Aquarium fish "black knife": maintenance and care (photo)

2024 Author: Priscilla Miln | [email protected]. Last modified: 2023-12-16 00:21

Among the huge aquarium diversity, one of the most interesting is the fish known as the “black knife”. Officially, it is called Apteronotus, and in English-speaking countries it is called "black ghost". Experienced aquarists willingly start such exotics in their glass pools. But beginners, perhaps, need to gain experience before venturing into such an acquisition: a black knife is a fish, the maintenance of which requires special attention and skills.

Where did Apteronotus come from

This exotic fish is native to the South American continent, where it has mastered the expanses of Peru, Brazil, Bolivia, Colombia - the top and middle of the Amazon. And in Paraguay, a black knife is found in the Parana River. He prefers ponds with a weak, unhurried course and rich underwater vegetation. The waters in such places are muddy, visibility is very low in them. Therefore, Apteronotus has a verypoor eyesight, but there is an alternative way to navigate - weak electrical impulses, the source of which are white rings covering the tail. By them, in nature, a black knife defends itself from attack and seeks food. Apteronotus appeared in aquariums very recently - only about twenty years ago. But I already managed to get some fans.

Appearance

In a home "reservoir" aquarium fish "black knife" can become its decoration. Smooth, soft outlines and plastic movements, even in people who are indifferent to aquarism, immediately attract attention. Apteronotus grows up to fifty centimeters (if, of course, he has enough space). The absence of scales gives the impression that the fish is velvety and makes its color deep and soft. The fish does not have a dorsal fin, but the anal fin stretches along the entire abdomen. Thanks to this structure, the black knife can swim in any chosen direction, correcting its movement with its pectoral fins. It is very common for Apteronotus to swim on its side. If a person had previously only had other fish in which such behavior indicates ill he alth, the aquarist may suspect something was wrong. But for knives, this style of swimming is common.

We equip the newcomer

If a black knife caught your attention, its content will be successful only in a large aquarium, at least 150 liters in volume. The lack of space will not only prevent it from growing to its possible size, but alsoundermine he alth, weaken immunity and make more vulnerable to various ailments. The temperature should be maintained at 23 degrees; when it is reduced to indicators less than 18, you are guaranteed to lose your pet - a tropical, heat-loving fish. A third of the water should be changed weekly. Moreover, the aquarium should be equipped with a reinforced aerator and a peat filter. The “landscape” is shaped by numerous shelters: the black knife is a nocturnal creature, it hides during the day, and there should be enough places for this. As for lighting, it is more necessary for underwater plants, since Apteronotus is active only at night, and its eyesight is poor. It is worth taking care of the glass cover on the aquarium: there are cases when black knives jumped out of the water.

Food

Under natural conditions, the black knife fish feeds on fry of other fish species and insect larvae, that is, it is carnivorous. When kept at home, she is fed live or frozen food: tubifex, bloodworm. Quite willingly, a black knife eats chopped shrimp and squid. Dry food, like any substitutes, is ignored by fish until they are completely starved. In principle, it is possible to accustom them to such a diet, but it is impractical. Feeding is done once a day, after turning off the aquarium lighting. Apteronotuses often die from overeating, so you need to calculate the norm for your pet and give a little less.

Whom to let in neighbors

In principle, a black knife is a peaceful and non-aggressive fish. Skirmishes occur only between malessort of in territorial disputes. However, given the predatory nature, it is better not to add small fish like neon and guppiks to Apteronotus: they will eat it. To larger neighboring knives are absolutely indifferent. However, it is better not to let too mobile fish, for example, barbs, into the same aquarium with them. Apteronotuses are shy and can become stressed from too much movement around. In addition, such neighbors can fray the thin fins of black knives.

He alth related

Since the black knife is devoid of scales, it is especially vulnerable to ichthyophthyriasis. Its treatment is complicated by the fact that it is categorically impossible to use drugs that contain zinc, so when buying drugs, you must carefully read what is included in their composition. Signs of illness are:

1. white small tubercles from half a millimeter to one and a half in diameter. Aquarists call this rash semolina;
2. frayed or stuck together fins is a secondary sign, showing that the process has gone quite far. In addition, this symptom is characteristic of other diseases;
3. swelling of the body. It is also observed in various diseases.

Ichthyophthyriasis in other fish species is often treated by s alting the water in the aquarium. But a black knife may die from such measures. If you want, you can look for some patented remedies. However, it has been verified by many - quite malachite green. It is harmless to plants, does not impair biofiltration, so you can safely add it directly to the aquarium water. The usual concentration for the treatment of ichthyophthyroidism is 0.09 mg / l. However, given the lack ofApteronotus scales, it should be reduced to 0.04 mg/l. The product is added to the water daily, before each application, a quarter of the water in the "pool" is changed, and this is done until the "semolina" disappears, plus two days after that.

Reproduction of black knives

Apteronotus is a viviparous fish. Breeding it at home is quite difficult and rarely successful. However, you can try. To do this, the selected pair is planted in a spawning tank with a volume of 100 liters; The water temperature should be stable at 25 degrees. At the same time, it is constantly necessary to gradually add clean water - this is an imitation of the rainy season. Plus, provide a stream of water in which caviar is deposited. At the end of spawning, the parents are removed from the spawning area. The fry will hatch in 2-3 days. All this time it is necessary to monitor the situation in the aquarium and remove the dead eggs.