Do carp eat other fish

What does a fish like carp actually eat?

A better question would be, what does he not eat in natural circumstances?

Under no circumstances are pastries such as rolls, pretzel sticks, bread, croissants and the like.

Baked goods have next to no nutritional value, but a lot of salt that is not good for the fish.

Under natural living conditions, fish also do not eat crops such as wheat, barley, peas, rye, May etc. These feeds are perhaps suitable for pigs and cattle fattening, but these feeds hardly ever get into the water naturally.

The carp's digestive tract is not really designed to utilize vegetable protein sufficiently well.

If your fish are fed a lot of corn, they will form an excessively large, bad-tasting layer of oil containing fat. These fish are not suitable for consumption.

In my experience, the energy generated when digesting grain is just enough to maintain the vital functions of the fish.

Plant-based protein may make vegetarians happy, but the muscle mass gain with plant-based protein is limited. A body picture who eats a vegetarian diet certainly has a harder time than a meat eater.

Boilies, Frolic and Junks are also very expensive to buy, but are unsuitable for feeding fish.

The argument of boili hobby cooks that only the best and biologically sound cereals are used in the bait and catch feed sounds good, but has nothing to do with a healthy fish diet.

Muscle mass is best built with animal protein.

In principle, our non-predatory fish are actually pure carnivores (Amur and rudd). Most of them have unsuitable trapping tools to hunt their species, but luckily there are other creatures that share the habitat with the fish.

The smallest group of edible organisms and thus an animal protein supplier is called zooplankton.

Zooplankton are very small organisms, usually very poorly or not visible to the naked eye.

The animal plankton (zooplankton) is divided into two groups.

1. single cell:

Eyelash animals, shell amoebas, sun animals, ...

As the name suggests, the unicellular cells consist of only one cell.

As a feed supplier for our fish rather uninteresting. Most representatives of the animal plankton, however, are made up of multicellular (multicellular) animals.

2. Multicellular:

There are mainly two groups: rotifers, lower crustaceans.


With the tufted mosquito larva, the insects send the only representative of zooplankton.

The multiplication of the multicellular cells takes place viviparously, as well as through egg release.

The main representatives in my ponds are the water fleas (daphnia), followed by mosquito larvae. The daphnia are very important representatives of the lake and pond plankton.

The zooplankton occurs in large quantities in spring and is therefore the main food source for our fish.

If the zooplankton is abundant in the fish water, the progress of the carp fry can be observed with the naked eye almost every day.

Our fish also eat: aquatic insects, worms, snails, mussels, crabs, larvae, etc.

Just as our fish need food for reproduction and for life, the zooplankton of course also need an energy supply.

Zooplankton eats phytoplankton. Phytoplankton are small algae such as green algae, blue algae, brown algae, diatoms, etc.

Algae are small plants that are differently colored and consist of one or more cells. In single-cell algae, reproduction takes place by dividing the cell twice or more. Multicellular forms have a reproductive organ.

The phytoplankton have two important tasks to fulfill in our waters.

On the one hand, it produces organic substances from minerals (nutrient salts) that serve as food for fish feeding animals (zooplankton) in the water. Furthermore, with the help of assimilation, it produces oxygen during the day, which dissolves in the water and supplies our fish with it. At night, however, oxygen is consumed through dissimilation (breathing) and carbon dioxide is released into the water.

Natural feed cycle

Nutrient salts - phytoplankton - zooplankton - non-predatory fish - predatory fish - cormorant

If the water in your lake or pond is very poor in nutrients, the feeding cycle will not really get going. The water remains clear, as the formation of phytoplankton (algae) does not occur, the fish used will soon have eaten up the sparse small organism population and will later suffer from malnutrition. In the case of nutrient-poor water, you can help yourself with fertilizer.

This can be done in two different ways.

1. Organic fertilization

Bringing in all kinds of manure.

The manure is poured on a shallow spot in the pond. Due to the impact of the waves, the manure is mixed with the pond water over time.

2. Artificial fertilizers (as used in agriculture)
The artificial fertilizer is well distributed and introduced into the water. For smaller ponds from the bank, for larger ones with the help of a boat.

Please do not fertilize your fish water without professional advice! That could be a shot backwards.

My company is located in the Marchfeld region. Due to the intensive agriculture in the Marchfeld, the water is very highly enriched with nutrients, which means that fertilizing, if at all, has to be carried out very carefully and deliberately.

Over the summer, my carp are supplemented with commercial wheat. The only purpose of feeding is to satisfy the fish's urge to eat with wheat, so that to a certain extent the zooplankton in the pond is spared.

If the fish are busy eating and digesting wheat, they cannot eat zooplankton mother animals.

This gives the small creatures a real opportunity to multiply. Targeted supplementary feeding makes it possible to maintain the zooplankton population throughout the year, which means that the fish are supplied with valuable animal protein throughout the entire growing season.

It would be advantageous for the zooplankton population to settle a reasonable proportion of aquatic plants in your body of water. On the one hand, the plants serve as a hiding place for the zooplankton, as well as a breeding ground for the fish hatchlings. On the other hand, aquatic plants are often used as a spawning substrate by most fish.

Beware of too many aquatic plants. These can remove too much of the nutrients from the water, which means that the phytoplankton 's feeding basis is missing again.

A simple but more costly solution to enable your fish to get a good diet would be supplementary feeding with ready-made feed.

Ready-made feed is offered floating or sinking from specialist retailers.

The feed should be given to the fish using an automatic feeder (usually a shuttle machine). Thanks to the automatic feeding system, the fish is able to get the desired amount of food itself. If you just pour the sink food into the water, it could dissolve before it is eaten.

In the case of swim food, care must be taken to ensure that it is not driven onto the bank by the wind and the impact of the waves and thus becomes inaccessible to the fish.

The ready-made food for non-predatory fish usually contains approx. 30% crude proteins (protein) and a large number of essential vitamins and trace elements that are important for the growth of the fish.

The finished feed also contains approx. 10% raw fats, which are stored as fat in the fish and serve as energy stores in winter.

In our part of the world, winter is a long time of deprivation for fish.

The fish reduce their metabolism in the cold season, but a certain residual amount of energy is still required for vital functions. In deep winter, when a thick layer of ice has laid over the fish water, perhaps with a layer of snow on top (snow means no incidence of light - no incidence of light produces no phytoplankton - no incidence of zooplankton produces no food), life underwater becomes a pure struggle for survival. With every movement the fish loses valuable energy, which it cannot renew until spring.

Ice skating, ice stock sport, walking on the ice on the fish water cause the fish to riot, valuable energy is wasted by fleeing, which can lead to fish failures in the spring after the ice melts.

If the fish are fed a generous amount of ready-made feed for at least three weeks in autumn, you will surely get through the winter more easily and with fewer losses.

The food or feeding of our predatory fish is much easier to manage than with the non-predatory fish.

Pike, pikeperch and perch usually eat other fish that are appropriate for their size. The exception is the catfish. The catfish with its small, poorly performing eyes looks for its food for acoustic rather than optical stimuli. As a result, his prey animals are not just fish, but all animals that somehow got into the water and fit into his mouth. The food spectrum ranges from fish, frogs, crabs, snakes, ducks, mice, rats, aces, small dogs, etc. to hedgehogs

(I've seen that myself on the Po in Italy.).

There are of course some methods to maintain or even increase the abundance of predatory fish in your fish water. Probably the worst would be to simply replenish the desired amount of roughage without taking into account the space and food available. (By the way, not every predatory fish fits in every water.)

In the case of a stock of predatory fish, which is certainly not cheap, you should clarify in advance whether there is enough food of the right size.

For example, if a pike with a body weight of 1 kg is to gain another kg in the coming year, it needs at least 12 kg of the appropriate size forage fish.

With a fish population of 100 two-year-old pike weighing 1 kg each, at least 1200 kg of fodder fish would have to be available. In view of the fact that not every feed fish is caught, you will need at least 2000 kg of feed fish to turn the 100 pike into ready-to-catch fish with a live weight of approx. 2 kg.

You shouldn't be fooled by the amount of feed fish in the water.

In autumn, schools of non-predatory fish can be seen in most fishing waters just below the surface of the water. These collections are mostly arbors. A schooling fish that only appears in groups, with its mouth above. (Mouth opening points upwards, so the fish is able to effortlessly eat food from the surface of the water.)

In autumn, when the flying insects die and fall into the fish water, the arbors are busy collecting food, giving the impression that the pond or lake is full to the brim with feed fish. Every pond owner would like to immediately stock his pond with pike or pikeperch.

In a pond with 2 to 3 hectares of water, you can usually see 2 to 3 schools of arbors or rudd. (Usually where the wind blows the dead insects together on the bank edge.)

If such a school of fish houses 1000 fish and a fish weighs an average of 0.040 kg, that would be 120 kg for three schools of fish. This results in a theoretical increase in predatory fish of 12 kg. Of course, if too many predatory fish are put into the water to eat away the 120 kg of non-predatory fish, the weight of the predatory fish will not increase. If there is a lack of food, the predatory fish, especially the pike, are even more prone to cannibalism, with a mixed fish population of pikeperch and pike, the pikeperch, if it is only slightly smaller than the pike, is the first to be eaten. With some ill-considered stocking of predatory fish, less predatory fish meat remains in the end than before the stocking!

The natural feed chain and its production

The pond or lake water is mixed with nutrient salts, which allows micro algae (phytoplankton) to grow. The tiny algae are eaten by the microorganisms of the zooplankton. These creatures are in turn the feeding base for the non-predatory fish, which in turn are consumed by the predatory fish. The smaller predatory fish are also used as food by the larger ones.

Sample calculation:

1000 kg of phytoplankton eaten results in - 100 kg of small organisms eaten results in -

Eating 10 kg of food fish results in - 1 kg of predatory fish.

These numbers can only be achieved under the very best of circumstances. Normally you have to calculate about 1 in 12-15.

The catfish again makes a small exception. Its efficiency in terms of meat production is significantly higher. I was able to produce 1 kg of catfish meat with about 6 kg of feed meat.

In the rarest of cases, you should stocking predators without adding food fish. If you spend a third of your spending on suitable fodder fish for your predatory fish, you have certainly made no mistake. The size of the food fish should match the size of the predatory fish. Food fish that are too big or too small do not bring the desired success.

Many fishing clubs have a rule that fish over a certain size or weight must be released. A fish over 3 kg loses profitability every year. It eats a lot more in relation to its smaller conspecifics and gains much less body weight. Over time, the pond accommodates too much fish mass, as a result of which the feeding pressure of the fish consumes the entire population of the small organisms. Without the zooplankton, the algae multiply too much, which in turn leads to extreme fluctuations in oxygen in the water, which can lead to the death of the fish. The algae keep dying and sinking to the bottom of the pond, creating a layer of sludge that is unsuitable for the production of zooplankton or aquatic insects. The fish then suffer from malnutrition and may be fed. The excreted excrement of the fish continues to fertilize the water, which produces even more algae. If this process continues for years, the pond can become so silted that the water quality becomes too poor for the fish.

It would often be more sensible to seek expert advice on stocking fish and not just follow the wishes of the individual fishermen.

Unfortunately, I cannot tell you whether you should feed your fish or not without further information about your body of water.

Fish master

Christian Lock-Machacek

02/12/2014 (The pictures are updated on 05/06/2018)