Cruziensis Cory / Santa Cruz Cory C012 (Hoplisoma cruziense)

Meet Corydoras cruziensis, the Santa Cruz Cory

Corydoras cruziensis is a small, spotted armoured catfish from Bolivia, known in the hobby as C012 or C12 and as the Santa Cruz Cory. Its sandy-beige body is covered with rows of round dark spots, a dark band runs through the eye, and the dorsal fin and tail carry neat rows of spots too. Adults stay under about 5 cm, so a group fits a modest planted aquarium, where it spends the day sifting the sand with its barbels in a busy little shoal.

Knaack described the species in 2002 from Guarayos in Bolivia's Santa Cruz Department, at an elevation of 215 metres, and named it after that department. Planet Catfish places it in the Madeira River basin in Bolivia, and Seriously Fish adds that the range is unclear but may include the Mamoré and Beni drainages. ScotCat lists it from the Santa Cruz and Beni Departments, while an early Practical Fishkeeping report describes it as widely distributed.

Check the names on the label

The change of genus comes from a large study by Dias and colleagues published in 2024. Seriously Fish explains that it split Corydoras into five genera; ScotCat adds that this species belongs to lineage 9, the short-snouted corys whose type species is C. punctatus, which now carries the old name Hoplisoma. The fish and its care are unchanged. Browse more corys in our corydoras shop and the wider South American catfish category.

Tell it apart from its look-alikes

Planet Catfish compares it with the Spotted Cory, Corydoras punctatus, a species found only in Suriname. The Santa Cruz Cory has fewer, larger body spots, and the spots along the join between the upper and lower body plates may run together into an irregular broken stripe; Practical Fishkeeping adds that it is smaller, with more clearly defined spots. ScotCat says it is very similar to Hoplisoma copei from Peru, and that the two are difficult to tell apart. Other spotted corys, such as the Julii Cory, can look similar at a glance, so buy from a named, coded batch rather than a mixed "spotted cory" tank.

Know what one purchase supplies

One purchase supplies one live Santa Cruz Cory at the standard size offered on this listing. It is a shoaling fish that feels secure only in company, so order the whole group at once and let it settle together. Young fish are smaller than the adult sizes below.

Sex is not specified. Planet Catfish describes females as a little larger and heavier, with rounded, fan-shaped pelvic fins, while males have slightly pointed ones; Practical Fishkeeping gives size as the only clear guide. These differences show only in adults. The photographs show the species; the number and size of spots vary between individuals, so expect some difference from the pictures.

Plan the shoal before you order

• Adult length: 43 mm standard length (Planet Catfish, FishBase) to 50 mm (Seriously Fish).
• Group: six or more, as ScotCat recommends.
• Aquarium: an 80 × 30 cm base, about 72 litres, or larger.
• Temperature: 23–25.5°C, the band the sources share.
• Floor: fine, smooth-grained sand.
• Company: small, calm fish only.

Read our delivery and Live Arrival Guarantee information before ordering, and make sure the aquarium is fully cycled and at temperature when the fish arrive.

Give a 5 cm cory an 80 cm floor

Seriously Fish gives a minimum base of 80 × 30 cm, about 72 litres, for this species, and OATA's catfish guidance gives at least 80 litres for a shoal of corydoras. Practical Fishkeeping notes that the fish is small and needs little space, but floor area, not height, decides how many corys an aquarium can hold, because all of them feed on the same sand.

A longer tank lets the group spread out and forage naturally, and gives timid fish room to keep away from busier neighbours. Our stocking calculator helps you check that the shoal and its tank mates fit the aquarium you have.

Run a three-step space check

1. Measure the base: at least 80 cm long and 30 cm from front to back.
2. Count the floor fish: include every cory, loach and other bottom dweller you keep or plan to keep.
3. Leave open sand: keep at least the front third of the floor clear of décor for feeding.

Recreate a planted Bolivian stream

Practical Fishkeeping recommends a well-planted aquarium with a fine, smooth-grained substrate, a few rocks and bogwood, and Planet Catfish agrees that fine, smooth sand matters most, with other décor relatively unimportant. Seriously Fish adds that some cover should be provided for security. A quiet planted tank with a soft sand floor, a piece of wood and a few smooth stones suits this timid little cory well.

Plants also help the shoal feel safe: a group that can retreat under leaves comes out to feed more readily. Our range of planted tank fish includes many small species that share this kind of set-up.

Choose the substrate with the barbels in mind

• Best: fine aquarium sand, which Seriously Fish calls ideal and OATA recommends to protect the barbels.
• Acceptable: smooth, rounded fine gravel, kept very clean.
• Avoid: sharp or coarse gravel, which wears down the barbels.
• Keep clean: siphon the sand surface at every water change so waste does not build up where the fish feed.

Hold the water in the band the sources share

The published values differ, partly because the species is known from few places. The safest target is where they overlap.

Aim for 23–25.5°C and pH 6.0–7.0, with soft to moderately hard water of 2–12 dGH. Practical Fishkeeping calls the species fairly tolerant of water conditions but says soft, acidic water is ideal. Hardness in UK tap water differs widely between regions, so test it, or check your water company's report, before deciding whether to blend in softer water, and make changes slowly. Our water matcher shows whether your water and your other fish fit this range, and our guide to aquarium pH explains how to read and adjust it.

Separate habitat values from waste readings

Temperature, pH and hardness can sit anywhere in the range above. Waste readings cannot: OATA's limits are zero ammonia, zero nitrite and nitrate no more than 20 mg per litre above your tap water. Small bottom-dwellers live closest to the waste that settles in the sand, so test weekly and more often in the weeks after new fish arrive.

Filter gently and keep the sand clean

Choose a filter rated for the aquarium volume, with a gentle outlet that keeps the surface moving without sweeping small fish across the floor. FishBase and Seriously Fish note that the species is a facultative air breather, so an occasional dart to the surface is normal; keep a gap below the lid so the fish can always reach air.

Follow a weekly maintenance sequence

1. Test: ammonia, nitrite, nitrate and pH, at least weekly.
2. Change water: at least 25%, as OATA advises, siphoning lightly over the sand.
3. Condition: treat replacement water and match its temperature.
4. Rinse media: in removed tank water only, so the filter bacteria survive.
5. Check the shoal: count the fish and look at the barbels while they feed.

Feed small foods on the sand

Practical Fishkeeping says that in the wild the species eats small insect larvae, shrimps and crustaceans, and in the aquarium takes crushed flake, tablets and small frozen foods, with small live foods such as brine shrimp, grindal worm, cyclops and sifted daphnia to keep it in top condition. Planet Catfish and ScotCat confirm that tablet, granular and flake foods are accepted, along with bloodworm and other worms.

OATA advises feeding once a day and giving only what the fish eat within a few minutes. Make sure food reaches the bottom: in a busy community tank, faster fish can take everything before a timid shoal of corys gets a share.

Build one measured meal

• Base: small sinking granules or a crushed tablet, enough for the shoal to finish in a few minutes.
• Live or frozen: brine shrimp, daphnia or small bloodworm two or three times a week.
• Timing: feed when the tank is calm, so the shoal is out on the sand.
• Clear up: siphon away anything left after feeding.

Settle a timid shoal in gently

OATA recommends double-bagging catfish, because the spines can pierce a bag. Turn off the aquarium lights, float the sealed bag for 10 minutes, then add small amounts of tank water over up to 20 minutes before releasing the fish, keeping the bag water out of the aquarium. Our guide to acclimatising new fish goes through each stage. Seriously Fish warns that the stiff pectoral spines can give a painful sting, so avoid handling the fish by hand.

Use a first-week checkpoint plan

Read the shoal's behaviour

A settled group of Santa Cruz Corys forages together over the sand and rests in a loose cluster. OATA's warning signs include clamped fins, flicking against décor, hanging at the surface, rapid breathing, white spots and loss of appetite. Planet Catfish describes the species as slightly timid, so a shoal that stays hidden for long after the first week is a sign that something in the tank needs to change.

Pair each observation with an action

Pick small, calm tank mates

Planet Catfish calls the Santa Cruz Cory a small, peaceful and slightly timid species that should not be kept with boisterous or aggressive fish, and suggests small tetras or small cyprinids as ideal tank mates. ScotCat agrees that it is very peaceful and suits small to medium tank mates such as tetras, rasboras and danios, or a species tank for breeding.

Screen each tank mate with four questions

1. Does its temperature range overlap 23–25.5°C?
2. Is it calm enough not to chase a timid shoal off the sand?
3. Is it too small to swallow a cory, and too small to bully one?
4. Is there still open sand once every bottom dweller is counted?

Our tank mates checker works through these questions for you, and our corydoras care guide covers the family's general needs.

Breed it in a species tank

The Santa Cruz Cory has been bred in aquariums: Practical Fishkeeping reports spawnings in the UK and Germany, and Planet Catfish holds breeding reports from keepers. ScotCat suggests a species tank for anyone who wants to breed it, which keeps eggs and fry away from tank mates. Our sources do not publish a spawning method, so a written record of your water values, temperature and foods would help other keepers. FishBase and ScotCat list the species as Data Deficient on the IUCN Red List, which makes aquarium-bred stock all the more worthwhile.

Answer Corydoras cruziensis buying questions

Is Corydoras cruziensis the same fish as Hoplisoma cruziense?

Yes. Dias and colleagues split the old genus Corydoras in 2024 and placed this species in Hoplisoma, changing the ending to cruziense. Seriously Fish, Planet Catfish, ScotCat and FishBase all file the old name Corydoras cruziensis as the same fish.

What does C012 or C12 mean?

It is the C-number the fish was given before it had a scientific name. ScotCat notes that C012 was assigned before Knaack described the species in 2002, and Practical Fishkeeping records that it was known in the hobby as C12.

How big does the Santa Cruz Cory grow?

It is small. Planet Catfish and FishBase give 43 mm standard length, Practical Fishkeeping 45 mm and Seriously Fish 50 mm; ScotCat gives males 4.0 cm and females 4.5 cm.

How many should I keep?

Keep at least six. ScotCat says they do better in a group of at least six, and Seriously Fish gives a minimum of four to six. One purchase is one fish, so order the whole group together.

What size aquarium does it need?

Seriously Fish gives a minimum base of 80 × 30 cm, about 72 litres, and OATA gives at least 80 litres for a shoal of corydoras. A longer tank gives the group more sand to forage.

What water does it need?

Aim for 23–25.5°C and pH 6.0–7.0, the band the sources share, with soft to moderately hard water of 2–12 dGH. Practical Fishkeeping calls it fairly tolerant but says soft, acidic water is ideal.

How do I tell it from the Spotted Cory?

Planet Catfish and Practical Fishkeeping say it looks like Corydoras punctatus, a species only found in Suriname, but has fewer, larger spots, and the spots along the join of the upper and lower body plates may form a broken stripe.

Has it been bred in aquariums?

Yes. Practical Fishkeeping reports aquarium spawnings in the UK and Germany, and Planet Catfish holds breeding reports from keepers. ScotCat suggests a species tank for breeding.

Consult the care references

• Seriously Fish: Hoplisoma cruziense (Santa Cruz Cory) — current name Hoplisoma cruziense, type locality, Madeira basin range, 50 mm SL, 80 × 30 cm base, 20–28°C, pH 6.0–8.5, 2–12 dGH, group size, the 2024 move to Hoplisoma, air breathing and the stinging spines.
• Planet Catfish Cat-eLog: Hoplisoma cruziense (C012) — C012 and Santa Cruz Cory names, type locality, 43 mm SL, the comparison with Corydoras punctatus, sexing by the ventral fins, pH 6.0–7.2, 22.5–25.5°C, foods, timid temperament, tank mates and aquarium breeding reports.
• ScotCat: Hoplisoma cruziense (C012) — the C012 number, similarity to Hoplisoma copei, lineage 9 and the 2024 name change, male 4.0 cm and female 4.5 cm, 23–26°C, pH 6.0–7.2, groups of six, foods, tank mates and the IUCN Data Deficient listing.
• FishBase: Hoplisoma cruziensis, Santa Cruz cory — classification, 4.3 cm SL maximum, Madeira basin distribution, facultative air breathing and the IUCN Data Deficient status.
• Practical Fishkeeping: Corydoras cruziensis (Ian Fuller) — the C12 trade code, Bolivian origin, 45 mm SL maximum, pH 5.5–7.0, 2–12 dGH, a planted set-up with fine sand, wild and aquarium diet, sexing by size and breeding in the UK and Germany.
• OATA: How to look after freshwater catfish — UK guidance for catfish on water quality limits, weekly testing and 25% water changes, double-bagging, the floating-bag method, feeding amounts, sand for the barbels and warning signs.
• Tropical Fish Co delivery policy — current dispatch days and Live Arrival Guarantee terms.