L127 Marble Pleco (Peckoltia lujani)

Choose the L127 pleco for a peaceful community tank

The L127 pleco, sold as the L127 Marble Pleco, is Peckoltia lujani: a medium-sized suckermouth catfish from the Orinoco river system in Colombia and Venezuela. It has a light tan body covered in dark brown to black marbling, with four darker saddles across the back and banded fins. ScotCat places the first saddle below the middle of the dorsal fin, the second just behind it, the third near the small adipose fin and the fourth at the base of the tail. It is a hardy, unfussy fish that spends the day around rocks and wood and becomes more active as the lights dim.

This fish waited a long time for its name. It was first shown with the number L127 in the German magazine DATZ in 1993, and again as L207 in 1996; ScotCat confirms the two numbers are one species. Because it shared features with several genera it was traded for years as "Ancistrinae sp. L127", and some shops still call it a Hemiancistrus or Hypancistrus. In 2015 Armbruster, Werneke and Tan described it formally as Peckoltia lujani, naming it after the ichthyologist Dr Nathan Lujan, who collected the best specimens known at the time.

Planet Catfish gives its range as the Meta drainage near Villavicencio and the Orinoco from the mouth of the Meta to around Ciudad Bolívar. The type specimens came from the río Orinoco at Paso Ganado, 38 km north-north-west of San Fernando de Atabapo, where the river forms the border, so some sources file the locality under Colombia and others under Venezuela. The IUCN Red List assesses the species as Least Concern (2020).

Match the names you will see for this fish

Select one fish and plan its cave

One purchase supplies one live L127 Marble Pleco in the standard size we receive. Sex is not specified. Every fish has its own arrangement of marbling, and juveniles often look paler and more contrasting than adults, so the gallery images show the type of fish, not the individual you will receive. The images are prepared from a reference photograph.

Decide how many to keep

• One fish: the simplest choice for a community tank; give it one cave or a sheltered gap under wood.
• Two or more: possible in a larger tank. ScotCat says males may spar but that this is usually harmless when each fish has its own cave, so add one cave per fish plus a spare.
• With other plecos: count every cave-dwelling bottom fish together when you plan floor space and hiding places.

Read our delivery and Live Arrival Guarantee policy before you order, and have the aquarium running and tested before the fish arrives.

Plan the aquarium around a 12 cm adult

Planet Catfish gives a maximum of 120 mm standard length, measured without the tail fin, and ScotCat agrees on 12 cm. FishBase lists a much smaller 7.5 cm, taken from the specimens it used, so we plan for the larger figure. Some shops quote even more; we stay with the published sizes.

No care profile publishes a minimum tank for this species. As a comparison, Seriously Fish gives a 120 × 30 cm base for two other Peckoltia of the same 120 mm size, including P. wernekei from the upper Orinoco. We recommend at least a 120 × 30 cm base for one L127, and 120 × 45 cm if you plan two or more fish or other bottom dwellers. Floor area matters more than height for a fish that lives on rocks and wood.

Use a three-step space check

1. Measure the base: at least 120 cm long and 30 cm front to back.
2. Work out the volume with our tank volume calculator, so filter and heater sizes are right.
3. Count the caves: one per pleco, plus one spare, before you add any other fish.

Build rock piles and wood tangles

Planet Catfish recommends rock piles and wood tangles and notes that plants are not vital. Build the layout so it gives the fish cover by day and broken lines of sight, so it can rest out of view of its neighbours.

Divide the footprint by function

Keep the lighting moderate and leave a shaded area under wood. The fish will come out more in the evening.

Set water values within the published range

ScotCat gives 23–27°C and pH 6.5–7.2, and notes that the species tolerates other conditions if it is acclimatised slowly. It also warns that it does not like nitrate rising too high. The OATA guidance for catfish sets the limits that apply to any tank: ammonia and nitrite at zero, and nitrate no more than 20 mg per litre above your tap water.

Match UK tap water to the range

Many UK homes have harder, more alkaline tap water than this range, especially in the south and east. Test your tap water for pH and hardness before the fish arrives. If your pH is a little above 7.2, a slow, steady adjustment is better than a quick change, and ScotCat's note that it adapts when acclimatised slowly means stability matters more than hitting a single number. Always treat new water with a tap water conditioner to remove chlorine and chloramine. Our water chemistry guide explains pH, hardness and buffering in plain terms.

Filter well and change water weekly

Plecos eat steadily and produce a lot of waste for their size, and this species dislikes rising nitrate. Choose a filter rated for more than your tank volume, with good mechanical media to trap fine debris and plenty of biological media. A gentle current along the floor helps carry waste to the intake. Our guide to aquarium filtration covers filter types and media.

Follow a weekly maintenance sequence

1. Test ammonia, nitrite, nitrate and pH, as OATA recommends at least once a week.
2. Change about 25% of the water, siphoning waste from the sand and around the caves.
3. Remove uneaten vegetables before they soften and foul the water.
4. Rinse filter sponges only in the tank water you removed, never under the tap.
5. Refill with conditioned water at the same temperature.

If nitrate keeps climbing, ScotCat's advice is to increase water changes or add more plants.

Feed vegetables, tablets and small frozen foods

ScotCat describes the L127 as an omnivore that takes vegetable foods, tablets and pellets, insect larvae, zooplankton and soft wood. Its favourites are courgette, half-cooked, sliced and frozen, and peas now and then, along with algae wafers, tablet food and frozen bloodworm. It is not a strong algae eater compared with Chaetostoma plecos, so it must be fed every day rather than left to graze. OATA advises washing vegetables well, or buying organic, because pesticide residues can harm fish.

Build one measured meal

Feed after the main lights go off, close to its cave, so faster fish do not take everything. Adjust the portion so almost nothing is left after a few hours.

Introduce it gently and watch the first week

Set up and mature the aquarium first: OATA advises checking that ammonia and nitrite are at zero before adding fish, and adding fish slowly so the filter bacteria can keep up. Catfish travel double-bagged because their spines can puncture a single bag. On arrival, switch off the tank lights, float the bag for about 10 minutes to match temperature, then add small amounts of tank water over up to 20 minutes before netting the fish into the tank. Our guide to acclimatising new fish shows each step.

Use a first-week checkpoint plan

Take care when netting: like most catfish, plecos have spiny fin rays that tangle in nets, so OATA recommends careful handling. Guide the fish into a container rather than lifting it out in a fine net where possible.

Watch its behaviour and act on changes

A healthy L127 rests in or near its cave during the day, comes out in the evening to feed, and has a rounded belly and clear eyes. OATA lists clamped fins, flicking against décor, shimmying and fast breathing as warning signs in any fish.

Pair each observation with an action

For more on keeping plecos healthy, read our pleco care guide.

Choose tank mates from a very wide range

Planet Catfish calls this a medium-sized pleco that can be combined with a very wide range of tank mates thanks to its unfussy nature. It is perfectly safe with small fishes and shrimp, yet robust enough to withstand the attention of all but the largest cichlids. ScotCat calls it an ideal community catfish.

Decide from the suits and avoid list

For other mid-sized plecos with similar care, see the L134 Leopard Frog Pleco, the L006 Pleco (Peckoltia oligospila), the L103 Pleco and the L128 Blue Phantom Pleco. Browse all our Peckoltia plecos, the wider range of L-number plecos and South American catfish, or everything in our catfish and plecos range. Check any mix with our tank mates tool before you buy.

Know what the breeding reports describe

The L127 is a cave spawner, and Planet Catfish holds two hobbyist breeding reports with photographs of captive-bred fry. ScotCat calls breeding difficult: good water quality and timely water changes help, the eggs are laid inside a cave or pipe, and the male guards them for about 10 days. A diet rich in courgette and peas is said to be a precondition for spawning in the genus. To tell the sexes apart, Planet Catfish notes that mature males develop small tooth-like odontodes on the leading pectoral-fin rays and over the rear half of the body, plus an unusual bristly growth on the cheeks; ScotCat adds odontodes behind the gill plates and on the tail-fin rays. Females stay smooth, are darker and less colourful, and look wider behind the pectoral fins when seen from above.

Answer L127 Marble Pleco buying questions

Which species is the L127 pleco?

L127 is Peckoltia lujani, described by Armbruster, Werneke and Tan in 2015. For many years it was sold as an unnamed "Ancistrinae sp." The number L207, issued in 1996, is the same species.

How big does an L127 Marble Pleco grow?

Planet Catfish and ScotCat give 12 cm standard length, measured without the tail fin. FishBase lists a smaller 7.5 cm, taken from the specimens it used, so plan the tank for a 12 cm adult.

What size aquarium does it need?

No profile publishes a minimum for this species. Seriously Fish gives a 120 × 30 cm base for other Peckoltia of the same 12 cm size, and we recommend at least that, with more floor space if you keep more than one.

What water does it need?

ScotCat gives 23–27°C and pH 6.5–7.2, and says it adapts to other water if acclimatised slowly. Keep ammonia and nitrite at zero and nitrate low.

Will it clear algae from my tank?

Only a little. ScotCat notes it is not a strong algae eater. It is an omnivore that needs vegetables such as courgette, sinking tablets and some frozen foods such as bloodworm.

Can I keep more than one?

Yes, in a tank with enough floor space. Males may spar, but ScotCat says this is usually harmless when each fish has its own cave.

Is it safe with small fish and shrimp?

Planet Catfish describes it as perfectly safe with small fishes and shrimp, and robust enough to live with all but the largest cichlids.

How can I tell males from females?

Mature males grow small tooth-like odontodes on the leading pectoral-fin rays and the rear half of the body, and a bristly growth on the cheeks. Females stay smooth and look wider behind the pectoral fins when seen from above.

Consult the care references

• Planet Catfish: Peckoltia lujani: scientific name and authors, L127 and L207, type locality, distribution, size, sexing, décor, tank mates, cave spawning and IUCN status.
• ScotCat factsheet no. 242: Peckoltia lujani: L-number history, size, water values, sexing, foods, community behaviour, caves and the breeding account.
• ScotCat: Peckoltia lujani species page: habitat, the light tan colour with four dark saddles, and the omnivorous diet.
• FishBase: Peckoltia lujani: classification, the smaller published length, fin-ray counts, range and IUCN assessment date.
• Seriously Fish: genus Peckoltia: tank bases and water values of other Peckoltia of the same size, used only as a comparison.
• OATA: How to look after freshwater catfish: UK guidance for catfish on water quality, sand, handling spines, bagging, acclimatising and weekly maintenance.
• Tropical Fish Co delivery policy: current dispatch days and Live Arrival Guarantee terms.