How to cultivate copepods?

There are many kinds of copepods, and the species suitable for cultivation should be selected. The species suitable for cultivation should be: strong adaptability to the environment; miscellaneous food habits, can eat animal and plant bait and organic matter debris, etc.; strong reproductive ability, fast growth; as bait for ornamental fish larvae, high nutritional value.

The main results are as follows: (1) the main culture equipment are culture container, agitator, inflating device, heating device and so on.

Small culture containers use more than 1 meter. The left and right plastic sink. Most of the large culture containers are cement ponds, with capacities ranging from a few cubic meters to hundreds of cubic meters. The depth of the pool is generally 1 to 1.3 meters. Small culture containers are often mixed with aerated stone, and there is no special mixer. There are two kinds of agitators for cement ponds: one is a special agitator with wings, which runs slowly and stirs the water body with wings; the other is to stir with air with a plastic pipe laid on the bottom of the pool. The water temperature required for copepod growth and reproduction is generally high, and it is necessary to be equipped with heating devices.

(2) the treatment of culture water is best filtered by sand, and if there is no sand filtration equipment, it can also be filtered with silk screen to filter out the large animals in the water.

(3) there are two sources of inoculation. First, copepods collected from natural waters are separated, enriched and cultured, and then inoculated in large culture containers; second, copepods eggs are collected for hatching. The amount of inoculation is very good. The amount of inoculation is large, the time of multiplication to harvest density is short, and the production efficiency is high. The maximum amount of inoculation can reach half of the maximum density under the culture conditions at that time.

(4) the attachment medium is needed to cultivate benthic and semi-benthic copepods. For example, the tiger spot water flea has the habit of crawling on the wall and bottom of the pool or swimming near it. In order to increase its habitat, the attachment base has obvious effect. The types of attachment base are mosquito net cloth, sieve silk net, plastic corrugated plate, polyethylene film and so on. Hanging mosquito net as the attachment base will not reduce the ventilation capacity, and the mosquito net has moss growth, which plays the role of adhesion base, bait and stable water quality.

(5) Management

The suitable food for ① feeding should be selected according to the feeding habits of copepods. There are many kinds of omnivorous copepods, which are suitable for mass culture. In addition to the types of bait, the amount of bait should be controlled. If a plastic flume with a capacity of 1 m / s is used as a culture container and mixed with shrimp compound feed and yeast, the shrimp compound feed is 30-75 grams per week and 2 grams per day, one week later, the tiger spot water flea proliferates to 14000 ~ 17000 per liter. The mixed feed of fish and yeast was fed with 5 grams of fish diet every 2 days and 10 grams of yeast every 2 days. One week later, the numbers of tiger spot water fleas proliferated to 16000 ~ 20 000 / L, and soy sauce lees 125 ~ 625g one or more times, and the numbers of tiger spot water fleas increased to 4000 / L after 1 week.

The function of ② stirring and aeration is to increase the dissolved oxygen in the culture water and to prevent the bait from sinking, which is an important measure of culture management. However, the intensity of stirring and inflation should be properly controlled. Benthic and semi-benthic copepods have the habit of living near the pool wall, and excessive stirring intensity or excessive aeration may adversely affect them.

The temperature and illuminance of ③ should be controlled in the most suitable range. The temperature should not change too much.

④ water quality control index should not change too much in copepod culture, especially when feeding artificial bait. In the process of culture, the dissolved oxygen should be more than 5 mg / L and the pH value should be controlled at 7.5-8.6. If dissolved oxygen and pH value are too low, ventilation should be strengthened.

The highest density of copepods harvested and cultured by ⑤ has a certain limit, and varies with different culture conditions. It is reported that the multiplication density of tiger spot water flea is 30, 000 / liter in 1 liter flume and 18000 / liter in 30 liter flume, 1 meter. The sink can reach 15000 / L, at 40 meters. In the pool (using oil yeast as bait) and in 200m s pool (using baker's yeast as bait), the multiplication density also reached 15800 / L. After the density reaches a certain level, it is necessary to harvest some of them, which is beneficial to the long-term and stable proliferation of copepods. The size of each harvest does not affect its proliferation. If the harvest is too small each time, the standing stock will be large, and copepods are in a high density state, which is disadvantageous to their growth and reproduction. On the contrary, if the harvest is too large each time, the standing stock will be small, the number of individuals involved in reproduction will be small, and the speed of proliferation will be affected. About 10% is suitable for each harvest. The harvest method is to use a net with a mesh of 0.33mm. The harvested individuals are mainly adults and late larvae.