Article © Chris Ralph, uploaded January 01, 2002.
Catfish, or any fish for that matter, fall into the following main categories in terms of their dietary requirements: carnivore, herbivore, limnivore and omnivore. There are a number of examples of catfish that fall into one or more of these dietary categories, which I will detail later in this article. I suppose we should look at what we eat in order to try to understand the requirements of our fish. Firstly why do we need to eat? The answer I guess is a little obvious as without food we would not survive for very long. Most people (myself included) eat on average three meals per day; there are of course exceptions to this, which also applies to our catfish as well. Eating a varied diet provides us with the necessary requirements in terms of vitamins, trace elements, carbohydrates, proteins etc that we need in order to survive. Catfish also need to be fed a balanced diet in order for them to survive.
Catfish that are generally portrayed as being carnivores or meat-eaters are best described as predators. In their natural surroundings these catfish would feed predominantly upon live foods, which in the wild would include other fishes. In most cases the stomachs of these catfishes are able to take a whole fish or other prey. Some of the larger predatory catfish may only feed once or twice per week or even once every few weeks, spending the rest of the time digesting their food.
Catfish that are generally portrayed as being herbivores or vegetable-eaters are best described, as we would be vegetarian. In their natural surroundings these catfish would feed predominantly upon algae, fruit and plants. Herbivores are described as not having a stomach, but instead have an expanded small intestine. These catfishes tend to feed often, and in an aquarium can be seen constantly grazing.
Catfish that are generally portrayed as being limnivores or mud-eaters feed upon vegetable matter and microorganisms found within the substrate. In their natural surroundings these catfish would predominantly feed upon algae, vegetable matter, detritus, small crustaceans and worms. These catfishes are constantly on the search for food investigating the substrate, rocks, plants and roots in order to find it. Limnivores are described as having small stomachs and long intestines.
Catfish that are generally portrayed as being omnivores are best described as preferring a general diet. These fish are neither predators nor vegetarians, with a preference for a diet which includes a little of both types of foods. These catfish are probably the easiest for the aquarist to feed.
Here comes the tricky bit, so far I have stated that the preferred diet of those catfish described as predators would be other fish in the wild. When housed in an aquarium however, this is not necessarily true, as most predatory fish will adapt to a diet that does not include live fish (I must point out that I am not suggesting or encouraging people to feed live fish to their predatory catfish, even though it is natural for them to feed in this way!). I have personally kept "Predatory" species of catfish and have fed them successfully on a mixed and varied diet that has included pieces of trout and frozen foods.
Feeding and NutritionThe following are listings of the food types that would best describe the various dietary categories that have been previously mentioned.
Typical foods for the carnivore diet include:
- Live and frozen foods such as:
- Mosquito larvae
- Gammarus (freshwater shrimps)
- Glass worm
- Artemia (Brineshrimp)
- Pieces of fish; such as fresh trout
- Chopped and whole mussel
- Whole prawns
- Aquatic snails, which are relished by Dorads!
- Lance fish
Typical foods for the herbivore diet include:
- Aquatic plants
Typical foods for the omnivore (and limnivore) diet include those or both the carnivore and herbivore diets plus the following items:
- Good quality flake foods
- Good quality sinking catfish pellets
- Good quality granular foods
- Good quality tablet foods
I guess that most of these foods are self-explanatory but just in case you are wondering why certain items have been included I will endeavour to explain why. Lets start with some of the items mentioned under the heading for herbivore diet. Frozen peas are an excellent food for most of the catfishes that are said to have a suckermouth (plecos for want of a better description). If you allow some peas to defrost and then remove the outer layer, the peas can be lightly crushed between your fingers, and allowed to sink to the bottom of the aquarium where the catfish will feed on them. With courgette and marrow I tend to chop it up into slices and freeze it. This makes it easier for the fish to feed on these foods as the freezing process disrupts the cell structure. With food items such as courgette, marrow and cucumber I tend to place a piece of plant weight through the middle of the slice in order for it to sink to the bottom of the aquarium where the catfish can then feed on it. Potato is another good food to feed to your catfish, as it is a good source of carbohydrate. I find this particularly useful when I have purchased catfish such as Otocinclus and Royal Panaques as quite often these species of catfish arrive into the aquarium trade with hollow stomachs where they have been starved of food prior to being exported from their native countries. When feeding potato care should be taken to avoid polluting the aquarium, any uneaten potato should be removed after a few hours. I should point out that the potato should be in the form of raw slices and not boiled, mashed, roasted or chipped! With regard to spinach the best form to purchase is frozen cubes, which can be allowed to defrost, and offered to the catfish by tying it to a rock or attaching plant weights in order for it to sink to the bottom of the aquarium. Lettuce is another popular green food to feed, which is probably best, blanched first in order to make it more palatable for the catfish. Again the lettuce can be tied to a rock or attached to plant weights. Aquatic plants are good for a number of reasons including the fact that they are a natural part of the catfishes diet, and that they help to make an aquarium look more pleasing to the eye. Bogwood, why do I need to use this I hear you ask? Well I advocate its use with all suckermouthed catfish as it not only provides them with somewhere to hide, but it provides them with a very important substance in their diet called lignin. Lignin is required in their diet as an aid to helping catfishes to digest their food.
The foods mentioned for the carnivore diet are those, which catfish would encounter in most cases in their natural environment (give or take a couple of items). As I stated earlier predatory catfish can be encouraged to feed on non-live foods in an aquarium environment, which in some peoples eyes would make them omnivores?! I suppose that what I am really getting at here is the fact that as long as your catfish are offered a wide range of foods then there should not be any detrimental problems encountered when keeping them.
When keeping catfish or any other type of fish prepared foods can and should be offered as part of their captive diet. Included in these foods are good quality flake and tablet foods. I personally feed quite a lot of sinking catfish pellets and granular food. These latter foods are high in protein and therefore, should be fed sparingly so as not to overload the filtration system that you are using.
Most fish keepers have at some stage assumed that all sucker mouthed catfish are herbivores. This is most definitely not the case especially when mentioning catfish such as the Gold Nugget (Baryancistrus spp.) and the Imperial Zebra (Hypancistrus zebra) to name but two of these wonderful L-numbered catfish. These catfish are ideally suited to an omnivorous diet. I have found that these catfishes thrive on a diet which includes chopped mussel and frozen bloodworm etc. I would suggest that before purchasing a catfish that you carry out some research prior to actually obtaining it from the retailer. If at all possible try to read up on the catfish that you are interested in so that you know in advance what foods to offer it (easier said than done I know!), and if you are still not sure then ask the retailer to tell you what the particular catfish has been feeding on before you take it home. Most good aquatic retailers will be able to offer this kind of information to you.
I find that when feeding the truly nocturnal species of catfish, they relish good quality granular foods, sinking catfish pellets and tablet foods. I also like to feed them on frozen bloodworm that I add to their aquarium just after lights out time. Some fish keepers swear by feeding live foods. When feeding live food you need to ensure that is disease free. If you wish to feed live foods such as Daphnia, I would recommend that you culture your own in an old bucket to which has been added some rabbit droppings or some fresh sheep droppings. Once established you should have a good supply of clean live food, that can be fed without the worry of introducing any diseases to your catfish.
Typical catfish that fall within the category of carnivores would include some of the following species:
- Tiger Shovelnose (Pseudoplatystoma fasciatum)
- Shovel-Nosed Catfish (Sorubim lima)
- Ornate Pimelodus (Pimelodus ornatus)
- Angelic Pimelodus (Pimelodus pictus)
- Electric Catfish (Malapterurus electricus)
- Ghost Catfish (Kryptopterus minor)
- African Glass Catfish (Eutropiellus spp.)
- Frog-Mouthed Catfish (Chaca chaca)
The above-mentioned species would all essentially feed upon meaty foods in their natural environments. In captivity I have known most of those species mentioned to feed on a very mixed and varied diet, to the point that you would call them omnivores.
Typical catfish that fall within the category of herbivores would include the following species:
- Whip tailed Catfish (Hemiloricaria spp.)
- Bristle-Nosed Catfish (Ancistrus spp.)
- Dwarf Sucker-Mouthed Catfish (Otocinclus spp.), although this species is also described in literature as being limnivorous.
Typical catfish that fall within the category of limnivores would include the following species:
- Twig Catfish (Farlowella spp.)
- Bubble nest Catfish (Megalechis spp.), although this species would probably be best described as omnivorous.
Typical catfish that fall within the category of omnivores would include the following species:
- Clown Catfish (Synodontis decorus)
- Up-Side Down Catfish (Synodontis nigriventris)
- Humbug Catfish (Platydoras costatus)
- Spotted Talking Catfish (Agamyxis pectinifrons)
- All Corys (Corydoras spp.)
Let me finish by posing this question, how would you feel being fed on a diet that consisted of the same food every day? The answer I would suggest is not very happy! I know that I would soon get fed up on a diet that was the same each day. It is for this reason that we should take a leaf out of our own book and look at what we feed to our catfish. You never know we might learn a few things about our catfish in this way!
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