Crucian carp, commonly known as crucian, with local names such as jiguazi, yuejizai and tuji, can produce many new varieties through artificial breeding and selective breeding. So at what size do crucian carp spawn? How many days does it take for the eggs to hatch into fry? According to farmer Mr. Zeng, the gonads of crucian carp mature earlier than those of other fish; fish in their second year can spawn, and they continue to grow in size while spawning. One-year-old crucian carp can already spawn. Moreover, the spawning period is long, lasting from spring all the way to autumn, and the number of eggs laid is large; the eggs are laid on aquatic plants or other objects in shallow water. The strong reproductive capacity of crucian carp is an important reason why it is widely distributed and abundant. There is another point: crucian carp still forage for food during the spawning period, which is different from other fish.
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<p style="text-indent:2em;"><span style="color:#FF0000">How many days does it take for the eggs to hatch into fry?</span></p>
<p style="text-indent:2em;">Generally, it takes 3—7 days from the laying and fertilization of the eggs to the hatching of the fry. If the average water temperature is 15—20°C, the hatching time is 5—7 days; if the average water temperature is 20°C, the fry can hatch in 4—5 days; if the average water temperature is 20—25°C, only 2—3 days are needed. In short, the lower the water temperature, the longer the hatching time.</p>
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<p style="text-indent:2em;"><span style="color:#FF0000">Crucian carp farming techniques</span></p>
<p style="text-indent:2em;">1. Pond conditions</p>
<p style="text-indent:2em;">Crucian carp has the habits of liking to gather in groups, burrowing into mud, and leaping upstream to escape. The pond area for mainly farming crucian carp should not be too large; generally about 2 mu is suitable, and it should not exceed 4 mu. The pond bottom should be relatively hard, generally with a mud thickness within 10 cm; when it exceeds 10 cm, the mud must be cleared to facilitate the catching (catching) of crucian carp. The pond embankment should be solid and not leak water, and sturdy and reliable fish-blocking screens should be installed at the water inlet and outlet. The fish-blocking screen should be 50 cm higher than the highest water level of the pond.</p>
<p style="text-indent:2em;">2. Variety selection</p>
<p style="text-indent:2em;">At present, there are many crucian carp varieties sold on the market, and it is inevitable that good and poor ones are mixed. Practice has proved that allogynogenetic silver crucian carp and high-back allogynogenetic silver crucian carp (abbreviated as high-back crucian carp) are suitable for main farming, and their growth speed is 2 times and 3 times faster than ordinary crucian carp respectively. Allogynogenetic silver crucian carp and high-back crucian carp are similar. The differences between allogynogenetic silver crucian carp and ordinary crucian carp are: allogynogenetic silver crucian carp has 31-32 scales along the lateral line, while ordinary crucian carp has 28-29; allogynogenetic silver crucian carp and high-back crucian carp have the same number of lateral line scales, but high-back crucian carp has a short head, high back, thick body, and round abdomen.</p>
<p style="text-indent:2em;">3. Stocking density</p>
<p style="text-indent:2em;">From the perspective of farming economic benefits, if the stocking number exceeds 2000 fish/mu, although a higher yield can be obtained, the individual commercial fish raised are small, the selling price is low, and the benefit is not ideal; if the stocking number is less than 1000 fish/mu, although the individual commercial fish are larger, the total yield is not high and the sales income is low. Stocking 1400 fingerlings of 30 grams each per mu or 1200 fingerlings of 50 grams each per mu, with an appropriate amount of silver carp, bighead carp and summer grass carp, with the total number of mixed fish not exceeding 600, can achieve a net yield of more than 500 kg of crucian carp and about 200 kg of other fish, giving an ideal effect.</p>
<p style="text-indent:2em;">4. Water quality management</p>
<p style="text-indent:2em;">The calcium and phosphorus content in the body of crucian carp is more than 2 times that of other fish, so the water is required to be rich in calcium and phosphorus to meet the physiological needs of crucian carp. Apply quicklime solution once about every 20 days, with 60 kg per mu each time; apply superphosphate once every 15 days, with 15-20 kg per mu each time. Superphosphate can only be applied 3-5 days after applying quicklime, to prevent the water from being too alkaline and reducing the effect of phosphate fertilizer.</p>
The crucian carp, commonly known as crucian, with folk names like crucian melon seed, moon crucian fry and native crucian, can produce many new varieties through artificial breeding and selective breeding. So at what size does the crucian carp spawn? How many days does it take to hatch the fry? According to farmer Mr. Zeng, the gonads of the crucian carp mature earlier than those of other fish, and fish in their second year can spawn, growing in size while spawning. One-year-old crucian carp can already spawn. Moreover, the spawning period is long, lasting from spring all the way to autumn, and the number of eggs laid is large, with eggs deposited on aquatic plants or other objects in shallow waters. The strong reproductive capacity of the crucian carp is an important reason for its wide distribution and large numbers. Another point is that the crucian carp still forages during the spawning period, which is different from other fish.
How many days does it take to hatch the fry?
Generally, it takes 3—7 days from the fertilization of the laid eggs to the hatching of the fry. If the average water temperature is 15—20°C, the hatching period is 5—7 days; when the average water temperature is 20°C, the fry can hatch in 4—5 days; when the average water temperature is 20—25°C, only 2—3 days are needed. In short, the lower the water temperature, the longer the hatching time.
Crucian carp farming techniques
1. Pond conditions
The crucian carp has the habits of liking to gather in groups, burrowing into mud and leaping upstream against the current to escape. The pond area for mainly farming crucian carp should not be too large, generally about 2 mu is suitable, and it should not exceed 4 mu; the pond bottom is required to be relatively hard, generally with a mud thickness within 10 cm, and when it exceeds 10 cm, dredging must be carried out to facilitate the catching of crucian carp; the pond ridge should be solid and not leak water, and the water inlet and outlet should be fitted with firm and reliable fish-blocking grilles, which should be 50 cm higher than the highest water level of the pond.
2. Variety selection
At present, there are many crucian carp varieties sold on the market, and it is unavoidable that good and bad are mixed. Practice has proved that the allogynogenetic silver crucian carp and the high-back allogynogenetic silver crucian carp (abbreviated as high-back crucian carp) are suitable for main farming, with growth speeds 2 times and 3 times faster than ordinary crucian carp respectively. The allogynogenetic silver crucian carp and the high-back crucian carp are similar, and the differences between the allogynogenetic silver crucian carp and the ordinary crucian carp are: the allogynogenetic silver crucian carp has 31-32 lateral line scales, while the ordinary crucian carp has 28-29; the allogynogenetic silver crucian carp and the high-back crucian carp have the same number of lateral line scales, but the high-back crucian carp has a short head, a high back, a thick body and a round abdomen.
3. Stocking density
From the perspective of farming economic benefits, if the stocking number exceeds 2000 fish/mu, although a higher yield can be obtained, the individual commercial fish raised are small, the selling price is low, and the benefit is not ideal; if the stocking number is less than 1000 fish/mu, although the individual commercial fish are larger, the total yield is not high and the sales income is small. Stocking 1400 fingerlings of 30 g body weight or 1200 fingerlings of 50 g per mu, with an appropriate amount of silver carp, bighead carp and summer flower grass carp, with the total number of accompanying fish not exceeding 600, can achieve a net yield of more than 500 kg of crucian carp and about 200 kg of other fish, with ideal results.
4. Water quality management
The calcium and phosphorus content in the body of the crucian carp is more than 2 times that of other fish, so the water is required to be rich in calcium and phosphorus to meet the physiological needs of the crucian carp. It is required to apply quicklime solution once about every 20 days, with 60 kg per mu each time; apply calcium superphosphate once every 15 days, with 15-20 kg per mu each time. Calcium superphosphate can only be applied 3-5 days after applying quicklime, to prevent the water from being too alkaline and reducing the effect of phosphate fertilizer.