The Effects Of Temperature And Salinity On Physiology And Metablism In Isognomon Ephippium

The effects of temperature and salinity on I. ephippium’s growth rate(GR),survive rate(SR),clearance rate(CR),ingestion rate(IR),oxygen consumption rate(OR),ammonia-N excretion rate(NR),oxygen-nitrogen value(O/N)and effect strength(Q10) were studied by using an method of indoor ecology.That the study founds the relation between the variation of temperature(18℃,22℃,26℃,30℃,34℃) or salinity(15‰, 20‰, 25‰,30‰, 35‰)and the physiology and metablism of I. ephippium aims to providing scientific basis for the exploitation of I. ephippium and ecosystem restoration.The results showed as that:1. The effects of temperature and salinity on I. ephippium’s growthThe effects of temperature variation on the growth rate of I. ephippium is significant(P<0.05). It has a positive correlation between I. ephippium and temperature when the temperature range 18-26℃.When the temperature exceeds 26℃, the growth rate of I.ephippium decreased slowly with increasing temperature.with the temperature at 34℃,that the survival of I. ephippium is only 59%.the study indicate that I. ephippium has suitable growth temperture range of 22~30℃.The regression curve between salinity and specific growth rate of I.ephippium is:WSGR=-0.1993T2+1.2298T-0.9965,R2=0.9234.Also, the effects of salinity on the growth rate of I. ephippium is significant(P <0.05).The peak growth rate of I. ephippium appeared when salinity at 25‰. The growth rate has decreased slowly when the salinity above or below 25‰. The regression curve between salinity(salinity range 20-30‰, suitable for the I. ephippium live) and specific growth rate of I.ephippium is: WSGR=-0.0054S2+0.2619S-2.2671,R2=0.9741。2. The effects of temperature and salinity on I. ephippium’s respiration and excretion.It has a positive correlation between temperature and I. ephippium’s oxygen consumption rate and ammonia excretion rate when the temperature range of 18~30℃.The effects of temperature variation on oxygen consumption rate and ammonia excretion rate of I. ephippium is significant(P<0.05). Within the normal fluctuation range, Q10 of the I. ephippium is higher than 1.0. Respiratory metabolism has significant inhibitory when temperature increase. When the temperature is above 30℃, the oxygen consumption rate decreased rapidly and the ammonia excretion rate has continued increase. Q10 of I. ephippium has below 1.0 when then temperature is 34℃. The O/N ofthe I. ephippium increases with the increase of temperature, and reached the peak at 26℃(12.53±0.24). Therefore, at the temperature of 22~30℃ is more conducive to the body protein Cumulation.Moreover, the effects of salinity on oxygen consumption rate and ammonia excretion rate of I.ephippium is significant(P<0.05). The oxygen consumption rate of I. ephippium increases with salinity increase when salinity variation bewteen 15~30‰. The oxygen consumption rate of I. ephippium reached the lowest 1.17±0.02mg/(g·h) when salinity at35. The ammonia excretion rate of I.ephippium reached the lowest 155.17±5.28ug/(g·h)when the salinity at 15‰ or reached the peak278.90±11.81ug/(g·h) when the salinity at35‰. The oxygen-nitrogen value of I. ephippium increases from 9.50 to 10.66 with salinity increase when salinity variation bewteen 15-30‰.The oxygen-nitrogen value of I.ephippium decreased rapidly and reach the lowest(4.19) when salinity at 35‰. The Q10 of I. ephippium lower than 1 when thesalinity between 30-35‰. Therefore, the salinity variation between 15~30‰ is more suitable for I. ephippium’s respiration and excretion.The test shows that the effects of salinity on clearance rate and ingestion rate of I.ephippium is significant(P<0.01).The clearance rate and ingestion rate of I. ephippium increases with temperature increase when temperature variation bewteen 18~30℃ and reached the peak(0.771±0.104 and 13.42±1.72) when the temperature at 30℃. The clearance rate and ingestion rate of I. ephippium decreased rapidly when the temperature at 30℃. So, the temperature variation between 18~30℃ is more suitable for I.ephippium’s ingestion metablism.3. The effects of temperature and salinity on I. ephippium’s ingestion metablism.The test shows that the effects of salinity on clearance rate and ingestion rate of I.ephippium is significant(P<0.01).The clearance rate and ingestion rate of I. ephippium increases with temperature increase when temperature variation bewteen 18~30℃ and reached the peak 0.771±0.104(cell/h) and 13.42±1.72cell/(g·h) when the temperature at30℃. The clearance rate and ingestion rate of I. ephippium decreased rapidly when the temperature at 30℃. So, the temperature variation between 18~30℃ is more suitable for I. ephippium’s ingestion metablism.The study shows that the clearance rate of I. ephippium increases slowly with the increase salinity when salinity variation bewteen 15~30‰. The clearance rate of salinity at 35‰ is lower than other group visibly. The ingestion rate of I. ephippium decreases with temperature increase when salinity variation bewteen 20~35‰. The clearance rate and ingestion rate of I. ephippium is larger than other group when salinity at 20‰ or25‰.therefore, the salinity variation between 15~30‰ is the suitable for I. ephippium’singestion metablism.