The plan of the year lies in the spring, for farmers after the beginning of spring will face a new challenge - fry cultivation, in theory, the earlier the breeding and breeding of fry means that the longer the growth cycle of fish in the year, but in early spring due to unstable temperatures, plankton in the water is sometimes difficult to grow up, so cultivating plankton is also a headache. According to practical experience, the fry rearing phase requires at least 10 days to feed zooplankton. Therefore, the cultivation of enough small zooplankton (rotifers, small branches, called "water spiders" or "water fleas" in many places for convenience referred to in this article as "water fleas") is the key to fry breeding.
Water fleas, which are usually 0.2 mm-0.5 mm in size (can pass through a 60 mesh sieve), are called "fine water spiders" and are high-quality bait for fry opening for 5 days. The large water fleas mainly refer to the branches of the horns, usually the size of 0.5-3mm, is the main food before the transformation of the nursery diet, according to the different fish species, a seedling period of the big water fleas as the main bait is about 7-15 days, so the water fleas for the traditional fry breeding is very important, so how to get more artificially cultivated water fleas?
At present, the more common breeding methods are chicken manure cultivation method, large grass cultivation method, fish pulp cultivation method, fermented bran cultivation method, yeast cultivation method, as follows:
1, chicken manure breeding method: first of all, the chicken manure is fermented in advance, usually fermented for more than a month, after the fish pond is disinfected, the chicken manure is put into the fish pond with good water about half a month before the planned seedlings. Small rotifers can be cultured in about 7-10 days. The amount per mu is 70-100KG, 1/3 of the total amount can be sprinkled in the pond, and the rest is packed in fiber bags and stacked in the corner of the pond, and then open the bag when the fertilizer effect in the water disappears after the seedlings are released. Let's talk about how fermented pig manure can be used if there is no chicken manure, but the dosage should be increased. The advantage of this method is that the operation is simple, and there are more water fleas obtained at the same time, and the disadvantage is that the chicken manure consumes more oxygen during the decomposition process, and at the same time produces ammonia, so it must pay attention to the change in water quality.
2, large grass cultivation method: the juicy stems and leaves of dicotyledonous plants into the pond water body, after a period of time, you can get some water fleas. The advantage of this method is that there is basically no cost, the disadvantage is that after 5 days of incubation time, the plant can rot, and the water spider time is after one week, and the number is unstable, which is damaging to the water quality.
3, fish pulp cultivation method: the ice fish crushed and then poured into the water body according to 10-20Kg/mu of water, continuously sprinkled 2-3 times, 3 days after sprinkling, fine water fleas can be found on the side of the pond. The advantage of this method is that the ice pulp is easier to obtain, the disadvantage is that the water spider is not a carnivorous aquatic animal, mainly to eat detritus, so it needs fish pulp to become flea food after decay, the rotting fish pulp is easy to destroy the water quality, causing a foul odor, and it is easy to cause a large number of fish fry to die when the same pond seedlings, so it is not recommended to do so if you are not a veteran.
4, fermentation of raw bran cultivation method: the commercially available raw bran soaked in lactic acid bacteria or yeast, fermentation after 3 days of the whole pond sprinkled, 15-20 kg per mu of water body, open the aerator to stir the water, generally about 3 days can appear a large number of water fleas. This method supplements the organic detritus that water fleas like to eat, which can promote the large reproduction of water fleas. However, raw bran is rough, the particle size is large, and it is easy to sink after use, resulting in a lot of waste.
5. Yeast cultivation method: 500g/mu of active dry yeast is sprinkled on the water body after hydration, and the yeast that the water fleas like to eat is replenished to promote its reproduction and growth, and the flea is obtained. According to experience, the effect of this method is not ideal if used alone, and if it is used in combination with the other cultivation methods mentioned above, it will play a good auxiliary effect. In addition, some biologics can also be used in combination with the above methods.
Having talked about the cultivation method, what do you need to pay attention to in the cultivation process? It is recommended to pay attention to the following matters;
1. Due to the difference between pond conditions and climate, it is necessary to flexibly apply it according to local conditions in the process of cultivating water fleas.
2. Before the cultivation of water fleas, the pond should go through the steps of sunning, clearing and disinfection, which can effectively enhance the germination of water flea eggs.
3. After the pond is dried and cleared, the pond water should be filtered by a sieve of more than 40 mesh to avoid the introduction of predators of water spiders.
4. When the number of water fleas is too large, it will quickly eat algae in the water body, resulting in a rapid increase in the transparency of the water body, causing the water quality to be thin, therefore, in the process of cultivating water fleas, we should pay attention to the changes in water quality in time, and when the water quality is too thin, we must replenish fertilizer in time, so as not to cause the phenomenon of fish fry eating residue caused by the lack of bait supply.
5. When a large number of flea outbreaks are easy to cause hypoxia in the water body, when fry and flea are cultivated in the same pond, attention should be paid to timely oxygenation.
The above is only a personal experience of stepping on the fire, if you have a good way to welcome the next method to discuss, more aquatic products, aquatic experience sharing also please watch the stepping fire leisure said fish, thank you!