Studies Of Oxygen Consumption Rate, Asphyxiant Point And Acute Toxicity Experiment Of Four Common Drugs On Elopichthys Bambusa Juvenile

Elopichthys bambusa(Richardson) is a special kind of fish as well as one of the important breeding species in China,because of its great economic,nutritional value and better productive performance.Now,only a few research focus on its growth and feeding,and studies on its oxygen consumption rate(OCR),the asphyxiant point(AP) and acute toxic experiment of common using aquaculture drugs against Elopichthys bambusa have not been conducted.This paper is to determinate the rate of dissolved oxygen consumption,critical oxygen,point of asphyxiation to Elopichthys bambusa juvenile(experiment 1).Furthermore,Tolerance of Elopichthys bambusa juvenile to trichlorfon,strong chlorine,dibromohydantoin,cypermethrin was investigated in acute toxicity experiments.In the experiment 1,The oxygen consumption rate(OCR) and the effect of water temperature on the asphyxiant point(AP) of Elopichthys bambusa juvenile enclosed in 2000ml respiratory chamber were studied.The results demonstrated that under the controlled temperature(20～28℃) the oxygen consumption rate(OCR) and the asphyxiant point(AP) increased while temperature rose.OCR of Elopichthys bambusa juvenile was lowest,0.3006 mg/g.h at water temperature 20℃.while when water temperature at 24℃or 28℃,OCR of the asphyxiant point(AP) 0.3770 mg/g.h and 0.4821 mg/g·h,respectively.The power exponential function relationships between OCR(M2) and water temperature can be described as M2= 0.00305T^1.399 (R²=0.9548).If oxygen consumption(M1) instead of OCR,the relationship between oxygen consumption and water temperature can be described as M1=0.00997T^1.2579 (R²=0.940).The asphyxiant point(AP) of Elopichthys bambusa increased while temperature rose as well.AP of Elopichthys bambusa at 20℃,24℃,28℃water temperature were 1.28 mg/L,1.36 mg/L,and 1.52 mg/L respectively.Based on pre-experiment,acute toxicity test of four reagents to Elopichthys bambusa were established in static water with different time,no additive regent group as control,and their impacting factors of four drugs toxicity were determined with mortality of Elopichthys bambusa.The results showed the 48h,72h and 96h LC50(median lethal concentration) values for trichlorfon against fingerling of Elopichthys bambusa(with average body length 6.0±0.5cm,average bodyweight2.5g) were found to be 15.78 mg/L,12.19 mg/L,and 10.10 mg/L,respectively.Tlm values for dibromohydantoin against juvenile of Elopichthys bambusa were highest among four regeats.Those of 24 Tlm,48 Tlm and 96 Tlm were 20.82 mg/l,18.44 mg/l and 16.33 mg/l respectively.Among four drugs,The toxicity of cypermethrin was strongest,which the concentration(mg/L) of 24 Tlm,48 Tlm and 96 Tlm were 2.60, 2.527 and 2.319.According to Turubell formula,deriving the safety concentration (SC) for trichlorfon,strong chlorine,cypermethrin and dibromohydantoin to Elopichthys bambusa were 2.18mg/L,0.72mg/L,4.43mg/L and 0.003 mg/L.Among four drugs the order of toxicity to Elopichthys bambusa juvenile was cypermethrin＞strong chlorine＞trichlorfon＞dibromohydantoin.So,it's more relatively safety using cypermethrin,strong chlorine,trichlorfon than dibromohydantoin in Elopichthys bambusa practical breeding.