
Sixray Corydoras
Gastrodermus pauciradiatus
- Care level
- Intermediate
- Adult size
- 2.5–3.5 cm
- Minimum tank
- 45 litres
- Temperature
- 22–26 °C
Species profile
Hoplisoma schwartzi
Common names: Schwartz’s Corydoras, Schwartz's Cory, Schwartzi Corydoras

Schwartz’s Corydoras is a peaceful South American callichthyid catfish recognised by several dark longitudinal stripes across a pale body and a tall patterned dorsal fin. It should be kept in a same-species group over fine sand in clean, oxygen-rich freshwater.
Schwartz’s Corydoras has a pale silver body with rows of dark spots that form broken horizontal lines, plus a dark band through the eye. The dorsal fin is tall and may show an extended leading ray in mature specimens.
Identify this profile by the combination of several dark longitudinal stripes across a pale body and a tall patterned dorsal fin. Older sources commonly list this fish as Corydoras schwartzi; the current profile follows the accepted or revised placement Hoplisoma schwartzi. Colour alone can be unreliable in stressed, juvenile, or poorly conditioned fish, so body shape, snout length, fin pattern, and provenance should also be checked.
Mature females are generally larger and fuller-bodied when viewed from above. Males remain slimmer and may show more pointed fins, but pattern and dorsal-fin height vary too much to sex every fish reliably.
Use fine sand, shaded retreats beneath wood or plants and open floor space for a group. Clean substrate and regular water changes are important because this species can suffer barbel damage when kept over dirty or abrasive material.
This is a peaceful shoaling cory that is often reserved when first introduced. A proper group and calm midwater fish usually encourage more confident daytime foraging.
Keep at least 6 of the same species or coded population, with 8 or more preferred where space permits. A mixed collection of single corys does not fully replace a proper same-species group.
It is not territorial. Males may briefly chase one another or follow females during courtship, but sustained aggression is unusual when the group has adequate floor space.
It works well with peaceful tetras, rasboras, pencilfish and other calm community species. Avoid aggressive cichlids, fin-nippers and territorial bottom dwellers.
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Xilong XL-803D canister filter – up to 100 LAn external-filter option for the moderate-flow setup described above. The seller lists a 400 L/h pump and an aquarium capacity of up to 100 litres.
Check the volume of your actual aquarium and the needs of its complete stocking. Use the flow control or spray bar to avoid a concentrated current. A larger tank or a species requiring strong river flow needs a different filter selection.
Cut-to-fit aquarium filter media padA cut-to-fit pad for compatible filter compartments. The listing describes a sheet approximately 16 by 12 inches; check the offered variant and the space inside your filter.
The seller description varies between five and eight layers, so confirm the actual sheet before ordering. Keep the filter manufacturer’s media arrangement and avoid obstructing the flow.
Xinyou ceramic filter rings – 300 gA biological-media option for a filter with a suitable media basket. This listing is a 300 g pack of ceramic rings.
Check the ring size and available basket space. Installing new media does not make a new aquarium instantly cycled, and these rings do not replace routine water-quality checks.
Soft, mildly acidic water best reflects the natural habitat and usually gives the most reliable breeding results. Stable clean water is more important than forcing an exact pH.
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Manual aquarium siphon and gravel cleanerA manual siphon for routine aquarium water changes and accessible waste removal. The seller lists a hose approximately 1.6 m long.
Control the flow and keep the intake clear of fish and delicate planting. Clean the areas appropriate for your substrate and layout rather than disturbing the entire planted bed.
Feed quality sinking pellets, granules and tablets together with frozen or live invertebrate foods. Ensure food reaches the bottom and that every fish eats rather than relying on leftovers.
Feed after faster surface and midwater fish have taken their share, and confirm that every individual reaches food. Use small portions once or twice daily, remove persistent leftovers, and vary prepared and frozen or live foods.
Captive breeding is documented but can be less predictable than with common bronze or peppered corys. Adults use the typical cory spawning sequence and attach eggs to surfaces; the eggs can be fungus-prone and should be kept clean and well oxygenated.
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