What Does a Fish Warden Do?

Cultivation of fry, from the selection of breeding fish to successful conception and subsequent hatching until cultivation, requires the administrator to be careful and responsible, and be able to devote himself wholeheartedly, to keep an eye on the growth of fry and environmental changes, and to give timely response measures and treatment Properly cultivated.

Fry cultivation

1.

Although fry to fingerling cultivation takes a short time, its survival rate and physical condition have a great influence on the breeding effect of the entire fingerling, so it must be taken seriously.

Feeding and fertilizing In the early stage of fry cultivation, the main purpose is to cultivate natural bait to satisfy the nutrients needed for fish growth. The length of this period depends on the polyculture density and fish growth rate. In the later stage, when the fish fry grows up, it should be supplemented with commercial bait. The quantity should be freshly eaten or slightly surplus. Several bait and fertilizer application methods:

(1) Soymilk application Soymilk can not only provide nutrients for fry, but also quickly fertilize water. Soak the soybeans in water for 5-6 hours, and then grind them into a slurry (about 1.5 kg of soybeans into 25 kg of soybean milk) for feeding. The daily feeding amount of soybean milk is 7.5-10 kg per 100 square meters of water surface, and it is increased to 80-100 kg after 5 days. The feeding was divided into 2 times, the first time was from 9 to 10 am, and the second time was from 3 to 4 pm. Feed according to the "three sides and two full ponds" feeding method, that is, sprinkle the full ponds in the morning and afternoon, and sprinkle it on the four sides, and sprinkle it along the side once at noon.

(2) Organic fertilizers can be used to meet the nutritional needs of grass carp, catfish, and catfish summer flower species under the condition of proper cultivation density. Common organic fertilizers are manure, pig manure and cow manure. Fertilized aquaculture fry, if soybean milk is not applied, the second day should be sprinkled with rotten organic fertilizer in an amount of 15 to 22.5 kilograms per 100 square meters of water surface, generally sprinkled at 9-10 am, and then topdressed every 2 days .

Pull net exercise

A few days before the fish fry comes out of the pond, pull the net to exercise 2 to 3 times. The purpose is to adapt fry to a dense environment to facilitate pond counting and transportation; check the growth of fry and estimate fry production in order to make a distribution plan. Method of pulling nets: Pull the nets for the first time, gather Xiahuawei in the nets, check the fitness of the fish, and then put them back into the pool after the estimated quantity, or put the water on the surface for a dozen seconds to estimate the quantity and then quickly return In the pond, cooked soybean milk was fed once after 1 hour. After the first pull, the second pull was performed every other day. Transfer the fry into the cage, or densely fill the fingerlings in the net, and let the top water automatically enter the cage. Push the cage slowly in the pond to avoid floating fish heads, which will be dense for about 2 hours (depending on the tolerance of the fish) ) Put it back into the pool, and feed the cooked soy milk 1 time after 1 hour. This time the net should try to catch all the fish species. If the fish species are self-supporting and not used for transportation, they can be reared in separate ponds after intensive exercise after pulling the net into the box for the second time. Note: It is not advisable to move the net too early, especially when it is out of scale; it is not allowed to move the net in the case of rainy days, fry, and weak fish. 1 to 2 days before moving the net, stop fertilizing and feeding, and remove weeds and moss from the pond. Netting should be done on a sunny morning or afternoon. ^[1]

Out of the pond

After pulling the net for the second time, pull the net for the third time every other day to catch the fry and transfer them to the net cage. After about half an hour, remove the dirt on the bottom of the net cage and use a fish sieve to separate the fry with different specifications Net cage, you can count out the pool. For long-distance transportation, fry should be placed in pond cages with relatively clear water quality for "hanging" for one night, and can be shipped in the early morning of the second day. Summer flower fingerlings are generally counted in a bowl and several methods. The bowl measurement method is to first determine the number of 1 bowl (sampling the average number of fry in the bowl), and then multiply by the number of bowls to get the total. For several methods, use small plates (or bowls) of catfish fry, once every 5 (weigh 1 hand), and keep counting, this method is suitable for counting a small number of fry. After exiting the pond, the fry survival rate can be calculated. The survival rate of fry cultivation (%) = number of summer flowers out of the pond / number of flowers in the pond × 100 carp fry. The phenomenon of eating big and small is more serious, and it should be raised in ponds at the stage of larvae (2 cm) to meet the fry's bait. If there is no pond rearing, the big fish should be screened and raised at any time. ^[1]