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A fishkeeper's guide to Panaque

Julian Dignall begins a two-part article on Panaque – a group of gorgeous suckermouth catfish with a knack of reducing your bogwood to sawdust! This month he looks at the larger members of the genus.

Copyright © Practical Fishkeeping

Panaque is an indigenous term applied to the suckermouth catfish that were found eating their way through the most common mode of transport around in tropical South America; the ubiquitous canoe!

Panaque is also one of those local common names that we adopted as the scientific name, and because of that found their way back into existence as common names in another part of the world.

Many aquarists are turned off by the discussion or even use of scientific names. But they have an important role to play in helping us understand how to keep fish – or they can do – and Panaque is a currently contested case in point.

The debate on Panaque centres on the splitting of the genus in 2001. In the broadest of terms, the upshot was that all small Panaque were moved into a new genus called Panaqolus and all the big species remained in Panaque.

Simply, this split is helpful to keepers of these fish as dietary, care and reproduction information could be generically described at that level rather than having to worry about differing requirements for the bigger “classic” Panaque species.

Thus, Panaqolus species were smaller, showed more marked sexual dimorphism and “did all the same things” as other Panaqolus.

The big guns remained in Panaque. This split appears to have only found consistent published use in German hobby literature and, despite PFK also being hobby literature, I’m not going to propagate its use here because I haven’t done so elsewhere. I may be wrong, but at least I’m consistent!

To further mess things up from the viewpoint of someone who actually wants to understand how to keep these fish alive and in top condition, there is a view that the genus Scobinancistrus also is considered as a Panaque.

This is because the spoon-shaped teeth which Panaque possess are also evident in Scobinancistrus species; however, they are greatly elongated and used for finding very different foods.

We’re not going to talk here about species originally described as Scobinancistrus under the banner of Panaque.

Since the early 90’s, the number of so-called exotic plecs available to the hobbyist has greatly increased. All these and indeed every plec belong to the catfish family Loricariidae, home also to Whiptails, Otos and many other species that all share an adapted suckermouth and at least some form of external armour plating.

In fact there are just fewer than 800 species in this family and many more out there that remain without formal description by scientists despite much work being done within the field at this time. In fact that many of these new species are seen and cared for by aquarists long before the science of taxonomy catches up.

This constant exposure to new fish has brought with it its own set of challenges. The first piece of vital knowledge to absorb is that plecs have widely different needs when it comes to adequate aquarium care; try and treat them all the same and you will likely fail to get the best from your fish and may actually end up causing it more harm than good.



A look at the teeth
Luckily for plec and keeper alike, the past few years have seen plec know-how become much more widely distributed and accepted. This has led to successful breeding of many exotic plec species and even more information being gathered and disseminated – primarily via the Internet. So, aside from growing large, what do all the Panaque we’re going to look at in part one of this article have in common?

The most characteristic thing is the spoon-shaped teeth. These are arranged in rhombus formation, centred within the suckermouth and with both the lower and the upper jaw having an equal compliment and size of teeth. These are built like tiny ice cream serving spoons and you can image them being used to similar effect in dragging or rasping away at submerged soft woods.

However, you need to look closely at the underside of the fish to see this feature. Paying attention to this small detail is important as dentition tells us a lot about diet. In Panaque the teeth tell us this is a fish that continually rasps at a surface with the intent of scraping away at it.

Rather than removing a surface layer of algae like common plecs (Liposarcus etc) or Bristlenoses (Ancistrus spp.) might do, or doggedly munching away on a carcass like a Cactus plec (Pseudacanthicus spp.) or prising into a mollusc like a Vampire plec (Leporacanthicus spp.) Panaque use a scraping action, and a relentless one at that.

Put a 15cm/6” Royal plec into a polystyrene fish box, let it settle and you’ll soon hear it squeaking away as it tries to work out if polystyrene is edible or not. That reminds me; don’t keep any Panaque in a Perspex tank. In a few months it’ll look like you’ve tried to sandpaper it from the inside!



Less streamlined
In terms of appearance, the other feature that aquarists will notice about (particularly the larger) Panaque is the high-bodied shape that makes them look a lot less streamlined than many other plecs, the overall appearance being like the upside-down keel of a rowing boat.

These fish aren’t really found in rapids; just flowing bodies of water. In the flow of a river, this design is effective in helping you keep stuck firmly in place without total reliance on the suckermouth for anchorage.

What’s available?
There are quite a few big Panaque species available to the aquarist. There are three described species and a whole host of undescribed or at least unidentified imports.

The described species are Panaque cochliodon (Steindachner, 1879) described from the Rio Cauca, Magdalena, Colombia. P. nigrolineatus (Peters, 1877) described from Calabozo, Venezuela and also known as L190 and Panaque suttonorum (Schultz, 1944) from the Rio Negro river that flows into the Maracaibo basin, North Western Venezuela.

In fact, Panaque suttonorum, the Maracaibo Panaque is the only one that is unknown to the hobby. Now is a good time to discuss this phantom species as many of you will be thinking you’ve seen fish in books and so forth with this name – or something similar. Indeed this is correct; much of the older hobby literature will have this species listed as the Blue-eyed plec, Panaque suttoni.

Aside from its appearance in books, aquarists from time to time saw for sale a striking black plec with piercing blue eyes up until the late nineties. At the time we thought this was Panaque suttoni.

This is more correctly and currently known as Panaque suttonorum as in the past few years it has come to light that the species was named for a couple with the surname Sutton, rather than an individual man (in which case it would be called P. suttoni) or an individual woman (P. suttonae). P. suttonorum was described from a river flowing into the Maracaibo basin.

As it turns out, this isn’t the species we used to commonly call the Blue-eyed plec. It was a case of mistaken identify (amongst other things, the scientific description mentions the P. suttonorum having white edges to its fins).

Rather ironically, at about the same time the suttonorum correction was made, it became apparent that the species we know by this name wasn’t the imported Blue-eyed plec anyhow!

Sixty-five years earlier a species was described as P. cochliodon and, as German aquarists have eloquently pointed out, this, also German, earlier scientific description matches the imported Blue-eyed plec perfectly.

Having looked at the descriptions of both species I have to say I’m hard put to tell any difference.

The fact that the striking blue eyes may fade very quickly after death in a specimen that has been preserved in alcohol or formalin also lends weight to the view that in fact the species may be one and the same.

Anyway, aside from the Blue-eyed plec matching the description, P. cochliodon is the older name and, perhaps more importantly in this instance, came from the right part of Colombia for the export trade to have been collecting it.

Sadly, imports of this species have stopped since around the late ‘90’s. Colombia is a difficult country in which to set up an export business; in many areas it is dangerous or even impossible.

Hopefully the plecs and their habitat are undisturbed waiting for the political landscape to change. The locals know this is a fish that money can be made from. If they can’t get them to exporters it’s either because they’re no longer there or it’s too dangerous to do so.

Panaque cochliodon by oscar300.

From time to time individual Blue-eyed plecs are offered for sale; in the last year I’ve seen a pretty old-looking one offered on eBay for £450 (it didn’t sell in that auction) and Aquarium Glaser in Germany recently advertised that they had imported one and sold it for an equally high sum. But these are all one-offs; unless a new population is found or the areas in which they occur naturally become safer, we will just have to wait to find out more.

The Royal plec is one of the most commonly encountered exotic plecs around. Typically they’re sold at about the 5cm/2” stage, are really very attractive at this size and do not dull with age. Panaque nigrolineatus (literally the Black-lined Panaque) is the true Royal plec. It was “originally discovered” in the area around Calabozo in the Venezuelan llanos or high plains.

In 2002 I travelled there and managed to find them in their natural habitat. It takes practice to remove a plec from a submerged trunk, but with some trial and error I soon had more than I feasibly knew what to do with. I found that the deeper and further you go into larger channels, the bigger the Panaque found.

Panaque sp. "L27 golden line" by Scissorfight.

There are also several undescribed species of Brazilian Royal plecs. Collectively known as L27, we have one from the Rio Tocantins, the Gold line royal from the Rio Araguaia in the Tocantins system, the Xingu Royal known also as LDA63 and the Tapajos royal known also as LDA77. There are a host of other less than useful common names. It’s easiest to refer to them as L27 and give their origin.

Panaque sp. "LDA65" by Rarefishaqua.

To the casual observer they may look the same, but their colouration and shape differs considerably. With all these Brazilian species, the colouration of the young can be different for the adult too.

The Xingu Royal is interesting as it has a lower, more streamlined profile as a younger fish and has a rusty red tinge to its fins at this stage too. Adults appear to show different dentition to other Panaque although I lack firm information at present. All these species can take higher temperatures and shouldn’t be kept below 25.5°C/78°F.

Buying, keeping and feeding
In this group of large Panaque there are some great specimen fish but they are high maintenance. “Waste matter” is normally thought of as excrement produced by the fish that is broken down by varied forms of filtration.

However with Panaque a lot of this is made up of what can best be described as sawdust. Great amounts of finely chiselled bogwood will quickly start to build up and if you’ve not designed it right, will wreak havoc with your filtration system.

As they grow, keeping them well fed means that a vast amount of waste matter is generated by just one fish and filter systems must be doubled or tripled in capacity to cope.

A drop in dissolved oxygen due to water flow being cut by a sawdust clogged filter sponge might be enough to kill off a larger Panaque in the time it takes you to get to work and back in a day. This is doubly important with species that also prefer higher temperatures, as the dissolved oxygen issue is an even more volatile one.

Other water parameters aren’t so important for these species, I’m not aware of any of them occurring out with white water and so, aside from the usual dechlorinating, you shouldn’t have any trouble keeping them in normal water.

Alongside oxygen levels, water quality is also important. To deal with the “sawdust” problem you need to ensure either a prefilter takes out this waste or you keep the fish in relatively tall tanks and remove water into the filter from above where sawdust is normally present.

The latter option works best in my opinion. Base-drilled tanks with overflow-based drop tubes work very well.

The sawdust must then be periodically removed by syphoning which greatly prolongs the life of the filter and media.

In effect, you’re looking at a custom-built set-up to keep groups of these fish for any length of time. With a fish whose lifespan is measured in decades, that’s dedication.

It is my experience that within a group of fish collected from the same place and exposed to the same export and import processes, you’ll find some that settle much more readily than others. Often fishkeepers have trouble with Panaque in their first few days at home in a regular community tank.

A lot of this is down to fish bought in poor condition, lack of proper acclimatisation at home and sometimes incorrect diet.

When looking at any plecs “in store”, avoid any with hollow bellies, sunken eyes, fanning fins that give the appearance of a static fish paddling to stay in one place and red sores on the fishes body or fins.

Hollow bellies can be remedied by purchasing the fish, placing it in isolation in an acclimatisation tank or area and feeding it properly for 4-6 weeks.

If the eyes are also sunken then you’ve got a problem and the fish might be past saving. Use the same approach but you must get the fish to eat within a few days. Fanning fins is sometimes mistaken for breeding behaviour.

It certainly is not. More often found in larger specimens, it means that the fish is on its last legs and needs food and better accommodation (and often more oxygen) fast.

Red sores are a sign of a bacterial infection and treating these is best left to specialists – this is especially true for Panaque species because of their highly specialised diet – more next month.

Buying Panaque from stores where you can see them feeding and they aren’t suffering from the telltale signs I mention above is obviously the ideal, but sadly many shops do not know how to condition these fish correctly for sale and long-term housing. Often all you can do is get good at “bringing them round” at home.

But I think a car journey of a few hundred miles to a great retailer is a better way to spend my money. I wouldn’t recommend keeping Panaque in planted aquaria unless you’re fed up with the colour green. It’s the equivalent of taking kids to a sweetie shop and saying “fill your boots”.

It’s my opinion that Panaque species can be maintained in community aquaria but it’s a hit or a miss if you do this directly with unacclimatised stock and aren’t prepared to offer specialist foods for the life of the fish. An acclimatisation tank should be easily cleaned, well oxygenated and have plenty of bogwood in it.

Offer smaller fish sinking algae wafers, courgette and cucumber. Regular or sweet potato should be substituted for larger specimens. Offer flake only now and again. Only offer higher protein foods as a last ditch effort. Remove all food that is not eaten with 24 hours, water change 20% twice weekly.

Video by Scissorfight.

It is normal for no food to be eaten for a couple of days and up to a week and this can be a real test of nerve as if you get into the tank and fiddle with it or, worse still, move the fish, you’ll unsettle it further. If the fish hasn’t been fed properly prior to this point, you might lose it.

Keeping them with other plecs is a matter of space and heavy-duty filtration, but can be achieved (although you’re moving out of the realms of a normal community set-up). It’s easier if you select other plecs with specialist but non-Panaque diets.

Panaque should eat like cows; they’re almost constant grazers with a high throughput and you wouldn’t feed them meat. Once the fish is eating it can be transferred into the community but you’ll still have to ensure the filtration is adequate and that its specialist foods are not stolen by other residents.

Expect a period of a few days where the fish goes off its food after transfer; keep offering food until it is found and taken.

You can ease this process by adding new food a little while before lights out, putting it in the same place. Keeping the plecs can be a challenge in a well decorated tank; ensure bits of vegetation don’t clog filters or rot somewhere.

This article was first published in the August 2008 issue of Practical Fishkeeping. It may not be reproduced without permission.

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Julian Dignall 2912 (words, 10917 hits)
Published online: 04.23.09


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