Threestripe corydoras, leopard catfish, false julii cory (Corydoras trilineatus) care guide

Group

Freshwater fish

Other names

Three-line cory, Three-stripe corydoras, Leopard cory, Leopard catfish, False julii cory, Julii cory (usually a mislabel), Hoplisoma trilineatum

Family

Callichthyidae (armoured catfishes)

Origin

Central and upper Amazon basin in Peru, Colombia and Brazil (including the Marañón, Ucayali, Pastaza and Purus), plus coastal rivers of Suriname.

Water

freshwater

Maximum size

6.1 cm

Temperature

16–25°C

pH

5.8–7.2

Hardness

Soft to medium, 1–12 dGH

Minimum tank

41 litres

Care level

beginner

Temperament

peaceful

Care

The three-line cory is one of the best catfish for anyone new to Corydoras: hardy, peaceful and always busy. PlanetCatfish calls it a perfect community tank citizen that tolerates most water conditions in a reasonably kept aquarium. Like all corys it is a social fish, so keep a group of at least six of the one species, and more if you have room; a bigger group is more confident and spends more time out in the open. A tank with a base of at least 45 × 30 cm (around 41 litres) will hold a small group, though a longer tank gives a larger group more room to forage. Use a soft sand substrate if you can: corys spend their day sifting through the bottom with their barbels, and sharp or dirty gravel can wear the barbels down or lead to infections. Keep the substrate clean, add some driftwood, plants and a few shady spots, and use gentle-to-moderate filtration. PlanetCatfish gives 16–25 °C and pH 5.8–7.2, which are the figures shown here; this is a cooler and wider range than the 22–26 °C quoted by Seriously Fish, and most keepers keep it at around 22–25 °C. It copes with a fairly wide range, but it does not tolerate neglect: rising nitrate, a fouled substrate and poor water quality show up quickly as eroded barbels and fins. Regular partial water changes are the key. As with other corys, be careful with salt and with many medications, which they handle poorly. It is quite normal to see them dart to the surface now and then for a gulp of air, as they can breathe air through the gut. PlanetCatfish gives a maximum of 6.1 cm standard length, a little larger than the 5.5 cm quoted by Seriously Fish. Females grow larger and fuller-bodied (best seen from above); males develop more pointed fins as they mature. Hoplisoma trilineatum is the current name after the 2024 split of the old genus Corydoras (PlanetCatfish also lists C. dubius and C. episcopi as synonyms), but it is still almost always sold as "Corydoras trilineatus". It is also very often sold as "Corydoras julii". The true julii (now Hoplisoma julii) is rare in the trade; the two look very alike, but the three-line has pale and dark lines along the body and some maze-like (reticulated) markings, while true julii has no reticulation and is covered in separate, distinct spots. Patterns vary a lot from fish to fish, so collection locality is the surest guide. It is one of the most widely available corys. PlanetCatfish lists it as not evaluated by the IUCN, while FishBase lists it as Least Concern. Sources: PlanetCatfish (planetcatfish.com/common/species.php?speciesid=508); Seriously Fish (seriouslyfish.com/species/corydoras-trilineatus/); FishBase (fishbase.se/summary/Corydoras-trilineatus.html); Wikipedia (en.wikipedia.org/wiki/Corydorastrilineatus). Checked October 2026.

Diet

An easy-going omnivore that forages on the bottom for worms, small crustaceans, insect larvae and plant matter. Feed a good sinking pellet or tablet as the staple and add live or frozen foods such as bloodworm, Daphnia and brine shrimp several times a week. Make sure food actually reaches the bottom: corys should be fed in their own right, not left to live on leftovers.

Breeding

Often said to be one of the easiest Corydoras to spawn, with many breeding reports on PlanetCatfish. A breeding tank of about 45 × 30 × 30 cm with a sand or fine gravel base and a sponge filter works well; use two males to each female. Condition the group well on live and frozen foods in clean, soft water, then do a large (50–70%) water change with slightly cooler water each day until they spawn; a drop in temperature is a common trigger. Spawning follows the typical cory T-position: the female holds a few eggs in a pouch formed by her pelvic fins while the male fertilises them, then sticks them to the glass or plants, repeating until up to around 100 eggs are laid. The adults give no care and may eat the eggs, so move either the eggs or the adults. The eggs are prone to fungus, so keep them in clean, well-aerated water. They hatch in 4–5 days, and once the fry have used up their yolk they will take microworm and newly hatched brine shrimp. Clean water is essential while raising them.

Compatibility and tank mates

Very peaceful and an excellent community catfish. Good tankmates include small tetras and other characins, rasboras and other small cyprinids, gouramis and other peaceful anabantoids, dwarf cichlids such as Apistogramma, and other peaceful catfish. Avoid large or aggressive fish and anything that would harass bottom-dwellers. Keep in mind the sharp fin spines if a larger fish tries to swallow one.

Last updated 5 October 2026. Community-edited care guide on Aquatic-Auctions.