Artificial breeding of the Yunlong grouper succeeds, a new breakthrough in aquaculture technology
?
?
The picture shows the Yunlong grouper.
Recently, the project "Establishment of breeding populations and families of the Yunlong grouper and cultivation of improved fry," carried out jointly by the Yellow Sea Fisheries Research Institute of the Chinese Academy of Fishery Sciences and Shandong Laizhou Mingbo Aquatic Co., Ltd., passed on-site acceptance by experts, marking the success of artificial breeding of the Yunlong grouper.
Preparatory work for the artificial breeding of the Yunlong grouper began in 2010; from the early technical reserves and research on sperm cryopreservation technology to the rearing of broodstock and then to breakthroughs in the difficulties of artificial propagation, the first hybrid Yunlong grouper was born in 2014. The research group led by Tian Yongsheng solved countless problems over four years. "We simply wanted to breed a new variety with fast growth, a low deformity rate, and at the same time maintaining delicious flesh." Tian Yongsheng told this writer that the hybrid-bred Yunlong grouper combines the above advantages. Its hybrid male parent is the giant grouper, also called the Queensland grouper, the largest grouper species, with wild individuals reaching several hundred jin in weight. The female parent is the delicious-fleshed kelp grouper, currently the only grouper species that can be used to make sashimi, widely exported to Japan, South Korea and other countries, with a market price in places such as Fujian reaching as high as 140 yuan/jin.
Most grouper species grow in the high-temperature waters of Southeast Asia, while the female parent of the Yunlong grouper, the kelp grouper, is the grouper variety that grows in the northernmost environment in China, tolerates low temperatures, and can grow in the sea areas of Fujian, China. As an aquaculture species, although the kelp grouper has delicious flesh, it grows slowly and has high requirements for the farming environment; it generally takes 3 to 5 years to reach the size for export to Japan, South Korea and other countries. Judging from the current farming situation, the newly bred Yunlong grouper grows quickly, reaching more than 1 jin in body weight in 8 to 10 months, and after two years of farming, its body weight can reach more than 3 kg. "It is now recognized by customers in Japan, South Korea and other countries; its flesh is no less delicious than the kelp grouper, and it can replace the kelp grouper for making sashimi."
"The water temperature required for farming the Yunlong grouper is around 18°C, considerably lower than the 25°C water temperature requirement of ordinary groupers, which can reduce farming costs." Mao Dongliang, a relevant person in charge of Laizhou Mingbo Aquatic Company, told this writer that the kelp grouper currently has a high deformity rate and a low survival rate in artificial farming, and the newly bred Yunlong grouper overcomes this shortcoming. Next, they will gradually expand the scale of fry breeding and farming of the Yunlong grouper and bring the new variety to market. At present, the ex-farm price of the Yunlong grouper in the Fujian area exceeds 50 yuan/jin, "which counts as a high price among farmed fish, and the current market response is good."
This writer learned through interviews that there are currently more than a dozen grouper species that can be artificially bred, and grouper farming is mainly concentrated in the sea areas of Fujian. Laizhou Mingbo Aquatic can currently breed 9 species of grouper fry, mainly sold to southern regions, among which the spotted knifejaw and the rat grouper are the main species. "In artificial farming, the pearl gentian grouper and the green grouper are currently the most farmed species in southern regions. With the gradual promotion of new varieties, the Yunlong grouper will gradually open up the market and occupy a place in the grouper farming market," Mao Dongliang said.
Recently, the project "Establishment and application of a frozen repository of grouper germplasm cells," completed jointly by the Yellow Sea Fisheries Research Institute and Laizhou Mingbo Aquatic Co., Ltd., also passed on-site acceptance by experts. Since 2010 to the present, this project has gradually mastered the sperm cryopreservation technology for 6 grouper species, including the giant grouper, the seven-banded grouper, the kelp grouper, the red-spotted grouper, the brown-spotted grouper and the brown-marbled grouper, cryopreserving more than 2,000 sperm samples of each of the above 6 grouper species. The project established China's first grouper sperm cryobank, which will play a strong supporting role in the breeding of new grouper varieties and the development of the industry in China.