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Some time ago, I wrote a major post on the subject of Catfishes of the Family Doradidae, and I thought I'd reviit this Family, [1] for those who joined the Board relatively recently, and [2] for those who have a soft spot or special interest in these fishes.

The principal feature of the Doradidae is heavy armour. While a professional taxonomist might point to more arcane anatomical features as being diagnostic of the Family, from the standpoint of visual inspection by the aquarist, the heavy armour is the feature that stands out the most. Not only are the bony scutes particularly thick and well-developed in Doradid Catfishes, but they are accompanied by spines: in the case of the larger species, the appearance is one of a fish that is trying to become an underwater porcupine, as the spines are not only large and easily visible, but very sharp. This makes netting or transporting these fishes somewhat problematic.

Another reason why the armour adds to the netting and handling problems is because Doradids possess an exceptionally strong pectoral fin, equipped with powerful muscles, and the first ray is hardened into a large spine. Frequently, this ray boasts a fairly vicious-looking array of additional spines running along it, in some cases double or even triple rows of spines that should deter most predators from even trying to eat one. One of the defensive mechanisms used by Doradids if caught, is to try and trap some part of its adversary between the body and the pectoral fin. If it succeeds, then whichever creature has mistakenly tried to capture the Doradid for food is going to suffer a very painful experience. Not only does the Doradid Catfish possess a vice-like grip when performing this defensive act, but the area where the pectoral fin naturally clasps to the body is equipped with yet more spines. As a result, an aquarist may find that if the fingers become trapped here, the flesh on said fingers is going to be very badly torn in the process of extricating them from the Catfish's grip. Needless to say, considerable caution is advisable if these fishes have to be handled!

In some cases, such as Lithodoras dorsalis, the hardened first ray of the dorsal fin is also equipped with a vicious-looking double row of spines, which must make this well-armoured and spiny fish an exceptionally difficult mouthful even for large predators such as Spectacled Cayman: indeed, Doradids are the underwater main battle tanks of the aquarium, with a level of armour protection possessed by some species that looks as if it can withstand artillery fire! All Doradids possess heavy armour and thickened, hardened first rays to the pectorals and dorsal fins, and many possess additional spines adorning these in addition: these fins can be 'locked' in an erect position to make a predator's attempts at swallowing them all the more difficult, and indeed some species are, in effect, chestnut burrs with fins, as noted by the venerable Innes book in its piece on Acanthodoras spinosissimus.

Amidst all of these spines, one oddity is the adipose fin. All Doradids possess one, and surprisingly, this is not supported by a spine, as is the case with Corydoras and Loricariids. This is apparently the one 'weak link' in the Doradid armour chain, but then the rest of the fish well and truly compensates for this omission!

The other notable feature of these fishes is the barbels. While many species have simple barbels (all have 4 pairs of barbels), some have branched barbels, sometimes to a degree of elaboration that has to be seen to be believed. The classic example here is Opsodoras stubeli, whose barbels look as if they were designed to pick up military communications signals via satellite! Leptodoras, Trachydoras and Hassar species all have elaborately branched barbels, in some cases remarkable to behold.

As befits South American catfish species that are found in Amazonian waters, the Doradids in the main prefer soft, slightly acidic water, though they can tolerate a surprising range of water chemistry parameters, provided that said water is well oxygenated and well filtered. Although they can be found in stagnant and fairly unwholesome waters in the wild, it should be no surprise that they will prosper far more in aquaria subject to a proper maintenance régime. They generally prefer temperatures hovering around the middle of the 21°C to 28°C range, although it is wise to check upon individual species for deviations from this norm. What they all do have in common, however, is a liking for subdued lighting, floating plants to provide shade, and complex arrangements of bogwood and/or rounded rocks to provide caves a-plenty. This is especially important if more than one individual is to be kept in the same aquarium, as several Doradid species can be territorial. However, if enough hiding places are provided, compatibility poses fewer problems than with, say, bad-tempered large Cichlids, but if Doradids do decide to quarrel, then be prepared for spectacular fireworks to erupt in the aquarium, as the larger species in particular are powerfully muscled, and capable of destroying aquascaping with ease during their quarrels. Having said that, however, provision of ample hiding places should be sufficient to allow Doradids to coexist with relatively few problems, provided of course that the bigger ones have sufficient space.

Another common feature of the Family is a liking for animal matter in the diet. This means that while some of the smaller species can be kept alongside carefully chosen community aquarium inmates (i.e., too large to swallow), large Doradids can present problems in finding companions that do not tempt them to indulge in expensive predation. However, in the case of the large Doradids, their exceptional armour protection means that they can be kept with big, bad-tempered Cichlids such as Green Terrors (which some Doradids share their home waters with): even the nastiest of Cichlids will give a spine-covered Doradid a wide berth unless provoked to attack by an assault on eggs or fry, and the Cichlid would probably be the loser in combat in any case. Not for nothing have I likened these fishes in my previous post to the M1 Abrams main battle tank - large species in particular even look the part. However, the smaller species, and juveniles of the larger species, will happily dine on Tubifex and Bloodworms, the live articles being greatly relished, and freshwater mussels are an item appreciated by the larger Doradids in particular. Some species (the Genus Amblydoras has been cited in this respect) will also devour snails.

A third item concerns habits. Doradids tend to be crepuscular (twylight active) or nocturnal in the wild, and some are very efficient nocturnal 'stealth predators'. Acclimatising them to a routine more in keeping with the aquarist's waking hours involves the traditional 'lights out' feeding régime: Doradids soon learn to associate the aquarist with food, and if provided with sensitively furnished aquaria replete with shade, will soon venture out into the open during more aquarist-friendly hours in search of food.

Among the more frequently encountered Doradids is Platydoras costatus, known for reasons that mystify me as the Raphael Cat, the very similar-looking (indeed, colouration is almost identical in some individuals) Orinocodoras eigenmanni, the old favourite from the Innes book, Acanthodoras spinosissimus (this is one of the smaller species less likely to dine on other fishes, but even so, try not to tempt it too carelessly!) and Amblydoras hancocki. Both of the last two species are known as 'Talking Catfish', because they can make a very audible grunting sound that resembles the noises from a pigsty! Indeed, several Doradids appear to possess this ability, although why is something of a mystery to me at least: whn first heard, however, the volume of the sound produced by these fishes can be alarming! More rarely encountered, principally because of size, are the Hassar species, and then there are the really big ones, that need spacious quarters and which should be kept well away from fishes other than similarly big bruisers: the heavily armoured Lithodoras dorsalis cited above is definitely one of the big Doradids, and then there is the aptly named Megalodoras irwini. This fish begins life resembling a Raphael Cat with extra light markings, these positioned along the body to highlight the truly awesome-looking body serrations, advertising it as a 'touch me not' fish to potential predators, but changes colour scheme as it matures into an adult fish that reaches 2 feet with ease, and at this size is truly a battle tank with fins! While some catfishes become drab with age, Megalodoras irwini swaps its Raphael Cat lookalike coat for a quite handsome one of orange blotches on a purplish-brown background, but one look at a mature adult should warn all but the foolhardy or the dedicated 'Big Cat' keeper into taking one on, especially as it is a nocturnal predator par excellence if unwisely housed with fishes small enough to swallow. But, for the aquarist who is a dedicated fan of large and tough catfishes, and has the resources to keep one properly, Megalodoras irwini is definitely a fish with presence: while its largely sedentary lifestyle, punctuated by stealthy predatory episodes, make for some observational difficulties, when it does swim in open water, it defintely has presence. Not a fish to be ignored when it does show itself!

For the aquarist who finds the idea of an underwater battle tank curiously appealing, a Doradid Catfish could be a cherished acquisition. Give it sensitive furnishings, subdued lighting, lots of caves to explore, and reasonably clean surroundings, and chances are it will settle in happily. The smaller species provide an interesting diversion from the perennial choices of Corydoras and assorted Plecs, and the larger ones can provide big Cichlid owners with a solution to the problem of finding a fish that will survive the attention of the aquarium ruffians. Indeed, the big Cichlids may find a shock coming to them when they come face to face with one of the larger Doradids, as they are armoured bruisers capable of fending off virtually all comers! Plus, several species will liven up the fish house with their loud noises ...




Panda Catfish fan and keeper/breeder since Christmas 2002