Artificial Cultivation Methods and Technical Key Points for Daphnia
How to artificially cultivate Daphnia?
Daphnia is a representative type of fish food organisms. It belongs to the Cladocera. There are as many as 20 to 30 species, and it is one of the best baits that ornamental fish love to eat. Cladocerans mainly reproduce by parthenogenesis, also known as asexual reproduction; only when environmental conditions are harsh do they carry out sexual reproduction. Therefore, sexual reproduction occurs only a few times a year. Each adult cladoceran can lay eggs about 10 times in its lifetime, about 100 eggs each time, for a total of about 1,000 eggs. With proper cultivation, the yield is still quite high. The optimum temperature for cladoceran reproduction is 18°C to 25°C.
(1) Small-scale cultivation. Generally, households can use fish-rearing basins, flower pots, glass tanks, etc. as culture vessels. For example, use a fish-rearing basin 85 cm in diameter, first spread 6 to 7 cm of fertile soil on the bottom of the basin, pour in tap water until it is 80% full, then place the culture basin in a place with suitable temperature and reliable light, so that bacteria and algae multiply in large numbers, then take 2 to 3 g of cladocerans as the seed source, and after a few days they can reproduce offspring. Their yield varies depending on water temperature and nutritional conditions. When the water temperature is 16°C to 19°C, after 5 to 6 days, 10 to 15 g of cladocerans can be harvested. During the cultivation process, when the fertility of the culture liquid decreases, soybean milk, rice washing water, urine fertilizer, etc. can be used for supplementary fertilization. In addition, old water exchanged from fish ponds can also be used as the culture liquid. Because this water
contains various algae, all of which are good food for cladocerans, so the cultivation effect is relatively good. However, there should not be too much algae in the water; too much is instead unfavorable for cladocerans to feed.
(2) Large-scale cultivation is suitable for ornamental fish farms. Because when producing commercial ornamental fish, a relatively large quantity of cladocerans is needed, it is advisable to use earthen ponds and cement ponds for large-scale cultivation. The area size depends on the need. But the depth of the pond should reach about 1 m. Fill with water to 70% to 80% full, add previously composted and fermented green grass and human and livestock manure, and apply fertilizer at a rate of 500 kg per 667 sq m of water surface, so that fungi and single-celled algae multiply in large numbers, then introduce adult cladocerans as the seed source, and after 3 to 5 days of cultivation, when a large number of fish food organisms are seen to have reproduced, the organisms can be harvested to feed the fish. After harvesting the fish food organisms, new water should be added in time, and at the same time fertilizer should be applied once more. In this way, cultivate successively and harvest successively.
(1) Small-scale cultivation. Generally, households can use fish-rearing basins, flower pots, glass tanks, etc. as culture vessels. For example, use a fish-rearing basin 85 cm in diameter, first spread 6 to 7 cm of fertile soil on the bottom of the basin, pour in tap water until it is 80% full, then place the culture basin in a place with suitable temperature and reliable light, so that bacteria and algae multiply in large numbers, then take 2 to 3 g of cladocerans as the seed source, and after a few days they can reproduce offspring. Their yield varies depending on water temperature and nutritional conditions. When the water temperature is 16°C to 19°C, after 5 to 6 days, 10 to 15 g of cladocerans can be harvested. During the cultivation process, when the fertility of the culture liquid decreases, soybean milk, rice washing water, urine fertilizer, etc. can be used for supplementary fertilization. In addition, old water exchanged from fish ponds can also be used as the culture liquid. Because this water
contains various algae, all of which are good food for cladocerans, so the cultivation effect is relatively good. However, there should not be too much algae in the water; too much is instead unfavorable for cladocerans to feed.
(2) Large-scale cultivation is suitable for ornamental fish farms. Because when producing commercial ornamental fish, a relatively large quantity of cladocerans is needed, it is advisable to use earthen ponds and cement ponds for large-scale cultivation. The area size depends on the need. But the depth of the pond should reach about 1 m. Fill with water to 70% to 80% full, add previously composted and fermented green grass and human and livestock manure, and apply fertilizer at a rate of 500 kg per 667 sq m of water surface, so that fungi and single-celled algae multiply in large numbers, then introduce adult cladocerans as the seed source, and after 3 to 5 days of cultivation, when a large number of fish food organisms are seen to have reproduced, the organisms can be harvested to feed the fish. After harvesting the fish food organisms, new water should be added in time, and at the same time fertilizer should be applied once more. In this way, cultivate successively and harvest successively.