Maintaining a moderate amount of zooplankton in the pond is conducive to the growth of fish and shrimp fry

zooplankton

Zooplankton is a general term for heterotrophic invertebrates and chordate larvae that often float in water and cannot make organic matter by themselves.

Zooplankton are economic aquatic animals, important food for fish and other economic animals in pelagic waters, and there are many species that can be used as indicator organisms for water pollution.

For example, in eutrophicationic water bodies, species such as naked-bellied water fleas, sword water fleas, and arm-tailed rotifers generally form dominant populations. Some species, such as pear-shaped tetramembranous worms and large dipteras, are used as laboratory animals in toxicological tests.

The food of these zooplankton is mainly algae, bacteria, copepods and some food debris.

The reason for the large number of insects (zooplankton) is that the bottom of the pond and the water body are relatively fat, and the bacteria and organic debris (bottom feed residue bait) are too abundant.

Ecological chain of zooplankton

In the pond ecological chain, zooplankton are linked to high-level consumers such as producer phytoplankton (algae) and filter-feeding fish, and are in a central position.

That is, water and fertilizer feed algae, algae feed zooplankton, and zooplankton feed filter-feeding fish.

In terms of nutrition, a plankton is a nutrient-balanced feed, and the healthy development and healthy growth of shrimp fry play an incomparable role in the current feed.

In terms of water quality, the feeding of zooplankton is an important reason for the number of phytoplankton (algae) in ponds.

Too many zooplankton will affect the number of algae in the water body, interrupt the nitrogen cycle in the water body, and lead to an increase in the water body nitrite or ammonia nitrogen.

Biologically, zooplankton feeding also reduces the amount of organic debris and bacteria in ponds. Bacteria are an important source of food for zooplankton and require biological control of the number of bacteria.

For nature, zooplankton in seawater waters are more likely to form red tides if the feeding rate is small, which is also a contribution of zooplankton to humans, and it cannot be considered that zooplankton are bad.

In culture ponds, feeding on microplankton may also interfere with blooms in water bodies.

Effects on shrimp farming

In addition to phytoplankton feeding, the algae that keep the water quality of the pond from flooding; eating organic debris and bacteria in the water body plays an important role in improving the water quality of the pond.

The feeding effect of zooplankton on bacteria in shrimp ponds plays an important role in regulating the number of bacteria.

For ponds where fish and shrimp are polyculture, zooplankton are direct bait for shrimp and other fish, and since they prey on phytoplankton, the phytoplankton of shrimp ponds provide more than just phytoplankton.

And for improving the water quality of shrimp ponds also plays an important role, well-cultivated ponds, zooplankton feeding on bacteria will be equal to or higher than the amount of bacteria produced, significantly reducing the biological infectious diseases of seedlings.

Eats phytoplankton

Among zooplankton, small flexpods are the main group of zooplankton that feed on phytoplankton.

If zooplankton ingests poisonous microalgae, the relationship between the two is slightly different.

On the one hand, toxic microalgae can inhibit the feeding of zooplankton, and on the other hand, it can transmit and accumulate toxins to the next trophic level through zooplankton feeding, further expanding the harm to the ecosystem.

Although some studies have shown that toxic microalgae can act directly on zooplankton and kill them.

But the vast majority of studies have confirmed that toxic microalgae toxins do not directly harm the survival of zooplankton. So this is something to be aware of.

Zooplankton feeding rates are affected by water temperature, and are generally higher in summer than in winter. Therefore, the water temperature at the time of seedlings is also a factor.

Prevention and response to this bug

The bottom water of the pond is relatively fat, and the bacteria and organic debris (bottom feed residue bait) are too abundant. Therefore, to prevent too many bugs, do as follows:

1. Dredging as much as possible to reduce the organic fertilizer, bacteria, and organic debris at the bottom of the pond (bottom feed residue), that is, to reduce the food source of bugs.

2. For the eutrophication of the breeding environment, after disinfection of the inlet water, use Bacillus once for 1 to 2 days before feeding the seedlings.

The aim is to reduce the abundance of organic fertilizer, bacteria, and organic debris (bottom feed residues) in water, that is, to reduce the food source of bugs.

3. Comparing the eutrophication breeding environment, after the seedlings are cast, it is necessary to see whether it is necessary to feed according to the routine, and the pond where the insects have appeared can be reduced. The aim is to get shrimp to eat more of these nutrient-rich natural baits.

4. In the eutrophication breeding environment, do not use live bacteria in large quantities at will, the purpose is to reduce the total number of bacteria at the bottom of the pond and the water body, that is to say, to reduce the food source of insects.

5. Use potassium persulfate to clean up the bottom organic matter as needed in the breeding process, and avoid the use of live bacteria as much as possible.

For shrimp fry, each zooplankton is a nutrient-balanced feed, and the healthy development and healthy growth of shrimp fry play an incomparable role in the current feed.

Ponds with a moderate amount of zooplankton, the seedlings will grow relatively quickly and healthily. At the same time, there are live zooplankton in the pond, which can feed on bacteria through zooplankton.

It plays an important role in the control of the total amount of bacteria in pond water bodies and plays a role in biosecurity. These are the reasons why shrimp farming needs to be cultivated – that is, to cultivate algae to cultivate zooplankton.

However, due to too much silt in the relative ponds and eutrophication of the outer waters, there are often too many bugs in some areas.

Too many zooplankton in water bodies will lead to the interruption of nitrogen circulation in water bodies, and the nitrite in water bodies will be seriously exceeded and other adverse consequences will occur.

It is possible that the zooplankton in the water body accumulates too much pollution, resulting in the consequences that Vibrio is easy to exceed the standard.

Therefore, in the breeding process, especially the breeding of aquatic animals, it is necessary to control too many phenomena of zooplankton, and the method of control is based on why zooplankton will flood, rather than blindly killing and detoxifying. (This article is reproduced from [Fisheries Research Society].) If you have copyright questions, please contact [email protected]. ）

【Keywords】: Zooplankton fish and shrimp pond aquaculture