水体中饵料投喂量对不同规格光裸方格星虫耗氧率及排氨率的影响

Effects of Suspended Feed Amount on Oxygen Consumption Rate and Ammonia Excretion Rate of Different Sized Sipunculus nudus Linnaeus

关键词:  光裸方格星虫  饵料悬浮  规格  耗氧率  排氨率

Key words:  Sipunculus nudus Linnaeus  Suspended feed concentration  Body weight  Oxygen consumption rate  Ammonia excretion rate

摘要:

为研究饵料投喂量对不同规格光裸方格星虫(Sipunculus nudus Linnaeus)呼吸代谢的影响，采用实验生态学方法，研究了不同螺旋藻(Spirulina platensis)投喂量(5、10、15、20和25 mg/L)对3种规格[小(S)(1.58±0.48) g、中(M)(4.90±1.06) g和大(L)(7.96±0.94) g]光裸方格星虫耗氧率和排氨率的影响。结果显示，饵料投喂量对耗氧率和排氨率均影响显著(P<0.05)，饵料投喂量和规格的交互作用对光裸方格星虫耗氧率和排氨率影响极显著(P<0.01)。当饵料投喂量达到15 mg/L时，3组规格光裸方格星虫的耗氧率和排氨率均出现显著下降。光裸方格星虫耗氧率和排氨率均随着饵料投喂量增加而明显降低，且与饵料投喂量呈一元三次函数关系：y = ax3+bx2+cx+d。对于耗氧率，a值的范围为0.003~0.033，b值的范围为–1.698~ –0.053，c值的范围为–1.805~18.873，d值的范围为–15.675~79.940。对于排氨率，a值的范围为0.0003~0.004，b值的范围为–0.172~ –0.003，c值的范围为–0.326~1.972，d值的范围为3.634~14.008。光裸方格星虫耗氧率和排氨率均随着体重增加表现出曲线增加的规律。耗氧率与体重呈指数函数关系：y=aebx，a值的范围为8.082~20.934，b值的范围为0.217~0.270；排氨率与体重呈幂函数关系：y =axb，a值的范围为1.441~3.598，b值的范围为0.521~0.747。光裸方格星虫的氧氮比(O/N)范围为1.26~10.60。研究表明，高浓度饵料投喂量会对光裸方格星虫的呼吸代谢产生负作用，当饵料投喂量达到20 mg/L时，光裸方格星虫的耗氧率和排氨率波动较大且显著下降。

Abstract:

Peanut-worms Sipunculus nudus are exploited as a popular seafood in international and domestic markets due to high nutritional and pharmaceutical value. In recent years, over-exploitation of S. nudus has caused that natural resource to be degraded greatly, therefore study on S. nudus respiratory metabolism needs to be carried out to better understand the culture capacity and sustainable development of S. nudus resources. The effects of suspended feed concentration (5 mg/L, 10 mg/L, 15 mg/L, 20 mg/L, 25 mg/L) and body weight S(1.58±0.48 g), M(4.90±1.06 g) and L(7.96±0.94 g) on oxygen consumption rate (OR) and ammonia excretion rate (AR) rate of Sipunculus nudus Linnaeus were studied using experimental ecology methods. The results indicated that suspended feed concentration had significant effects on OR and AR (P<0.05), and interaction of the both factors had a significant effect on OR and AR (P<0.01). When feed concentration reached 15 mg/L, the OR and AR decreased significantly. Both the OR and AR decreased with the increasing feed concentration. The relationship between OR or AR and suspended feed concentration can be represented by the cubic function y＝ax3＋bx2+cx+d, where a values of OR or AR ranged in 0.003~0.033 and 0.0003~0.004, b values ranged in –1.698~–0.053 and –0.172~–0.003, c values ranged in –1.805~18.873 and –0.326~1.972, d values ranged in –15.675~79.940 and 3.634~14.008. Both the OR and AR increased with increasing body weight. The relationship between OR and body weight can be represented by the exponential function y=aebx, where a values ranged in 8.082~20.934 and b values ranged in 0.217~0.270. The relationship between AR and body weight can be represented by the power function y=axb, where a values ranged in 1.441~3.598, and b values ranged in 0.521~0.747. The O/N value ranged from 1.26 to 10.60. The study showed that high suspended feed concentration had a negative influence on S. nudus; once it reached 20 mg/L, the OR and AR fluctuated and declined significantly