Phototaxis Of Oncomelania Hupensis And Molluscicidal Activity On Oncomelania Hupensis Of The Zingiberis

Part 1 Phototaxis of Oncomelania hupensis for different intensity and color of light .Objective To study phototaxis of Oncomelania hupensis for different intensity and color of light .Method we applied the self-made equipment,with the normal Oncomelania hupensis as experiment subject,with white light as illuminant,intensity of light was 500,1000,1500,2000,2500,3000,3500,4000,4500and5000Lux. The colors of light were red ,yellow,green and blue.All intensity of light was 100Lux for the test of the phototaxis.Result The reseach results showed that Oncomelania appeared positive phototaxis,when the intensity of light was less than 2000Lux,the phototactic index(IP) increased with the boosted light intensity ,IP was maxmum when the light intensity was 2000Lux, IP has no obviouse difference among 500Lux,1000Lux and 1500Lux (P>0.05), but it had obviously significant difference between 500Lux and2000Lux (P<0.01),when the intensity of light was above 2000Lux, IP decreased with increasing of light intensity,Ip has no obviouse difference among 2500Lux,3000Lux and 3500Lux(P>0.05), there was significant difference between 3500Lux and 4000Lux (P<0.01).Oncomelania appeared positive phototaxis with all of the four colors. The phototaxis difference between green and red had the most significant(P<0.01),the result showed that the phototaxis of these four colors respectively were green>blue>yellow>red .Conclusion Based on this research we have the conclusion that Oncomelania appeared positive phototaxis,.when the intensity of light was less than 2000Lux,the phototactic index(IP) increased with the boosted light intensity;IP was maxmum when the light intensity was 2000Lux,when the intensity of light was above 2000Lux, IP decreased with increasing of light intensity.The result showed that the phototaxis of oncomelania on green and blue were greater than red and yellow,the phototaxis of these four colors respectively were green>blue>yellow>red . Part 2 to Part 4 molluscicidal activity on Oncomelania hupensis of the zingiberisObjective To study the molluscicidal activity and mechanism on Oncomelania hupensis of the zingiberis fluid and offer a reference for researching new plant molluscacides and the utility of zingiberis on schistosomiasis .Methods:molluscicidal experiment was carried out , in which the snails were soaked in different concentrations of zingiberis solusion ( 1 g/ L ,2 g/ L,5g/L ,10 g/ L and 20g/ L) for 24 , 48, 72 and 96 hours,the death rate of snails were observed after 24 ,48 ,72 and 96 hours and compared with controls. Snail eggs were immersed in different concentration of zingiberis solution(0.25/ L,0.5 g/ L ,1 g/ L,2.5 g/L ,5 g/ L and 10g/ L),the rate of hatching and the change of embryo were also observed after treatment for 24 hours and compared with controls.The ginerol crude extracts were lixiviated from zingiberis by the acetidin soluvent, the DMF was used to be adjuvant and the concentration of the DMF was 1ml/L,the snails were soaked in different concentrations of zingiberis solusion ( 5mg/L,10mg/L,20mg/L,40mg/L,80mg/L) for 24 , 48, 72 and 96 hours,the death rate of snails were observed after 24 ,48 ,72 and 96 hours and compared with DMF(1ml/L) and controls. The experiment of molluscicidal mechanism was to test the content of protein and DNA of soft tissues of snails after treated for 48 hours in 20g/L concentration.Result:(1) It was found that the death rate of snails was increasing along with the increasing concentrations and the prolonging time.It was≥56.7% after the snails were treated for 72 hours. At 96 hours,the death rate was up to 100%.(2) When the concentration was <1g/L,the hatching rate of snails eggs was no difference compared with controls(P>0.05).However, it was 56% when the concentration was1g/L.There was obvious difference compared with the concentration of 0.25g/L,0.5g/L and controls(P<0.01). Until the concentration was>1g/L,it was 0%, It was significant difference compared with controls.(P<0.01).(3) After the snail eggs were soaked for 24h in the concentration of 0.25g/Land 0.5g/L, the embryos were still clear,which was no change compared with controls.At the concentration was 1g/L, the embryos began to change.The structure of embryos were unclear and the embryos were no action in the eggs membrane.The colour of the embryos came to dark from brown.As the concentration was increasing, the change of embryos were more significant and inclined to broken.(4) The death rate of snails was increasing along with the increasing concentrations of ginerol crude extracts and the prolonging time.When the snails were treated for 48h in different concentration,the minimal death rate was 53.3%,the maximum was 100%.After 72 hours, the death rate was≥90%.When the snails were treated for 96h ,the death rate was all 100%.(5) The content of protein of soft tissues of snails was lower than controls after treated for 48 hours in 20g/L concentration(P<0.01).The content of DNA had no obvious decline(P>0.05).Conclusion The zingiberis fluid had good effect on killing snails and snail eggs. The death rate of snails was increasing along with the increasing concentration and the prolonging time.When the concentration was <1g/L,the hatching rate and the morphology of snail eggs had no obvious change.When the concentration was≥1g/L,the hatching rate and the morphology of snail eggs began to change significantly.The ginerol crude extracts shows an adequate molluscicidal activity.The ginerol maybe has effective molluscacidal compound . Zingiberis fluid could make the content of protein of soft tissues of snails decline and affected the energy metabolism of snails,but there was no obvious effect on DNA .