and Habitat: Amazon River basin (Ecuador and northern Peru). Prefers small tributaries, oxbow lakes and shady forest rivers with a bottom of sand or soft clay, covered by leaf litter.
Taxonomy and Morphology: Black-Top Corydoras (Corydoras acutus). A "long-snouted" corydoras, specialized for sinking its head deeply into the soft substrate in search of prey. The mouth is equipped with sensitive barbels.
Social Behavior: Exquisitely peaceful and highly gregarious. Essential to keep them in schools of no less than 6 specimens, otherwise they will suffer lethal stress, chronic shyness and food refusal. Spends the day rummaging the bottom.
Coloration and Sexual Dimorphism: Presents a silvery/gray body heavily dotted and spotted with black. The distinctive feature is the black spot (black-top) on the upper dorsal fin and the elongated snout. Females are visibly wider and taller than males.
Cuidado, criação e companheiros de tanque
Aquarium Setup: Tank of minimum 80 cm (32 inches). THE BOTTOM MUST BE FINE SAND. Any angular gravel or sharp quartz will irreparably wear away the delicate barbels, causing lethal fungal infections. Wood and dry leaves complete the layout.
Diet and Feeding: Bottom micro-predator. Requires sinking protein-rich pellets and a constant supply of frozen food (bloodworms, brine shrimp, tubifex). Avoid feeding them only with the "scraps" of surface fish.
Water Quality: Loves very well oxygenated waters (essential for corydoras) and moderate temperatures (24°C / 75°F ideal). Nitrates strictly below 20 ppm; they are bottom fish and are immediately affected by the accumulation of pollutants on the ground.
Compatibility and Cohabitation: Absolute pacifists. Perfect companions for Discus, Angelfish, small and large Characins (Tetras) and dwarf Cichlids (e.g. Apistogramma, although during spawning the latter will brutally chase them away).
Aquarium Breeding: Long-snouted Corydoras are harder to breed than short-snouted ones. Requires sudden stimulation: a massive change of very cold water (monsoon simulation) prompts the female to glue the eggs on the glass in strong current.
Risks and Diseases: Lethal bacterial infections to the barbels caused by poor bottom hygiene (anaerobic bacteria). They emit toxins if threatened or transported in bags with little water.
Origem e distribuição geográfica
Amazon River basin (Ecuador and northern Peru). Prefers small tributaries, oxbow lakes and shady forest rivers with a bottom of sand or soft clay, covered by leaf litter.
Origem
Oceanos tropicais e recifesAmazônia, Orinoco e Guianas
Perfil de peixe
- Temperamento
- Semi-aggressive
- Corydoras acutus are peaceful, social schooling fish that thrive when kept in groups. Keeping them in numbers of at least six individuals greatly reduces their stress and promotes natural behaviors. They are completely harmless to plants and other tank inhabitants.
- Dieta
- Omnivore
- These are omnivorous bottom feeders that require a varied diet to thrive. Their meals should include high-quality sinking pellets, wafers, and live or frozen foods like bloodworms. A balanced diet ensures proper growth and vibrant coloration for Corydoras acutus.
- Expectativa de vida
- 5-10 years
- Tamanho adulto
- 5.5 cm
- Proporção sexual
- Specific M:F ratio
- Maintaining a ratio of two or three males for every female is ideal for breeding purposes. This ratio encourages natural spawning behaviors and increases the chances of successful fertilization. In non-breeding community tanks, the exact ratio for Corydoras acutus is less critical.
- Frequência de alimentação
- Twice daily
- They should be fed small amounts once or twice a day. It is important to provide only what Corydoras acutus can consume within a few minutes to prevent water fouling. Occasional fasting days can also be beneficial for their digestive health.
- Carga biológica
- Low
- The Corydoras acutus has a relatively low bioload compared to many other species of similar size. They are efficient scavengers that help keep the substrate clean, which slightly offsets their waste production. However, adequate biological and mechanical filtration is still necessary to maintain optimal water quality in the aquarium.
- Fluxo
- Stagnant
- They prefer moderate water movement that simulates their natural riverine habitats. A gentle current provides necessary oxygenation without exhausting the fish. Avoid overly strong flow that could sweep Corydoras acutus away or cause stress.
- Risco de salto
- No
- Reprodução
- Oviparous
- Breeding Corydoras acutus in captivity is possible but requires specific water conditions and conditioning. They are egg layers that typically deposit their adhesive eggs on broad leaves or the aquarium glass. Parents may eat the eggs, so it is often best to raise the fry in a separate tank.
- Compatibilidade e companheiros de tanque
- Community
- They are incredibly peaceful and make excellent additions to community aquariums. Corydoras acutus gets along well with most other peaceful, similarly sized fish. Aggressive or large tank mates should be avoided as they may intimidate or harm them.
- Nível do tanque
- Bottom
- They are obligate bottom dwellers that spend the majority of their time on the substrate. Corydoras acutus constantly rummage through sand or smooth gravel in search of food. Very rarely will they be seen swimming in the middle or upper levels of the water column.
Modelos e parâmetros científicos
FishBase
Acesso aos dados científicos oficiais da espécie
FishBase v25.04Dados sincronizados em: 15/06/2026
- Nível trófico
- 3 ± 0,3 se
- Resiliência
- Alta (menos de 15 meses)
- Unicidade filogenética (PD50)
- 0.5
- Relação bayesiana comprimento-peso
- a = 0.00741, b = 3.14
- VulnerabilidadeVulnerabilidade baixa (10 / 100)
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