L141 Ghost Pleco (Ancistomus snethlageae)

Choose the L141 Ghost Pleco from the Rio Tapajós

The L141 Ghost Pleco is Ancistomus snethlageae, a suckermouth catfish from the Rio Tapajós basin in Brazil. It is a spotted, grey-brown to beige pleco, and young fish carry a white edge on the tail and dorsal fin that gives the species its other English name, the white-edged pleco. Planet Catfish confirms that L141 and L215 are the same fish, and the Ghost Pleco grows larger than many shop labels suggest: up to about 18–22 cm.

It was described by Franz Steindachner in 1911 from specimens taken in the Rio Tapajós near Villa Braga and Goyana. The species name honours the German ornithologist Maria Emilie Snethlage (1868–1929), who collected the type specimen. For a UK fishkeeper the L141 is a peaceful, robust, mid- to large-sized pleco for a warm, rocky aquarium with a current, best kept with calm South American companions.

Check the names on the label

The genus has moved several times. In 2015 Armbruster, Werneke and Tan, writing in ZooKeys, recognised Ancistomus as a valid genus with this fish as its type species, and placed in it several relatives including Ancistomus feldbergae, the L012 Gainsboro Pleco. That is why older books list the Ghost Pleco under Peckoltia or Hemiancistrus; you will find its former genus-mates in our Peckoltia plecos category.

Tell L141 from L161

Planet Catfish notes that L161, from the Rio Xingu, may be the same species. The only difference it records is the tail edge: yellow in L161, bluish-white or white in L141 and L215. ScotCat also summarises evidence that colour patterns vary between localities, which may point to distinct populations. Expect some variation in shade and spotting between individuals, and buy by the code and the scientific name together.

Understand why this pleco is Endangered

The IUCN Red List rates Ancistomus snethlageae Endangered (criterion A3c, assessed 2018). As ScotCat summarises the assessment, it is endemic to Brazil, found in the middle Tapajós and Jamanxim river basins in Pará, infrequent and not very abundant, and associated with rocky areas and rapids. Collecting for the aquarium trade does not appear to have a significant impact. The main threat is hydroelectric dams planned in the Tapajós and Jamanxim drainages, which could affect about half of the river stretches where it is recorded and are expected to reduce the population by at least half over three generations.

Keep it in a way that respects its status

• Plan for its whole life: buy only if you can house an 18–22 cm adult for many years.
• Never release it: unwanted fish go back to a shop or another keeper, never into the wild.
• Share what you learn: breeding records for this species are scarce, so any spawning is worth reporting to a catfish society.

Know exactly what you receive

One purchase supplies one live L141 Ghost Pleco. The size option is "Standard": the fish is sent at the size currently available, normally a juvenile well below the adult size. Sex is not chosen or guaranteed; the differences between males and females show only in mature fish.

The photographs show the species, not the individual you will receive. Spotting, background colour and the white fin edges differ between fish and change with age, mood and lighting.

Plan the group before you order

• One fish: the usual choice for a community aquarium.
• A small group: ScotCat finds the species non-aggressive in a group, given a large tank and a cave for every fish.
• A mix of plecos: keep each one in its own territory of rocks and caves, as Planet Catfish advises for its relative L012.

Before you order, read our delivery and Live Arrival Guarantee information, and make sure the aquarium is matured and heated before the fish arrives.

Plan the aquarium around an 18–22 cm adult

Sources give different maximum sizes. Planet Catfish gives 220 mm standard length, measured without the tail; FishBase gives 22 cm total length, including the tail; and ScotCat gives 18 cm. Either way this is a substantial pleco, so plan the tank around the adult, not the juvenile that arrives.

No minimum aquarium size has been published for this species. For comparison, Seriously Fish recommends a base of 120 × 45 cm, about 243 litres, for the 16 cm snowball pleco; the Ghost Pleco grows larger, so treat that as a minimum, not a target. For its close relative L012, Planet Catfish suggests giving each fish about a 30 cm (12 in) square of floor broken up with décor, which is a useful rule when you plan caves for more than one pleco.

Run a three-step space check

1. Measure the base: at least 120 × 45 cm, longer if you plan a group.
2. Share out the floor: roughly a 30 cm square of rocks and caves for each pleco, not counting other bottom fish.
3. Check the stocking: our tank volume calculator gives the litres and our stocking calculator helps you judge how many fish the tank can carry.

Keep the aquarium away from radiators, windows and draughts and fit a lid. A heater is needed all year round, and our tropical tank temperature guide explains how to keep the reading steady.

Build a rocky layout with caves and wood

In the wild it lives around rocks and rapids, and one of the Planet Catfish habitat photographs shows the middle Rio Tapajós at Itaituba. Build the aquarium around stacked rocks, caves and wood over a soft floor, with a current running through.

Divide the floor by function

Use sand or fine gravel, because OATA notes that catfish have sensitive barbels that need a soft bottom. Stand rocks on the glass before adding sand so the stacks cannot collapse onto a resting fish. Choose caves that an adult can turn round in: a cave that fits a juvenile will be too small within a couple of years.

Soft lighting and plenty of shade bring a pleco out more often. Tough plants such as Anubias and Java fern can be tied to wood or rock if you want greenery.

Keep the water warm, clean and stable

Planet Catfish gives 23–27°C. ScotCat gives 25–30°C and pH 6.0–7.2 and says to keep it in warm, soft to medium-hard water. Because the sources disagree on temperature, we suggest 25–27°C, where both ranges overlap.

Match your water to the targets

UK tap water ranges from soft to very hard depending on where you live. If yours is hard and alkaline, mix it with reverse-osmosis water to bring the pH and hardness down gradually, then keep the mix the same at every water change. Use a conditioner every time to remove chlorine or chloramine. Our water matcher compares your readings with this fish's range, and our water chemistry guide explains pH, hardness and the nitrogen readings.

Filter for flow and a large bioload

A pleco of 20 cm produces a lot of waste, and a fish from rapids needs clean, oxygen-rich water. Choose filtration generously: Seriously Fish's guidance for rapids plecos is a filter turning over four to five times the tank volume each hour, plus extra water movement where needed, and weekly water changes of 30–50%.

Follow a weekly routine

1. Test ammonia, nitrite, nitrate and temperature.
2. Change 30–50% of the water with conditioned water at tank temperature; OATA's minimum is 25% a week.
3. Siphon the sand and the spaces under rock overhangs, where pleco waste collects.
4. Check that the outlet still moves water past the caves.
5. Rinse filter media in old tank water only, never under the tap.

Keep the surface moving for gas exchange, and add a powerhead if parts of the tank stay still. Our guide to aquarium filtration explains how to size and combine filters.

Feed vegetable foods with small frozen extras

ScotCat describes its diet as vegetarian with added tablet foods and fine to medium-sized live and frozen foods such as mosquito larvae and brine shrimp. In other words it is an omnivore that leans towards plant food. Base the diet on sinking vegetable tablets and wafers, add fresh vegetables, and offer small frozen foods a few times a week.

Build one measured meal

• Staple: a sinking vegetable-based tablet or wafer near its cave.
• Fresh greens: blanched courgette, cucumber or softened spinach, removed within a day.
• Frozen extras: thawed mosquito larvae or brine shrimp, two or three times a week.
• Timing: after lights-out, when the fish is most active.
• Portion: what has gone by the next morning.

Watch the belly: a well-fed pleco is gently rounded underneath. A hollow belly in the first weeks means it is not getting enough, often because other fish reach the food first.

Introduce it calmly to a mature aquarium

Add the fish only to a filtered aquarium that has run long enough to process waste, with zero ammonia and nitrite and the temperature in range. Our pleco care guide covers the general set-up for suckermouth catfish.

OATA recommends acclimatising with the aquarium lights off: float the sealed bag for about 10 minutes, add small amounts of aquarium water over up to 20 minutes, then release the fish with as little bag water as possible. OATA also advises double-bagging catfish because of their fin spines. Our guide on how to acclimatise new fish shows each step.

Use a first-week checkpoint plan

A new pleco often hides for several days; that is normal. Rapid breathing, gasping at the surface or lying on its side is not, and calls for an immediate water test.

Choose calm South American tank mates

ScotCat describes the Ghost Pleco as no problem to keep and non-aggressive, even in a group. Choose companions that share its warm, flowing water and leave the bottom to the plecos. Peaceful eartheaters and characins suit a South American layout; aggressive cichlids and pushy bottom feeders do not.

Screen each companion

For related plecos with similar care, see the L134 Leopard Frog Pleco, the L075 Para Pleco and the L006 Pleco, or browse our L-number plecos, the wider South American catfish range, all catfish and plecos and our rare and collector fish. Check a planned mix with our tank mates tool.

Watch for problems early

OATA describes a healthy fish as having clear, bright eyes, undamaged fins, no ulcers or bumps, normal swimming and steady breathing, and lists clamped fins, flicking against décor and shimmying as warning signs. A newly imported pleco should have a rounded belly and eyes that are not sunken.

Pair each sign with an action

Test the water before deciding anything. Most changes in a pleco's behaviour start with water quality, and the fix is usually a water change and better filtration rather than medication.

Breed the Ghost Pleco in caves

Planet Catfish records that it has been bred in aquariums, and its photo gallery includes eight-day-old fry in a cave, but no detailed breeding report has been published. Sexing adults is possible: ScotCat says males have a longer, broader head with longer bristles behind the gill cover and on the pectoral-fin spines, and mature males grow fine odontodes on the plates of the rear body.

Set up for a spawning

1. Start with a group: several young fish give the best chance of a male and a female.
2. Offer adult-sized caves in the current, more caves than fish.
3. Condition the fish: stable, warm water, large water changes and a varied diet with frozen foods.
4. Leave the cave alone if a male starts guarding it.
5. Record everything: water values, temperature and dates, and share them with a catfish society.

Answer L141 Ghost Pleco buying questions

Which species is the L141 Ghost Pleco?

L141 is Ancistomus snethlageae (Steindachner, 1911), a suckermouth catfish from the Rio Tapajós basin in Brazil. Planet Catfish confirms that L141 and L215 are the same fish; ScotCat also calls it the white-edged pleco.

Why do some labels say Peckoltia or Hemiancistrus?

The species has been placed in several genera since 1911, including Ancistrus, Lasiancistrus, Peckoltia and Hemiancistrus. Armbruster, Werneke and Tan recognised Ancistomus as a valid genus in 2015, with this fish as its type species.

How big does an L141 grow?

Larger than many shop labels suggest. Planet Catfish gives 220 mm standard length, FishBase 22 cm total length and ScotCat 18 cm. Plan for a fish of about 18–22 cm.

What size aquarium does it need?

No minimum is published for this species. Seriously Fish recommends a 120 × 45 cm base for the 16 cm snowball pleco, and the L141 grows bigger, so treat that as the minimum and give each pleco its own cave and floor area.

What temperature does it need?

Planet Catfish gives 23–27°C and ScotCat 25–30°C with pH 6.0–7.2, so we suggest 25–27°C, where both agree, in soft to medium-hard water.

What does it eat?

ScotCat describes a mainly vegetarian diet with added tablet foods and small to medium live or frozen foods such as mosquito larvae and brine shrimp. Feed sinking vegetable foods as the base, with frozen foods a few times a week.

Is it endangered?

Yes. The IUCN Red List rates it Endangered (assessed 2018), mainly because planned dams could affect about half of its known range in the Tapajós and Jamanxim rivers. Aquarium collection is not considered a significant threat.

How many fish come with one purchase?

One live fish of the standard size currently available. Sex is not chosen or guaranteed.

Consult the care references

• Planet Catfish: Ancistomus snethlageae (L141) — names, L141 = L215, the L161 comparison, size, temperature and breeding status.
• ScotCat: Ancistomus snethlageae — synonyms, sexing, care, diet, size, water values and a summary of the IUCN Endangered assessment.
• FishBase: Ancistomus snethlageae — maximum length, distribution and IUCN status.
• Armbruster, Werneke & Tan (2015), review of Hemiancistrus, Peckoltia and allied genera, ZooKeys 480: 97–123 — peer-reviewed review recognising Ancistomus as a valid genus for A. snethlageae and A. feldbergae.
• Planet Catfish: Ancistomus feldbergae (L012) — names, L013 as a young L012, type locality, size, sexing, temperature, feeding, décor and compatibility.
• Seriously Fish: Hypancistrus inspector (L102) — the closest relative, the snowball pleco: aquarium base, hardness, maintenance and filtration guidance used here as a comparison.
• OATA: How to look after freshwater catfish — UK group-level catfish guidance on water quality, substrate, bagging, handling, introduction and maintenance.
• OATA: How to test water quality in your freshwater aquarium — UK guidance on water testing, conditioners and weekly water changes.
• Tropical Fish Co delivery policy — current dispatch days and Live Arrival Guarantee terms.