Recommended Easy-to-Raise Freshwater Fish Species for Ponds and Disease Prevention and Control Methods
Pond farming of freshwater fish is a fairly common farming method; raising fish is easy to manage and yields relatively high output. Even so, the species chosen for pond farming of freshwater fish is crucial. Today let us take a look at which species of freshwater fish are easy to raise in ponds and how to prevent disease outbreaks.
I. Which species of freshwater fish are easy to raise in ponds?
1. Silver carp
The silver carp (Hypophthalmichthys molitrix) has a white body. It is a filter-feeding fish that mainly feeds on phytoplankton. It has a lively temperament, is good at jumping, has strong adaptability to the environment, is widely distributed, and grows quickly. It is often polycultured with other fish and is one of the main freshwater aquaculture fish in our country. Fry can be reliably produced in large numbers through artificial breeding. It is prone to disease in summer.
2. Grass carp
The grass carp (Ctenopharyngodon idella) is a herbivorous fish that mainly feeds on green grass, Vallisneria, Potamogeton crispus, and the stems and leaves of submerged terrestrial higher plants, and it is fond of overeating. Its body surface is grass-yellow. It has a relatively lively temperament and prefers to inhabit the middle and lower layers and nearshore waters with abundant aquatic plants. It has strong adaptability to the environment, is widely distributed, and grows quickly. It is often polycultured with silver carp, bighead carp, common carp, crucian carp, etc., and is one of the main aquaculture targets in our country. Fry are also produced in large numbers through artificial breeding. It suffers from many diseases in summer, with the “three old diseases of grass carp” (bacterial gill rot, red skin disease, and enteritis) being the most common and serious.
3. Black carp
The black carp (Mylopharyngodon piceus) is a carnivorous fish that mainly feeds on mollusks such as snails and clams. Its body surface is blue-gray. It prefers to inhabit the middle and lower water layers. It grows rapidly and is often polycultured with other fish, and is one of the main aquaculture targets in our country. The black carp has the advantages of a robust constitution, fast growth, a high survival rate, a large meat gain multiplier, and high yield.
II. How can disease outbreaks be prevented in pond freshwater fish farming?
1. Carefully clearing and disinfecting the pond is the basic guarantee for disease prevention. Killing pathogens through pond clearing will effectively prevent fish diseases. Disinfection drugs include quicklime, at a water depth of about 10 cm, 50-75 kg/mu, and at a water depth of about 1 m, 120-150 kg/mu. Tea cake (bran), at a water depth of about 1 m, 50 kg/mu; there is also bleaching powder, strong chlorine, etc.
2. Fish fry must be strictly disinfected before being put into the pond, and great care must be taken to prevent pathogens from being carried into the pond. The disinfection method is soaking: commonly 3-5% salt water for 5-7 minutes, potassium permanganate at 20 mg/L for 10-15 minutes; there is also bleaching powder, povidone iodine, etc.
3. In the high-temperature season, after each catch, the whole pond must be disinfected immediately. Great care must be taken to prevent abrasions from becoming inflamed or triggering explosive hemorrhagic disease. Disinfection drugs include quicklime, at a water depth of 1 m, 15-20 kg/mu; chlorine dioxide or strong chlorine at 0.3 g/m3; copper sulfate at 0.5 g/m3; bleaching powder at 1 g/m3 as a mixture, etc.
4. Pay close attention to the fish conditions in the pond. During seasonal disease outbreak periods, feed medicated bait. For enteritis, mix and feed oxytetracycline at 2 g/kg of bait or garlic at 250 g/kg of bait for 4-6 consecutive days. To prevent hemorrhagic disease, add VC at 3 g/kg of bait to the bait. For the hepatobiliary syndrome that has appeared in recent years, add Chinese herbal medicines that clear heat, detoxify, and protect the liver and gallbladder to the bait, such as plantain, rhubarb, Radix Isatidis, and Artemisia capillaris, etc.