Selection and conservation of carp species

If any good variety does not pay attention to seed selection and conservation, it will often lead to the degradation of quality, the decrease of yield and the deterioration of other characters. Jian carp has stable genetic characters and can pass on the excellent and dangerous characteristics of this variety to its offspring through self-breeding. However, different carp breeds are easy to mate and mix with each other, and there are differences among individuals of the same breed, and the living environment will also have a great impact on the characters of the species. Therefore, we must pay attention to the breeding of improved varieties, and according to the index of the variety, we should select the fish with good characters for parent fish breeding and let them reproduce. In the selection of Jian carp, attention should be paid to three indexes: growth rate, body shape and body color. The growth rate is mainly shown in two aspects: weight gain and body length gain, especially weight gain, that is, under the same feeding conditions, the largest individual is selected from the same batch of fish; the body shape also directly affects the market market and price, and the existing masses prefer the long body type. Jian carp should choose the excellent individuals whose ratio of caudal stalk length to caudal stalk height is equal to or greater than 1, the ratio of body length to body height is greater than the population average, and the body color of Jian carp should be bluish gray and whitish. According to the characteristics of different developmental stages of Jian carp and combined with culture measures, the selection methods were used to screen summer flowers, winter slices or spring slices, backup parent fish and prenatal parent fish for 4 times. Summer flowers are mainly screened, with growth rate as the main index, winter or spring slices are mainly hand-selected, pay attention to growth speed and body shape, eliminate red carp; backup parent fish focus on comprehensive comprehensive evaluation; prenatal parent fish should be reviewed and male-to-female ratio and matching group. In order to protect the species, we should pay attention to the specialization of production, that is, one unit or fishing ground, and it is best to produce only one kind of carp. All units that produce Jian carp should not produce other carp, let alone hybrid carp; they should pay attention to breeding in special ponds to strictly prevent mixing with other carp; they should also pay attention to the renewal of parent fish, and the best age for parent fish is limited. Female fish is generally 3-5 years, need to be constantly replenished by backup parent fish. At the same time, in order to prevent inbreeding and genetic drift of small populations in fishing grounds, new purebred parent fish should be introduced regularly from original breeding farms or research units.