Abstract:Anthocidaris crassispina, which possesses high pharmaceutical and nutritive value, is one of the most important fishery species in the southeast China Sea. Because of continued over-fishing, the population of A. crassispina has been decreased sharply in last several years. Thus, it is urgent to take some actions to improve this situation. In order to study the growth rate and survival state of juvenile A. crassispina, we designed several experimental facilities, and threw them in Dayawan Bay to simulate the natural growing environment in the sea from September 2013 to May 2014. The superficial area of specially made experimental facilities was 0.473 m2. The diameter of shells was between 3 mm and 9 mm, and the density was between 3 ind and 25 ind per experimental facility (6 ind/m2 and 52 ind/m2), while the weight range was between 1.48 g/m2 and 13.32 g/m2. Fourty-five experimental facilities of Juvenile A. crassispina had been divided into 15 groups according to 3 different diameter of shells and 5 various densities (each group has three parallel facilities). The result indicates that the diameter of shells and density affected the death rate significantly. The highest death rate was in the group of smallest diameter of shells and lowest density. At the early stage of the culture, there is a significant negative correlation between 3 growth rates, Growth rate of Shell Diameter (GSD), Special Growth Rate of Shell Diameter (SGR) and Net Yield of Shell Diameter (NY), with density in groups whose diameter of shells is 5−7 mm or 7−9 mm. Two months after the culture, these differences disappeared. There is also a significant difference in production between different weight ranges. The highest production is in the group of the weight of 10 g/m2. From November to March in the next year, the juvenile A. crassispina grew more slowly and the GSD was lower.
