Evelyn's Corydoras
Hoplisoma evelynae
A mysterious and elusive species with a highly variable pattern: broken black mask, fragmented lateral band, and a dazzling gold spot at the base of the neck.
Température de l’eau
22 - 26 °C
Valeur du pH
6 - 7.2
Type d'eau
Eau douce
Niveau dans le bac
Fond
Taille adulte
4,5 cm
Volume minimal du bac
>= 80 L
Groupe minimal
>= 6
GH
2 - 12 dGH
KH
2 - 10 dKH
TDS
50 - 280 ppm
Conductivité
78 - 438 uS/cm
Description de l'espèce
Geographical Origin and Habitat: Upper Amazon rainforest (Solimões River basin) in the area bordering Brazil, Colombia, and Peru. Prefers slow amber waters or isolated oxbows surrounded by dense primary jungle, with thick deposits of organic matter and soft sand.
Taxonomy and Morphology: Often labeled with C-numbers. Quite rare and of medium-small size, does not exceed 4.5 cm (1.8 inches). Belongs to the complex of small short-snouted Corydoras with tiger/leopard patterns that share ecological niches similar to C. arcuatus and C. trilineatus.
Social Behavior: Very peaceful species, perpetually busy on the substrate. Fearful by nature, the absence of a large school (minimum 6-8) makes them subject to severe stress. If reassured by a group and a not overly bright environment, they become curious and intrepid.
Coloration and Sexual Dimorphism: Light livery adorned with a large black orbital mask, and two or three fragmented bands or large black "broken spots" along the flank and on the back, highly variable between individuals. The dorsal fin is partially transparent or spotted. Females decidedly more gravid and wider than males.
Soins, reproduction et cohabitation
Aquarium Setup: The use of impalpable sand is non-negotiable; even small gravel will damage the delicate barbels. Recreate a protected area with coconut half-shells, dense branches (Red Moor Wood), and Catappa leaves. The addition of peat will soften the lighting making them very active.
Diet and Feeding: Insatiable omnivorous detritivore. The base should be top-quality commercial tabs rich in vegetable and animal proteins. Absolutely necessary to supplement with frozen Daphnia and Bloodworms: if fed on "leftovers" they waste away in a few weeks.
Water Quality: Extreme cleanliness of the bottom required. Recommended temperatures between 22 and 26°C (72-79°F). Low to medium hardness (GH 2-12). It is essential to keep the water acidic or sub-neutral (pH 6.0-7.2) and proceed with abundant water changes to avoid fatal nitrate loads.
Compatibility and Cohabitation: Perfectly shares the habitat in peaceful community tanks with medium-small species. Excellent pairings with South American Tetras (e.g. Nematobrycon palmeri, Paracheirodon innesi), dwarf Corydoras, and Apistogramma or Ramirezi. Totally unsuitable with goldfish or large predators.
Aquarium Breeding: Documented but not very frequent: breeders are pushed to the T-Position by the ingestion of heavy quantities of live food and sudden temperature fluctuations (cold water in top-offs). They lay single adhesive eggs among plants (e.g. Java Moss). Adults to be removed to avoid cannibalism.
Risks and Diseases: Lethal for them is the loss or ulceration of barbels caused by sharp substrates, leading to starvation. They suffer severely and die with direct or prolonged administrations of Malachite Green or Copper-based curatives.
Origine et répartition géographiques
Upper Amazon rainforest (Solimões River basin) in the area bordering Brazil, Colombia, and Peru. Prefers slow amber waters or isolated oxbows surrounded by dense primary jungle, with thick deposits of organic matter and soft sand.
Origine
Amazonie, Orénoque et Guyanes
Profil de poisson
- Tempérament
- Semi-aggressive
- The temperament of Hoplisoma evelynae can only be described as completely peaceful and highly gregarious. They are a schooling fish by nature and absolutely must be kept in groups of at least six individuals of their own kind to feel secure. When kept in insufficient numbers, they will become extremely stressed, reclusive, and susceptible to disease. In a proper school, they are active, inquisitive, and highly entertaining to watch as they scurry around the bottom together like a busy little cleaning crew. They pose absolutely no threat to any other inhabitants in the aquarium.
- Régime alimentaire
- Omnivore
- In the wild, Hoplisoma evelynae is a micro-predator and scavenger that sifts through the substrate for small insects, worms, and crustaceans. In the aquarium, they readily accept a wide variety of high-quality sinking foods, including pellets, wafers, and granules designed for bottom feeders. To ensure optimal health and coloration, their diet should be supplemented with live or frozen foods such as bloodworms, daphnia, and brine shrimp. They are not true algae eaters, so feeding them solely algae wafers is a common mistake that can lead to malnutrition. A varied diet will keep their immune system strong and encourage natural foraging behaviors.
- Espérance de vie
- 3-5 years
- Taille adulte
- 4.5 cm
- Ratio des sexes
- School
- When keeping Hoplisoma evelynae, the exact sex ratio is not strictly critical for their day-to-day well-being, as they do not exhibit aggression toward each other. However, if the goal is to breed them, a ratio of two or three males for every female is strongly recommended. This multiple-male approach increases the chances of successful fertilization during the spawning process. Females are typically larger and noticeably broader when viewed from above, especially when conditioned with high-quality foods. Maintaining a healthy, mixed-gender school allows for the observation of their fascinating natural social dynamics.
- Fréquence d'alimentation
- Twice daily
- It is generally recommended to feed Hoplisoma evelynae small amounts of food once or twice a day. The key is to provide only what the fish can completely consume within a few minutes to prevent uneaten food from rotting in the substrate. Because they are bottom feeders, you must ensure that enough food reaches the bottom before faster mid-water fish consume it all. If feeding twice a day, offering a staple sinking pellet in the morning and a frozen treat in the evening works exceptionally well. Observing their bellies can help you gauge if they are getting enough food; they should look gently rounded but not bloated.
- Charge biologique
- Low
- The bioload of Hoplisoma evelynae is relatively low to moderate, making them an excellent choice for a community aquarium. They do not produce excessive amounts of waste compared to larger or more predatory fish. However, because they are a schooling species and should be kept in groups, the cumulative bioload of the school must be accounted for when sizing the filtration system. Regular water changes and a properly cycled aquarium are still essential to maintain the high water quality they require. It is important to avoid overfeeding, as uneaten food will negatively impact the water parameters.
- Courant
- Stagnant
- Hoplisoma evelynae appreciates a moderate amount of water flow in the aquarium, simulating the gentle currents of their native South American streams. The flow should be strong enough to keep the water well-oxygenated and prevent detritus from settling on the bottom, but not so strong that the fish struggle to swim or rest. Using a standard hang-on-back or canister filter usually provides the perfect amount of water movement. They will often be seen actively swimming against the current for exercise, but they also need quiet resting areas among plants or hardscape. Providing a balance of moving water and still zones is the best approach to their habitat.
- Risque de saut
- Yes
- The risk of Hoplisoma evelynae jumping out of the aquarium is generally very low, as they spend the vast majority of their time navigating the bottom of the tank. However, like all Corydoras, they possess an adaptation that allows them to dart to the surface to gulp atmospheric air. During these rapid ascents, an accidental jump or splash can occasionally happen if the fish misjudges the surface. For this reason, a secure lid or cover glass is highly recommended to prevent any tragic accidents. A lid also helps maintain a humid layer of air above the water, which makes breathing easier for them.
- Reproduction
- Oviparous
- Breeding Hoplisoma evelynae in captivity is entirely possible and often highly rewarding for dedicated aquarists. They are egg scatterers, typically laying their adhesive eggs on broad-leaved plants, aquarium glass, or smooth stones after an elaborate courtship dance. To trigger spawning, aquarists often perform a large, cool water change to simulate the onset of the rainy season in the Amazon basin. Once the eggs are laid, the parents provide no parental care and may even consume their own eggs if not removed. For the best survival rate, the eggs should be transferred to a separate rearing tank and the fry fed infusoria or freshly hatched brine shrimp.
- Compatibilité et compagnons
- With caution
- Hoplisoma evelynae is incredibly peaceful and makes a fantastic addition to most community tanks. They get along well with other peaceful, similarly sized fish such as tetras, rasboras, and dwarf cichlids. It is crucial to avoid keeping them with large, aggressive, or predatory species that might view them as food or nip at their fins. They are also completely safe to keep with most ornamental snails and adult dwarf shrimp, although baby shrimp might occasionally be eaten. Their bottom-dwelling nature means they rarely compete for space with mid- or top-dwelling tank mates.
- Niveau dans le bac
- Bottom
- As classic bottom-dwellers, Hoplisoma evelynae will spend nearly all of their time foraging and resting on the substrate. They use their sensitive barbels to meticulously search the sand or fine gravel for any edible morsels that have sunk to the bottom. While they are primarily benthic, it is completely normal to see them periodically make lightning-fast dashes to the water's surface to take a gulp of air. Aside from these quick trips to the top, they will almost never be found swimming in the middle or upper levels of the water column. Providing a large footprint with plenty of open bottom space is far more important than tank height.
Modèles et paramètres scientifiques
FishBase
Fenêtre sur les données scientifiques officielles de l’espèce
FishBase v25.04Données synchronisées le : 15/06/2026
- Niveau trophique
- 3 ± 0,4 se
- Résilience
- Élevée (moins de 15 mois)
- Singularité phylogénétique (PD50)
- 0.5
- Relation bayésienne longueur-poids
- a = 0.00741, b = 3.14
- VulnérabilitéVulnérabilité faible (10 / 100)
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