Corydoras robinae

Robine's Cory

Scientific Classification

Kingdom:Animalia

Phylum:Chordata

Class:Actinopterygii

Order:Siluriformes

Family:Callichthyidae

Genus:Corydoras

Species:robinae

Related Species:Corydoras robinae

IUCN Status:Least Concern

Quick Stats

Difficulty

Medium

Environment

Freshwater

Temperature

22°C - 26°C

pH Level

6 - 7.5

Water Hardness

36 - 215 ppm

Lifespan

5 years

Origin

South America

Adult Size

4 - 5 cm

Diet

Omnivore

Creature Type

Fish

TDS

250 ppm

Water Flow

Medium Flow

Aquarium Building Information

Minimum Tank Size

10L

Swimming Zone

bottom

Minimum School Size

Oxygen Consumption

Low

Waste Production

Low

Metabolism Rate

Low

Activity Level

Active

Feeding Frequency

Daily

Food Types

Sinking Pellets

Wafers

Frozen Food

Live Food

Flakes

About This Species

Basic Description

The Robine's Cory, also known as the Flagtail Cory, is an active and peaceful bottom-dwelling catfish perfect for community aquariums with its unique pattern. These charming little fish are a fantastic addition for those looking to add life to the lower level of their tank. As social creatures, they feel most comfortable and exhibit their most interesting behaviors when kept in a group, so a small school is essential for their well-being. They spend their days busily sifting through the substrate in search of food, which helps keep the tank tidy. To protect their delicate barbels (whiskers), a soft sand substrate is highly recommended over gravel. They are not picky eaters but require a diet of sinking foods specifically meant for bottom dwellers, as they cannot survive on leftovers alone. You might occasionally see them make a quick dash to the water's surface for a gulp of air; this is a natural and fascinating behavior that allows them to supplement their gill-breathing. Their peaceful temperament makes them excellent tank mates for other small, non-aggressive fish like tetras, rasboras, and guppies. With their constant activity and engaging social dynamics, Robine's Corys bring a lot of personality to a properly maintained aquarium.

Detailed Description

Corydoras robinae, commonly known as Robine's Cory or the Flagtail Corydoras, is an engaging and energetic benthic species originating from the river systems of South America. In their natural habitat, they are often found in tributaries and streams with a noticeable current, typically over sandy bottoms littered with leaf litter and driftwood. Replicating this environment is key to their long-term health in captivity. An aquarium for this species should feature a fine, non-abrasive sand substrate to protect their sensitive barbels, which are vital sensory organs used for locating food. Sharp gravel can cause erosion and infection, hindering their ability to forage. The inclusion of driftwood, catappa leaves, and other botanicals will not only provide hiding places and a sense of security but also encourage the growth of beneficial biofilms, which they enjoy grazing on. While they are adaptable to a range of water parameters, they thrive in clean, well-oxygenated water with some gentle circulation to mimic their native streams. Stability is more important than chasing exact numbers, so a mature, well-established filtration system and a consistent water change schedule are paramount.

As a highly social and active species, they must be kept in groups. A solitary individual will be stressed, shy, and prone to poor health. A larger school will display more confidence and natural foraging and shoaling behaviors, creating a dynamic display as they move in a coordinated fashion across the tank bottom. Their 'fast swimmer' characteristic is most apparent when they are comfortable in a group. Diet is a critical aspect of their care. Being omnivores, they require a varied diet consisting of a high-quality sinking pellet or wafer as a staple. This should be supplemented multiple times a week with frozen or live foods such as bloodworms, daphnia, brine shrimp, and tubifex worms to ensure a complete nutritional profile. One of their most interesting traits is their ability to breathe atmospheric air. They possess a modified, highly vascularized intestine that allows them to absorb oxygen from gulps of air taken at the surface. This is a supplementary adaptation for surviving in low-oxygen conditions and is not a substitute for proper tank aeration. Due to their small size and peaceful nature, they are ideal for community tanks, but tank mates should be chosen with care to avoid any fish large or aggressive enough to view them as food.

Scientific Description

Corydoras robinae is a fish in the class Actinopterygii, belonging to the family Callichthyidae, which encompasses the armored catfishes. As a member of the extensive genus Corydoras, it shares the characteristic feature of possessing two rows of bony plates or scutes along its body, providing defense against predation. The species name, robinae, is a patronym honoring Mrs. Robine Schwartz. Its fusiform body shape is hydrodynamically efficient for its benthic lifestyle, allowing for swift movements along the substrate. This species is endemic to South America, specifically found within the Rio Negro basin in Brazil. Ecologically, it inhabits slower-moving sections of tributaries and flooded forest areas characterized by soft, sandy substrates, clear or blackwater conditions, and an abundance of submerged vegetation and leaf litter. C. robinae is a micro-predator and detritivore. Its foraging behavior involves using its sensitive maxillary and rictal barbels to sift through the substrate, detecting and consuming small invertebrates, crustaceans, and organic detritus. This activity, classified as 'plant rooting' and 'biofilm consumption', plays a role in benthic nutrient cycling. A significant physiological adaptation within the genus, and observable in C. robinae, is its capacity for aerial respiration. The fish can supplement its branchial (gill) respiration by swallowing atmospheric air, which is then passed to a modified posterior section of the intestine where oxygen exchange occurs. This facultative air-breathing is an evolutionary advantage in environments prone to hypoxia. Metabolically, the species exhibits low oxygen consumption and low waste production, resulting in a modest bioload factor (1.6) relative to its size, making it an efficient organism within its ecosystem. Its current IUCN Red List status is 'Least Concern' (LC), indicating that at present, it is not considered a high priority for conservation efforts due to a relatively stable and widespread population.

Breeding Description

The captive propagation of Corydoras robinae is considered to be of moderate difficulty, achievable for the dedicated hobbyist who can provide specific environmental triggers. Proper identification of the sexes is the first step. Sexual dimorphism is subtle but discernible in mature, well-conditioned adults. Females are typically larger, with a broader and more rounded body profile, particularly when viewed from above, to accommodate egg development. Males are comparatively smaller, more slender, and streamlined. For successful breeding attempts, a breeding group should be established, with a recommended ratio of two or three males per female to improve fertilization rates and stimulate spawning activity. Conditioning the group for spawning is crucial. This involves a period of several weeks where the fish are fed a rich and varied diet of high-protein live and frozen foods, such as bloodworms, daphnia, and brine shrimp. This robust diet helps the female to become gravid (full of eggs) and brings the males into prime breeding condition. The primary trigger for spawning is a simulation of the rainy season in their natural habitat. This is best achieved by performing a large water change (50-75%) with water that is several degrees cooler than the tank's current temperature. The combination of a sudden drop in temperature and changes in water chemistry often induces spawning within 24-48 hours. During the spawning event, the fish will become very active. The male will court the female, leading to the characteristic 'T-position' where the female collects the male's milt. She will then release a small clutch of adhesive eggs into a basket formed by her pelvic fins and deposit them on a chosen surface, such as the aquarium glass, plant leaves, or a spawning mop. This process is repeated until the female has deposited all her eggs. Since adult Corydoras are known to consume their eggs, it is standard practice to either remove the adults to a separate tank or, more commonly, to carefully move the eggs into a dedicated hatching container with an airstone for aeration and gentle water movement to prevent fungal growth.