Feed for delaying sex reversal time of finless eels and preparation and implementation methods of feed

Abstract

Aiming at the technical problems that the fry propagation quantity and scale are limited due to the fact that the female finless eels are small in parental size and brood amount in the existing finless eel cultivation, the invention provides a feed for delaying the sex reversal time of the finless eels. The feed for delaying the sex reversal time of finless eels consists of a finless eel compound feed and the Chinese medicinal herbs. A Chinese medicinal herb formula comprises radix rehmanniae praeparata, fructus corni, rhizoma dioscoreae, fructus lycii, liquorice and poria cocos. A preparation method of the feed is provided as follows: after the Chinese medicinal herbs are ground and mixed uniformly, and 3% to 5% by weight of the Chinese medicinal herbs are mixed in the feed for finless eels. In addition, an implementation method of the feed is provided as follows: selecting the finless eels at the age of 2 years with the consistent specifications and healthy physique; artificially feeding the feed containing 3% of the Chinese medicinal herbs from June to November every year; overwintering and stopping feeding from November to next April; and continuously feeding the feed containing 5% of the Chinese medicinal herbs in May. According to the feed for delaying the sex reversal time of the finless eels, the parental sex reversal time of the finless eels is delayed for above half of a year, and the female ratio is above 96%; and the parental reproductive capacity of the female finless eels is improved by above 30% and the fry amount is improved by above 23%.

Description

technical field [0001] The invention belongs to the technical field of fishery science application, and in particular relates to a feed for delaying the sex reversal time of rice field eels and a preparation and implementation method thereof. Background technique [0002] Field eel (Monopterus albus), commonly known as eel, belongs to Teleost, Synbranchia, Synbranchidae, and Monopterus genus, widely exists in Asia, and only one species is produced in China. Its body is thin, its shape is like a snake or eel, and its nutritional value is extremely high. In the life history of rice field eel, there is a special phenomenon of reproductive development—natural sex reversal. Studies have shown that during the first sexual maturation and development cycle, rice field eels develop as females. After the females mature and lay eggs, the egg cells in the gonads are aborted, and the ovarian structure gradually degenerates. At the same time, the male germ cells begin to develop, and tra...

AI Technical Summary

Problems solved by technology

However, due to the sex reversal phenomenon in their life history, the number of individuals and fecundity of female eel parents in the eel breeding population is small, and the fecundity is very low. Difficult to select, the number and scale of seed propagation are limited, which greatly limits the scale and level of eel artificial propagation

Therefore, it is one of the key points for mass production of eel seedlings to obtain female eel parents with large individuals and a large number of eggs. Artificial feeding or injection of exogenous hormones is one of the effective ways to control the sex reversal of eels. For example, the patent No. is " The patent of 200910091119.3" adopts the method of injecting estrogen to delay the time of eel's sex transition. However, under the current situation of green environmental protection and serious pollution of environmental hormones, using this method will undoubtedly damage the environment, and Chinese herbal medicine is a natural medicine. Rich, less toxic and side effects, not easy to pollute the environment, so it has incomparable advantages