A preliminary study on food consumption, preference and day-night predatory difference of Asterias amurensis on Scapharca broughtonii

多棘海盘车对魁蚶摄食量、选择性及昼夜摄食差异的初步研究（英文）

In order to study the food consumption, preference and day-night predatorydifference of Asterias amurensis on Scapharca broughtonii, the experiments werecarried out at the temperatures ranging from 16 ℃ to 20 ℃, salinity of 28.2 ± 2.1,dissolved oxygen of 7.5±0.7 mg/L and pH of 8.0 ± 0.3.The results provided basic datafor promoting steady and healthy development of the multiplication and cultivation of S.broughtonii. The results of food consumption suggested that the food intake of starfishincreased with the density of S. broughtonii at all conditions. The food consumption ofstarfish in different sizes on S. broughtonii in the same size had no significant difference(p>0.05), but it was significantly different among S. broughtonii in different sizes. Thestarfish had the highest feeding rate on the smallest S. broughtonii. Our findings alsoverified the positive relation between the weight of food intake of starfish in differentsizes on the density and size of S. broughtonii. The feeding rhythm of starfish onS. broughtonii in different sizes showed a certain day-night difference, higher at nightthan in the day. The maximum food consumption occurred when the size of S.broughtonii became larger. The results showed that 30 ind/m2 was the suitable seabottom sowing density for S. broughtonii. Our data indicated that the ability to avoidpredators and rivals increased as the shell length rose. Based on prey selectivity,bivalves that have a lower commercial value may be used to clear away A. amurensis.

在水温为16~20℃、盐度28.2±2.1、溶解氧为(7.5±0.7)mg/L、pH为8.0±0.3的条件下,研究了3种规格多棘海盘车(Asterias amurensis)对4种规格魁蚶(Scapharca broughtonii)的摄食量、摄食选择性和摄食昼夜差异。研究表明:多棘海盘车对不同规格魁蚶摄食数量均随魁蚶底播密度的增加而上升;不同规格多棘海盘车对同一规格魁蚶摄食数量无显著差异(p>0.05),但对不同规格魁蚶摄食数量存在一定差异,对于最小壳长组的摄食数量最大;多棘海盘车对不同规格魁蚶软体部摄食量与魁蚶规格呈成显著正相关;多棘海盘车对不同规格魁蚶摄食数量均存在一定的昼夜差异且夜间的摄食数量大于昼间,魁蚶规格越大,多棘海盘车对魁蚶最大摄食数量时间出现的越晚。结果表明:魁蚶适宜底播密度在30 ind/m^2左右,底播规格越大越能有效防御敌害。根据多棘海盘车对贝类捕食特点,可采用浅水低值贝类作为诱捕生物对多棘海盘车进行清除。