背角无齿蚌摄食率及对水中叶绿素a清除能力的研究

STUDIES ON ELIMINATION OF CHLOROPHYLL-A AND INGESTION RATE IN EUTROPHIC WATER BY ANODONTA WOODIANA ELLIPTICA

椭圆背角无齿蚌是云南滇池的一种主要贝类物种。为探索该物种应用于滇池水体生物操纵的可行性,采用半野外模拟和原位围隔的方法,文章研究了背角无齿蚌的摄食率及对水中Chla的清除能力。结果表明:在23—28℃的温度范围内,背角无齿蚌的摄食率(IR)和湿重(W)呈现显著的相关冪指数关系:IR=aWb,1龄蚌和3龄蚌符合下列关系式:IR=6.2283X0.45,(R2=0.94);IR=0.0002X2.2,(R2=0.93)。3龄蚌的摄食率高于1龄蚌,且随生物量的增加摄食率有所减少。实验同时证明,背角无齿蚌有良好的清除水体中Chla的效果,对降低CODMn、TP含量同样具有较好的效果,且3龄蚌优于1龄蚌。通过方差分析综合分析得出,在生物量为4.17只/m3时,清除水体Chla的效果最优。

The Anodonta woodiana Heude is one of the major bivalve species cultured in Dianchi in China.The intensive aquaculture of this species has led to depressed growth and increased mortality in recent years.In order to estimate the carrying capacity for anodonta in the lake,it is necessary to determine accurately the ingestion rate and the capacity of eliminating Chlorophyll-a by the anodonta.The results showed that the relationship between ingestion rate（IR） and wet weight of tissue（W） could be represented by the allometric equation IR=aWb under nature temperature（23—28℃）.The IR of three-year-old anodonta（shell height and wet weight） was higher than that of the one-year-old anodonta.The three-year-old anodonta was found to be able to eliminate Chlorophyll-a better in water efficiently.By analysis of variance,we concluded that the effect of elimination was remarkable after 8 days in the lab.The enclosure study indicated that the effect of elimination was the best when the density of mussels was 4.17 ind./m^3.