Suckermouth Catfish Gold (Hypostomus plecostomus)

A gold armoured catfish that grows into a big fish

Suckermouth Catfish Gold is a gold colour form of Hypostomus plecostomus, an armoured catfish in the family Loricariidae. The family is named for the rows of armour-like scutes that cover the upper parts of the head and body, and this fish carries the underslung sucker mouth that gives it its common name. Each purchase is one live fish at the size you choose, from 4 cm up to 10–12 cm. The size you select is the size supplied, not the adult size.

That distinction is the heart of the buying decision. FishBase records a maximum of 25 cm standard length for the species, and the Wikipedia summary gives up to 50 cm. A 4 cm juvenile fits almost any aquarium; the adult does not. Buy it for a large, established aquarium you already have, or one you are building for it, rather than to solve an algae problem in a small community tank.

FishBase describes a tropical freshwater and brackish catfish from the coastal rivers of the Guianas in South America, from the Oyapock to the Essequibo basins. It lives on the bottom in the lower reaches of rivers still under tidal influence, where water flows quietly over mud, and in swamps. It feeds on algae and small crustaceans and can breathe air when it needs to. FishBase also notes that it is cultured in ponds in Singapore and Hong Kong for the aquarium trade.

The gold colour is the reason this form is chosen, and it does not change what the fish needs. Its care is the care of Hypostomus plecostomus as a whole: space, clean and steady water, and a grazing diet. Expect the colour to vary a little from fish to fish, as it does in any live animal.

One naming point is worth knowing. Wikipedia notes that the name Hypostomus plecostomus is often used for the common plecos sold in aquarium shops, even though most of those belong to other genera. Whatever the label on a pleco elsewhere, the planning advice on this page is the same: allow for a large catfish.

Choosing a size and what you receive

You receive one live fish for each one you order, at the size named on your chosen option. Six sizes are offered:

• 4 cm, 5 cm and 6 cm: young fish with a lot of growing ahead of them.
• 7 cm: a slightly larger juvenile.
• 9–10 cm and 10–12 cm: larger fish that are further along, useful when you want something more substantial from the first day.

Sizes are not always all open for ordering, so check the size menu on this page for the current choice. Whichever size you pick, the aquarium plan is the same, because every one of these fish is heading for the same adult size.

Sex is guaranteed only when the selected option explicitly states male or female. This Suckermouth Catfish Gold listing has no sex-guaranteed option.

One of the photographs shows two fish together, but each purchase is a single fish. Gallery images have been digitally enhanced to improve image quality. Natural colour, pattern, size and maturity can vary between live animals.

If you are still deciding which bottom-dwelling fish suits your aquarium, you can compare our catfish and plecos, which range from small species to large ones like this.

Planning space for the adult fish

OATA's care sheet for tropical algae eaters opens with a warning that fits this fish exactly: some species bought to deal with algae can grow too large for most aquariums. Its general rule is to buy an aquarium as large as you reasonably can, because a larger volume keeps temperature and water quality more stable.

What to look for in the tank

• Footprint first: this is a demersal fish that lives on the bottom, so the length and width of the base matter more than height.
• Room to turn: an adult recorded at up to 25 cm standard length, longer with its tail, needs to turn and graze without scraping decor at every move.
• Filtration to match: a big fish produces a lot of waste, so the filter has to be sized for the adult, not the juvenile you start with.
• A plan for later: if you are starting with a 4 cm fish in a smaller tank, know when and how you will move it on to its final aquarium before it outgrows the first.

If you are unsure whether your aquarium is large enough, send us its length, width and height before ordering and we will talk it through with you. It is far easier to change the plan now than to rehome a large catfish later.

A tropical fish, not a pond fish

FishBase gives a wild temperature range of 20–28 °C, so this catfish needs a heated indoor aquarium. It is not a fish for an outdoor pond in the UK climate, however often large plecos are suggested for algae in ponds.

Setting up and maturing the aquarium

OATA's general aquarium requirements apply here in full: a filter is always essential, the tank should have aquarium gravel or sand, and it should ideally have live plants for cover. If you do not use live plants, add plastic plants and suitable ornaments such as plant pots or model caves so the fish has shelter.

Why the filter matters so much

The RSPCA stresses that no fish should be kept without a well set up and maintained filter. Fish release ammonia, which is toxic. A working biological filter lets beneficial bacteria break waste down, turning ammonia into nitrite, which is also toxic, and then into nitrate, which is safer. With a large catfish the amount of waste grows as the fish does, so the filter that copes with a juvenile needs to be able to cope with the adult too.

Matured before it arrives

Those bacteria take time to establish, so the aquarium should be running and matured, with ammonia and nitrite both reading zero, before the fish goes in. Our step-by-step guide to setting up a first tropical tank safely covers filling, heating and maturing in the right order.

Layout for a bottom-dwelling catfish

• Keep a broad, open area of gravel or sand along the bottom for the fish to move across.
• Provide shelter large enough for the adult, such as caves or wood arranged so the fish can slip under cover.
• Make sure rocks and ornaments sit firmly on the base of the tank, as a large fish moving underneath them can shift anything that is loosely placed.
• Leave the front glass and at least one side of the tank clear enough that you can see the fish and reach the bottom for maintenance.

Water values: wild range and aquarium target

Two kinds of figures describe this fish's water, and it helps to keep them apart. FishBase records the environment the species lives in; OATA gives recommended aquarium values for the algae-eating fish it covers. The routine aquarium target on this page is where the two agree.

The aquarium values come from the recommended parameters in the OATA algae-eater care sheet, which are group guidance for the algae-eating fish it describes rather than figures measured for this species alone. Keeping inside both sets of figures, and keeping the water steady from week to week, is the safest plan.

Testing

OATA calls water testing kits essential and recommends checking water quality regularly, once a week, so that it never slips outside the values above. Test the tap water too, because the nitrate limit is measured against it and because UK tap water varies widely in hardness and pH. Our guide to aquarium water parameters explains what each test tells you, and the water matcher tool compares your readings with a set of target values.

Heating

A heater with a thermostat and a thermometer you can read easily will hold 22–27 °C through a UK year. Check the thermometer daily during the first weeks and whenever the weather turns sharply hotter or colder.

Feeding a grazing catfish

FishBase records that this species feeds on algae and small crustaceans. In an aquarium, the algae growing on glass and decor is only a small part of what a catfish of this size needs. OATA is clear that algae-eating fish all need their diet supplemented with prepared feeds, such as algae-based wafers or flakes, and ideally fresh vegetables such as cucumber.

A simple feeding plan

• Everyday food: algae-based wafers or flakes, sized so the fish can reach and graze them on the bottom.
• Vegetables: cucumber and similar fresh vegetables, bought organic or washed thoroughly, because residual pesticides can harm fish and invertebrates.
• Portion: offer modest portions that the fish finishes, while allowing extra time for the fish to graze algal foods and vegetables.
• Tidy up: lift out vegetables and wafer pieces the fish has not finished, so they cannot break down in the tank.

OATA warns against overfeeding, because uneaten food breaks down and releases toxic waste into the water. With a large catfish that effect is magnified, so let the water tests guide you: if nitrate climbs faster than usual, reduce portions before anything else.

Algae control is a side benefit, not a job

OATA points out that persistent algae problems may point to underlying water chemistry issues caused by incorrect maintenance, and that algae-eating fish are not a substitute for regular maintenance and appropriate stocking levels. Enjoy the grazing, but feed the fish properly and deal with algae at its cause.

What its wild home tells you

FishBase places this catfish in the lower parts of rivers that are still influenced by the tide, in quiet-flowing water over a muddy bottom, and in swamps. Wild conditions are a guide to what the fish meets in nature rather than a recipe for the aquarium, but they point to three practical choices.

• A comfortable bottom: a fish that lives over mud spends its life on the substrate, so choose sand or a smooth gravel it can rest and graze on without scraping its underside.
• Steady rather than fierce flow: its rivers flow quietly, so the aim is a filter strong enough to keep the water clean for a large fish, with the outlet placed to spread the flow rather than blast one corner of the bottom.
• Fresh water at home: FishBase lists brackish water among the places the species is found, which reflects the tidal reaches of its rivers. A freshwater aquarium within the values on this page is the right home; there is no need to add salt.

The wild temperature range FishBase gives, 20–28 °C, spans the conditions the species meets across its range. In the aquarium the aim is the steadier middle of that span, which is why the target on this page is narrower.

Growing a young fish on

Most of the sizes sold here are juveniles, and the fish you receive will keep growing for a long time. How well it grows depends on the same things as its health: steady water, enough food and enough space.

Habits that help a young catfish grow well

• Feed at the same time each day, and make sure the wafer or vegetable reaches the fish rather than the midwater fish above it.
• Keep an eye on nitrate as the fish grows. The same feeding routine produces more waste every few months, so a tank that tested well in spring may need more attention by autumn.
• Note the fish's approximate length every few months. It shows you clearly when the aquarium, filter or shelter needs to be scaled up.
• Upgrade before the fish is cramped. Moving a medium-sized catfish into a ready, matured aquarium is far easier than rescuing a large one from a tank it has outgrown.

A healthy young catfish grazes steadily, holds on to surfaces well and shows a full, rounded body rather than a hollow belly. If growth seems to stall, check water quality first and then look at how much food is reaching it.

What to budget for before you buy

A small juvenile is an easy purchase; the aquarium it will need is the real commitment. Before ordering, check that you can provide each of these for the adult fish:

If any of these is not in place yet, it is worth waiting. The fish will be the same fish in a few months, and it will arrive into an aquarium that is ready for it.

Arrival and the first weeks

We hand-pack each fish, bagged in pure oxygen inside an insulated poly box, with a heat pack when the weather calls for it, and a licensed live-animal courier carries the parcel. You receive a tracking number and your confirmed delivery date by email.

1. Arrange for someone to be at the delivery address to receive the parcel, because live fish cannot be left unattended.
2. Start a continuous unboxing video before the box is touched, showing the sealed parcel with the outer box visible, you opening it, and the fish still inside its sealed bag.
3. Open and inspect the parcel on the day it arrives.
4. Acclimatise slowly by floating the bag in the aquarium for 20–30 minutes.
5. Release the fish and never pour the bag water into your tank.

If anything has gone wrong, contact us the same day with your order number and that unboxing video; WhatsApp is the quickest way, and we will arrange a replacement or refund under the Live Arrival Guarantee. Our delivery and Live Arrival Guarantee terms set out the full conditions.

Settling in

Have a cave or wood ready so a new catfish can find shelter straight away. Keep feeding light for the first few days and remove anything left uneaten, and test ammonia and nitrite more often than usual during the first fortnight, because a new fish adds waste the filter bacteria must catch up with.

Routine care and health checks

A large catfish rewards a steady routine. The weekly check below keeps the basics under control:

• Test ammonia, nitrite and nitrate once a week, as OATA recommends.
• Make regular partial water changes, treating the new water with a tap-water conditioner and matching its temperature to the aquarium.
• Check that the filter is flowing freely and clean its media gently in water taken from the aquarium, so the bacteria living in it survive.
• Count the fish and look at each one: fins, body, breathing and appetite.

Air breathing is normal

FishBase describes this species as a facultative air-breather, meaning it can take air from the surface when it needs to. An occasional trip to the surface is part of its biology. Repeated gasping at the surface, or a fish that stops grazing and hides constantly, is different: test the water straight away, because a problem with ammonia, nitrite or temperature is the most common cause and the quickest to put right.

When to get in touch

If a fish loses interest in food, shows damaged fins, marks on the body or changes in breathing, send us your water test results and a description or photo of what you are seeing, and we will help you work through the likely causes.

Planning a community around a large catfish

Compatibility for this fish is mainly a question of space and food. It grazes the bottom and, in the wild, feeds on algae and small crustaceans, so the companions that work best are those that fit the same large aquarium comfortably and are not small enough to be treated as food.

Sharing the bottom

Every bottom-dwelling fish in the aquarium competes for the same floor space and the same sinking foods. Before adding another catfish or loach, ask whether the base of the tank can hold both at adult size, with a shelter each, and whether food will reach each of them.

Feeding in a mixed aquarium

Faster fish often reach food first. Sinking wafers placed near the catfish's shelter, and vegetables left for a longer grazing period, help make sure it eats well even when the midwater fish are busy.

Adding fish later and other algae eaters

OATA recommends checking with your retailer before adding any algae-eating fish, and that applies to this catfish as well as to anything you might add alongside it. Check with us before combining it with another pleco or algae eater, and tell us the aquarium size and the fish already living in it.

• Add new fish in small numbers so the filter bacteria can keep pace with the extra waste.
• Check the adult size of every fish you add, not just its size on arrival.
• Test ammonia and nitrite for a week or two after each addition.
• Watch the first few feeds to confirm the catfish still reaches its food.

Plants and decor in a shared aquarium

Choose sturdy plants and anchor them firmly, or attach them to wood and rock, because a large fish moving along the bottom can dislodge anything loosely planted. Space caves and wood so that each bottom-dwelling fish has its own shelter, and leave open water above for any midwater species.

Other products shown alongside this one are options to compare, not a recommendation to keep them together.

Common questions

How big does Suckermouth Catfish Gold get?

FishBase records the species at up to 25 cm standard length, and the Wikipedia summary gives up to 50 cm. Standard length is measured to the base of the tail, so the whole fish looks longer. Plan for a large catfish whichever size you buy, because the size you receive is only its length on the day it is packed.

What size aquarium does it need?

Buy the largest aquarium you reasonably can, with a long, wide base for a bottom-living fish that is recorded at up to 25 cm standard length. OATA warns that some algae-eating fish grow too large for most aquariums, so send us your tank dimensions before ordering if you are unsure.

How many Suckermouth Catfish Gold should I keep together?

Plan on one per aquarium in most homes. Each adult needs a large share of floor space and adds a heavy load to the filter, so a second fish only makes sense in a genuinely large aquarium with room for two fully grown catfish.

Is it a good fish for a beginner?

It is straightforward to feed, but it suits beginners only when a large, matured and filtered aquarium is ready before it arrives. The commitment is space and steady maintenance for a fish recorded at up to 25 cm standard length, rather than any special skill.

What does Suckermouth Catfish Gold eat?

In the wild it feeds on algae and small crustaceans. In the aquarium, OATA advises supplementing grazing with prepared feeds such as algae-based wafers or flakes, and ideally fresh vegetables such as cucumber, washed thoroughly or organic. Offer modest portions and remove leftovers, giving algal foods longer to be grazed.

What temperature and pH does Hypostomus plecostomus need?

Aim for 22–27 °C and pH 6.2–8.0, with general hardness around 4–12 °dH, zero ammonia and nitrite, and nitrate no more than 20 mg per litre above your tap water. This routine target combines OATA algae-eater guidance with the wild range FishBase gives for the species, 20–28 °C and pH 6.2–8.2.

Is Suckermouth Catfish Gold aggressive, or does it nip fins?

Its natural food is algae and small crustaceans, so it is a grazer rather than a hunter of fish. The practical issues come from size: a large armoured catfish needs plenty of floor space, and very small tank mates such as shrimp can be treated as food.

Which kinds of animals can live with it?

Choose fish that are comfortable at 22–27 °C and pH 6.2–8.0 and that fit a large aquarium alongside a big bottom-dwelling catfish. Take particular care with small shrimp, because Hypostomus plecostomus feeds on small crustaceans in the wild.

How does Suckermouth Catfish Gold arrive alive in the UK?

Our team hand-packs each fish, bagged in pure oxygen inside an insulated poly box, with a heat pack when the weather calls for it, and a licensed live-animal courier carries the parcel. Be in to receive it, film one continuous unboxing video from the sealed parcel, open and inspect it the same day, float the bag for 20–30 minutes and release the fish without the bag water. For a Live Arrival Guarantee claim, contact us the same day with your order number and the video.

References

• FishBase: Hypostomus plecostomus — family, wild environment and distribution, diet, air breathing and maximum recorded length.
• Wikipedia: Hypostomus plecostomus — armoured scutes, common names, a larger reported length and the use of the name for other plecos in the trade.
• OATA: how to look after tropical algae eaters — aquarium size, set-up, recommended water values, testing and feeding for algae-eating fish.
• RSPCA: fish environment — why a maintained biological filter is essential.
• Tropical Fish Co delivery and Live Arrival Guarantee page, linked in the arrival section — packing, courier, unboxing video and acclimatisation steps.