STUDY ON ARTIFICIAL PROPAGATION MODES OF MANDARINFISH (SINIERCA CHUATSI) IN SPRING, SUMMER AND AUTUMN BY SEASONS

In order to meet the demands of mandarin fish culture in different regions and seasons, and to achieve the requirement of fingerling supply of a balanced marketing, in this study, two batches broodstock were alternate artificial induced for 4 times in different seasons, and established a seed breeding mode of fry and fingerling breeding by month. The results showed there were 4 peaks of gonadasomatic index for broodstock cultivated in the cage after 4 times of artificial spawning, while broodstock naturally cultivated in pond showed only 2 peaks of gonadasomatic index. The total spawning eggs and hatching fry quantity of artificial propagation were positively correlated with the peak of gonadasomatic index. The gonadasomatic index, total spawning eggs and hatching fry quantity of second artificial propagation were the highest, which were significantly higher than the other three times (P<0.05). The fertilization rate, incubation rate, fry and fingerling survival rates in of the second, third and fourth propagation were significantly higher than those in first propagation (P<0.05). The temperature was the main factor affecting fertilization rate, incubation rate, fry and fingerling culture survival rate. The survival rate of induced broodstock decreased with the increaseding artificial propagation frequency. The survival rate of first propagation was up to 93.33%, significantly higher than that of third and fourth propagation (P<0.05). To sum up, it was feasible to solve the balanced supply of fingerling in mandarin fish by the modes of artificial breeding by seasonal echelon. This provides a scientific basis for changing culture mode of mandarin fish, and also has important referential significance for balanced supply of fingerling in other species.In summary, the results show that it is feasible to solve the balanced supply of seedling production by the artificial breeding mode according to the seasons. This provides a scientific basis for the changing culture mode of mandarin fish, and also provides a reference for the balanced production of other fish species.