The project focused on comprehensive research on reproductive biology, reproductive endocrine regulation, large-scale breeding ofhalf-smooth tongue soleand healthy aquaculture technology. We overcame the key technologies such as broodstock domestication and reproductive regulation, and formed a large-scale breeding and healthy aquaculture technology system. The breakthrough and stable development of the Soleidae culture has formed a large-scale industry in China. The main innovations of the project are as follows:

1. The reproductive biology and physiological ecology ofhalf-smooth tongue solewas systematically investigated. The gonadal development and reproductive endocrine mechanism were explored. The key techniques of reproductive regulation such as artificial induction of gonad maturation and natural spawning were overcome.

2. The feeding control and mechanism, digestion and nutrition physiology of the half-smooth tongue sole were revealed. The suitable compound feed was developed, and the key points of the larval feed, feed conversion and feeding strategy were solved.

3. The germplasm resources and sex genetic characteristics of the half-smooth tongue sole were studied. The females were found to have sex chromosomes for the first time. The sex-related genes and female specific molecular markers were cloned and genetic sex identification techniques were established.

4. The factory industrialized large-scale breeding technology system and energy-efficient culture mode were constructed for half-smooth tongue sole. We also has developed a series of technologies, such as full artificial breeding and seasoning breeding, and developed high-efficiency and energy-saving industrialized circulating water and engineering pond culture mode and technical process suitable for half-smooth tongue sole, achieving high-yield and stable production of healthy farming.

The project was awarded 5 national invention patents and 1 utility model patent. In addition, we had published 64 papers, 1 monograph and 4 technical standards through this project. It is promoted and applied in coastal areas across the country. The annual aquaculture production is 10,000 tons, and the annual direct economic benefit is 1.5 billion yuan. The economic and social benefits are remarkable.