Effects Of Partial Environmental Factors On Oxygen Consumption Rate,Ammonia Excretion Rate And Activities Of Related Enzymes Of The Snail Oncomelania Hupensis

Objective: To explore the effcts of ambient temperature,p H,salinity on oxygen consumption rate,ammonia excretion rate and the activity of respiratory metabolism related enzymes(HK and LDH)of Oncomelania hupensis.Methods:1.The oxygen consumption rate and ammonia excretion rate of the snails were determined by spectrophotometric method and hypobromite oxidation method at different temperatures,p H and salinity respectively.Explore the effects of the change of environmental factors on the oxygen consumption rate and ammonia excretion rate of Oncomelania hupensis.2.After the oxygen consumption rate and ammonia excretion rate experiment,crushed and unshelled the snails rapidly on the ice plate and sopped up the tissue moisture with filter paper;collected and weighed the soft tissue;placed in the 1.5 ml centrifuge tube;put the tube into liquid nitrogen rapidly,and stored in the-80 ?Ultra-low temperature freeze.Put 0.05 g tissue into 0.45 ml PBS buffer,grinded sufficiently in ice water;centrifuged at 3500r/min with desktop refrigerated supercentrifuge after grindding;subpackaged the tissue homonate into EP tube.The activities of HK and LDH were determinded by enzyme-linked immunoabsorbent assay(ELISA)method.Results:1.The effects of environmental factors on the oxygen consumption rate of snails are as follows:(1)The effect of environmental temperature on the oxygen consumption rate of snails was significant within 1? to 40?(F=131.176,P<0.01);The oxygen consumption rate of the snails was increasing with temperature increasing from 1? to16? and reached maximum at 16?(53.100±0.748×10-2mg/g·h);When the ambient temperature exceeded 16 ?,the oxygen consumption rate was decreasing with temperature rising and dropped to 11.770±3.102×10-2mg/g·h at 31 ?;The oxygen consumption rate showed a slow growth above 31 ?,but the difference was not significant(P>0.05).(2)The effect of p H value on the oxygen consumption rate of snails was significant in the range of p H 6.0 to 8.0(F=50.679,P<0.01);When the p H value exceeds 6.0,the oxygen consumption rate decreased with p H value rising and reached minimum at p H 7.0(4.184±1.573×10-2mg/g·h);The oxygen consumption rate of the snails was increasing with p H value rising from 7.0;There was no significant difference between p H 6.5 and p H 7.0(P>0.05).(3)The oxygen consumption rate of the snails was increasing with salinity rising from 0.3 and reached maximum at 0.8(19.356±1.232×10-2mg/g·h);And the rate was decreasing with salinity increasing from 0.8 to 1.8 and reached minimum at 1.8?(1.829±2.643×10-2mg/g·h);The effect of environmental salinity on the oxygen consumption rate of snails was significant,too(F=12.410,P<0.01).2.The effects of environmental factors on the ammonia excretion rate of snails are as follows:(1))The effect of environmental temperature on the ammonia excretion rate of snails was significant within 1 ? to 40 ?(F=523.480,P<0.01);The ammonia excretion rate of the snails was decreasing with temperature increasing from 1? to13?;When the temperature dropped below 10 ?,the difference of the ammonia excretion rate of the snails was not significant(P>0.05).The rate fluctuated in a certain range with temperature increasing from 13? to 34? and decreased gradually whentemperature was above 34 ?.The difference was not statistically significant when temperature was above 37?.(2)The ammonia excretion rate was increasing with p H value rising in the range of p H 6.0 to 8.0,and the difference was significant(F=352.439,P<0.01);And the ammonia excretion rate reached maximum at p H 7.5(14.616±0.494×10-2mg/g·h).There was no significant difference in the ammonia excretion rate between p H 7.5 and p H 8.0(P>0.05).(3)The ammonia excretion rate of the snails was increasing gradually with salinity rising from 0.3 to 1.3,the difference was statistically significant(F=7.876,P<0.05);When salinity was 1.3,the ammonia excretion rate reached maximum(6.750±0.041×10-2mg/g·h).3.Activity of HK of 0.hupensis was first increased and then decreased(P<0.01).However activity of LDH showed a rising price,then a drop,then another rise(P<0.01).With the increase of the experimental p H,activity of HK displayed a decreasing trend,while activity of LDH first increased,then decreased.Activities of HK and LDH did not show significant difference under different p H values(P> 0.05).Salinity had a significant effect on both activities of HK and LDH(P <0.05).Their activities decreased with the increase of salinity.Conclusion:1.Temperature,salinity and p H value have a significant effect on the metabolism of Oncomelania hupensis.2.Temperature and salinity have significant effects on activities of HK and LDH and the respiratory metabolism of O.hupensis.Activities of HK and LDH did not show significant difference under different p H values.