Method for delaying sex reversal of finless eels

Abstract

The invention relates to a method for delaying the sex reversal of finless eels, which is characterized by comprising the following steps of: under artificial breeding condition, obtaining a great number of 2-age physically-healthy finless eels of the same specification by adopting soilless aquatic breeding in a cement pit; selecting the 2-age finless eels of the same specification for breeding in the soilless cement pit in the June to November of every year, and adding a small amount of nilestriol into compound feeds for feeding the finless eels; keeping breeding the finless eels in the cement pit and stopping the feeding in the November of the same year to the March of the next year; keeping breeding the finless eels in the cement pit and feeding the finless eels again in the April to the May of the next year; and from 2 weeks before the induced spawning of the finless eels on, stopping adding the nilestriol into the feeds for feeding the finless eels. The method has the advantages of delaying the sex reversal of finless eel parents by more than 6 months, achieving the female rate of 95 to 100 percent, improving the fecundity of female finless eel parents by 18 to 25 percent, increasing the number of fries by 15 to 20 percent and meeting the requirements of large-scale eel breeding on the fries.

Description

Technical field: [0001] The invention relates to a method for delaying the sex change time of rice field eel, which belongs to the technical field of fishery science application. Background technique: [0002] Swamp eel is one of the main famous and high-quality fishes in my country, and its aquaculture has developed very rapidly in recent years. Its main aquaculture production areas are located in Hubei, Hunan, Anhui, Jiangxi, Zhejiang and other provinces. Field eel farming has become the leading industry in aquaculture in some regions. [0003] But at present, the seedlings needed for rice field eel breeding are mainly wild resources, and the wild rice field eel seedlings cannot meet the scale and industrialization needs of rice field eel breeding in terms of stocking time, quality, quantity and source. Therefore, the rice field eel seedlings Manual mass production is an inevitable requirement for large-scale eel farming. However, there is a sex reversal phenomenon in th...

AI Technical Summary

Problems solved by technology

[0003] But at present, the seedlings needed for rice field eel breeding are mainly wild resources, and the wild rice field eel seedlings cannot meet the scale and industrialization needs of rice field eel breeding in terms of stocking time, quality, quantity and source. Therefore, the rice field eel seedlings Manual mass production is an inevitable requirement for large-scale eel farming

However, there is a sex reversal phenomenon in the life history of the rice field eel, that is, the first half of the life of the rice field eel is a small functional female, and the second half of its life is a large functional male, which eventually leads to the individual and pregnancy of the female eel parents in the artificial breeding process. Due to the small number of eggs and the uncoordinated size of the male and female parents, the number and scale of seed reproduction are limited