A detailed guide to new red sandworm (ragworm) farming techniques, farming methods and key technical points
Perhaps everyone does not know much about the red sandworm, and it is indeed rather uncommon in daily life, but the red sandworm is very nutritious, rich in protein, and is the best bait for fish, shrimp, crabs and so on. Let's take a look together with the editor below!
New red sandworm farming techniques
The red sandworm is nutritious, containing abundant protein, amino acids and eicosapentaenoic acid, and is the best fresh, high-quality live bait for fish, shrimp, crabs and so on. In taxonomy, sandworms belong to the phylum Annelida, class Polychaeta, order Errantia, family Nereididae, and are commonly known as sea worms, sea maggots, sea centipedes and sea leeches. There are about 80 or more species of sandworms in China, and the main economic species and varieties used for farming include: the Japanese nereid (Nereis japonica), the spiny ragworm (Perinereis species), and the two-toothed ragworm (Perinereis aibuhitensis). They like to inhabit coastal tidal flats with freshwater inflow, and sandy mud from the mid-intertidal zone to the subtidal zone; the larvae feed on plankton, and the adults feed on humus. Sandworms have very high nutritional value and are widely used in aquaculture.
Sources of red sandworm broodstock
There are two sources of broodstock for red sandworm breeding and production: first, collecting sexually mature heteronereis forms from the seaside and salt fields during the sandworm breeding season; second, using fully grown sandworms that are about to transform into heteronereis forms for artificial intensive culture to make them transform into heteronereis forms.
Artificial seedling rearing and farming methods
1. Broodworm cultivation. 30 days before the breeding season, select prospective broodstock sandworms that are complete in body, robust and quick to react for intensive cultivation. Feed them 3~4 times a day with golden algae, small diatoms, marine red yeast and compound feed, with a daily feeding of 150,000~200,000 cells/liter of unicellular algae and 30~50 grams/sq m of compound feed. Control the water temperature at 23~25°C and the salinity at 28~30.
2. Artificial reproduction. The breeding period of the red sandworm is generally from January to March in spring and from August to November in autumn. When the broodstock gonads mature, select heteronereis forms (heterotypic forms) with bright body color, no mechanical injury, strong vitality and full gonads, and place them into the spawning net cage in the water tank at a female-to-male ratio of (7~8):1, then add an appropriate amount of disinfected seawater to induce spawning and sperm release. After spawning is complete, remove the spawned broodstock and the spawning net cage, and wash the eggs several times with seawater to wash away excess semen.
3. Hatching of fertilized eggs. Control the hatching density at 10~20 per milliliter, apply 2 milligrams/liter each of EDTA and antibiotics, control the water temperature at 23~25°C, the pH value at 7.8~8.6 and the salinity at 25~28, and keep the aeration rate at more than 1.5% of the total water volume per minute. During hatching, water quality must be strictly controlled to avoid invasion by protozoa; at the same time, the bottom must be stirred frequently to prevent the fertilized eggs from sinking and dying from lack of oxygen. After the larvae emerge from the membrane, collect them with a 350-mesh silk screen and transfer them to another pond for culture.
Cultivation of red sandworm larvae
1. Cultivation of newly segmented larvae. Under a water temperature of 22~24°C, three-segmented setigerous larvae can hatch in about 2 days. The newly hatched larvae use the yolk oil globule in their bodies as nutrition and need no feeding. After 2 days the yolk oil globule disappears, and at this time feeding must be carried out promptly. The feed is mainly unicellular algae such as marine yeast, golden algae, Dunaliella, Platymonas and small diatoms. Feed 3 times a day, each time with 0.5~1.0 milligrams/liter of marine red yeast and 100,000~200,000 cells/liter of unicellular algae. After reaching the five-segmented setigerous larva stage, an appropriate amount of golden algae powder, small diatom powder and spirulina powder may be added at 0.5~1.0 milligrams/liter; maintain the water temperature at 22~25°C, the salinity at 28~30, the pH value at 8.0~8.6 and the light at 1000~3000 lux; during the planktonic stage, change the water twice a day, 50% each time, once in the morning and once in the evening, with the water-change mesh gradually decreasing from 300 mesh to 100 mesh, and at the same time apply photosynthetic bacteria, Lipeilu, Lishengsu and so on to regulate water quality. When the larvae develop to the five-segmented setigerous larva stage, they should be transferred by pouring the pond into a larval cultivation pond to continue cultivation.
2. Larval cultivation. The larval cultivation pond needs to be laid with fine sand of 5~10 millimeters in particle size, with a sand bed thickness of 5~7 centimeters. Put the larvae that have developed to the five-segmented larva stage into the pond at a stocking density of 200,000~300,000 individuals/sq m. Change the water 5 times a day at fixed times, and drain it after the water has covered the sand bed for 30 minutes. Feed when changing the water, with the feed being 80% diatom powder and golden algae powder + 20% powdered feed, at a daily feeding amount of 3~5 grams/sq m, following the principle of small amounts and many meals. After 30~45 days of cultivation, the young sandworms can grow to a body length of 2~3 centimeters, that is, 11 segments or more, at which point the seedlings can be harvested and transferred to separate ponds for farming.
Adult red sandworm farming
During the adult farming period, the sand bed thickness is 12~15 centimeters, with sand and gravel of 0.5~1.0 centimeters in particle size, a stocking density of 8000~12000 individuals/sq m, a farming water temperature of 6~30°C, and a salinity of 20~30. Change the water 3 times a day at fixed times, and drain it after the water has covered the sand bed for 30 minutes. Feed when the water is let in, with the feed being 70% powdered feed + 30% diatom powder and golden algae powder; the feeding must be uniform, with a daily feeding amount of 3%~5% of the sandworm body weight, increased or decreased as appropriate according to the amount of residual feed on the surface of the sand bed. During the farming period, the sand bed should be washed according to the condition of the sand bed and pond bottom, and some water quality improvers should be appropriately applied to keep the farming environment clean and improve the farming survival rate. After 5~6 months of farming, 2~3-centimeter larvae can reach the commercial size of 10~12-centimeter adults.
In any kind of farming, mastering its farming techniques is actually very necessary. Only by mastering its farming techniques can you take fewer detours in the farming process and avoid reducing unnecessary risks.