Posted by Tsing Mui in Tropical Fish Hobbyist Blog on October 21, 2010 at 6:24 am
Book Excerpt: Catfishes
The Complete Guide to the Successful Care and Breeding of More Than 100 Catfish Species
The variety found among catfishes is nothing short of amazing. While on any given visit to your local aquarium store you might see a reasonable selection that most likely will be heavy on South American Corydoras and loricariid (plecos) species, over time you’ll begin to grasp the great amount of other catfishes that exists. Many species are seasonal in their hobby appearance, and new species (or old ones that haven’t been imported for some time) are constantly becoming more available. When the whole picture is put together, you’ll see what makes this group so desirable and attractive to so many aquarists.
As you work your visual way through the catfishes available to you, it’s good to try to learn as you go. You obviously won’t be purchasing all of the catfishes that you see, but you should take mental notes on at least some of those species and try to research them. This will set the stage and make you better prepared should you at some time see a particular species again and say, “I’m going to take some of those (or that one) home.”
With many groups of catfishes you can deal more or less in generalities. A great many of the Corydoras species, a South American group, will fall into this niche. But generalities may not always be successful, and you will have to make, for example, some differentiation between the more standard Corydoras species (C. aeneus, C. delphax, C. paleatus, etc.), and the genus’s smaller mid-water swimmers, such as C. pygmaeus and C. hastatus. Likewise, generalities apply also to the popular Synodontis species. As a group these African catfishes adapt exceedingly well to aquarium life, but you must make decisions in regard to the size range that you would like to maintain—4 inches (10 cm) or 1 foot (30 cm)—and the behavioral characteristics that you are looking for. Do you want a model catfish for a peaceful tank or a species that’s tough enough to hold its own with a batch of rowdy tankmates? If you’re at least partially armed with such information, you’re already on the way towards success with a chosen fish. Of course, not every catfish can be easily known or figured out, but as long as you do your best conferring with various literature sources (paper and electronic), other aquarists, and store personnel, you have embarked on the proper path.
Three Important Traits to Consider
As I’ve already mentioned, there are three major areas in the pursuit of catfish knowledge that are very important in your preparatory stages. Of course, there are numerous other aspects as well, and many of those aspects will be looked at as we move along.
The first area is that of behavior. If you have a tank of peaceful fishes and wish to add an interesting catfish or two, the last thing that you want is to add a species that’s going to upset the pastoral pleasantness that you’re enjoying. As an example, there are two Synodontis catfishes that are at least superficially similar in appearance—S. congica and S. notata. Both have a silvery to grayish body coloration and are adorned with varying numbers of round black spots on their sides. S. congica would be a model catfish for such a peaceful tank. S. notata, although not a terribly destructive catfish, can be more than a bit boisterous, especially as it grows. S. congica is pretty much always going to be peaceful. The same cannot be said with certainty about S. notata.
Trying to figure out who might eat who also needs consideration. This might sound a little flip, but it’s truly a serious consideration. Many catfishes eat other fishes, and their capacities in this regard can be downright amazing at times. Many years ago, when I was predominately a cichlid keeper, I had a couple of tanks of various catfishes. On one shopping trip I returned home with a cute pseudopimelodid, Batrochoglanis raninus, that was about 3½ inches (9 cm) long. I knew that this large-mouthed species had a reputation for eating smaller fishes, so I chose its tankmates carefully. The smallest fish in the tank was a nice South American whiptail cat, Rineloricaria sp., that was about 5½ inches (14 cm) long. No problem, right? Wrong! The following morning I went down to the fishroom and was greeted with an amazing sight. Protruding from the new fish’s mouth was about 3 inches (8 cm) of the rear end of the whiptail cat! Over the next few days the whiptail disappeared into the pseudopimelodid. I wasn’t amused, but I did learn an important lesson—never underestimate what a predatory catfish might be able to swallow.
Lastly I must say a word about the potential size of catfishes intended to be kept in home aquaria. Some simply don’t belong in home aquaria; they get too big or too nasty or both. This is my personal opinion, and I do feel some discussion on this is necessary.
As might be expected of a group of fishes containing over 3,000 species, there are some very large catfishes. Large is, of course, a subjective word, and I take it herein to mean in relation to the size of the containers (aquaria) that we keep our fishes in. To set the stage for the following I will note that the catfish group of fishes also contains an amazing number of species that are small to medium-sized (say 1 foot [30 cm] or less) and are therefore more or less ideal to acceptable inhabitants for the home aquarium. (A lot depends on the size of your aquarium, obviously—many aquarists would consider a foot-long fish to be a good deal bigger than “medium-sized.”) There are quite a few that get a bit larger than this but, based on their mild deportment and habits, can still be considered for keeping in big tanks if that’s your cup of tea.
If there’s a poster cat for large catfishes not belonging in aquaria it’s surely the South American redtail catfish, Phractocephalus hemioliopterus. At a small size (2 to 3 inches [5 to 8 cm]) this colorful pimelodid is almost irresistible. It pretty much has everything going for it: color, interesting appearance, and personality. But things can turn sour when you realize that this catfish eventually reaches a total length of almost 4½ feet (1.4 m)! If anything else is needed to cap this, a healthy redtail of this size weighs in at about 100 pounds (45 kg).
What is the home aquarist to do with a fully grown redtail, or even one that attains between half and three-quarters of the maximum size, which is still an enormous fish? The potential problem is actually twofold. The first scenario is maybe the worse of the two. This is where an unknowing, and often newer, aquarist purchases a small redtail without knowing its size potential. Or, worse, even knowing it goes ahead with the purchase. This will eventually lead to an unhappy catfish and an owner of equal sentiment. Sometimes a store might take the fish back, but this isn’t a certainty. What then? Will the fish languish and eventually die in cramped and environmentally poor conditions? Will it be euthanized? Will it be released into local waters? None of these outcomes is acceptable and/or fair to such a potentially magnificent catfish.
Certainly at least some dedicated aquarists like to keep large fishes. While such aquarists have large tanks for their charges, it’s impossible in a realistic sense to provide a big enough tank for an adult redtail catfish unless something akin to a public-style aquarium is built in one’s home. Extremely rare are even the most dedicated of aquarists who might be willing to go this necessary extra mile.
I could list many other catfishes and note the potential sizes that they might reach, but hopefully by now you’ve gotten the point. If you’re new to catfishes, research your purchases and make sure that you’re ready to proceed. If you’re a large-fishes aquarist, start saving up for that new large tank!
Making Your Decision
The potential last step of the buying process is to purchase or not to purchase any of the catfishes that you see. Although the store workers can assist you in such decisions, in the end you’re the final arbiter. Aquarium stores don’t want to sell you sick fishes, as this will not be good for their business in the long run. But, again, you have the final say with your purchases, and extra vigilance regarding them will benefit you greatly.
Pick from a Healthy Tank
First, you want to look around a store tank and make sure that it has healthy-looking fishes. If one fish, of any kind, has what might be a spreadable condition or disease, move on. This isn’t a tank that you want to choose fish from. Most stores will recognize such problems and quarantine the tank, but you should do your own overview just to be sure.
You should give any potential purchase a good visual going over. With this you should carefully consider both the positive and negative aspects of the particular catfish. This should include a basic health check regarding the physical condition and close observation of the behavior exhibited by the fish. With many catfishes this might present some initial problems in that they may very well, after their travel, be more of a mind to hide away among the tank’s decor than to present themselves to you for inspection. Here is where store personnel can be helpful by gently going into the tank with a net or other object and making sure that you can get a good look at your potential purchase.
For general physical conditions, you will want to make sure that the catfish has no bloody areas on the body or the fins (especially at the edges). Also look for any fuzzy patches that might indicate a wound that will lead to a subsequent fungal infection. Such funguses often appear at the ends of the dorsal or pectoral spines of many catfishes. They aren’t an immediate threat, but if you do purchase such a catfish you will then be responsible for taking the appropriate actions to treat the infection. You will also want to look closely at the body to make sure that there is no thin grayish/whitish coating, which might be indicative of an external bacterial infection. The eyes are a good place to check extra close for this. Many catfishes will show a deep reflective appearance, but this is normal. Some catfishes, such as talking cats (doradids), may normally show a whitish cast to the eyes and body (especially the head area), but with some experience you can easily differentiate this condition from a potential bacterial infection.
Parasitic infections also need to be considered. Ich, also called white spot disease, is one to watch for, especially during cool-to-cold times of the year. In one stage of its life cycle the parasite shows as small scattered white spots on the body and fins of an infected fish. Some driftwood catfishes (auchenipterids), such as Auchenipterichthys coracoideus, show a definite pattern of small white spots on their bodies. While these spots may superficially resemble ich, the regularity of the pattern—as opposed to the randomness of ich—is the tip-off that the spots are normal.
The barbels are another area to check out. Try to make sure that they are not shortened, bloody, or missing. You can compare the barbels of a fish you’re interested in against those of an ideal specimen if you’re familiar with the species, or you can compare the fish with others of the same species in the tank.
Thinness: Many catfishes, especially those that have recently arrived at a store, may often be quite thin. This is common, as feeding is often quite light along the various stages of transit. Thinness is normal, but there are extremes to the situation that are best avoided. This situation is especially notable with various loricariids. Because these catfishes usually stay close to the substrate it can often be difficult to get a good look at their abdominal areas. It’s a good idea to get a store worker to net a potential purchase from among these fishes so that you can get a good look at the fish’s underside. Some thinness is acceptable, but if the stomach area is heavily caved in you might want to consider coming back later, after the fish is settled in and eating, before making a purchase. Another area to check on loricariids is the eyes. Beware if the eyes are sunken into the head, below the rim of the eye socket. This is often a sign of severe starvation, usually coupled with a noticeably caved-in abdominal area. While loricariids in this condition might be brought back into good health with proper feeding, this cannot be considered a sure thing, and generally speaking such a catfish should be avoided. There are some loricariids, such as the royal pleco, Panaque nigrolineatus, that can actually pull their eyes down into the socket, but this is a form of protection, and the eyes don’t stay sunken for very long. If you see such a royal pleco in which the eyes are sunken, and remain so, you will be better off avoiding it and waiting for another one.
Behavior in the Seller’s Tank
How catfishes are behaving is another important consideration. Observe their breathing to make sure that it’s normal. A steady respiration can be judged by observing the movements of the mouth and their gill covers. A rapid respiration observed on a resting catfish can often be a sign of a bacterial or parasitic infection on the gills or some other form of physical stress.
Also observe how a fish holds itself in the water. Here you do need to know something regarding the behavior of a particular species or group of species. For example, take some of the standard Corydoras species such as C. aeneus, C. paleatus, and many of the spotted forms that may collectively be sold as C. punctatus. These are primarily bottom-based catfishes, and if you see them hanging in mid-water or at the surface, you can be assured that there’s a problem of some sort. It could be poor water conditions in the tank, but it could also indicate some type of organic problem. In either case, these sick fish shouldn’t be brought home. These Corydoras should be actively moving around the lower part of the tank, with the occasional dash to the surface to grab a bubble of air (which they swallow and extract oxygen from in their gut). On the other hand, there are some Corydoras species that spend more time away from the bottom. Members of the C. elegans complex (C. elegans, C. napoensis, etc.) often fit into this group. And some of the smaller cories, such as C. pygmaeus and C. hastatus, are normally mid-water swimmers. If these diminutive species are lying on the bottom, or are swimming around near the surface in a dopey fashion, it’s not a good sign, and they should be avoided.
Additional Sources of Catfishes
One additional area that needs to be touched on is the purchase of catfishes that you can’t see in advance. Previously this type of business was generally done by mail or via the telephone, but the Internet and e-mail are now more typically the methods used for communication. There is nothing wrong with purchasing catfishes in this way. Many of the specialty dealers will often have a much wider variety of hard-to-find catfishes in stock than you might usually find at your local stores. But this availability does come with the fact that you can’t see the catfishes beyond a digital photo or possibly a short video. In cases of purchasing catfishes by this method it’s better to use the phone and talk with the party or parties involved. A short phone call can provide good information on the potential purchase much better than an e-mail can. That is my opinion and I’ll stand by it. A phone call is also much better for developing a relationship with such a provider.
A more recent method of obtaining catfishes also comes to us via the Internet—the purchase of catfishes by auction. While some aquarium fishes have been seen for some time on larger Internet auction sites, the specialty sites are a bit newer, and some of them serve as a platform for the auctioning of an amazing amount of fishes—catfishes included. I haven’t personally obtained any catfishes by this method, so I cannot offer specific comments beyond, as mentioned earlier, working on developing a good rapport with the source.
I’m returning you now to your local store and your recent purchase. Your store will bag your fishes, and many stores will use a double-bag method for most catfishes. This is good practice, but for certain species, such as the larger Synodontis, it is rarely sufficient. Such catfishes, with their large pectoral fin spines, will often need three or more bags. And even with this, a quick movement by the fish will easily send a pectoral spine right through the multiple bags. For moving such catfishes I would suggest using a plastic bucket with a cover. It’s always good to have some of these buckets handy. Most stores have them and will probably be happy to lend you one if necessary. Another way of moving larger catfishes is with a large shipping bag (stores will also have these on hand) inside a rigid foam shipping box. Catfishes are moved all over the world like this—why not to your home from the store?
During those times of the year when it’s too cold or too hot, it’s best to have an insulated container into which you can put your bagged catfish. Rigid foam fish shipping boxes, often enclosed within a cardboard box, are ideal for this purpose; usually your store can supply you with one for a minimal charge. Likewise, you can also carry a picnic-style cooler along with you on shopping expeditions. This little bit of extra protection is well worth having.
What Topics to Research
When researching the catfishes that interest you, look first for information on their behaviors, diets, and full adult sizes; look also for recommendations about potential tankmates, if such recommendations are made. These topics can help you decide whether the catfishes would do well in a small community tank, a tank devoted to large fishes, or a single-specimen tank.
to Your Tank
The journey made by most wild-caught catfishes to your home tank is often a long one: from the collector of the fish in its native waters to the exporter, then from the importer to the wholesaler and then to your local store and then lastly to your tank. Breeding of catfishes by commercial breeders and local hobbyists forms an important exception to this pathway. Although there is an increasing variety available, most domestically bred catfishes will consist of some loricariids (e.g., Ancistrus spp.) and various Corydoras. Another group often available is some of the Lake Tanganyikan Synodontis species, such as S. lucipinnis and
Most catfishes offered for sale come from the wild, from fish farms in Florida or Southeast Asia, and from breeders in eastern Europe. Some of the fishes from this last-named source, however, are hybrids (see the Synodontis section in Chapter 5).
The Catfish-Barbel Connection
Catfishes are famous for their barbels. In fact, the order Siluriformes, to which all of the catfishes belong, got its common name from the fishes’ barbels. They almost look like a cat’s whiskers. Other freshwater fishes, including carps, arowanas, and loaches, also have barbels, but usually the first fish that comes to mind when a hobbyist hears the word “barbel” or “whiskers” is a catfish. Catfish barbels vary in length from species to species. Cory cats have small barbels to match their small size, while others, such as Sorubim lima and Pimelodus spp., have barbels that are several inches long.
Taken from the book Catfishes: The Complete Guide to the Successful Care and Breeding of More Than 100 Catfish Species. ISBN 9780793816774; October 2009. © T.F.H. Publications, Inc. Used with permission.