Marine fisheries are facing a crisis of overfishing, resulting in a shortage of resources. The aquaculture fishery faces challenges such as 1. It is not easy to obtain species of fish, 2. Competition in the international market, 3. The imbalance of domestic production and sales, 4. The threat of disease. Therefore, there is an urgent need to accelerate the breeding technology of emerging species to enhance the competitiveness of the aquaculture market.
This research aimed at fish and crabs such as Atrobucca nibe, Psenopsis anomala, R anina ranina, Dentex hypselosomus, and Branchiostegus japonicus. Through the method of fishing grounds survey, wild seed fish are obtained from the coastal waters, and then the breeding technology is developed. It is very challenging but worthy of development. Since each species has a different process with the goal of developing breeding technology, different goals are drawn up separately. Significant results were achieved in several goals this year: 1. Atrobucca nibe's live fish acquisition technology, 2. Sperm freezing and preservation technology, 3. Investigation of Psenopsis anomala live fish collection methods, 4. Ranina ranina live crab collection and stocking technology, 5. Biological investigation of Dentex hypselosomus and ranchiostegus japonicus.
The research ship and the longline fishing boat cooperated with each other to successfully catch the Atrobucca nibe live fish in the southwestern seas from January to May. Fish decompression technology and weaning technology were incorporated to complete onshore stocking. After mastering the maturity of the gonads of Atrobucca nibe, Hank's dilution and DME/F12 dilution were used for cryopreservation of Atrobucca nibe sperm, and both DMSO and PG were suitable to be used as antifreeze. After thawing, the sperm motility can reach 71.33%±1.53 and 69.00%±2.52. From April 7 to April 10, 9 fish were collected and sperm survival rate was 50 ~ 90 %. After thawing on November 9 (about freezed 210 days), the sperm still had 40 % survival rate.
Set net and light fisheries have the opportunity to successfully harvest Psenopsis anomala individuals in good condition. However, it is still necessary to improve in the transportation and storage technology.
As for the collection of Ranina ranina species, a total of 7 batches of Ranina ranina were collected this year by research ship operations and sampling from traps fishing boats in the Penghu area. They were transported through a selfdeveloped method to reduce stress, and they were kept in Tainan Mariculture Research Center, and after breeding and management, the female crabs complete their eggs.
This study also completed the gonad survey for target fish species that lacked basic biological data. According to the Gonadosomatic index (GSI) of Dentex hypselosomus, the reproduction period is around January to May and November, and the peak period is March. In addition, the GSI and gonad tissue sections of Branch iostegus japonicus preliminarily predict that the spawning period is around September to November.
It is hoped that through the implementation of the plan, we will continue to develop technologies for enriching important economic species in the coastal waters to provide more options for my country's aquatic food sources. It is hoped that the technologies can be used to return resources to the ocean and enhance marine fishery resources.