鼠尾藻(Sargassum thunbergii)对刺参生长及水环境的影响

The Effects of Sargassum thunbergii on the Growth of Sea Cucumbers and the Water Environment

关键词:  鼠尾藻  刺参  平均日增重率  特定生长率

Key words:  Sargassum thunbergii  Sea cucumber  Average daily gain rate  Specific growth rate

摘要:

研究了在一定养殖空间内刺参–鼠尾藻适宜的养殖容量和养殖密度。将不同密度的平均体重为(16.70.95) g的刺参和鼠尾藻混养在1 m3水体的塑料桶内，实验分为12组，每组设3个重复，对刺参、鼠尾藻的生长及养殖水环境因子的变化情况进行了研究与分析。结果显示，1) 刺参、鼠尾藻平均日增重率(Mdwg)和特定生长率(SGR)受刺参密度和鼠尾藻密度影响显著(P<0.05)。作为对照，无鼠尾藻、刺参密度为750、500、250 g/m3时，其生长均相对较差；刺参密度为250 g/m3、鼠尾藻密度为1000、1500 g/m3时，刺参生长相对最好。刺参密度为750 g/m3、鼠尾藻密度为500 g/m3时，鼠尾藻特定生长率(SGR)最大；刺参密度为250 g/m3、鼠尾藻密度为1500 g/m3时，鼠尾藻特定生长率(SGR)最小；2) NH4+-N、NO2–-N、NO3–-N和PO4–-P含量变化受刺参和鼠尾藻养殖量的影响显著(P<0.05)。无鼠尾藻，刺参密度为750、500、250 g/m3时，实验组NH4+-N、NO2–-N、NO3–-N和PO4–-P含量相对较高，其中，刺参为750 g/m3实验组含量最高；刺参密度为250 g/m3、鼠尾藻密度为1000、1500 g/m3时，实验组NH4+-N、NO2–-N、NO3–-N和PO4–-P含量相对较低。研究结果显示，鼠尾藻密度的大小对促进刺参的生长有非常显著的影响，同时对养殖水体中的营养因子具有较强的吸收能力。本研究条件下，刺参密度为250 g/m3、鼠尾藻密度为1000、1500 g/m3模式参藻搭配比例较合适，其生态互利效果最好。

Abstract:

To determine the appropriate farming capacity and the density of sea cucumbers and Sargassum thunbergii in certain volume of water, we analyzed the growth of sea cucumbers and S. thunbergii and the changes in the condition of the water from April to May, 2014. The results showed that the mean daily weight gain rate (Mdwg) and the specific growth rate (SGR) of sea cucumbers and S. thunbergii were significantly affected by their densities (P<0.05). In the absence of S. thunbergii, sea cucumbers showed poor growth performance when the density was 750, 500 and 250 g/m3. The growth was much improved when the sea cucumber density was 250 g/m3 and the S. thunbergii density was 1000 g/m3 and 1500 g/m3 respectively. The highest SGR of S. thunbergii appeared when the densities of sea cucumbers and S. thunbergii were 750 g/m3 and 500 g/m3 respectively, and the lowest SGR of S. thunbergii appeared when the densities of sea cucumber and S. thunbergii were 250 g/m3 and 1500 g/m3 respectively. The levels of NH4+-N, NO3–-N, NO2–-N and PO4–-P were significantly affected by the density of sea cucumbers and S. thunbergii (P<0.05). The levels of NH4+-N, NO3–-N, NO2–-N and PO4–-P in the experimental group was relatively high when the sea cucumber densities were 750, 500 and 250 g/m3, and reached the highest when the density was 750 g/m3. The levels of NH4+-N, NO3–-N, NO2–-N and PO4–-P in the experimental group were relatively low when the sea cucumber density was 250 g/m3 and the S. thunbergii density was 1000 g/m3 and 1500 g/m3. In conclusion, the growth of sea cucumbers was significantly affected by the density of S. thunbergii, and S. thunbergii had high absorption capacity to the trophic factors in water. Under the experimental conditions, the appropriate density of sea cucumbers should be 250 g/m3 and the density of S. thunbergii should be 1000 g/m3 or 1500 g/m3.