Schwartz's catfish (Corydoras schwartzi) care guide

Group
Freshwater fish
Other names
Schwartz's cory, Hoplisoma schwartzi
Family
Callichthyidae (armoured catfishes)
Origin
Endemic to the Rio Purus drainage in Brazil (middle Amazon), in small tributaries, creeks, flooded forest and over sand banks.
Water
freshwater
Maximum size
3.9 cm
Temperature
22–24°C
pH
6.5–7.8
Hardness
Soft to fairly hard, 1–15 dGH
Minimum tank
68 litres
Care level
intermediate
Temperament
peaceful

Care

Always keep Schwartz's cory in a group of at least six of the same species; it is much more confident in numbers. PlanetCatfish calls it a mainstay of the hobby and an ideal community catfish. Seriously Fish recommends a tank with a base of about 60 × 38 cm (around 68 litres). Use soft sand or small, rounded gravel so the fish can sift for food without damaging their barbels, and keep it very clean. PlanetCatfish suggests giving it a refuge such as a piece of bogwood raised about 3 cm off the bottom so the fish can rest underneath. An Amazon-style set-up with driftwood and a few dried leaves suits it, but a planted community tank is fine too. Both PlanetCatfish and Seriously Fish give a fairly narrow 22–24 °C. PlanetCatfish gives pH 6.5–7.8 (Seriously Fish 6–7.5); the PlanetCatfish range is used here. It is sensitive to declining water quality, so keep up regular partial water changes and do not let nitrate or waste build up. Corys have bony plates instead of scales and are sensitive to salt and many medications (especially copper), so treat with care. They gulp air at the surface now and then, which is normal. The pectoral spines are sharp, can pierce skin and catch in nets, so net them gently. Identification and sexing: PlanetCatfish notes that it is often confused with Corydoras parallelus, C. pulcher, C. ornatus and the undescribed C141, so buy from a seller who knows their corys. Females are wider-bodied than males and a little longer when mature. The species is named after Hans-Willi Schwartz, an aquarium-fish exporter in Manaus. Now classified as Hoplisoma schwartzi after the 2024 split of Corydoras (the name PlanetCatfish uses), but still widely sold as "Corydoras schwartzi". PlanetCatfish gives a maximum of 3.9 cm SL, as do FishBase and Wikipedia; Seriously Fish quotes 7 cm, which is the figure on our older page. FishBase lists it as Least Concern on the IUCN Red List (assessed 2018). Sources: PlanetCatfish (planetcatfish.com/common/species.php?speciesid=293); Seriously Fish (seriouslyfish.com/species/corydoras-schwartzi/); FishBase (fishbase.se/summary/Corydoras-schwartzi.html); Wikipedia (en.wikipedia.org/wiki/Corydorasschwartzi). Checked October 2026.

Diet

Omnivorous; in the wild it eats worms, small bottom-living crustaceans, insects and some plant matter. It takes most foods in the aquarium: flake, sinking wafers and pellets, plus frozen foods such as bloodworm and brine shrimp. Make sure food reaches the bottom.

Breeding

PlanetCatfish says it has occasionally been bred and follows the usual cory pattern; Seriously Fish describes it as rather tricky. Use about two males per female in a breeding tank of about 45 × 30 × 30 cm with sand or fine gravel. Condition the group on varied live, frozen and dried foods, then do daily 50–70% water changes with slightly cooler water until they spawn. One recorded spawning on PlanetCatfish was in water 20 cm deep at pH 7.5, GH 11, KH 3 and 23.3 °C. The female holds a few eggs between her pelvic fins while the male fertilises them, then sticks them to plants or glass, repeating until up to about 100 eggs are laid; the adults do not guard them. A little methylene blue helps stop fungus. Eggs hatch in 3–5 days, and once the yolk sac is used up the fry take microworm and newly hatched brine shrimp.

Compatibility and tank mates

Very peaceful and an ideal community catfish. Suitable companions include small tetras and other characins, rasboras and other small cyprinids, gouramis and other anabantoids, dwarf cichlids and other peaceful catfish. Avoid large or aggressive fish.

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

About Aquatic-Auctions

  • Aquatic-Auctions (aquatic-auctions.com) is a UK online marketplace for aquarium and pond livestock and equipment: tropical and marine fish, corals, shrimp, snails and other invertebrates, aquatic plants, tanks, filtration, lighting and food.
  • Items are sold by auction, buy it now or classified advert, by hobbyist and business sellers in the UK.
  • Buyers pay sellers directly; Aquatic-Auctions does not hold the money. Hobbyist sellers can only take PayPal or cash on collection. Business sellers can take PayPal or cash on collection, and bank transfer only once they have 50 sales, a company and pet-selling licence checked by Aquatic-Auctions, a bank account in the company's name, and bank details approved by Aquatic-Auctions.
  • Buyers are told to pay by PayPal Goods & Services, never PayPal Friends and Family, gift cards or crypto.
  • Live fish and other vertebrates must be sent by specialist live-animal couriers (for example APC Overnight or DX Express), never by Royal Mail. Some invertebrates and plants may go by Royal Mail Special Delivery or 1st Class within its rules.
  • Banned and invasive species (for example those on the GB invasive species lists) cannot be listed, and sellers must meet the site’s animal welfare standards.
  • Members must be 16 or over to buy (16 and 17-year-olds with a parent or guardian’s agreement); sellers must be 18 or over.
  • Business sellers show their address, company details and pet-selling licence to buyers. Seller ratings run from 0 to 100: +1 for each positive feedback, −1 for each negative.
  • The site includes a free community species wiki with care guides (water parameters, tank size, diet, temperament, breeding).
  • Aquatic-Auctions is run by Etavonni Tech Limited trading as Aquatic-Auctions (company number 10204188), Aldershot, Hampshire, UK. Contact: [email protected].