| Serranidaes are one of the major economic Marine fish in Southern China coastal regions, including Taiwan, Hainan, Fujian and Guangzhou Provinces. Breeding seedlings is basically out of natural fishing and imports, but the stability of the number of seedlings is affected by NNV and three death phase. Therefore, Serranidae seedling is one of the important factors that directly limits the Serranidae aquaculture development. Based on the environmental factors and Serranidaes survival, growth and feeding property relations are briefly summarized. Progress on artificial breeding technology of Serranidaes are described. In order to provide some scientific basis and guidance for seedling raising and breeding of Serranidaes. The results were briefly summarized as follow: 1. Experiment of artificial seed breeding Epinephelus moara with full-closed water systemThe modifided seeding-raising method with full-closed water system were applied to study artificial seed breeding Epinephelus moara. By adding EM bacteria and Environmental Improvement Agent to adjust the physical and chemical of water, maintain the stability of water quality. we measured the change of physical and chemical factors and the number of fish larvae. The fertilized eggs could hatch completely and develop into normal larval fishes under the following conditions: 24~30.2℃, 30~32 salinity, p H 7.18~8.10, DO≧6mg/L. we bought a fertilized egg 1.604 kg, hatched larvae of 1.014 milliom tail, hatching rate was 57.7%, after 41 days, the average length of grouper larvae reached 19.00 mm, and the number of triploids was 1.7×105 tail, the survival rate was 16.80%, the malformation rate was 10%. 2. Feeding habits and growth of larval and juvenile Epinephelus moaraThe results of morphological data measurement showed that total length, length of anus, body height and the age larval, juvenile showed significant correlations. The relationship between total length and age could be expressed as y=0.0095x2+0.04072x+ 2.0938, R2 = 0.9887, the relationship between length of anus and age could be expressed as y=0.0050x2+ 0.0050 x +0.9250, R2=0.9900, the relationship between body height and age could be expressed as y=0.0020x2-0.0000x+0.8290, R2=0.9930. Under the condition of artificial feeding, we observed the 7d and 18 d larvae of day and night feeding rhythm, the results showed that the plump coefficient of stomach of 7d larvae was 1.087, the average intake amount was 16.7 rotifers; the plump coefficient of stomach of 18 d larvae was 1.877, the average intake amount was 87 rotifers, more significantly increased than intake amount of 7d larvae. Epinephelus moara larvae, juvenile feeding peak period was 16:00 to 18:00, feeding during the day and no feeding in night. 3. Studies on the feeding habits and growth of Epinephelus coioide in early development stagesThe ecological way of simple random was observed morphological features, growth and feeding during larval development of Epinephelus coioide. The results showed that the larvae opened its mouth to feed fertilized eggs and trochophore of oyster in 2 days, then rotifer, halogen worms, artificial diet. The results of morphological data show that total length, body weight and the age larval, juvenile Epinephelus coioide.showed significant correlations, The relationship between total length and age could be expressed as y=2.2496e^(0.0592x), R^2=0.9031; the relationship between length of anus and age could be expressed as y=1.2384e^(0.0558x), R^2=0.9535; the relationship between body height and age could be expressed as y=0.6908e^(0.0535x), R^2=0.9504. Based on the observation of the larvae, it was found that the feeding rate reached 100% in 4 days, the fullness rate reached 90% in 10 days. Rhythm of feeding intensity was obvious during the day and night. Under the condition of natural light, higher feeding intensity was found from 16:00 to 18:00 p.m. for the larvae and juveniles. Little feeding activities were observed during the night.4. The effect of salinity on the survival activity, first feeding and feeding of the larval of Centropristis striataThe influence of different salinity gradient(7, 12, 17, 22, 27, 32, 37, 42, 47, 53) on survival activity, the first feeding and feeding of larvae of Centropristis striata was studied. The first feeding rate(FFR%), feeding rate and feeding intensity of the early larvae were also recorded and analyzed. Newly-hatched larvae of Centropristis striata were used to carry out starvation tests to figure out the survival activity index(SAI) at different salinity. The results showed that salinity had an significant effect on survival, actvity and feeding of larvae, the suitable salinity for the survival and feeding of newly-hatched larvae was 12-37, and the optimum salinity ranged from 27 to 32. Survival rate, the first feeding rate and the feeding intensity reduced gradually when salinity was below 12 and it also showed a significant decrease when salinity was above 37.The SAI values of newly-hatched larvae at different salinity were 0.034 to 6.401,the SAI of groups with salinitiy 12 to 37 showed a significant difference with groups with salinitiy 7, 42, 47 and 52(P<0.05). When the salinity was 32, the SAI was 6.041, reaching the maximum. The relationship between SAI(y) and salinity(x) could be described as y=-5.894+1.155x-0.034x2+0.000x3, R2 =0.895. When salinity were 7, 42, 47 and 52, survival rates of larvae were lower than 50%; the survival rates were reduced to 0 after 3 and 4 day when salinity were 52 and 47 respectively; when salinity were 22, 27 and 32, survival rates of larvae were above 80% after five days. Within the scope of salinity from 17 to 37, lavae ate well with the first feeding rate60%-85%, whensalinity was 32, the first feeding rate reached maximum 85%. When the salinity was 32, the larvae feeding achieved the best state with the feeding rate 85%, feeding intensity of larvae was 5.45 rotifers per larvae at 8d. |
