How to Grow Pearls from Freshwater Mussels: A Detailed Guide to Farming Techniques

SummaryCommon freshwater mussels can hardly produce pearls. Generally, pearl mussels or triangle sail mussels (Hyriopsis cumingii) are chosen: nucleus insertion in the second year, mantle tissue implantation in the third year, and harvesting in the fifth year. 80-120 triangle sail mussels can cultivate about 500 grams of non-nucleated pearls. Farming method: single-suspension culture is preferable; the water environment for the mussels should be sunny and well ventilated, with a water depth of over 1m, no aquatic plants, a weak current, and neutral water quality. Prevent toxic sewage from entering the pearl farm, and keep the mussels in the water layer with the most abundant food.

You are probably all quite familiar with pearls. They have high ornamental value, are made into all kinds of jewelry, and are deeply loved by women. Pearls can also be ground into powder, which has whitening and spot-removing effects. We all know that pearls are generally produced in freshwater mussels, so what should be done to raise this kind of pearl-growing freshwater mussel?

How to Grow Pearls from Freshwater Mussels

I. Farming Methods

1. The farming area of the pond should be adapted to local conditions. Small ponds are 3-5 mu, and large ponds range from over ten mu to several dozen mu. The water quality is generally fairly fertile, with abundant feed organisms. Grass carp, bream, and crucian carp can be polycultured in the pond. It is not suitable to stock food-competing fish such as silver carp, and it is strictly forbidden to stock carnivorous fish such as black carp and snakehead.

2. Choose unpolluted rivers with sufficient oxygen, fresh water quality, flowing water, and full material exchange, which are suitable for the growth of triangle sail mussels.

3. If choosing lakes, reservoirs, etc., the water area should be relatively large. Choose shallower waters along the shore or in bends for pearl mussel farming, with good water mobility, clear water quality, and rich dissolved oxygen.

II. Precautions

1. When farming pearl mussels, pay attention to these three points: water quality environment, mussel farming techniques, and the selection of species for fish-mussel polyculture.

2. When farming pearl mussels, fish can be polycultured in the farming pond, such as crucian carp, bighead carp, silver carp, yellow catfish and other fish species, but predatory fish such as catfish and snakehead must not be polycultured.

3. When polyculturing fish, do not polyculture fish with diseased pearl mussels, otherwise both the pearl mussels and the fish will die. If diseased pearl mussels appear, they should be treated with medication promptly.

Freshwater Mussel Farming Techniques

1. Farming methods: At present, freshwater mussel farming mostly uses suspension culture and cage culture. Suspension culture methods include single-suspension culture and string culture, in which two or more mussels are suspended on one line. The number in cage culture depends on the size of the cage (net cage, net clip), and it is generally appropriate that each mussel can touch the bottom of the cage.

2. Stocking density: Pearl-producing freshwater mussels are generally 800-1200 per mu in farming ponds and 600-800 per mu in open waters. The specific farming density depends on body weight and fatness. Water flow, water depth, and other physical, chemical, and biological factors should be increased or decreased appropriately according to mussel size.

3. Strengthen water quality management: When raising freshwater mussels in closed, still waters without flowing water, high temperatures, shallow water, and low pressure can cause oxygen deficiency and mussel death. Therefore, water must be added in time, or the water changed, or water quality kept fresh and oxygen content sufficient, so as to avoid slow growth of mussels and pearls under oxygen-deficient and low-oxygen conditions.

4. Remove attachments: After pearl-producing mussels have been suspended for a period of time, a large amount of attached mud and organisms (such as algae, freshwater sponges, Zoothamnium, etc.) often grow on the suspension cages, net bags, and mussel bodies, affecting the growth of the pearl-producing mussels, so they must be cleaned regularly. From April to October, rinse once every month.

What Do Freshwater Mussels Eat?

The food of freshwater mussels is mainly unicellular algae, protozoa, and organic detritus, such as rotifers, flagellates, Euglena, Chlorella, Scenedesmus, Navicula, dinoflagellates, Tetrastrum, spindle-shaped diatoms, Asterionella, crustacean debris, and plant leaves. The main easily digested food is diatoms.

Mussels cannot actively chase food. They rely on the opening and closing of the shells and the beating of the cilia on the inner side of the mantle and the gills to create a water current, and the food enters the mussel body with the water. Food enters the mantle cavity with the water, and particles move upward along the gill filaments to the base of the gills, then forward to the labial palps. After selection by the labial palps, small particles enter the mouth, while large particles move backward along the inner gill edge, and at the intersection of the two gills, enter the mantle scar to the rear end, and are expelled from the body when the two shells snap shut.

The Habitat Environment of Freshwater Mussels

In the natural environment, mussels generally live in rivers, lakes, ponds, and small streams among mud, sand, or gravel. When it is cold in winter and spring, they use their axe foot to dig into the mud, causing part of the mussel body to be buried in the mud and sand, with the front ventral edge downward and the rear dorsal edge upward, exposing only the rear edge of the shell for breathing and feeding. When it is hot, most of the body is exposed outside the mud. Toothless mussels generally live in muddy bottoms, in still or slow-flowing, relatively fertile water with a pH value of 5-9.

That is all for the introduction to freshwater mussel farming methods. We hope it is helpful to everyone. Although freshwater mussels can grow pearls, not every freshwater mussel can grow them. Their formation has certain causes, so everyone still needs to maintain a calm, Buddhist-like mindset.