rm
Passport
- Family
- Corydoras Catfish
- Grows to
- 5.5 cm (2.2")
- Lives
- 10+ years
- Temperament
- Peaceful
- Care
- Beginner
- Swims
- On the bottom
- Keep
- In a group of 4 or more
- Water
- 20–26 °C (68–79 °F)
Brazil
Care requirements
i
On record for Julii Cory: adult size, lifespan, minimum tank, temperature, ph, hardness, minimum group, diet, care level, swim level, tank length.
A figure that is not on record is left out rather than guessed. One marked Suggested comes from keeping knowledge rather than a page.
- Minimum tank 76 L / 20.0 US gal
- pH 5.5–7.5
- Hardness 2–12 dGH
- Diet omnivore
- Tank length 90 cm minimum
Care notes written from general aquarium knowledge, not from the cited sources.
About
The first thing to know about julii corys is that you probably don't have one. The true julii is uncommon in the trade, and the great majority of fish sold under the name are three-stripe corys — a closely related species that looks similar and is kept identically.
You can tell them apart by the head. A real julii carries fine, separate dark spots scattered over the head and shoulders; the three-stripe has those markings joined into a maze of connected squiggles. Neither is better, and the mix-up matters only if you care what you're calling it.
Either way it's a good fish: a small, busy, patterned cory that spends its day working the bottom in a group and looks smarter than the plainer bronze and albino forms.
Tank setup
Give your corys sand. This is the one non-negotiable thing about the genus — they feed by pushing their snouts into the substrate and sifting, and sharp gravel wears the barbels back until they cannot do it properly. A fish that can no longer forage will lose condition, so this is worth getting right from the start rather than correcting later.
Keep them in a proper group. They're social to the point that a lone cory sits in a corner and does nothing, while a group works the floor together all day.
Leave open floor space. They need ground to patrol, so a long footprint beats a tall tank, and heavy planting across the whole bottom takes away what they use.
Give them shade and cover to retreat under: wood, broad leaves, a cave or two.
Leave an air gap. Corys dart to the surface for a gulp of air, which is normal — they absorb oxygen through the gut — and a tank filled to the lid stops them.
Feeding
Julii corys are omnivorous scavengers, and the most common mistake is assuming they'll live on what other fish drop.
Feed them their own food. Sinking pellets and wafers as a staple, with frozen bloodworm, daphnia and brine shrimp regularly. They need it to reach the bottom before anything else eats it.
Feed after lights out if the tank is busy. They'll happily feed in daylight but they're slower than most community fish.
Avoid: relying on leftovers, which is how corys end up thin, and avoid coarse substrates that stop them foraging at all.
Filtration and flow
Moderate flow suits them and they enjoy a current across the bottom.
Keep nitrate low and the substrate clean. Corys live in the layer where waste settles, and their barbels are the first thing a dirty tank damages.
Good oxygenation helps, though their gut-breathing gives them a margin most fish lack.
With plants
Julii corys are safe with plants and don't eat or uproot them.
Plant round the edges and leave the middle of the floor clear. That's the arrangement that suits a foraging bottom fish, and it looks better than a fully carpeted tank anyway.
Broad-leaved plants give them shade to rest under during the day.
Health
Barbel erosion is the signature problem, and it is a symptom to look into rather than a diagnosis on its own. Substrate and water quality are the first two things to check, and a worn barbel can pick up a secondary infection as well. Some regrowth has been demonstrated once conditions are corrected; do not count on it for a badly damaged fish.
Salt suits them badly. Anything else should be checked against its own species list before it goes in and then followed as instructed, because a gentler version invented on the spot tends to leave you with a fish that is still ill and now also stressed.
Watch for a cory resting on its side or breathing hard at the surface repeatedly. Corys gulp air normally, but constant trips up mean the water is short of oxygen or the fish is in trouble.
Breeding
They spawn readily and the trigger is a cool water change. Dropping the temperature with a partial change mimics the rainy season and often produces spawning within a day.
The female carries a few eggs in a pouch formed by her pelvic fins, fertilises them, and sticks them one by one to glass, plants or wood. Expect them scattered all over the tank rather than in a nest.
The adults eat the eggs, so move them or move the fish. Fry are straightforward, taking infusoria then microworm and baby brine shrimp, and they need very clean water and a sand bottom to sift.
Tank mates
Avoid10
- Convict Cichlid Convict Cichlid grows to 15 cm against Julii Cory at 6 cm, big enough to eat it.
- Jewel Cichlid Jewel Cichlid grows to 15 cm against Julii Cory at 6 cm, big enough to eat it.
- Least Killifish Julii Cory grows to 6 cm against Least Killifish at 2 cm, big enough to eat it.
- Scarlet Badis Julii Cory grows to 6 cm against Scarlet Badis at 2 cm, big enough to eat it.
- Common Goldfish Common Goldfish is not safe with Julii Cory: common goldfish and corydoras catfish are a bad pairing.
Only with care8
- Chinese Algae Eater Chinese Algae Eater is aggressive and Julii Cory is peaceful.
- Clown Loach Clown Loach is a risk to Julii Cory: corydoras catfish and loaches and botia are a pairing to watch.
- Dwarf Chain Loach Dwarf Chain Loach is a risk to Julii Cory: corydoras catfish and loaches and botia are a pairing to watch.
- Hillstream Loach Julii Cory and Hillstream Loach are an uneasy mix: corydoras catfish and loaches and botia are a pairing to watch.
- Kuhli Loach Kuhli Loach is a risk to Julii Cory: corydoras catfish and loaches and botia are a pairing to watch.
No conflict is recorded with the other 88 species in the database, so nothing to flag. 2 species are not covered at all, so they could not be judged either way.