A native inhabitant of freshwater reservoirs in North America, channel catfish appeared in the Russian territory as early as the seventies of the last century. This representative of the iktalurov family is the most prey of the many commercial species of catfish that live on the North American continent, in our country, the southern regions, as well as specialized ponds formed at the thermal power plant, became the habitat for fish.
This structure will tell about its structure, habits and features of life.
Natural habitat
Found mainly in subtropical latitudes, the American channel catfish is extremely thermophilic and feels great in bodies of water with a water temperature of 25-28 ° C. Apparently, these features contributed to the settlement of warm freshwater lakes, which are enough in the central regions of America and northern Mexico. Like other types of catfish, canal catfish reaches a very impressive size, but clearly does not reach the giants, such as ordinary catfish or river catfish. The average size of channel catfish is no more than one and a half meters in length and 5-9 kg in weight. But then this fish is well cultivated in the conditions of artificial ponds and pools.
Channel catfish: breeding in artificial reservoirs
The Americans nicknamed him cat-cat for the simplicity of "domestication" and high adaptive qualities to captivity. Channel catfish is growing very quickly, its meat is highly valued, it is tasty, tender and healthy.
Industrial cultivation of this fish, which is today the main object of fish farms, has long been very effectively engaged in the United States. Fish is especially popular with American anglers, as this aquaculture is widespread throughout the country, grows rapidly and builds up body weight.
Channel introduced in the 70s to Europe, channel catfish successfully took root in the Kuban and Don river basins, where today there is a stable population growth. Catfish are also bred in moderate latitudes - in ponds of fish farms of the Moscow Region and the Urals region, which are in close proximity to hydroelectric power stations and cogeneration plants, which simultaneously heat water in reservoirs. Warm waters provide fish with year-round comfortable development.
Pond cultivation
When breeding this species, one of three methods is used: in aquariums, pool gardens or ponds. Pond breeding is most often used as the simplest and most economical method that does not require the purchase of expensive equipment, and labor costs are minimal. Choosing a site for the construction of a pond, take into account the features:
- topography of the area;
- soil quality and composition;
- volume and quality of water.
Optimum for such a reservoir is considered a depth of 0.9-2 m from the south side and 1.8-3.5 m from the north, where in severe winters it is possible to freeze shallow water. Ponds are stocked in the spring, when the water has already warmed up to 13-15 ° C. At this time, the loss of fry is noticeably less than during the autumn launch of juveniles. In addition, the "spring" fry immediately begin to grow rapidly. Despite the fact that artificial feed is the main food under such conditions, the channel catfish receives a certain amount of food due to the natural forage base of the pond.
Species features
Channel catfish looks very similar to burbot. The color of the fish is uneven, spotty. The back is colored in brownish-black or pistachio-gray tones, the belly is light, almost white, the scales are absent, the body is naked.
Males differ markedly from females. Their coloration is darker and therefore more pronounced, and the head is shorter and wider. Adult females are fuller than males. In age-related, older fish, body coloration is also noticeably darker. Due to the spotty sides, the catfish was called “channel”, which means “speckled” in translation. Albino catfish are also found in aquarium breeding. The head of the canal catfish is decorated with four pairs of antennae located in pairs near the nostrils, at the corners of the mouth and on the chin. The fish is equipped with sharp spiky fins. It should be remembered about the toxicity of the pectoral and dorsal fins of fish. In contact with her, do not forget about caution.
In the bulk, catfish grow up to 0.5-0.7 m, reaching a mass of 4.5 to 9 kg, acclimatized - even less. For example, in the Don and Kuban catfish no more than 5 kg are caught. But history also knows the record catfish: there is a known case when a channel catfish was caught in South Carolina, weighing 26 kg.
Lifestyle
Channel catfish is a fast-growing predatory species. Young catfish live in moving packs, but with age, their lifestyle changes: they become single, adjusting themselves to live on a “staked out” territory.
These fish can be very aggressive, which is especially evident during the spawning period. For channel catfish shelters are needed - various snags, holes, and indentations. Preferring clean and deep places with a sandy or pebble bottom, the catfish leads a solitary lifestyle, showing an enviable activity in the hunt.
What does channel catfish eat?
The catfish diet is traditional: small fish, crustaceans and invertebrates. Less commonly, various aquatic insects or small mammals serve as food for it. It is believed that channel catfish is almost omnivorous; bottom feeding is characteristic of it.
Spawning: preparation
The most important event in the life of any inhabitant of a reservoir is spawning. Channel catfish, a photo of which is presented in the publication, is no exception. In nature, catfish spawn from mid-April to July. He seeks and finds calm river backwaters, small quiet lakes. Water that is optimal for spawning should be warmed up to 20-25 ° C. Like many animals, aggressive fights organized by males precede spawning. Often, such fights result in injuries, injuries or even the death of weaker opponents.
As soon as the steam has formed, and the water in the pond has warmed up to the required temperature, the male selects a secluded place, usually under the shore, and begins the construction of the nest with a thorough cleaning of the bottom of silt and various debris.
Masonry care
The female lays 2-3 layers of eggs in the prepared nest, each of which immediately fertilizes the male, spending from 4 to 12 hours on the whole process. The masonry is an elastic formation visually similar to a sponge and consisting of bright orange round eggs tightly connected to each other. At the end of spawning, the male, as an exemplary father, begins to guard the eggs, and drives the female away. He takes the process very seriously and not only protects the precious masonry, but occasionally shakes it with fins, creating access for fresh water to the caviar layer. Caviar develops over 120-122 hours. Before hatching, the eggs darken and you can see the clumsy, whiskered embryos in them, which the male still carefully monitors.
He no longer shakes the caviar, but carefully fans it with his fins. When the eggs turn into embryos, their mobility is still very small, and they remain in the nest, making up dense, changing clusters. Embryos in these cloud clusters are located head to center, and the tails are in constant motion. Nature is wise, and this placement allows embryos to create internal whirlpools of water, washing away waste products and dead eggs. With age, they become more active, but still stay near the nest. After 2-3 days, the larvae are already able to swim to the very surface of the water. In this case, the swimming bubble of the larvae is filled with air for the first time, and the pigmentation of the body is enhanced, and the larvae acquire a gray tint.
Catfish larvae begin to feed on plankton on the fourth day, and after a few days they are already actively eating zoobenthos, minced sea fish, combined feeds. Ducted catfish fry grow very intensively, gaining weight rapidly.
