Studies On Biology And Control Techniques Of Limnoperna Fortunei (Dunker) In Water Supply System Of Shenzhen City

Limnoperna fortunei (golden mussel) adheres to raw water transmission pipe wall in massive numbers and affects normal water supply. A preliminary biology of L. fortunei and methods how to control and wipe it off were studed. Followings are the results:1. L. fortunei is dioecious, females typically comprise two-thirds of population, internal fertilization; continuously spawned from February to September, the threshold temperature level associated with the onset and termination of reproduction was 16-17℃, gonad mature in February and degenerate in September; shell growth velocity was 9.07mm per half year.2. Some physical methods controlling L. fortunei, including obdurating conduit being lack of oxygen, desiccating, and preventing L fortunei attaching to water pipes with dopes, were examined, and killing effect of these methods was compared. In the first method, at high water temperature, the bigger volume ratio of L. fortunei to raw water, the faster of golden mussel be killed. With the second method, survivorship of L. fortunei in air significantly decreased with prolonging aerial exposure time, increasing temperature, decreasing relative humidity. Examining five kinds of dopes, we found that preventing mussel dope was the most effective dope in inhibiting attachment of L. fortunei, however, it will release heavy metals step by step. The worst effect antifouling towards L. fortunei is achieved on concrete surface.3. The effects of killing the mussels by three methods,which were continuous chlorination, short-term chlorination and intermittent chlorination releasing into water with chlorine and sodium hypochlorite. Effect of killing its embryo, capacity of dissolving byssus with chlorine and sodium hypochlorite were also tested. The results...