低盐胁迫对刺参存活、摄食和生长的影响

采用实验生态学的方法设置包括自然海水在内的4个盐度组,分别为31(自然海水,对照组A)、26(B组)、22(C组)、18(D组)。按逐步降盐(DG)与盐度突变(DS)两种盐度变化模式对各组刺参进行盐度胁迫实验。结果表明,B组仅个别较小个体出现死亡现象,C组和D组刺参个体的DG与DS实验组的成活率均出现显著差异(P<0.05),DS-D组的成活率最低,仅为45.67%。不同盐度胁迫的各实验组之间,摄食率与食物转化率存在显著差异(P<0.05);而各实验组内,DG处理和DS处理的刺参个体的FR和FCR差异均未见显著(P>0.05)。B组内的两种降盐方式在降盐后的前10d生长有显著差异(P<0.05),之后20d内差异不显著(P>0.05)。C组和D组的刺参个体在实验中均出现体重负增长,与其余各组的SGR差异显著(P<0.05)。

Effects of low salinity stress on survival, growth and feeding rate of sea cucumber Apostichopus japonicus

Survival, growth and feeding rate of sea cucumber Apostichopus japonicus were studied in two different salinity change modes (DG: salinity Decreased Gradually; DS: salinity Decreased Sharply). In each mode, sea cucumbers were kept in seawater at 4 different salinities (31-A, 26-B, 22-C, 18-D) for 30d. The results showed that there were only a few individuals died in group B. There was significant difference between group C and D in DG and DS modes (P<0.05). The lowest survival rate was in group DS-D as 45.67%. There was significantly different FR and FCR between treatments under different low salinity stress (P<0.05). However, no significantly different FR and FCR appeared between different salinity change modes (DG and DS) during the experimental period (P>0.05). In group B, there was significant difference on growth of sea cucumber between two salinity change modes in the first 10d after the salinity decreased (P<0.05), but no significant difference in the next 20d (P>0.05). During the experiment, there were negative growth in group C and D, being significantly different from the other groups (P<0.05).