L168 Butterfly Pleco (Zonancistrus pulcher)

Understand the L168 Butterfly Pleco before planning its aquarium

The L168 Butterfly Pleco (Zonancistrus pulcher) is a tropical freshwater, demersal suckermouth armoured catfish in the Loricariidae family. It comes from South America, with records from Brazil, Colombia and Venezuela, and reaches a recorded maximum of 14 cm total length. It suits a keeper prepared to build the aquarium around strong water movement, substantial cover, stable water quality and the fish’s adult proportions.

FishBase now lists it as Dekeyseria picta and treats Zonancistrus pulcher as a synonym. FishBase records the 14 cm maximum and a Least Concern conservation assessment. Both scientific names refer to the same L168 fish.

Read its natural habitat as a design brief

Wikipedia places this catfish in the Rio Negro basin in Brazil and the Orinoco basin in Colombia and Venezuela, around rocks, rapids and sunken logs. FishBase adds that it is always associated with fast-flowing water, on large bedrock in strong currents and on the large logs of floating houses where the current is swift. Those details make flow, wood, rock and secure retreat areas central planning decisions rather than decoration added at the end.

OATA’s tropical algae-eater guidance stresses that algae-grazing fish are not substitutes for regular maintenance or appropriate stocking. Choose this pleco for the animal and its habitat needs, not as a quick solution to persistent algae.

Know what one purchase supplies

One purchase supplies one live L168 Butterfly Pleco. The dispatch size for this offer is 3–4 cm, while the recorded adult maximum is 14 cm. Treat 3–4 cm as the size at dispatch and plan the permanent aquarium around the fish reaching 14 cm.

Sex is guaranteed only when the selected option explicitly states male or female. This L168 Butterfly Pleco listing has no sex-guaranteed option.

Make the purchase decision in the right order

1. Start with adult size: reserve space for a fish reaching 14 cm total length.
2. Check the water plan: use 22–27°C, pH 6.0–8.0 and 4–12°dH as the OATA group planning range.
3. Check the habitat: provide strong water movement with rock, wood and protected crevices.
4. Check filtration: use a well-established biological filter and test the aquarium regularly.
5. Assess companions: treat every proposed combination as conditional rather than relying on a universal community-fish label.

The L-number and common name help identify this aquarium fish, and Zonancistrus pulcher is the same animal now listed as Dekeyseria picta. Wikipedia also records the trade names Urubaxi butterfly pleco and flounder pleco, as well as the numbers L168 and L052. Use these names to recognise the same fish, then plan its care around the 14 cm adult size, water conditions and habitat needs.

If you are comparing bottom-dwelling freshwater fish before deciding, browse the catfish and pleco collection, then assess each animal against your measured water, established aquarium and existing livestock.

Plan the aquarium around the 14 cm adult size

Use 14 cm as the adult planning figure throughout the aquarium design. FishBase records that maximum as total length for male or unsexed fish. Total length includes the tail, so plan space, stocking and growth around the full 14 cm.

OATA advises choosing an aquarium as large as reasonably possible because greater water volume makes environmental conditions such as temperature and water quality more stable. For this pleco, combine that principle with the 14 cm adult maximum, its demersal habit and its association with large logs and bedrock. The useful aquarium is one that provides both stable water volume and enough bottom-level structure for the adult fish to move among cover.

Test the layout before adding the fish

• Mark out 14 cm against the front glass so the adult figure is visible rather than abstract.
• Check that wood, rock and crevices do not consume the entire usable bottom area.
• Keep a continuous route through the lower part of the aquarium instead of creating a visually attractive but impassable wall of hardscape.
• Allow water movement to pass around the principal logs and rocks, reflecting the swift-current habitat recorded for the species.
• Leave sheltered spaces within that structure so the fish can settle away from the strongest exposed route.

A litre figure alone cannot show whether the layout works for a demersal fish. Two aquariums with similar capacity can offer very different bottom footprints, flow paths and amounts of cover. Judge the whole arrangement against the adult body length and habitat structure, not simply the volume printed on the aquarium.

The 3–4 cm fish can grow beyond its dispatch length. Establish the adult plan first so the same aquarium can support the animal as it grows without rebuilding its flow, cover and water-quality conditions later.

Recreate a flowing habitat with rock, wood and cover

Build the lower aquarium around strong water movement, substantial wood, rock and protected crevices. FishBase records this species mainly from black waters of the Rio Negro and its tributaries, always associated with fast-flowing areas. Field collections found it on the large logs used on floating houses where the current was swift and on large bedrock in strong currents.

Use those habitat elements together rather than choosing only one. Wood provides the log-like structure linked to the fish’s natural setting, while rock creates bedrock-style surfaces and changes how water travels across the aquarium. Crevices and model caves add protected spaces within the overall layout. Add aquarium gravel or sand, and provide cover with live plants or, where live plants are not used, plastic plants and suitable ornaments such as model caves, as OATA’s broader aquarium guidance advises.

Shape the current around the hardscape

• Main flow route: direct water movement past open rock and wood surfaces instead of allowing all circulation to bypass the lower aquarium.
• Covered route: include crevices and spaces behind or beneath the principal structures so cover remains accessible.
• Waste check: inspect the areas behind hardscape during routine maintenance because uneaten food and waste must not be allowed to undermine water quality.
• Filter access: keep the filter usable and maintainable after the final wood and rock arrangement is in place.

FishBase recorded two dimorphic males inside crevices in floating logs while tending clutches of eggs. The males remained over the eggs, fanning them with branched pectoral-fin rays while enlarged pelvic fins covered the clutch. This behaviour reinforces the value of enclosed log-like retreats. The offer is unsexed, so plan those retreats as habitat rather than around a male-female breeding arrangement.

Arrange the current so water moves effectively through the rock-and-log layout while the aquarium remains filtered, stable and maintainable. Check both exposed surfaces and sheltered routes after the hardscape is complete.

Keep water within the group planning range

Keep the aquarium at 22–27°C, pH 6.0–8.0 and 4–12°dH. OATA’s freshwater tropical algae-eater sheet gives these figures as broad group guidance, so use them as a routine planning range while prioritising stability within the range.

Test the water before introduction and then at least once a week. The same OATA sheet gives 0 mg/l for ammonia and 0 mg/l for nitrite. These waste compounds must remain at zero because an aquarium can look clear while biological filtration or stocking pressure is failing.

Interpret the numbers as decisions

Use the water chemistry guide to understand what each test measures, then compare your readings with the stated range using the water matcher. Record actual results rather than describing the aquarium loosely as soft, neutral or tropical.

Stability does not mean ignoring a value outside the range. It means holding suitable temperature, pH and hardness steady while the biological filter keeps toxic waste under control. A reading of pH 8.1, for example, remains outside the 6.0–8.0 planning range even when it changes very little. Similarly, temperature movement within 22–27°C does not excuse detectable ammonia or nitrite.

Compare replacement water with the aquarium water before each water change so routine maintenance does not cause a large shift. Keep a written weekly record so gradual movement is visible early and decisions are based on measurements rather than appearance.

Establish biological filtration before introduction

Use a well set up and maintained filter from the beginning. The RSPCA’s aquarium welfare guidance explains that fish release toxic ammonia, while a working biological filter supports beneficial bacteria that convert ammonia to toxic nitrite and then to safer nitrate. Clear water alone therefore cannot show that an aquarium is biologically ready.

Prepare and mature the aquarium before livestock arrives. Our first tropical aquarium guide covers the practical setup sequence. For this pleco, readiness also means that the final wood, rock, substrate and flow arrangement is already installed; adding major hardscape later can change circulation and reduce access to cover.

Use four readiness checks

1. Filtration: the biological filter is established, working and accessible for maintenance.
2. Waste readings: ammonia and nitrite test at 0 mg/l.
3. Water match: temperature is 22–27°C, pH is 6.0–8.0 and hardness is 4–12°dH under the OATA group range.
4. Habitat function: strong water movement reaches the rock-and-log zone while crevices and covered spaces remain usable.

Stocking and feeding both affect the amount of waste the filter must process. A filter that copes with one established stocking level should not be treated as limitless. Any later addition requires a fresh check of adult space, waste capacity and measured water quality.

Keep the filter working during normal aquarium operation and maintain it without destroying its biological function. The essential outcome is continuous processing of fish waste, supported by weekly testing. If ammonia or nitrite becomes detectable, treat that reading as a water-quality failure requiring correction rather than waiting for visible symptoms in the fish.

Filtration also has to work with the habitat plan. Positioning the return so water circulates through the lower hardscape can support the species’ strong-current setting, but the rock and wood must not prevent routine filter access. Complete the arrangement and test its circulation before the fish is introduced.

Feed a complete diet instead of relying on aquarium algae

Offer controlled portions of prepared food and vegetables, and allow extra time for the fish to graze on algal foods. OATA’s tropical algae-eater guidance says these fish need prepared foods such as algae-based wafers or flakes and, ideally, fresh vegetables such as cucumber.

Do not judge the feeding plan by the amount of visible algae in the aquarium. OATA warns that algae-eating fish are not substitutes for maintenance, while a persistent algae problem can point to water-chemistry or maintenance issues. The animal’s ration and the aquarium’s algae management are separate decisions.

Build the feeding decision

• Prepared food: feed an algae-based wafer or flake as a regular part of the diet.
• Vegetable variety: ideally also offer fresh vegetables such as cucumber.
• Preparation: choose organic vegetables or wash them thoroughly because pesticide residue may harm fish or invertebrates.
• Portion: begin with a controlled amount and check how much the fish consumes.
• Waste control: inspect for uneaten food and remove it before decomposition adds toxic waste to the aquarium.

Start with one controlled portion rather than adding several foods together. Check whether the presentation gives the fish access around its lower rock-and-wood habitat. If food remains, reduce the next portion and remove the leftovers before they break down.

Variety does not mean unlimited quantity. Prepared food and vegetables still contribute organic waste, so adjust portions according to consumption and remove excess food. Weekly water tests provide an independent check on whether feeding, stocking and biological filtration remain in balance.

Keep wood as habitat structure and continue offering the supplemented diet. Natural grazing surfaces and wood do not replace prepared food and suitable vegetable variety.

Use weekly tests to guide aquarium maintenance

Test the aquarium at least once a week and keep ammonia and nitrite at 0 mg/l. Record temperature, pH and hardness alongside the waste readings so the full 22–27°C, pH 6.0–8.0 and 4–12°dH plan is checked rather than relying on a single measurement.

Use the results to decide what needs attention. Detectable ammonia or nitrite points to a failure in waste processing. A gradual temperature, pH or hardness shift shows that the aquarium is moving away from its planning range. Persistent algae should trigger a review of maintenance, water chemistry and stocking rather than the addition of another algae-grazing animal.

Make the weekly check repeatable

1. Measure temperature, pH, hardness, ammonia and nitrite under similar aquarium conditions each week.
2. Write down each result instead of relying on memory or a broad description of the water.
3. Compare the new result with both the planning range and the previous reading.
4. Inspect the filter and confirm that water is still moving through the lower rock-and-wood layout.
5. Look for trapped or uneaten food around crevices and hardscape.
6. Reduce the next portion if uneaten food remains and remove the leftovers before they break down.

The first comparison is against the limits: 22–27°C, pH 6.0–8.0, 4–12°dH and zero ammonia and nitrite. The second comparison is against the trend. A reading can remain inside the range while moving steadily towards an edge, so a written record gives earlier notice than an isolated test.

Observation complements testing but does not replace it. Note where the fish settles, whether it reaches the offered food and whether the strong-current and sheltered areas remain accessible. If behaviour or feeding changes, check the measured water and filter function first because visual inspection cannot reveal toxic ammonia or nitrite.

Keep maintenance proportionate to the measured aquarium rather than following algae growth alone. The goal is a stable, filtered habitat in which food, waste processing, flow and stocking remain in balance around a fish that can reach 14 cm.

Follow the arrival and acclimatisation procedure

Prepare the established aquarium before the parcel arrives. Check that temperature is 22–27°C, pH is 6.0–8.0, hardness is 4–12°dH, and ammonia and nitrite are 0 mg/l.

Our delivery and Live Arrival Guarantee policy explains the packing, receipt and claim procedure. The fish is hand-bagged in pure oxygen and packed in an insulated poly box, with a heat pack added when the weather calls for it. A licensed live-animal courier carries the parcel.

When the parcel arrives

1. Be present to receive the parcel; live fish must not be left unattended.
2. Start a continuous unboxing video before opening anything, with the parcel still sealed and the outer box visible.
3. Open and inspect the parcel on the day it arrives while continuing the video, showing the fish inside the sealed bag before anything is disturbed.
4. Float the bag for 20–30 minutes before releasing the fish.
5. Release the fish without pouring the bag water into the aquarium.

Film every delivery from the sealed parcel onwards. The continuous sequence records the sealed outer parcel, the opening and the fish while it remains inside the sealed bag. Keep the order number with the recording.

If anything has gone wrong, contact us on the same day with the order number and continuous unboxing video. The Live Arrival Guarantee requires someone to receive the parcel, same-day opening and inspection, and the sealed-parcel video sequence described above.

After release, keep the established feeding, filtration and testing plan consistent. Do not compensate for uncertainty by adding excess food. Offer a controlled portion, inspect whether the fish reaches it and confirm the aquarium remains within the planned water range.

Screen every proposed tank mate individually

Treat every proposed pairing as conditional. The aquarium must work for the L168 Butterfly Pleco’s 14 cm adult size, tropical freshwater conditions, strong-current rock-and-log habitat, cover requirements and biological waste load as well as for the other animal.

Screen every algae-grazing addition individually before it enters a community aquarium, because a broad community label cannot show whether two animals share suitable water, use the same limited cover or create more waste than the filter can process.

Use one compatibility screen

Do not infer safety from the fact that two animals are both freshwater, tropical or bottom-associated. Those labels do not establish a shared water range, compatible space use or adequate filtration. Likewise, do not use this pleco as a compatibility choice made solely to control algae.

Before combining multiple L168 Butterfly Plecos or adding one to an established community, run the screen above against the actual aquarium. Work from the aquarium dimensions, measured temperature, pH and hardness, current livestock, filter details and hardscape plan rather than from general labels.

Plan multiple fish without assuming a group rule

Choose the number of L168 Butterfly Plecos only after assessing adult space, cover, flow, filtration and the other animals already using the aquarium. Build the calculation around 14 cm per adult fish rather than the 3–4 cm dispatch length.

Provide meaningful rock, wood and crevice structure within the strong-current lower habitat. When considering more than one fish, check that adding further structure does not remove so much open route or bottom area that the completed layout stops working for full-sized animals.

Separate three different questions

• Purchase unit: one purchase supplies one live fish.
• Aquarium number: the suitable number depends on an individual stocking and compatibility assessment.
• Sex: the offer does not guarantee male or female, so do not build a pairing plan around an assumed sex combination.

Plan the group count from adult space, cover and filtration, and do not expect two unsexed fish to form a breeding pair.

Assess the combined waste load before increasing the number. The RSPCA explains that fish produce toxic ammonia, which a working biological filter converts through nitrite towards safer nitrate. More fish and more food increase what that system must process, so maintain zero ammonia and nitrite and continue weekly testing.

Observe access to food and the principal covered areas after any stocking change. If an animal cannot feed or use the habitat effectively, the combination is not working as planned. Reconfigure the arrangement or separate the animals rather than relying on the fact that their headline water requirements appear similar.

Answer common L168 Butterfly Pleco questions

How big does the L168 Butterfly Pleco get?

FishBase records this fish at a maximum of 14 cm total length. Plan the aquarium, hardscape and stocking around that adult figure.

What size aquarium does this pleco need?

Choose as large an aquarium as practical and plan its bottom area around a 14 cm adult, strong flow, substantial wood, rock and accessible crevices. OATA notes that larger aquariums provide more stable temperature and water quality.

How many L168 Butterfly Plecos should I keep together?

Set the number only after an individual stocking assessment covering each fish’s 14 cm adult size, bottom-level space, cover, strong-flow habitat and the filter’s ability to maintain 0 mg/l ammonia and nitrite.

Does this fish suit beginners?

It suits a prepared keeper who can establish biological filtration, test water weekly, maintain strong flow and cover, and hold the aquarium within OATA’s 22–27°C, pH 6.0–8.0 and 4–12°dH group range.

What does the L168 Butterfly Pleco eat?

Offer controlled portions and remove uneaten food before it breaks down. OATA’s algae-eater guidance says these fish need their diet supplemented with prepared foods such as algae-based wafers or flakes, ideally alongside fresh vegetables such as cucumber that is organic or thoroughly washed.

What temperature and pH does Zonancistrus pulcher need?

Keep this fish at 22–27°C and pH 6.0–8.0, with hardness of 4–12°dH. These figures are OATA’s broad tropical algae-eater group guidance, and weekly tests should also show 0 mg/l ammonia and nitrite.

Is this pleco aggressive or likely to nip fins?

Treat aggression and fin-nipping as individual compatibility questions rather than assuming either behaviour. Screen the proposed combination for adult space, water match, cover, feeding access, flow and filtration, then observe how the arrangement works.

Which animals can the L168 Butterfly Pleco live with?

Screen community fish and invertebrates individually rather than using a universal tank-mate list. The combination must share suitable water and leave enough adult space, cover and filter capacity for a 14 cm demersal pleco.

How is this fish packed and handled for live arrival?

Tropical Fish Co bags the fish in pure oxygen, uses an insulated poly box and adds a heat pack when the weather calls for it. Be present to receive it, film the sealed parcel continuously while opening, inspect it the same day and float the bag for 20–30 minutes before release.

Consult the public identity and care references

• FishBase — Dekeyseria picta: accepted name, synonymy, distribution, habitat, maximum length, conservation assessment and field biology.
• Wikipedia — Dekeyseria picta: family, range, habitat and aquarium trade names.
• OATA — Tropical algae eaters: group water, feeding, cover, filtration, testing and aquarium-planning guidance.
• RSPCA — Aquarium environment: biological filtration and the processing of ammonia, nitrite and nitrate.