Articles > General Guides > Feeding Your Fish: Diet, Nutrition, How and What Fish Eat
Feeding Your Fish: Diet, Nutrition, How and What Fish Eat
Published by Goldnugget on 15/10/2008 (63997 reads)


In the natural world, a fish can expect to come across many hundreds of different types of foods, some have adapted to make use of all these sources of nourishment, where one species generalises however one will specialise and so many fish have adapted to take advantage of the scraps others would leave behind.

The intricately balanced ecosystems and food chains in the wild shaped over thousands of years cannot be easily recreated in the domestic aquaria we maintain, but the feeding habits and preferences of our fish remain.

This article explains the paramount importance of a balanced and complete diet for your fish. We'll look at the following issues/items in detail:

  • What fish need and the importance of research and species specific diets.
  • Why knowing what your fish will eat and how they eat it is so important when choosing your stock-list.
  • What we can feed, including a basic look at nutritional benefits and practicalities of:
     Dry goods
     Frozen foods
     Live foods
     Vegetable based and miscellaneous foods
  • How do I feed my fish? Techniques for shy or picky species.

Before I start I must stress that the information and advice given below is very general in nature, we'll discuss how variety in dietary requirements makes giving specific advice per species impossible in this short article. The important thing to remember is that research should always come before a purchase and is the only way you'll discover whether you can cater for the dietary requirements of your fish. Also we will look at freshwater species only as metabolic differences make marine fish's nutritional needs somewhat different, along with the complexity of feeding technique/acceptance issues for a hobby so reliant on wild caught specimens.


What "fish" need...

The basic building blocks of fish nutrition are proteins, carbohydrates, lipids (fats), small amounts of minerals and phytochemicals (like vitamins). The relative amounts of the substances above vary between species but you'll find some common ground, for example the dietary in-take of protein generally being higher in Carnivores than in Herbivores.

Identifying the general classification of your chosen species is the first step to tailoring a diet specific to his/her needs. Is your fish primarily herbivorous (plant and vegetable matter)? Carnivorous (meat, live or dead)? Or Omnivorous (Omni meaning all). Having this information will stop you from making costly mistakes with your fish's health.

Herbivores: Many herbivorous species such as plecs and rasping fish have a large elongated gut, with barely any stomach at all. The gut is designed for constant grazing of small amounts of vegetable/plant matter and the length of the digestive tract allows for breakdown of the complex compound cellulose. Representative herbivores of the family Cichlidae for example display a wide range of anatomical differences and many species are still evolving their own ways of dealing with the foods available to them.

Herbivorous fish do not have the capacity to take large meaty items of food. This often causes problems as many Cichlid keepers will know, despite inability to deal with these large items many fish simply can’t pass up the dietary protein these foods are so rich in. Common sense should rue the day here, care should be taken to match food size and variety with the fish’s ability not only to effectively eat it but also to digest it.

Very few fish are true herbivores, the majority will capitalise on available protein however it is made available. The key here is not to force fish to eat only plant and vegetable matter and thus suppress natural behaviour, but to ensure as aquarists we regulate the diet, keeping dietary intake of protein down to below 5%.

As well as supplementing their diet with protein many fish are known to eat wood. Some of the most notable wood eaters being sucker-mouth catfish (Loricariids), such as the Royal Pleco (Panaque nigrolineatus). Availability of bogwood/driftwood should be seen as a necessity for these species that surely will not thrive without it. Aside from ensuring that their teeth are kept in good condition it is believed that the wood absorbs excess nutrients from difficult to digest plant matter which the microbes present in the fish’s gut would otherwise be unable to digest.

Algae Eaters: Snails, shrimp, Plecostomus, and Otocinclus to name just a few of the animals often recruited to deal with problem algae in the aquarium. It is important to remember however that algae are a large and diverse group of organisms and often to the frustration of the keeper the cleaner employed has no interest in eating it. A reason I believe that algae in the aquarium should be re-assessed in our minds as a dietary requirement for certain species rather than a nuisance for them to clear up.

Twig Catfish (Farlowella sp.) and Hillstream Loaches (Balitoridae sp.) are excellent examples of micro predators which relish diatomic algae growth, but are often mistaken for vegetarians by their keepers for their affinity for these algaes, it is however the myofauna content inside the algae which these fish crave. Green algae is enthusiastically eaten by shrimp species, Dwarf Suckermouth Catfish (Otocinclus sp.) and a large number of Plecs making the mainstay of many of these fish’s diets for the vegetable content alone. It is important to recognise that algae supports a cornucopia of organisms which in turn support vast food chains, careful research around “algae eating” species is important to understand the specific needs of their diet.

Again, supplementation of micro foods and alternative plant matter and suitable protein where appropriate should be a matter of course.

NB Some algae are inedible and should be removed at first sight, such as Blue-Green Algae (Cyanobacteria), certain cyanobacteria produce dangerous cyanotixins.

Carnivores: In comparison with Herbivorous fish, Carnivores have a very different digestive tract, relatively short in comparison and containing a large stomach capable of part digestion of large bulky foods such as whole fish etc. This system is ill-equipped for dealing with plant matter and the breakdown of cellulose.

Smaller species are often stated as being micro predators or myofauna consumers preying on extremely small, often microscopic creatures found throughout their environment, such as infusoria/aufwuchs. Food offered should be appropriate in size and nature to cater for these more specialised feeding habits. As detailed above, many species will accept unsuitable food types when available, again, the responsibility for provision of suitable diet not only in nutritional content but in shape and form is the fish keeper’s.

Omnivores: Omnivorous fish can be stated as being something of a happy medium between carnivorous and herbivorous fish, both possessing a stomach and intestinal tract of reasonable size. Though specialising in neither food type.

Evolution has shaped the biology of fish as in any other animal to allow them to occupy a particular niche in their ecosystem. Some are so reliant on their niche's that they become dependant on a very small range of foods (lepidophages or scale eaters for example) and are wholly incapable of locating/catching or processing a wider variety of foods offered to them by their well meaning new owners.

This may seem very basic, but its very important that so far as diet is concerned we get the fundamentals correct, inappropriate diet can and does lead to poor health, poor growth and vitality and an extensive list of complications.


The principles above are sweeping and general, but once you know what group your fish best fits in to (by doing your research) you can start to look at a diet specific to your fish. For example, take two carnivores, one may be a piscivore (fish eater) whilst another may
be an insectivore (insect eater), the piscivore may not gain adequate nutrition from insects and the insectivore may be un-equipped to catch or eat fish etc.

There are many foods out there that claim to be a complete "Cichlid Food" or "Catfish Food" but no one food can cater for all species in one order/family. Siluriformes (catfish) for example as a group contains strict herbivores, strict carnivores and plenty of omnivorous species. Throw aside the “catch all” foods and spend a little time researching the specific dietary requirements of your species’, a tailored diet will ensure happy, healthy and long lived livestock.


Why knowing what your fish will eat is so important when choosing your stock-list

How often can we say that we think specifically about how and what we will feed a specific fish when introducing it to a bustling community or choosing it amongst the hundreds of species at our local fish shop? When compiling a stock-list do we consider where each species will occupy a niche and whether any feeding conflicts may arise from our choices? - Perhaps not as much as we should.

So let’s look at the basics; we can roughly divide our tanks into three bands, top, middle and bottom. Many fish have evolved to occupy a very specific portion of the water column, on the other hand some will go to where the food is. A fairly straightforward way to identify what position in the water column you’ll find a fish locating it’s food is by taking a look at the shape, structure or position of the mouth. Generally speaking, fish which feed from surface foods, such as surface skimming insects, often have mouths that are upturned which gives them greater positioning and agility when feeding on floating foods (see fig.1). Bottom dwellers who feed primarily from the substrate often have downward pointing or under-slung mouths and even complicated suckers (see fig.2, fig.3 and fig.4) allowing them to feed and/or graze on flat surfaces and the substrate with greater ease. Fish that feed from the middle layers of the water column and also the generalists happy to feed anywhere within their environment often have very centrally located forward facing mouths, neither significantly upturned nor under-slung (see fig.5). Looking at the adaptations of your fish will give you an insight into the area of the tank they are most comfortable eating. True, a hungry fish may feed from the bottom with an upturned mouth if made to adjust but likewise some fish will go hungry rather than dive to the scary depths of a tank away from its comfort zone, the key being adapting our ways of working not trying to force thousands of years of evolution to change!

Upturned Mouth
Typical upturned mouth
Underslung Cory Mouth
Under-slung mouth
of a Corydoras
Downward Mouth
Downward facing
Sucker-mouth catfish
Forward Facing Mouth
Forward facing

The position of the mouth on the fish tells us where the fish finds it’s food, but it doesn’t automatically tell us what the fish’s diet consists of, for that we look at the presence and arrangement of teeth either within the mouth or in close proximity to it.

Food items are generally eaten whole by most fish (this is why it’s so important to match food size with fish size) but some fish are capable of grating, crushing or grinding the food before swallowing. Often teeth are employed to catch and maintain a grip on prey, or to rasp away at a large food item impossible to fit in the mouth. In more advanced species, for example, many Cichlid species, separate sets of teeth are used for different purposes, teeth on the maxillary (jaw) are used to seize prey or bite off items of food and teeth on the pharyngeal bone are used to “chew” the item. These teeth have evolved to deal with specialised foods in mind, solely for the purpose of tackling the difficulty of attaining the food or breaking past it’s defences, whether the pronounced “beak” of a puffer fish, applied to the shells of aquatic snails and shell fish, the complicated mouths of the sucker-mouth catfish with rows of tiny teeth put to work on roots and bogwood, or the ferocious visage of the razor sharp teeth of the piranha used to rasp great chunks of flesh from it’s prey.

The mouth, of course tells us a great deal about what our fish should be eating, it’s shape and therefore the location of the fish’s niche is easy to see, but under the surface with a little research you can begin to see the occasional subtlety of evolution, the sometimes complicated sometimes beautifully simple adaptations present can truly tell us much of what we need to know about our fish’s dietary habits.

Stocking the tank

So, how does all this relate to stocking choices? Why does the shape and setup of the mouth tell me what fish I should have?

Much in the same way that we evaluate a species' temperament or suitability to our water conditions we must also evaluate where each will fit in the food chain and identify where conflicts may arise, by understanding the anatomical differences in our fish we can understand how best to provide a perfect environment for them and their neighbours.

Here are some examples of possible problems:

  • A tank containing many top feeders and one lone bottom feeder, most of the food whether sinking or not will not make it past the barrage of
    hungry fish at the surface.
  • Piscivores (fish eaters) kept with snack size companions, likewise scale and fin eaters kept with unsuitable tank-mates.
  • Over competition caused by fish all specialised in a very particular food group.
  • Nocturnal (active primarily at night) feeders kept with diurnal (primarily active during the day) fish and only fed during daylight hours.
  • Boisterous feeders kept with shy species. Mobbing shoaling behaviours during feeding.
  • "Fussy" eaters kept in a species tank where it is hard to target feed.
  • Species that can isolate an area with territoriality, and wont allow other species to feed in it (i.e. many cichlids, gobies etc, and fish that wont leave a territory to feed)
  • Differences in metabolism, an easy weight gainer in with shoals of tetras, vegetarian cichlid’s in with predators on a high protein diet, fancy goldfish with Hillstream loaches.

The list above is not exhaustive but encompasses the most common feeding problems you are likely to encounter whilst stocking your tank. We'll have a look at tips and tricks later in the article but I feel I can’t reinforce enough how important proper research is, the behaviours above can all be avoided with proper stock list planning. Unfortunately the examples above are all too common and result in the demise of many fish through malnutrition, bullying or avoidable predation.

We now have two things to consider when feeding our fish, their preferred food group and their preferred feeding environment. We'll now take a look at the most commonly available fish foods and try to relate them to the groups above and suitability for some of the most common aquarium species/groups.


What we can feed, including a basic look at nutritional benefits and practicalities of:

A complete, varied and nutritionally balanced diet is perhaps one of the most important things to consider for the long term health of our fish and success of us the fish keeper in helping them to thrive. The methods used to produce/preserve the below food groups carry with them their own nutritional problems. Production of the below foods will often result in the loss of a vitamin, mineral etc, this should help reinforce the principle need for varied diet, as you will see, foods lacking in one nutrient will often be plentiful in an alternatively produced food.

Dry foods
The most commonly used and most widely available fish foods around are the processed dry foods. Unfortunately, also one of the main culprits of inappropriate diet in many fish.

Dry foods have a low moisture content; this reduces spoilage and increase shelf life. When selecting a dry food opt for the highest quality you can afford, choosing cheap foods is little comfort to your conscience or your wallet when the health of your fish starts to deteriorate through malnutrition. Dry foods are not suitable for all fish, some will not accept it, some will readily eat it but still wane and starve as the food fails to provide for their specific dietary needs. Again researching your fish's dietary needs is essential when establishing a diet/feeding plan. For many fish, dry goods are used as a staple diet, their bread and butter, for most this is fine as long as additional variety is provided from other sources. Never use a single dry food as a long term feed, and also try to change brands periodically or alternate between different brands during the week to ensure a broad range of nutrients are provided and the inadequacies of one food are countered by the benefits of another.


Dry foods can be broken down in to some common forms listed below:

Flake: Many different flake foods are available of varying qualities and nutritional values, a good quality flake should provide a good nutritional balance for a vast array of fish but it is important to stress that no flake food (or any other dry food for that matter) can be said to be a "complete" food, despite advertising claims.

Flakes will float for a short time and then sink slowly so are ideal for top to middle feeders, if flake makes it to the bottom of the tank you may have fed too much. Flake foods are largely impractical for bottom feeders due to difficulty of delivery. Ideally flakes should be pre-soaked in tank water, and fed by placing them under the surface of the water and dropped allowing them to sink slowly. This reduces expansion of the dry food when inside the gut, which can cause serious digestive complications.

Crisps: A type of flake food, usually nutritionally balanced for a particular food group such as herbivore or containing some other beneficial additive such as colour enhancing compounds. Most flakes are targeted at omnivorous fish but there are high spirulina flakes and vegetable crisps available for herbivores along with high protein flakes for carnivores. Always make sure that the flakes you buy are for the type of fish you keep, Goldfish flakes for coldwater species, tropical freshwater flakes for tropical freshwater and marine flakes for marine species.

Pellets: Pellets usually come in two varieties, floating and sinking. Like flake foods, the same principles apply, buy the best you can afford and ensure they are as closely formulated for the species you are catering for as possible. As with flake there are "cichlid pellets" and "catfish pellets" available plus many more.

Floating pellets are excellent for Anabantoids such as Gourami, as the name suggests they float for long periods of time allowing surface feeders time to eat them before lower level feeders can capitalise on their presence.

Sinking pellets will sink straight to the substrate making them ideal for bottom feeders. Both varieties are available in carnivore, herbivore and omnivorous formulas, so match to the species where applicable.

Granules: Best described as very fine/small pellets, usually fast sinking and excellent for smaller fish unable to tackle pellets or flake. Appreciated by bottom dwelling fish also. Be careful not to overfeed as the food is often well packed and a small pinch can often cover the tank in food posing a pollution risk.

Varieties of powdered flake and granules are widely available for fry and the high quality brands make for an excellent first fry food.

Wafers: Wafers are large discs of food which sink rapidly, most are too large to be eaten in full on the way down and so they are an excellent method of getting food on to the tanks floor, the most common available are algae wafers though carnivore wafers are available.

Wafers can also be purchased in saucer shapes which mean they can be “stuck” on to a smooth surface such as a rock or glass of the tank, an excellent choice for vigorous eaters and rasping fish which can be seen chasing pellets round like footballs in their attempt to get a purchase on them.

Freeze dried foods: Tubifex is a prime example of a commonly found freeze dried food. Freeze dried foods are an excellent source of nutrients as most are locked in when frozen. Many will float and then slowly sink making them primarily used for top to middle feeders.

Storage of dry foods: Always keep the food container sealed when not in use, keep the container in a cool dry area and ensure moisture can not enter the container. Once opened dry foods can be expected to last for at most 3 months before losing significant nutritional value. Buying in bulk may seem cost effective but when you have to throw most of it away through spoilage it becomes a false economy. Only buy what you will use in three months, feeding out of date food in reality, is like feeding no food at all...

Should you ever notice unusual smells, or mould growths on any dry foods immediately discard them and do not use to feed your fish. Moisture has entered the container and allowed growth of moulds and fungi which can be lethal to your fish or at the very least cause some very worrying health problems. Look at the way your food is stored to limit chance of reoccurrence.

High quality brands contain an excellent range of vitamins and minerals but spoil fast. Vitamin A is often the first to degrade. Regular replenishment of old supplies is necessary to maintain quality.

Frozen foods
Versatility is the name of the game with frozen foods, easy to store, easy to feed, excellent nutritional value and fantastic palatability. Most of the live foods you can find will also be available frozen, these types of foods allow us to cater for those fish who shun dry foods and also allow us to supplement dry food diets, giving a broad range of nutrients, trace minerals and vitamins only found in fresh food. Also a convenient way to improve diet variety for vegetarian fish, vegetable cubes are widely available and you can experiment and make your own in ice cube trays.

We'll discuss the varieties available in the live foods section of this article, the list is expansive. Frozen foods range from worms and insects to crustaceans and fish meats and whole fish, you can cater for a wide range of tastes with these foods as long as the fish in question will accept dead foods, you should have significantly higher feeding success rates than with dried/freeze dried foods.

Some tips for the feeding of frozen foods:

  • Be careful not to overfeed, frozen blocks are surprisingly well compacted, cut the block in to slices if in doubt and feed a small slice at a time.
  • Frozen foods often contain high levels of Phosphates, wash/defrost the block/slices in a small amount of tank water in a separate container, then drain the liquid before feeding, this should lower the risk of phosphate induced nuisance algae growth.
  • Most frozen foods once defrosted will sink slowly in the case of most worms, or be suspended in the water column for a short time. This should allow you, with experience, to recognise which frozen foods will reach which fish.
  • Thoroughly defrost before feeding to minimise risk of discomfort when ingested.
  • For most fish these foods should be treats only as many are high in protein, some fish however will require a diet consisting of only frozen or live food, so again research is the key.

NB: Frozen foods are often gamma irradiated, this means harmful pathogens and bacteria are killed off making these fresh foods very safe for introduction to the aquarium, stored correctly frozen foods are significantly safer than their live counterparts.

Excessive use of frozen white fish carries with it serious risk of vitamin B1 deficiency and subsequent respiratory problems. The act of freezing causes cell lysis (bursting) this bursting causes Thiaminase (an enzyme) to come in to contact with Thiamine (vitamin B1). Thiamine is broken down or de-activated before consumption resulting in a Thiamine deprived food source. This deficiency passes on to the consumer and can result in severe immuno disorders, tissue deformity, gill damage and in severe prolonged cases, death. Tackling this problem is relatively easy; ensure foods such as white fish, some members of the cabbage family etc (foods high in Thiamine) are used fresh over frozen. Quality of dry staple foods becomes increasingly important here as high quality dry foods are often rich in Thiamine which can counter the deficiencies of frozen foods, unfortunately, poor quality, cheap, bulk foods are often devoid of Thiamine resulting in the same deficiencies.

Live foods
Live foods are eaten with relish by most fish, rewarding not only for the fish but often for the owner as feeding behaviour is displayed that is not encountered on a flake diet. There are many advantages to feeding live food, no food is fresher, and the foods contain all the vitamins, minerals and other nutrients that are potentially lost when processed into dry foods or frozen. Live foods not only provide excellent nutrition but simulate a more natural feeding behaviour in many fish, having to chase or dig for their food will increase levels of fitness and overall health.

Below is a list of Live food items commonly found or ones that can be cultured in the home (or rather the garden), but first I would like to cover the subject of feeder fish.

Feeder fish: Some species are notoriously hard to feed dead food items to, namely many carnivorous wild caught specimens and course fish. Many keepers therefore feed live fish (such as goldfish or guppies for example). Some keepers unfortunately garner a terrible amount of pleasure from the often slow and torturous deaths of the fish they use as feeders. Whilst feeding live fish is initially a necessity it is by no means a long term solution to a feeding problem. Every effort should be made on behalf of the keeper to encourage acceptance of dead fish as food and any glamorising of fish death/torture should be shunned by the fish keeping community.

The nature of predation does not imply an obligate need to feed on live food, many fish even prefer scavenging rather than calorie intensive hunting.

There are many reasons not to do this other than the obvious cruelty issues, feeder fish can carry disease and can be nutritionally poor not only because the choice of feeder species is limited, but also because feeder fish must have their own nutrition maximised for the predator (gut feeding etc, distinctly more difficult and more hit and miss with live feeders than dead). Having the control over feeding dead foods allows for greater governance of nutrition. Live feeder fish should only be used in the direst of situations where a distinct possibility of starvation exists and only as a short term solution, phased out with training. Once live food is sampled many fish will attempt to train the owner to provide only these foods to the neglect of others.

Even many of the fussiest fish can be trained to accept dead items, seek advice on the techniques used to accomplish this from an experienced keeper.

Crustaceans & Molluscs: The most commonly available live crustaceans include Brineshrimp/Artemia, Daphnia, Cyclops, and some of the larger groups include freshwater shrimps (ideal for larger fish) and crustaceans of the genus Asellus (water lice/hog lice).

Greater success is achieved with species of this group when they are "Gut Fed" beforehand; this is achieved by feeding up the live foods on waterborne algae/infusoria and the like. Anything they eat will be passed on to your fish during feeding. Members of this group are often nutritionally sparse by themselves.

Marine shellfish and shrimp can be used for freshwater fish in moderation, pre-soaking and squeezing to get rid of excess salt, any uneaten food (shellfish in particular) should be removed within a couple of hours as there is an immensely high pollution risk, frozen being safer than fresh.

Of the molluscs; Mussel (ground for micro predators, chopped for moderately sized fish and whole for larger predators) is high in Ascorbic Acid (Vitamin C), Cyanocobalamin (Vitamin B12) and Zinc. Cockles are an excellent source of Iron, Iodine and Selenium.

Aquatic insect larvae: Members of this group include bloodworms, whiptail larvae, mosquito larvae and Glassworms. Glassworms should be fed with caution as they are predatory and will kill young fry. These larvae are often high in dietary fat so not to be used in excess, unfed live larvae will become nutrient depleted unless used quickly or refrigerated. Bottom feeders will relish insect larvae such as these as many will attempt to burrow into substrate, and rarely stay very long in the water column.

Worms: The most common worm you are likely to encounter at your local fish shop will be tubifex, avoid feeding live tubifex, instead opt for freeze dried/frozen gamma irradiated supplies, tubifex often live by sewage outlets and are infamous for transmission of disease.

Other worms include the humble earthworm, (home raised from eggs in sterile soil being best as collected cultures tend to carry nematode worms) chopped or whole will be eaten enthusiastically by larger fish, clean all soil from the worms before feeding. Others you may encounter or wish to farm yourself are whiteworms, grindal worms and microworms. All excellent and nutritional feeds, of varying size suitable for a vast range of fish.

NB: Using live foods, especially those harvested from your local pond or stream carries a high risk of disease transmission, care should be taken when making use of them. Be considerate when collecting and ask permission from the land owner. Some live foods are now inappropriate to collect such as spawn and tadpoles of frogs, toads and newts. Many of which are now facing increasingly difficult times in the wild and should be protected wherever possible.

Vegetable and miscellaneous foods
We've covered insects, crustaceans, molluscs and worms but what foods can we use for our herbivores and to supplement diets with plant matter? Fish will happily eat a wide range of the vegetables and fruits we keep in our fridges and cupboards some examples being cucumber, courgette, broccoli (blanched), peas (cooked and shelled), potato, romaine lettuce (only romaine and blanched), carrot (cooked/softened), apple, strawberry, banana, tomato, peppers, the list goes on. Experimentation will help you learn what your fish will like and dislike, if in doubt blanch the food, this helps to break down cellulose which is indigestible for many fish, be careful not to over cook, foods should be lightly blanched and left to cool before feeding. Over cooking will release much of the nutritional content you want to keep locked in. Sugary fruits with high fructose levels and fruits very high in citric acids may pollute and change ph and should be removed fairly quickly if not eaten, some dried fruits, i.e. apricots and figs are good for use too and are often safer.

These foods by nature are messier and likely to cloud water somewhat but are fresh and an excellent source of nutrients not available in many commercial foods. Time should be allowed for these foods to soften in the tank (around 24 hours for most vegetables, no more than 2 hours for acidic fruits etc) thus making their consumption that little bit easier.

Algae, perhaps one of the most important organisms on the planet, a supporter of all manner of organisms. Algae can be grown easily outside of the tank and makes a fantastic food along with the organisms (Aufwuchs) that live in close proximity to it. Simply by submerging a rock in a bowl of tank water in the light of a window and left, will reward you with a fantastically rich food source for your herbivorous fish and the micro predators mentioned earlier. This method also provides an excellent starter food for fry.

Remember that some algaes are food and some are not!

Carnivorous and Omnivorous species will also need an intake of vegetative matter. As previously mentioned, in the wild animals absorb the nutrients of the prey they eat and also whatever they’re prey ate before its demise. Gut loading your live food and is an easy and highly effective way of making sure your fish get the all round diet they need.

Mammalian and bird meats should be avoided, frequent use can result in harmful fatty deposits building up inside the fish and is likely to cause long term health problems, it is widely accepted that the practice of feeding beef heart is no longer advisable on grounds that the steroids used in the raising of bovine stocks may cause increased cancer rates, increased levels of renal damage, and abnormal weight gain, metabolic and pituitary issues in fish.


How do I feed my fish? Techniques for shy or picky species.

We now know what our fish need, where they want it, and what makes up a varied diet. But how about those fussy feeders, that despite our bets efforts refuse to take the foods we offer?

No fish will willingly allow itself to starve to death, the reason behind many of the most finicky eaters is that we simply don’t understand what they want and need, whether that is the food we give them or how we offer it to them some simply fail to recognise an item as food, be it because it isn’t wriggling/swimming about or they have never seen it before in their natural habitats. For the purpose of this article we will label these problem fish as “fussy eaters”, though once you know how to cater for them you may realise there are surprisingly few fish which are actually very fussy about what they eat…

What I feel is key to ensuring that your fish get the diet they need is to never underestimate their intelligence. A fish is more than capable of teaching it’s owner to feed the foods it enjoys the most, whether good for them or not, many Cichlid keepers will be able to tell you that! To counter this you must persevere with new foods, some foods (especially vegetables and fruit etc) may not be recognised at first until the fish’s natural curiosity impels them to take a nibble.

New fish can be especially difficult to introduce a varied diet to, most having been reared on cheap low grade flake and pellets and simply don’t recognise anything else as food. Every attempt should be made to steadily increase diet variety, persevering with new types of food, gradually increasing variety once a new type is accepted. Remember the variety should be specific to each species, so carnivores should get a variety of meats/insects etc, herbivores a mix of vegetables, algae and fruits and omnivorous a good mix of them all, as well as a range of excellent staple dry foods.

Carnivores in particular can be difficult to coax into eating a varied diet, preferring to see their foods meaty or insectivorous in nature. A piece of flake or a pellet may not seem appealing to them. For these fussy eaters remember to gut load live food, and for bigger morsels of food for larger fish you can load the food with flake or pellets to ensure good diet variety simply by cutting a hole and placing a pellet inside. Once your fussy eater has “been tricked” into tasting you may find them much more agreeable when they see that unclaimed pellet lying on the floor of the tank next to them. Remember that persistence is key, cunning tactics such as “hook-less fishing” and “waggling” may be employed to get them started, especially for those fish who primarily respond to movement over smell. Remember that the process of evolution has equipped predators with a wide range of tools to track and catch their prey, research should tell you whether the species in question uses “line of sight”, key in on scent or respond to movement or distress to name just a few examples.

Nocturnal feeders in a diurnal community tank often suffer from malnutrition and are often the first species to wane and die because of it. Feeding is one of the most enjoyable aspects of fish keeping, but we must remember that we do it for the animals welfare more than our enjoyment, should your fish need feeding when all the lights are out then so be it. Nocturnal feeders should be fed just before, or preferably some time after lights out, separately from the diurnal species in a community if necessary. Some fish won’t come out to feed until all the lights are out including ambient room lighting, persist and cater for them until they become bolder and actively seek food during the daylight hours. An excellent way to ensure nocturnal bottom feeders receive a fair share is to weight morsels of food down, vegetables can be left for approximately 24 hours in the tank giving your fish ample night time feeding opportunity.

Shy species can be encouraged to feed when other community residents are more relaxed, such as just after the tank lights have gone out or just before they come on. By feeding boisterous fish in one section of the tank away from the shy species you can often slip food past hungry mouths. Research should be done on the suitability of a shy species to any community as some benefit but the majority suffer from over-competition.

Feed fish on their terms, shy fish won’t appreciate the efforts of their owners to hand feed them, allow the fish to behave in it’s most natural way, and take a step back from the hands on approach. Don’t be afraid to segregate fish on the basis of dietary needs, remember that diet is a stocking principle as well, providing a varied diet or a particular feeding strategy to one species can be to the detriment of another. Feeding your fish properly is a complicated but rich tapestry, getting the balance right is difficult but rewarding.

There are a number of other issues beyond the remit of this article that will cause feeding difficulties, poor water quality, general poor health/illness, unsuitable water chemistry (Ph, temp, oxygen levels etc), unsuitable environment (décor, lighting, planting etc), rivalry or over competition and inappropriate tank locations (noise, disturbance etc). Ruling these out, by researching your fish’s needs and reading articles on set up and water chemistry will allow you to approach the situation knowing you can effect dietary change for the better. If any of the above issues are relevant then they should be remedied or avoided altogether before attempting to tackle feeding habits.


In Conclusion:

Feeding your fish should be fun, you get the opportunity to see the fish at their best and most active. Examine your fish whilst feeding, this is often the time you’ll get the closest look at their health. Enjoy it, and enjoy the health benefits and increased vitality shown by your livestock. Good diet gives your fish the best chance of a healthy long life and fortifies their immune systems.

The cost of getting this wrong is great; it can mean the difference between a long lived fish and a short one, an adult fully grown fish and a dwarfed under developed one, normal behaviour and abnormal, breeding potential/success and none. It is a sad fact that many fish die through malnutrition and their subsequent weakness to disease, a tragedy that through education and enlightenment to our fish’s needs we can so easily avoid.


The bit to remember!

Look at what your fish would eat naturally then look at how you can meet those expectations to the best of your abilities. Look at how the fish can eat these foods and what is suitable for them both in ease of consumption and ease of digestion. Analyse where your fish will eat these foods, what part of the tank are they comfortable eating in? Consider when your fish should eat and how often, weighing activity levels and metabolic rates with volume and type of food needed, and most importantly, do the research, persevere and enjoy!

If in doubt… ASK!

Comments –

Special thanks go to Fishadmin for proof reading and help with publishing, and a very special thank you to LHG firstly for the excellent fish photos and secondly for his time, patience and guidance during writing.

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  • Plants  Adviser

 Re: Feeding Your Fish: Diet, Nutrition, How and What Fish...

Excellent article, well done

  • Home away from home

 Re: Feeding Your Fish: Diet, Nutrition, How and What Fish...

Thanks mate, Much appreciated.

  • Disease Adviser

 Re: Feeding Your Fish: Diet, Nutrition, How and What Fish...

Very nice, looks great on the page too.

  • Cichlid Adviser

 Re: Feeding Your Fish: Diet, Nutrition, How and What Fish...

very well done indeed informative and well written worth the wait bud

  • Home away from home

 Re: Feeding Your Fish: Diet, Nutrition, How and What Fish...

Absolutely Brilliant article.
Could have done with a list of which species eat what for idiots like me who are lazy, but still fantastically well written and easy to follow.
Kudos dude!

  • Home away from home

 Re: Feeding Your Fish: Diet, Nutrition, How and What Fish...

Thanks guys, means alot. Glad it was easy enough to follow, must admit I was worried I would lose people, I can lose myself sometimes when writing anything down! lol

Point taken on the list of species Flushfolder, certainly would have helped to have a list of typical examples, most common species etc...

Thanks for the feedback all!

  • Home away from home

 Re: Feeding Your Fish: Diet, Nutrition, How and What Fish...

Great post will read it in great detail. well done

  • Just popping in

 Re: Feeding Your Fish: Diet, Nutrition, How and What Fish...

Recently found out Chinese algae eaters like cheese paste very much.

I had to rehome mine to its own tank as it was bullying the other fish. It hasnt been eating anything and with tank being new and cycled just for Sid (my algae eater)dare say theres not alot of algae for munching.

So while preparing baits for my recent fishing trip thought id put a bit in see if he liked it.
He loves it n cant get enough.
Paste was made from Danish blue cheese, high protein base mix and egg.

Hes eating again and im happier now he is

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