Corydoras julii was described by the Austrian ichthyologist Franz Steindachner in 1906. The original description does not mention who the fish was named after.
Distribution & Availability
Found in the Rio Parnaiba in Brazil, C. julii is available very rarely with almost all fish advertised being C. trilineatus. It is seen occasionally in the better shops as a wild caught import and is sometimes sold at specialist and club auctions. Considering how rare these fish are they are not that expensive being around twice the price of the common bronze and pepper corydoras.
Males – a small, round-nosed catfish with typical corydoras profile of arched back and flat underside. Males will reach about 4.5cm only. Base colour is cream and the body is covered in fine black spots. There is a variable horizontal stripe from around the middle of the body reaching rearwards to the caudal peduncle. There is a black blotch on the dorsal fin and vertical bars on the tail. C. julii never show the heavy reticulations that characterise C. trilineatus nor do they show the pointed snout of C. leopardus.
Females – slightly larger than the male and more thick-set around the body. Otherwise the same.
Easy to keep in most water conditions, just avoid extremes of pH and temperature.
- Tank size: 90cm minimum
- Decoration: hiding places constructed from slate, bogwood and plants. Provide a thin covering of river sand in preference to gravel.
- Temperature: 22 – 26oC
- pH: 6 – 8 (Less than 7 for breeding)
- Hardness: not too hard, 2 – 15odH (At the low end of this range for breeding)
Typical corydoras food of sinking pellets and frozen food will be fine. Offer a treat of live food once or twice a week. If kept in a community tank it is a good idea to feed your catfish after the lights go out.
Straightforward to breed in the usual manner for the genus.
Condition a group of 2 females and 2 or 3 males on live and frozen foods such as frozen bloodworms, frozen blackworms, live daphnia and white worms. Decorate the tank with pieces of bogwood and provide clumps of fine-leaved plants such as Indian fern, and Java moss. Keep the water quality first-rate and provide some gentle water movement in the form of an air-powered sponge filter. Keep the pH to no more than 7.0 or preferably a little less. The hardness should be 1 or 2 degrees only.
The day after a 50% water change with cool water the adults spawned vigorously amongst the fine-leaved plants and up to 100 eggs were laid. I opted to leave the eggs in the breeding tank and removed the parents even though the adult fish ignored the developing eggs. The eggs hatched in about 4 days at a temperature of 26oC. The fry weren’t fed for the first week as the tank was mature and there was enough food in the plants and large sponge filter. First food was microworm and crushed pre-soaked flake. Newly hatched brine shrimp was fed when they were a couple of weeks old.
Water changes carried out twice weekly with aged water ensured the fry grew fast and showed the adult pattern with 2 months.
USA Show standards
- Size: 5cm
- Breeding category: B
- Show class: KA
C. julii is a beautiful, peaceful, easy to keep and breed catfish that is perfect for a community tank. It’s just a pity it is hardly ever seen in the shops.
- Fishbase species summary
- Fuller, I. A. M. and H. G. Evers. 2005. Identifying Corydoradinae catfish. Aspidoras–Brochis–Corydoras–Scleromystax and C-numbers.
- Catfish study reveals multiplicity of species (sciencedaily.com)