Study On Breeding Technique And Biology Of Early Developmental Stage Of Epinephelus Moara

This paper describes the technique of artificial breeding,feeding habits and growth characteristic of larva and juvenile,morphological development of larva,juvenile and young of Epinephelus moara,and the effect on growth and survival of young E.moara of changing temperature and salinity around the biology of early development stage of E.moara.May-July,2013,a batch of E.moara fry was breeded in Dongshan county,Zhangzhou city,Fujian province fengyuan aquaculture farms,and the breeding technique,the morphology change of post-embryonic development and the feeding behaviors and growth characteristic of the larva and juvenile of E.moara was studied.The main results are as follows:On the conditions of that the bait series was oyster zygotes,rotifers,artemia nauplii,copepods,surimi,seedling raising water temperature was 22.5-29.2℃,salinity was 31.65-34.67,pH 7.45-8.49,DO>5 mg/L conditions,from May 13 to the end of the experiment on July 10,lasted 59 d,we had produced an average length of 36.5 mm fry 53760,and the seedling survival rate is 3.0%.The post-embryonic development of E.moara was divided into larva stage（including prelarva and postlarva）,juvenile stage and youth stage according to the changes of the yolk sac,fin membrane,second dorsal fin spine and first pelvic fin spine,scales,and the pigment of the moire stripes;Cultivated the newly hatched larva in the seawater of water temperature was22.5-28.9℃,salinity was 31.65-34.67,DO>5 mg/L,pH was 7.45-8.49,larva begun feeding until to 4 days of age,yolk sac and oil ball of larva disappeared until to 6 days of age,late into the series,and fish fin membrane disappeared and into juvenile stage until to 29 days of age;The scales begun to grow until to 41 days of age,and the fish whole body covered with scales,completed metamorphosis and entered into larval stage until to 59 days of age.In addition,we also found that to control the ecological factors in the best level can improve the growth efficiency of the larva and the juvenile,and sped up the seedling.The bait series of oyster zygotes,rotifers,artemia nauplii,copepods,surimi was suitable for the larva and juvenile of E.moara;Larva and juvenile of E.moara has strong feeding ability,and vigorous feeding activities,larva started to eat oyster zygotes until 4 days of age,and the feeding rate was 40%,summed up the average feeding rate of larva and juvenile was 97.63%,individual feed rate after the 13 days of age was 92.25%,and can preliminarily determined 10-20%and8-20%of the average body weight as the recommended dietary allowance of larva and juvenile of E.moara;The larva and juvenile of E.moara showed an obvious feeding rhythm,fed mainly during the day and not fed at night,and was characterized by daytime,and had two feeding peaks,the larva feeding peak appeared at 9:00 and 15:00,the juvenile feeding peak appeared at7:00 and 13:00;The regression equation of total length（Lt）with age（D）was expressed as Lt=0.0088D²+0.1622 D+1.1145,the regression equation of weight（Wt）with age（D）was Wt=0.3660 D²-11.361D+59.0223,the regression equation of total length（Lt）and weight（W）was W=0.0117 Lt^3.0178,b=3.0178 was approximately equal to 3,it showed that the larva and juvenile of E.moara belonged to uniform growth type.The experimental results also showed that raising seedling water temperature in the optimum temperature range can promote the growth and development of larva and juvenile of E.moara.July-August,2013,the impact on the growth and survivability of early young E.moara of changing water salinity gradually,and the impact on survivability of early young E.moara of changing temperature suddenly was studied in dongshan county,zhangzhou city,fujian province fengyuan aquaculture farms,and August-September,2013,the effect on the growth and survivability of early young E.moara of changing temperature gradually was studied in Fisheries College,Jimei University water proving ground.The results of this study showed that the young were able to survival in salinity range of 14-40,and the optimal salinity range for grow was14-19.The suitable water temperature range was 21-30 degrees Celsius.In experiments of temperature change,the young was less active and ate less during lower temperature water than18 degrees Celsius,that reduced resistance and were more vulnerable to pathogenic bacteria;And the young was hyperactive during higher temperature water than 33 degrees Celsius,that exhausted more energy and inhibited growth.The results indicated that the young was able to tolerance the changing of salinity,and by reducing salinity appropriately could improve the growth rate of Epinephelus moara,and the young was requested more strictly to temperature.