Fish nutrition in nature
To properly feed the fish in captivity, it is important to know how they feed in nature, and what habits related to nutrition, there are the fish of each particular species.
In the wild, fish use very diverse sources of food:
— decaying organic matter;
— protozoa and other microorganisms;
— aquatic plants and algae;
— fruits and seeds;
— invertebrate animals (e.g. insects, worms, snails, crustaceans);
— other fish;
sometimes even birds, reptiles and mammals.
Not all fish are able to eat — most in varying degrees, specializing in a certain type of food. For example, some fish use mainly plant-based diet — they are called herbivores or plant-eaters. Others, including many large catfishes and some characins that prefer animal food (alive or dead) — such fish are called carnivores .
Perhaps the most famous — or rather infamous — carnivorous freshwater fish — red bellied piranha Serrasalmus nattereri, a larger family of tetras. Most fish eats quite diverse in their dietwhat and plant and animal food. Such fish are called omnivores .
Aquarists often think barbs (the carp family) of herbivores, however, anyone who watched the small barbs in the aquarium, knows that they readily eat Daphnia, Daphnia and Tubifex Tubifex, and other live foods. Although most of the fish in the aquarium uses “unnatural” food is very important at the same time give them food that is appropriate for their digestive systems. For example, herbivorous and omnivorous fish is usually very long intestine, and virtually none of this stomach, that is, their digestive system is adapted to the digestion of food arriving constantly and in small portions.
The carnivorous fish, on the contrary, usually have a stomach that can accommodate and partially digest the rather large pieces of food, after which they undergo further digestion in the intestine is relatively short. It is obvious that to feed herbivorous fish large pieces of food, for example, offer them a whole dead fish as inadmissible as to offer the plants the carnivorous fish. During the life of the fish preferred kinds of food for her can change.
Sizes and types of food can depend on the size of the fish (in particular, from the size of her mouth) and the stage of its development. For example, fish predators are unlikely to find on any other fish so small that they could eat. In addition, in the wild on the species and the number of available fish food, and, consequently, their diet is influenced by such environmental factors as water temperature and time of year.
Fish differ from each other not only because they prefer certain diets (that is food of a certain kind), but also the behavior during the meals. Predatory fish usually ambush invisibly matched to the production of still or remain motionless, waiting for sail past will be a suitable victim. Other predators, generally pursuing prey, rely primarily on their speed, trying to overtake and grab the victim. Fish of other species, such as Molly Poecilia sphenops, can spend many hours, feeding on algae and other plant foods.
Food herbivorous fishes consists of living or decaying plant tissues (sometimes some of them are leaves fallen in water). This writing is extracted fish, biting off pieces of plants or picking them up entirely. Some herbivorous fish eat mainly algae. As an example of plecostomus Plecostomus catfish. It has a modified mouth-suction Cup that enables it stick to the stones on which he was nibbling algae.
Other aspects of behaviour associated with feeding
The amount of food and frequency of its acceptance may vary in fish of different species, and, in addition, usually depend on the size of the prey. For example, large predatory fish, such as red-tail catfish Phractocephalus hemioliopterus, are accustomed to eat a portion of food in one go — for example, eat a whole fish, and that they have enough for a few days. At the other extreme, some herbivorous fish, particularly Molly Poecilia sphenops, spend a lot of time, pinching or picking algae out of the water fine food.
The necessary amount of food and frequency of its acceptance can also depend on the stage of development or reproductive condition of individuals, as well as on environmental factors such as seasonal availability of certain foods and water temperature. You need to consider another important aspect of fish behavior associated with food, namely, what position the fish takes in water when powered. For example, most catfish and loaches feeds mainly on the ground, while some viviparous and ikromechuschie toothcarps feed primarily at the water surface. Between these two extremes there are other fish that feed in the water column, these include the most popular aquarium fish species, including nearly all the barbs, Rasbora and tetras.
The location of the jaws in fish is useful, though not infallible sign that indicates, in any horizon of water she eats. If the jaws of the fish facing down or low, this fish usually feeds on the bottom, fish with jaws, directed forward, feed in the middle layers of water, with the jaws pointing upwards, poverhnosti water. Many fish are able to eat at any level.
However, some (particularly those whose jaws are oriented downward) it’s hard to take food on other levels, especially if they are forced to feed on the surface of the water, as they need to adopt a very unnatural posture for them. Moreover, some fish species are generally very reluctant to leave their preferred level. Therefore, not all bottom fish rise to the water surface to grab floating food, and some surface fish don’t want to swim after going to the bottom of the food through the water column.