The Research Of Adaptability In Salinity And Alkalinity Of Triplophysa Dalai

the tolerance of three cobitidae fish species i.e.Misgurnus mohoity Dybowsky,Paramisgurnus dabryanus Sauvage,Triplophysa dalaica to salinity and alkalinity were investigated by 96 h one-way acute toxicity test and uniform orthogonal test in this study,to study the feasibility of cobitidae fish farming in saline water.In addition,the gill and liver tissue microscopic structure and the change of antioxidant enzyme activity of the T.dalaica under the gradient alkalinity of Sodium Bicarbonate.The thesis did the research for T.dalaica adaptability adjust law for the alkalinity of sodium bicarbonate were studied.The results of research provide the theoretical basis for the development and utilization of the cobitidae fish in different carbonate type saline waters;meanwhile it provides the basic physiological and biochemistry data support of alkali-resistant capacity of T.dalaica.The following are the research and its results: 1?Tolerance of Triplophysa dalaica to NaCl salinity and NaHCO₃ alkalinityThe results showed that: the 24 h and 96 h LC50 of salinity in T.dalaica,M.mohoity,P.dabryanus were 15.64 g/L and 13.58 g/L,15.43 g/L and 14.18 g/L,14.00 g/L and 11.57 g/L,respectively,with the safe concentration?SC?were 4.12 g/L,4.03 g/L,3.74 g/L respectively.The sequence of salinity-tolerate were M.mohoity>P.dabryanus>T.dalaica.The 24 h and 96 h LC50 of carbonate-alkalinity in T.dalaica M.mohoity,P.dabryanus were 117.1 mmol/L and 72.62 mmol/L,128.4 mmol/L and 88.83 mmol/L,155.2 mmol/L and 120.0 mmol/L,respectively,with the SC were 18.77 mmol/L,23.66 mmol/L,36.30 mmol/L respectively.The sequence of salinity-tolerate were: T.dalaica>P.dabryanus>M.mohoity.The joint effect of salinity and alkalinity expressed coordination in M.mohoity and P.dabryanus,and the coordination coefficients first increased and then decreased,reached the maximum at 48 h.However,the joint effect presented coordination in T.dalaica within 0⁴8 h,whereas antagonism in 48⁹6 h,and the coefficient of antagonism gradually increased along the exposure time.This paper provided theoretical basis for promotion and breeding of cobitidae fish in salinity-alkalinity water in the future.2?The effects NaHCO₃ alkalinity on the structure and ultrastructure enzyme Activities of gill of Triplophysa dalaicThrough the observation of gill pathological tissue under the alkalinity,stress of Sodium Bicarbonate: CA30 and CA50 gill structure under the stress are similar to the control group,gill filament is bloom,branch leaf is long and its structure is intact.In early phase of the research,the experiment fish of CA70 gill filament atrophied,the gap between branch leaves enlarged,the apical cells of branch leaf was found hypertrophic and dropsically,then it rehabilitated later;CA90 gill filament atrophied obviously,the gap between branch leaf shrunk increasingly,epithelial cells were found edematous,and they were recovered after 7d without renewing as the control group.The fish under the condition of CA110 atrophied distinctly,and epidermis cell of gill filament fell off clearly,branch leaf could not stand and showed crooked close to the gill filament,and epithelial cells swelled and thickened obviously with detachment,and got more hurt with the increase of time and couldn't recovered during the experiment.Under the alkalinity stress of Sodium Bicarbonate,activity of SOD and CAT both showed the trend of recovery after the significant changes.With the different concentration,it showed different regularities:?1?the peak time of two kinds of antioxidant enzyme activity is slightly different,SOD peak appeared at about 6 hours,and CAT appeared around 12 hours.?2?The activity of SOD and CAT in gill of CA30 and CA50 are similar to the control group.?3?Except the SOD's activity in CA70 got stable and was higher than the control group,CA70 and CA90 SOD activity could recover to the degree as the control group.The activity of two antioxidant enzymes regained stability with the lower degree of the control group under the CA90.3?The effects NaHCO₃ alkalinity on the structure and ultrastructure enzyme Activities of liver of Triplophysa dalaicThrough the observation of gill pathological tissue under the alkalinity stress of Sodium Bicarbonate,The liver structure is similar to that of the control group under: CA30 and CA50 stress,liver cell nucleus located in the center.Part of liver cell nucleus deviated in the early period of CA70 and recovered later.The liver cells in CA90 appeared abnormally swelled slightly,the cell nucleus deviated the center,cytoplasm showed mildly and vacuolization from a few happened.The fish under the condition of CA110 aggravated the degree of abnormal.In the later period of experiment,the author could observe that liver cell membrane disappeared and there was a lack of the liver cells.Under alkalinity stress of Sodium Bicarbonate,SOD and CAT activity in the liver tissue showed the trend of recovery after significant changes,but with different concentration,it shows different rules.?1?the peak time of two kinds of antioxidant enzyme activity is slightly different with the different alkalinity,SOD peak appeared at 12 h-24 h,CAT appeared 24 h-2 d.?2?In addition to the CAT activity of CA50 experimental appeared the peak at 24 h,the SOD and CAT activity in liver of CA 30 and CA50 are similar to that of the control group.?3?The SOD and CAT activity in liver of CA 70,CA 90 and CA110 all showed obvious peak value,and with the experiments gradually began to recover to a stable state.However,the activity of CAT of CA90 and CA110 are higher than that of the control group.