| Solen grandis is one kind of significant economic shellfish of China, which distribute widely around the Bohai Sea, the Yellow Sea, the East China Sea as well as the South China Sea. In recent years,Solen grandis is endangered due to over fishing, at the same time artificial breeding technique of Solen grandis is behindhand, so it is significative to develop industrialized spawning and breeding biology energetically.This thesis aims to illustrate the key technique of breeding Solen grandis in a industrialized environment, including temporary holding of broodstock, spawning, hatching fertilized eggs, larvae aggregation and juvenile cultivation, which basically built the aquaculture system of Solen grandis. The main conclusions are as below:1. Placing 9 baskets(with a diameter of 50cm) into a pond,which is 4m×5m×1m, and each baskets laying 30cm in thickness of different size of sand;45 broodstock can be divided into 3 groups and every group includes 3 parallels. Broodstock was temporary held in baskets with sand and water, which had been prepared before. As a result shows that:The escape rate of Solen grandis was lowest in the experimental group on a substratum of sand with a diameter of 350～500μm, in this size, sand can provide a better condition to broodstock. The experiment solved the substratum problem during the temporary culture of broodstock.2. We use dry-in-shade stimulation to spawning, and in this process, stimulation time plays a vital role. Broodstock has been divided into 3 groups and dry-in-shade stimulated for 1.5h,3h,4.5h independently, then water stimulated for 5 min. After the stimulation, placing the shellfish into spawning pond, collecting the spawn. As a result shows that: When the exposure was longer than 3h, although the egg yield increased, an obvious reduction of hatchability was observed while the experimental group with a 3h dry-in-shade stimulation showed the highest hatching rate.3. As indicated in the experiment on the temperature effect on hatchability, we set up 3 groups(23℃,25℃,27℃) and each group includes 3 parallels, ambient temperature is 22℃±3℃. At the beginning of the experiment, we put 5 million hatchlings into different temperature groups and take samples every 0.5h, counting larva D and hatching rate. The results showde that:within a range from23℃ to 27℃, the hatching speed increased as temperature went higher. However, the hatching rate decreased from 91.3% at 23℃ to 79% at 27℃.4.As indicated in the experiment on the temperature and sand size effect on larva metamorphosis, we set up 3 groups, and each group includes 3 temperature dispose: 23℃,25℃,27℃. Before larva metamorphosis, laying different size of sand at the bottom of the water, larva density is 0.2/ml, when 95% of larva transformat, counting the metamorphotac rate. The results showed that: sand substratum with a particle diameter of 350～500μm and an ambient temperature of 25℃ were more beneficial than the other treatments.4. We use appendage for juvenile cultivation process. Appendage includes two parts:the upper layer and the lower layer, each part contains different size of sand. As a result shows that a higher growth rate could be seen in the juveniles aggregating on the upper layer (81.7μm/day,66.7μm/day,65.8μm/day) of the appendage than the lower layer (56.7μm/day,50.0μm/day,42.5μm/day). For each layer, Solen grandis juveniles grew faster on medium-sized sand (350～500μm) than on fine sand (150-350μm) and then coarse sand (500-700μm). |
