Corydoras CW101 V Cory (Brochis sp. CW101)

Choose Corydoras CW101, the V Cory, for a deeper-bodied Tapajós shoal

Corydoras CW101 is an undescribed armoured catfish from the Rio Tapajós drainage in Brazil, sold in the hobby as the V Cory. ScotCat records that it was discovered in 2014, found in the Tapajós alongside the cory then known as CW083, which has since been described as Corydoras caramater. The "CW" code is a Corydoras World number, used for distinct corys that science has not yet named. Planet Catfish describes CW101 as a peaceful, shoaling community fish.

It is a sturdier fish than the small spotted corys. ScotCat places it in lineage 8, the "intermediate long-snouts" with deeper bodies. When Dias and colleagues published their 2024 reclassification of the corydoradine catfishes, that group was moved into the revived genus Brochis, so the current label is Brochis sp. (CW101). Many import lists and older websites still use Corydoras sp. CW101, which is why we keep "Corydoras CW101" at the front of the title.

Match the names you will see

In the photographs on ScotCat's factsheet, CW101 is a deep-bodied cory with olive-grey to bronze flanks finely lined with dark speckles, a dark mask running through the eye, a metallic green sheen on the gill cover and a bright golden band curving down behind the head. The fins are clear. Colour shifts with lighting and mood, and some fish show a warmer, orange-bronze tone.

Tell it apart from its look-alikes

CW101 shares its streams with fish that look very similar. Tencatt and colleagues, describing Corydoras caramater in Neotropical Ichthyology in 2024, watched it shoaling in a Tapajós stream with CW101 and CW102, all sharing a similar colour pattern. They separate C. caramater from CW101 because CW101 has backward-pointing, blade-like serrations along the rear edge of its dorsal-fin spine. The table below compares CW101 with CW102, the look-alike you are most likely to see on the same import list.

Know what one purchase supplies

Each purchase supplies one live Corydoras CW101 in the standard size we receive, sex not chosen. Planet Catfish explains that adult females grow larger and more full-bodied, best judged from above, while males develop more pointed fin tips as they mature. The gallery images are representative, prepared from a reference photograph; they do not show the fish you will receive, and individual markings vary.

Plan the shoal before you order

Because this is a scarce, undescribed fish, it is best to buy the whole group at once rather than adding one or two at a time later, when matching fish may not be available.

Give a 6.5 cm cory enough floor

With adults of 6.0–6.5 cm, CW101 is close to twice the length of the smallest corys, and a group of deep-bodied fish needs real floor space. OATA sets at least 80 litres as the starting point for a shoal of small catfish such as corydoras; treat that as the absolute minimum here. As a yardstick for a similar fish, Seriously Fish suggests a base of 75 × 30 cm for the related and slightly larger Brochis pantanalensis. Length and depth of the floor matter more than height, because the shoal works the sand together.

Run a three-step space check

1. Measure the base: note the length and depth of the floor, not just the litres.
2. Keep sand open: plan for an open strip of sand along the front, with planting and wood behind.
3. Add up the stocking: enter the corys and every tank mate at adult size in our stocking calculator.

Recreate a sandy Tapajós stream

Tencatt and colleagues describe the stream where CW101 shoals as shallow, mostly up to about 30 cm deep and one to three metres wide, with slow to moderate current, a floor of fine sand and gravel, areas of leaf litter, submerged branches and logs, and aquatic plants. That is an easy picture to copy in an aquarium. Planet Catfish advises a sand substrate, with rounded gravel as an imperfect alternative, and warns against rough-edged, chipped gravel because it damages the barbels when the fish dig. Edge the sand with driftwood and plants, leave an open area for feeding and swimming, and add shade from arching wood, tall plants or floating plants.

Choose the substrate with the barbels in mind

Hold the water in a narrow, steady band

ScotCat gives 22–26°C and a pH of 6.5–7.2 for CW101. That pH band is fairly narrow, so stability matters more than hitting an exact number. No hardness value is published for this fish; OATA's general guide for catfish covers soft to hard water at 4–18°dH, and the softer part of that range is the safer choice for a Tapajós cory.

Tap water across the UK ranges from soft to hard and alkaline depending on where you live, and many supplies sit above pH 7.2. Test your tap water before the fish arrive and decide in advance how you will hold the pH inside the 6.5–7.2 band, for example by blending tap water with purified water and testing every change. Our guide to aquarium pH explains the options, and the water matcher tool compares your readings with the fish you plan to keep.

Separate habitat values from waste readings

Temperature, pH and hardness are the habitat values to hold steady. Ammonia, nitrite and nitrate are waste readings that must stay at or near zero. A mature filter, built up through the nitrogen cycle, is what keeps the waste readings down; our nitrogen cycle guide explains how it works and why a new tank needs time.

Filter gently and keep the sand clean

A filter is essential in every aquarium, as OATA says. For CW101, aim for clean, well-oxygenated water with a gentle to moderate flow across the floor, like the slow to moderate current of its home streams. Make sure the filter intake cannot pull sand or small fish against it, and position the outflow so that waste is carried towards the intake rather than settling in a corner of the sand.

Follow a weekly maintenance sequence

1. Test ammonia, nitrite, nitrate, pH and temperature.
2. Siphon the open sand lightly and the feeding area thoroughly.
3. Change about 25% of the water, as OATA recommends weekly, using conditioned tap water at the same temperature and pH.
4. Rinse media only in removed tank water and only when the flow drops, never under the tap.
5. Check every fish for whole barbels, clear eyes and a rounded belly.

Feed the shoal on the sand

Planet Catfish says CW101 readily accepts all prepared foods that reach the bottom, such as tablets, granules and larger flakes, and that live or frozen bloodworm, white worm, grindal worm, Daphnia and Tubifex are readily accepted and help condition a group for spawning. ScotCat recommends a good flake and tablet base with occasional frozen or live food. OATA describes corydoras as omnivores and says catfish should be given proper sinking foods, not left to live on scraps.

Build one measured meal

• How much: what the whole group clears within a few minutes, once a day, as OATA advises.
• Where: the same open patch of sand each time, so the shoal gathers and you can watch every fish eat.
• What: sinking tablets or granules as the staple, with frozen or live foods several times a week.
• When it goes wrong: if midwater fish strip the food first, feed the corys a little after the main lights go down.
• Afterwards: siphon leftovers so they do not foul the sand.

Settle new fish in gently

Add fish only to a mature aquarium where ammonia and nitrite read zero. OATA advises that catfish travel double-bagged because their spines can pierce bags, and describes the floating bag method: lights off, float the sealed bag for about 10 minutes, add small amounts of tank water to the bag over up to 20 minutes, then release the fish with as little bag water as possible. Our acclimatisation guide shows the steps. Corys can catch their fin spines in a net, so guide them into a container instead of lifting them out in mesh.

Use a first-week checkpoint plan

Read the shoal's behaviour

A settled group of V Corys forages together across the sand, rests in a loose huddle near wood or plants and grows bolder as it learns the feeding routine. OATA's catfish care sheet lists the warning signs to watch for: unusual swimming, colour turning darker or paler than normal, hiding more than usual, breathing faster or slower, white spots or fluffy growths, fin or scale loss, and changes in weight or appetite.

Pair each observation with an action

Pick tank mates that leave the floor free

ScotCat describes CW101 as very peaceful and best kept with small to medium tank mates such as tetras, rasboras and danios, or in a species tank. Choose fish that live in the middle and upper water, share 22–26°C and a pH around neutral or slightly below, and will not compete hard for food on the sand.

Decide from the suits and avoid list

From our range, consider the Rummy Nose Tetra, the Green Neon Tetra or the Three-Lined Pencilfish above the corys, checking that their own water needs overlap. For other members of the same genus, see the Delphax Cory, the Reticulated Cory and the larger Emerald Catfish, or browse all our Brochis catfish. The full range is in our corydoras collection, the South American catfish category and our rare collector fish, and our guide to keeping corydoras covers the group as a whole. Check any combination with the tank mates checker, and see the delivery page for dispatch days.

Record any breeding attempt

Planet Catfish has no breeding report for CW101, so spawning it would be genuinely useful information. ScotCat recommends a species tank for breeding attempts, and Planet Catfish names live and frozen bloodworm, white worm, grindal worm, Daphnia and Tubifex as good conditioning foods. Begin with a well-fed group in which the larger, broader females can be told from the slimmer males, keep the water clean and steady, and note temperatures, water changes and feeding so that any success can be repeated.

Answer Corydoras CW101 buying questions

What is Corydoras CW101?

It is an undescribed corydoras from the Rio Tapajós drainage in Brazil, sold as the V Cory. CW101 is its Corydoras World number. ScotCat records that it was discovered in 2014, and since the 2024 reclassification it is listed as Brochis sp. (CW101).

How big does Corydoras CW101 grow?

ScotCat gives about 6.0 cm for males and 6.5 cm for females. It belongs to the deeper-bodied, intermediate long-snouted group of corys, so it looks sturdier than the small spotted species.

Is it the same fish as CW102?

No. The two live together in the same Tapajós streams and look alike at a glance, but they are different fish. CW101 grows to about 6–6.5 cm and is now placed in Brochis; CW102 stays at about 3.5–4 cm and is placed in Hoplisoma.

How many should I keep?

At least five, as OATA advises for corydoras, and more if your floor space allows. Planet Catfish describes it as a peaceful, shoaling fish, and a group is more confident and active.

What water does it need?

ScotCat gives 22–26°C and pH 6.5–7.2. No hardness figure is published for this fish, so stay within the softer part of OATA's general catfish band and keep conditions steady. Ammonia and nitrite must read zero.

What does the V Cory eat?

Sinking tablets, granules and larger flakes, plus live or frozen bloodworm, white worm, grindal worm, Daphnia and Tubifex. Planet Catfish lists all of these as readily accepted.

Which tank mates suit it?

Peaceful tetras, rasboras and danios, as ScotCat suggests, and other calm bottom dwellers. Avoid large, boisterous or territorial fish.

Has it been bred in aquariums?

Planet Catfish holds no breeding report for CW101, so any spawning would add to what is known. ScotCat suggests a species tank for breeding attempts.

Consult the care references

• Planet Catfish Cat-eLog: Brochis sp. (CW101), V Cory: names (V Cory), current genus, distribution, sexing, foods, substrate and décor, compatibility and breeding status.
• ScotCat: Brochis sp. (CW101) factsheet: discovery in 2014, lineage and 2024 reclassification, distribution, adult size by sex, temperature, pH, tank mates and photographs.
• Tencatt et al. 2024, Neotropical Ichthyology 22(1): a new long-snouted Corydoras from the rio Xingu and rio Tapajós basins: peer-reviewed description of Corydoras caramater with field notes on the Tapajós streams where CW101 and CW102 shoal with it, how the look-alikes differ, and the list of corydoras known from the Tapajós basin.
• ScotCat: Hoplisoma sp. (CW102) factsheet (used for the comparison with CW102): Corydoras World number, lineage and 2024 reclassification, distribution, adult size by sex, temperature, pH, tank mates and photographs.
• Seriously Fish: Brochis pantanalensis (aquarium base used only as a size comparison): habitat, adult size, aquarium base, water values, maintenance, diet, compatibility, group size, sexing and the general corydoras breeding method.
• OATA: How to look after freshwater catfish: UK guidance on catfish water values, group size for corydoras, minimum aquarium for small species, sand, acclimatisation, weekly maintenance, feeding portions and health signs.
• Tropical Fish Co delivery policy: current dispatch days and arrival terms.