仿刺参与鼠尾藻、菊花心江蓠轮养时的生长及对环境因子的影响

Growth of Sea Cucumber and Water Quality Features in Polyculture of Sea Cucumber with Seaweeds Sargassum thunbergii and Gracilaria lichenoides

将初始体质量(5.07±0.45)g的仿刺参幼参放养在池塘内竹制的4m×4m×1.5m网格中,将夹有初始平均体长(31.7±10)cm,体质量(2.32±1.2)g的鼠尾藻和菊花心江蓠的聚乙烯苗绳均匀地系在网格竹竿骨架上。仿刺参初始放养密度为11头/m2,鼠尾藻和菊花心江蓠的密度分别为187.5g/m2、375g/m2、562.5g/m2、750g/m2和250g/m2、500g/m2、750g/m2、1000g/m2,后轮养的菊花心江蓠按密度从小到大分别放置于原混养鼠尾藻密度为187.5g/m2、375g/m2、562.5g/m2、750g/m2网格内。每隔15d检测一次不同轮养系统中仿刺参和藻类的生长及水体中叶绿素a,底泥中总氮、总磷和有机碳含量的变化。120d的饲养结果表明,轮养大型藻的仿刺参特定生长率高于单养对照组的仿刺参,混养鼠尾藻562.5g/m2后,轮养菊花心江蓠750g/m2的模式下,仿刺参的特定生长率显著高于对照组(P<0.05);轮养水体中叶绿素a含量明显下降,大型藻净产量越高,水体中叶绿素a含量下降越明显;轮养组底泥中总氮、总磷和总有机碳含量均明显低于单养组(P<0.05)。

Juvenile sea cucumber Apostichopusjaponicus with body weight of （5.07±0.45） g was stocked at a rate of 11 ind/m^2 and polycultured in a bamboo made 4 m（width）×4 re（length）× 1.5 m（height） grid tied by PVA strings of sea weeds Sargassum thunbergii with body length of （31.7±10） cm [body weight of （2.32±1.2） g] at a rate of 187.5 g/m^2（A1）, 375 g/m^2 （Ba）,562.5 g/m^2 （Ca）and 750 g/m^2 （D1）for 45 days and Gracilaria lichenoides with the same size at a rate of 250 g/m^2 （A2）, 500 g/m^2 （B2）,750 g/m^2 （C2）and 1000 g/m^2（D2） for 60 days in a pond. The polyculture was conducted alternatively, that is, G. lichenoides was stocked later into the grids （A1 ,B2 ,C2 andD2） which S. thunbergii was tied initially （A1, B1 ,C1 and D1）. The growth of the sea cucumber and sea weeds and levels of chlorophyll a, total nitrogen （TN）, total phosphorus （TP） and total organic carbon （TOC） were determined in a 15 day interval. The results showed that there was higher specific growth rate （SGR） in the sea cucumber polycultured with the seaweeds than in the sea cucumber in monoculture, significantly higher in polyculture C than in the monoculture（P〈0.05）. The chlorophyll a level was shown to be declined in the polyculture water with increase in net yield of the sea weeds. There were significantly lower levels of TN, TP and TOC in the sediments in the polyculture than those in the monoculture of sea cucumber（P 〈 0.05）.