L037 Honeycomb Pleco (Hypostomus faveolus)

Meet the L037 Honeycomb Pleco

The L037 Honeycomb Pleco (Hypostomus faveolus) is a suckermouth catfish from central Brazil, found in the Rio Tocantins basin, including the Rio Araguaia, and in the upper Rio Xingu basin. Scientists described it in 2008 and named it faveolus, from the Latin for honeycomb, after its colour pattern: large, mostly rounded pale blotches separated by narrow dark lines, so the whole body looks covered in a net. In living fish the pale blotches are more conspicuous and yellowish than in preserved specimens.

In the original scientific description, Zawadzki, Birindelli and Lima explain why the L037 pleco is special: most Hypostomus have dark blotches on a paler background, while this species has pale blotches on a darker one, and it was the first pale-spotted Hypostomus recorded from the Amazon basin. It also has conspicuous keels (raised ridges) on the head, in front of the dorsal fin and along the side plates. Those two features together separate it from every other species in the genus.

Check the names on the label

Do not confuse it with the honeycomb or "wabenmuster" bristlenose plecos, which are Ancistrus, a different genus with fleshy bristles on the snout. You can browse our other Hypostomus plecos, the wider South American catfish category or our full catfish and plecos collection.

Recognise a genuine L037

Because L-number names get mixed up, it pays to know what the real fish looks like. Use these points from the scientific description when you look at a fish in a shop or in your own tank.

Compare these features

The pattern varies with where the fish comes from. In most fish from the Xingu basin the dark lines are wider, about as broad as the pale blotches, and small Xingu fish under about 5 cm often have wavy, worm-like pale markings on the head; fish from the Tocantins basin show the adult pattern from a small size. The photographs on this page are representative and do not show the individual you will receive, so compare your fish with the features above.

Know what one purchase supplies

One purchase supplies one live L037 Honeycomb Pleco at the standard size offered on this listing. The largest of the 234 specimens measured in the scientific description was 206 mm standard length (body length without the tail), and FishBase and Planet Catfish both give 20.6 cm as the maximum. Plan for a fish of about 20 cm plus its tail, whatever its size on arrival.

Sex is not specified. Neither the scientific description nor Planet Catfish describes reliable external differences between males and females of this species, so do not plan on receiving a particular sex or a pair.

Plan from the adult, not the sale size

• Adult length: about 20.6 cm standard length.
• Aquarium: a base of at least 120 × 45 cm (the next section explains why).
• Temperature: 23–27°C, the range Planet Catfish gives.
• Social plan: one per tank unless every pleco has its own cave and floor space.
• Diet: a varied sinking diet with plenty of vegetable food and some frozen foods.

Have the aquarium mature and ready before you order, and read our delivery and Live Arrival Guarantee terms so you know when to expect the fish.

Plan the aquarium around a 20 cm pleco

No minimum aquarium size has been published for H. faveolus itself. For comparison, Seriously Fish's Hypostomus profiles give a base of 120 × 45 cm for species of 23–30 cm standard length, and a tank at least 120 cm long for the 20 cm L229. We therefore treat 120 × 45 cm, about 243 litres at 45 cm tall, as the minimum for one L037.

A heavy-bodied pleco uses the floor rather than the height of a tank, so the footprint matters more than the litres. Allow more floor for every additional large bottom dweller, and more again if you hope to keep two L037 together.

Use a three-step space check

1. Measure the base: at least 120 cm long and 45 cm from front to back.
2. Count the bottom dwellers: give each large pleco or catfish its own cave, placed apart from the others.
3. Plan for adult sizes: add up the adult lengths of every fish, not their sale sizes, before choosing the filter.

Our tank volume calculator converts the dimensions into litres, and the stocking calculator helps you check the whole community. Our pleco care guide covers the routines every suckermouth catfish needs.

Build a river layout with rock and soft ground

The scientific description calls H. faveolus eurytopic, meaning it copes with a wide range of habitats: it has been collected in rapids and in slow-flowing parts of middle-sized to large rivers, over both rocky and soft bottoms, and a few juveniles were found in small streams and oxbow lakes. Planet Catfish adds that, like all loricariids, it needs good hiding places.

Divide the tank by function

Set rocks and caves on the glass before adding sand so that digging cannot undermine them. If you add plants, choose tough species fixed to wood or rock; a large pleco can dislodge loosely rooted plants as it moves around.

FishBase notes that Hypostomus can breathe air when needed. If your L037 makes frequent dashes to the surface, treat it as a sign to test the water and check that the filter outlet is moving the surface and keeping oxygen levels up.

Set water values sensibly

Planet Catfish gives 23–27°C for this species. No pH or hardness range has been published for it. OATA's general guidance for catfish is pH 6.0–8.0 with a general hardness of 4–18 °dH, and the pH ranges in Seriously Fish's profiles of other Hypostomus all fall between 6.0 and 8.0. A stable pH within that band matters more than any exact figure, so avoid chasing a number with chemicals.

Separate habitat values from waste readings

UK tap water ranges from soft in many northern and western areas to very hard in parts of southern and eastern England, and conditioned tap water from much of the country falls inside OATA's broad catfish range. Your water company publishes the hardness for your postcode. Always add a conditioner that removes chlorine and chloramine, test your tap water and tank water rather than guessing, and use our water matcher to compare the results. Our water chemistry guide explains pH, hardness and the nitrogen cycle in plain terms.

Filter for a large, grazing pleco

A 20 cm pleco produces a lot of waste, and droppings collect around its cave. Seriously Fish sizes filters in its pleco profiles at four to five turnovers of the tank volume an hour; for a 243-litre tank that is roughly 970–1,215 litres per hour. A large external filter, or two filters, gives the extra capacity and a back-up if one stops.

Follow a weekly maintenance sequence

1. Test ammonia, nitrite and nitrate first, so you know the starting point.
2. Change at least 25% of the water weekly, as OATA recommends.
3. Add conditioner to the new water and match its temperature to the tank.
4. Siphon the sand, paying attention to the area in front of caves and under wood.
5. Check the filter intake and outlet for blockages and weak flow.
6. Rinse dirty filter media in the water you removed from the tank, never under the tap.

If ammonia or nitrite rises above zero, test again, check the filter and cut back the feeding until the readings settle. Clear water can still hold dissolved waste.

Feed a varied sinking diet

No study of this species' diet has been published. The scientific description records long, slender, two-pointed teeth, and Planet Catfish notes that it is not a member of the wood-eating Hypostomus cochliodon group, so treat driftwood as cover rather than as its food. OATA describes plecos in general as herbivorous and says catfish should be given appropriate sinking foods rather than left to scavenge.

A varied diet covers its needs: vegetable-based sinking wafers and tablets as the staple, blanched vegetables such as cucumber, courgette or spinach, and some frozen foods such as bloodworm for variety. Vary the menu through the week rather than relying on a single food.

Build one measured meal

• Staple: sinking vegetable wafers or tablets, enough to be cleared within about 30 minutes, the time OATA allows for grazing species.
• Vegetables: a slice of cucumber or courgette weighted to the floor, removed the next morning if not eaten.
• Variety: a small portion of thawed frozen food on some days in place of part of the staple.
• Timing: feed once a day, near lights-out, close to its cave.

Watch the belly when it rests on the glass. A rounded belly shows it is feeding well; a hollow one means faster fish may be taking the food, so drop it closer to the cave after dark.

Introduce it to a mature aquarium

Only add the L037 to a tank with a mature filter, zero ammonia and nitrite and a temperature already within 23–27°C. OATA's floating-bag method works well: turn the aquarium lights off, float the bag for 10 minutes to match temperatures, then add small amounts of tank water to the bag over up to 20 minutes and release the fish with as little bag water as possible. See our guide to acclimatising new fish for the detail.

Plecos have sharp fin spines, which is why OATA advises double-bagging catfish. Avoid netting it where you can; guide it into a container instead so the spines and plates do not snag.

Use a first-week checkpoint plan

If it still refuses food, breathes heavily or has a hollow belly after the first week, test the water and contact us with your readings.

Choose tank mates with floor space in mind

No compatibility notes have been published for H. faveolus specifically. Seriously Fish records that the larger Hypostomus regani is peaceful with most tank mates but territorial with similar-sized bottom dwellers, especially its own kind, and that the small H. mutucae is peaceful. We plan the L037 on the same cautious basis: easy-going with mid-water fish, but given its own cave away from other large plecos.

Screen companions with suits and caution

For comparison, our Common Pleco and Gold Suckermouth Catfish are other Hypostomus, and our common pleco guide covers that species in depth. The Gold Spot Pleco L001 comes from the same Araguaia river system: the scientific description mentions both species from that basin. The Leopard Sailfin Pleco shows the opposite pattern, dark spots on a paler body. Check any mix with our tank mates tool, and give each large pleco its own territory.

Watch for health problems early

OATA lists the warning signs for catfish: changes in swimming, colour, breathing, appetite, hiding and body condition, as well as white spots, fluffy growths and damaged fins. A pleco also tells you a lot through its belly and eyes, so check both regularly.

Pair each observation with an action

Change one thing at a time and record what you did, so you can see what made the difference. If problems continue after the water is right, contact us with your readings and a description of the signs.

Understand the breeding record

Planet Catfish records that H. faveolus has been bred in the aquarium, but no breeding report has been published there, so details such as egg numbers and spawning triggers are not documented. OATA notes that many plecos need changes in conditions, such as a drop in water temperature, to trigger spawning, which do not happen in a normal home aquarium, so treat breeding as a bonus rather than a plan.

Know what is documented

• Aquarium breeding: recorded by Planet Catfish, without a published method.
• Sexing: no external differences described for this species.
• Young fish in the wild: a few juveniles were found in small streams and oxbow lakes, away from the main rivers.
• Conservation: FishBase lists it as Least Concern on the IUCN Red List, assessed in 2018.

Answer L037 Honeycomb Pleco buying questions

What is an L037 pleco?

L037 is Hypostomus faveolus, the Honeycomb Pleco, a suckermouth catfish from the Rio Tocantins basin (including the Rio Araguaia) and the upper Rio Xingu basin in central Brazil. It was described in 2008 and named after its honeycomb pattern of pale blotches outlined by thin dark lines.

Is the tortoise shell pleco the same as L037?

Some sellers use "tortoise shell pleco" as a descriptive name, but it is not an established name for a species. The fish coded L037 is Hypostomus faveolus. Check the scientific name and look for pale, yellowish blotches outlined by dark lines.

What is L037a?

Planet Catfish notes that the Aqualog L-number book shows the real L037 under the code L037a and labels a different fish, Cordylancistrus platyrhynchus, as L037. Both codes may therefore be used for this species.

How big does the Honeycomb Pleco grow?

About 20.6 cm standard length, the size given by Planet Catfish and FishBase and the largest of the 234 fish measured in the scientific description. Plan for a fish of around 20 cm plus its tail.

What size aquarium does L037 need?

No minimum has been published for this species. We use a base of at least 120 × 45 cm, about 243 litres at 45 cm tall, which is what Seriously Fish gives for comparable Hypostomus of 23–30 cm.

What water conditions does it need?

Planet Catfish gives 23–27°C. No pH or hardness range is published for the species, so keep the pH stable within OATA's general catfish range of 6.0–8.0, with zero ammonia and nitrite and nitrate no more than 20 mg/l above your tap water.

What does an L037 pleco eat?

No diet study exists for this species. Feed a varied sinking diet: vegetable-based wafers and tablets, blanched vegetables such as cucumber and courgette, and some frozen foods, once a day in an amount it clears within about 30 minutes.

Can it live with other plecos?

With care. No compatibility notes are published for L037, but Seriously Fish records that the larger Hypostomus regani is territorial with similar-sized bottom dwellers, especially its own kind. Give every pleco its own cave and enough floor space.

Consult the care references

• Planet Catfish: Hypostomus faveolus (L037) — names, the L037 and L037a labelling confusion, size, distribution, temperature, habitat and aquarium breeding.
• FishBase: Hypostomus faveolus — classification, distribution, maximum length, diagnosis, habitat, air-breathing in the genus and conservation status.
• Zawadzki, Birindelli & Lima (2008), Neotropical Ichthyology 6(3): 395–402 — peer-reviewed original description: colour pattern, keels, fin rays, teeth, regional variation, distribution and ecology.
• Seriously Fish: genus Hypostomus — aquarium sizes, temperatures, pH ranges and behaviour of comparable Hypostomus, used where nothing is published for L037.
• OATA: How to look after freshwater catfish — UK guidance for catfish on water quality limits, testing, maintenance, acclimatisation, feeding and warning signs.
• Tropical Fish Co delivery policy — current dispatch days and Live Arrival Guarantee terms.