Carp fry breeds key management techniques

August 15, 2025

When the eel fry has been hatched for four days, its eye activity is still not developed. The entire body appears white and transparent. At this stage, under a microscope, you can see the gut and blood vessels clearly, indicating that the fry is ready to start feeding. Eel fry prefer to eat smaller fish, zooplankton, leeches, and aquatic insect larvae. Interestingly, if food is not available, they would rather starve than eat non-living matter. They have a strong preference for live prey, especially small fish. Therefore, when preparing for squid breeding, it's essential to raise a sufficient supply of live bait fish. Among the preferred options are swimming head lice and squid larvae, which are all cultured in advance. These are then introduced into grass carp breeding areas for natural reproduction. After three days, the squid's initial bait fish should be perfectly matched to their size and feeding habits. By day five, the carp fry have completely consumed the yolk sac in their bodies and must begin feeding on live fish. In the first two days, they consume 2 to 3 small fish. By day 4, this increases to 4 to 5 fish, and by day 8, they may eat as many as 8 to 12 fish. As the eel grows, so does its appetite. Therefore, it's crucial to ensure an adequate supply of live bait. Before introducing the carp fry into the pond, it’s recommended to stock the water with bait fish weighing 3 to 4 times the total weight of the carp. Over time, the ratio should gradually increase to 1:10, and then feed at 5% to 10% of the carp’s weight daily for 2 to 3 days. If the fry do not open their eyes or begin eating, they may struggle to survive. It's important to monitor their development closely. Bait fish should be carefully managed during this period. Eels have limited swimming ability and will only eat when they feel hungry. Even small prey like water fleas can be sufficient if they are available in large quantities.

Whitening Ingredient

Whitening supplements usually refer to nutritional supplements or food ingredients that can help improve uneven skin tone, reduce dark spots, and enhance skin brightness, thus achieving whitening effects. These components usually work by antioxidants, inhibiting melanin production, promoting melanin breakdown, or accelerating epidermal metabolism.


Here are some common whitening supplements:

1. Vitamin C (Ascorbic acid)

A powerful antioxidant, can inhibit tyrosinase activity, reduce melanin production, while promoting collagen synthesis, improve skin quality.

2. Glutathione

It is an endogenous antioxidant that can be used orally or topically to help reduce pigmentation and improve skin brightness.

3. Niacinamide (vitamin B3)

It can prevent the transfer of melanin to the skin surface, reduce the formation of stains, and has anti-inflammatory and moisturizing effects, improve skin barrier function.

4. Lipoic acid

A powerful antioxidant that can work with other antioxidants such as vitamins C and E to enhance the whitening effect.

5. Arbutin

Natural extract, can inhibit tyrosinase activity, reduce melanin production, commonly found in whitening skin care products.

6. Polyphenols (such as green tea extract, grape seed extract)

With antioxidant properties, can prevent skin damage caused by ultraviolet light, indirectly help whitening.

7. Collagen peptide

Although the direct whitening effect is limited, it can improve the elasticity and water retention of the skin, making the skin look fuller and brighter.

It is important to note that the effectiveness of whitening supplements varies from person to person, and usually requires a combination of good sun protection and reasonable lifestyle habits (such as adequate sleep, balanced diet, moderate exercise) to achieve the best results. When choosing a whitening supplement, it is recommended to consult a professional to ensure safety and suitability.

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