Super Parallelus Cory CW127 (Hoplisoma sp. CW127)

Choose the Super Parallelus Cory CW127 for a sandy community tank

The Super Parallelus Cory is an undescribed cory catfish from Brazil, catalogued by Corydoras World as CW127. Its scientific label today is Hoplisoma sp. CW127; you will still see it sold as Corydoras sp. CW127. It is a peaceful, shoaling bottom-dweller that grows to about 6 cm, and it brings bold stripes and an orange-gold body to a sandy community aquarium.

"Super Parallelus" is a trade name. The fish resembles Corydoras parallelus, but specialists consider it a different species, which is why it carries a CW number rather than a scientific name. This page sets out what is known, what is not, and how to keep a group well.

Understand what a CW number means

ScotCat's article on the subject, by Rob McLure, explains that C and CW numbers are placeholder codes for corydoras without a scientific name, so that fishkeepers everywhere can refer to the same fish. The C-number series ran in DATZ magazine from 1993 to 2009; Ian Fuller and Hans-Georg Evers then started the CW series through Fuller's Corydoras World. A CW number is not a formal description. Some coded fish are later described and named, many are not, and the number stays with the fish either way.

Learn how CW127 was told apart from C. parallelus

The story is unusually well documented. In 2015, McLure writes, an American importer brought in a batch described as Corydoras parallelus, said by the exporter to come from the Rio Tapajós. McLure already kept true C. parallelus, known as C002 before it was described in 1993, and saw that the new fish were different: broader stripes, darker overall and much larger as adults. When they spawned, the eggs were relatively small, unlike the large round eggs of C. parallelus. True C. parallelus comes from the blackwater upper Rio Negro, while the Tapajós is a clear-water southern tributary of the Amazon.

After reviewing the research, McLure's photographs and comments from other aquarists, Ian Fuller agreed that the fish was most likely a new species and gave it the code CW127. McLure also notes that the "Super" name was used in Asian markets and that such names can be a pricing tactic, which is one reason the CW code is the more reliable way to identify the fish.

Know the 2024 name change

In 2024, Dias and colleagues published a new classification of the corydoras group based on DNA and anatomy. Most species formerly in Corydoras moved to other genera. The short-snouted species of Lineage 9 became Hoplisoma, which Corydoras World describes as by far the largest genus, with 87 described species and more than a hundred coded ones. ScotCat places CW127 there. Care is unchanged; only the label has moved.

Recognise the striped Tapajós form

Photographs of CW127 on Planet Catfish and Corydoras World show a stocky, short-snouted cory with a warm orange-gold to tan body, a dark band through the eye, and two bold, dark stripes running along the flank to the base of the tail, separated by a pale band. The back below the dorsal fin is darker, and the fins are clear to lightly tinted. McLure describes the stripes as broader and the fish darker overall than C. parallelus.

Planet Catfish notes that females grow larger and fuller in the body, which is easiest to see from above, while mature males develop more pointed fin tips.

Select a group of six or more

One purchase supplies one live Super Parallelus Cory CW127 in the standard size we receive. Sex is not specified, and the price is for one fish. Because corys are shoaling fish, please order at least six; OATA advises groups of at least five and notes that corydoras kept singly or in small groups often become stressed. The gallery images are representative of the species, and pattern and colour vary between fish.

McLure reports that CW127 has since been bred in quantity on fish farms in Indonesia, so stock in the trade may be farm-bred or wild-caught. We cannot always confirm which for a given batch, so treat new fish with the care you would give a wild import.

Work from the group you intend to keep

• Six fish: the minimum for a settled group in a community of small, peaceful fish.
• Eight to ten fish: a better display, more natural behaviour and a fairer chance of both sexes for breeding.
• Mixed corys: CW127 shoals best with its own kind; add other species as separate groups rather than singles.

Check our delivery and Live Arrival Guarantee terms before you order. Other species are in our corydoras catfish range and our rare and collector fish.

Plan the floor space for an active group

OATA recommends an aquarium of at least 80 litres for a shoal of corydoras. Floor area matters more than height, because the group spends its day sifting sand along the bottom. Choose a tank with a long, wide base and keep the front of the floor open. Our stocking calculator helps you balance a group of six or more with the fish above them.

Use a three-step space check

1. Measure the floor: a long, wide base of soft sand is the real living space for this fish.
2. Count every bottom-dweller: other corys, loaches and plecos share the same floor and the same food.
3. Leave an open feeding area: keep a clear patch of sand at the front where food lands and you can watch the group feed.

Lay soft sand with shade and wood

Planet Catfish calls a sand substrate close to mandatory for this species, with rounded gravel an imperfect alternative. It warns against chipped gravel and sharp sand, which damage the barbels as the fish dig. It suggests bordering the sand with driftwood and plants, leaving an open area for feeding and swimming, and using overhanging wood, tall or floating plants for shade.

Divide the floor by function

Set water values for a clear-water fish

ScotCat gives 20–25°C and pH 6.0–7.2 for CW127. Planet Catfish gives no numbers for this species. The OATA catfish guide gives broad values for catfish as a group. The target column uses the band where they overlap. No source gives a hardness figure for CW127, so we use the OATA range and suggest staying in its softer half.

Much UK tap water is hard and above pH 7.2. Test yours first; if it is outside the range, blend in reverse osmosis water and change values gradually. Our water matcher and guide to pH for tropical fish explain how. Avoid running the tank above 25°C for long, which is warmer than ScotCat's range.

Separate habitat values from waste readings

Temperature, pH and hardness describe the habitat. Ammonia, nitrite and nitrate describe waste. OATA's targets are zero ammonia, zero nitrite and nitrate no more than 20 mg per litre above your tap water. Bottom-dwellers live where waste settles, so a clean floor matters as much as the water readings.

Filter gently and keep the sand clean

Corydoras need clean, well-oxygenated water rather than a strong current. A filter sized for the whole tank, with its outlet creating gentle movement across the surface, suits them. McLure found his group spawned best when the water was very clean and clear, which is a good standard to keep anyway.

Follow a weekly maintenance sequence

1. Test ammonia, nitrite, nitrate and pH, and check the temperature.
2. Siphon the open sand lightly to lift waste without stripping the substrate.
3. Change about a quarter of the water, as OATA advises, with dechlorinated water at the same temperature.
4. Rinse filter sponges in removed tank water, never under the tap.
5. Count the group and watch each fish feed for a minute.

Feed sinking foods once a day

Planet Catfish says this species readily takes 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 taken eagerly and good for conditioning a group to spawn. ScotCat recommends quality flake and tablets with occasional frozen or live food. OATA's rule for catfish is to feed once a day, only what is eaten within a few minutes, using sinking foods so the catfish get their share.

Build one measured meal

If fast mid-water fish take everything, feed just after the lights go out, when corys are active and the others are settling.

Introduce the group to a mature tank

OATA advises switching off the aquarium lights, floating the sealed bag for about 10 minutes to match temperature, then adding small amounts of tank water over about 20 minutes before netting the fish out with as little bag water as possible. Catfish should be double-bagged because their fin spines can pierce a bag. Our guide on how to acclimatise new fish covers this step by step, including the slower drip method OATA describes for sensitive fish.

Use a first-week checkpoint plan

Choose calm tank mates that leave the floor free

Planet Catfish describes CW127 as a peaceful, shoaling community fish. ScotCat suggests small to medium tank mates such as tetras, rasboras and danios, or a species tank for breeding. Good choices share its soft, clean water and leave the sand to the corys. Our tank mates checker helps you test a combination.

Screen tank mates before mixing

Our corydoras care guide and julii corydoras guide cover group size and community planning in more depth, and the South American catfish category and bottom-dwelling fish range show other floor-dwellers.

Watch the group and act on changes

OATA lists the signs of a healthy fish as clear eyes, undamaged fins, no ulcers or bumps, normal swimming and steady breathing. With corys, also watch the barbels: short or reddened barbels usually point to a dirty or sharp substrate. Like other catfish, corys have sharp spines in the dorsal and pectoral fins that catch in net mesh, so move them with a fine soft net or a small container.

Pair each observation with an action

Know what is recorded about breeding

Planet Catfish has no breeding report for CW127, and Corydoras World's full record is for members. McLure kept a group for years and spawned them only rarely, most successfully when the water was very clean and clear. The eggs were relatively small, the adults ate them quickly, and he raised eight fry from one collection. If you hope to breed them, condition the group with live and frozen foods, keep the water very clean, and move any eggs you find to a separate container, as OATA advises for corydoras eggs.

Answer Super Parallelus Cory buying questions

What is the Super Parallelus Cory CW127?

It is an undescribed cory catfish from the Rio Tapajós drainage in Brazil, catalogued by Corydoras World as CW127 and now placed in the genus Hoplisoma. "Super Parallelus" is a trade name: it looks like Corydoras parallelus but is thought to be a different, larger species.

Is CW127 the same fish as Corydoras parallelus?

Probably not. Rob McLure, who kept both, found CW127 larger and darker with broader stripes and smaller eggs, and it comes from the clear-water Tapajós rather than the blackwater upper Rio Negro. Ian Fuller agreed it was most likely a new species and gave it the code CW127.

How big does it grow?

ScotCat gives about 5.5 cm for males and 6.0 cm for females.

How many should I buy?

Six or more. Cory catfish are shoaling fish; OATA advises groups of at least five, and a larger group is calmer and more natural.

What size tank does a group need?

OATA recommends at least 80 litres for a shoal of corydoras. Floor area matters more than height, so choose a tank with a long, wide base of soft sand.

What water does it need?

ScotCat gives 20–25°C and pH 6.0–7.2. We suggest 22–25°C, where this overlaps the OATA catfish range, with clean, well-filtered water and zero ammonia and nitrite.

What does it eat?

Sinking foods: tablets, granules and quality flake that reaches the floor, plus frozen or live bloodworm, Daphnia, white worm or grindal worm. Feed once a day, an amount eaten in a few minutes.

Will it breed in my aquarium?

It is not easy. Planet Catfish has no breeding report, and Rob McLure spawned his group only rarely, mostly when the water was very clean and clear; the adults ate their eggs quickly, so eggs need moving to a separate container.

Consult the care references

• Planet Catfish: Hoplisoma sp. (CW127): names, genus, sexing, distribution, feeding, substrate, décor and compatibility.
• ScotCat: Hoplisoma sp. (CW127) factsheet: lineage, distribution, adult sizes, water values, diet and tank mates.
• ScotCat: "What the heck is a CW number?" (Rob McLure): what C and CW numbers are, and the story of how CW127 was separated from C. parallelus.
• Corydoras World: Hoplisoma sp. CW127: the Corydoras World species record and photographs for Hoplisoma sp. CW127.
• Corydoras World: Hoplisoma lineage: the Hoplisoma lineage and its place in the 2024 classification.
• Dias et al. 2024, Zoological Journal of the Linnean Society: the 2024 classification that moved most species out of Corydoras into Hoplisoma, Brochis and other genera.
• OATA: How to look after freshwater catfish: UK guidance for catfish on water quality, sand, introduction, handling, feeding and health signs.
• Tropical Fish Co delivery policy: current dispatch days and Live Arrival Guarantee terms.