Studies On Comparison Of Olfactory Electrophysiological Responses Between 2 Carnivorous Fishes And The Food Attractant Of Monomer Amino Acid In Micropterus Salmoides

Monomer amin o acid attractants not only can promote the fe eding of fish,but also have an important effect on the growth,development and reproduction of fish.Therefore,exploring m onomer amino acid attra ctants suitable for fish will help to promote the develop ment of efficient special food attractants,and provide a scienti fic basis for the preparation of artificial compound feed for fish and the development of fish bait at the same time.In order to achieve the purpose of saving fish culture costs and improvin g fish culture income,and provide valuable reference for th e development of fishing competitive sports industry.In this study,2 experiments were designed.Firstly,electro-olfactogram（EOG）was used to study the olfactory electrophysiological response of largemouth bass and hybrid grouper（Epinephelus lanceolatu s♂×E.fuscoguttatus♀）to 20 common monomer amino acids,and then the sea bass was taken as the object of study.The feeding effect of some monomer amino acids screened by EOG was verified by behavioral method.The results are as follows:Experiment 1:comparative study on olfactory electrophysiological response of largemouth bass and hybrid grouper to 20 common monomer amino acidsIn this experiment,the difference of olfactory response to 20 common monomer amino acids,the response to the concentration gra dient of 5 monomer amino acids and the olfactory response threshold were obtaine d by EOG.The relationship between the molecular structure of monomer amino acids and the effect of olfactory stimulation was discussed.The type and concentration of amino acids had an effect on the olfactory stimulation response of largemouth bass and hybrid grouper,which was larger than that of the control experiment.largemouth bass and hybrid grouper reacted strongly t o neutral aliphatic sulfur-containing amino acids conta ining 3 and 5 carbon atoms and no branched chain,respectively.The amplitude of olfactory response（y）of largemouth bass and hybrid grouper increased exponentially with the increase of logarithm（x）of the concentration of 5 amino acids,and satisfied th e equation:y=a+exp（b+c×x）,in which a,b,c were cons tants.In this experiment,the amplitude of olfacto ry response of largemouth bass and hybrid grouper did not reach the plateau with the increase of logarithm concentration of five amino acids.The relationship between the reaction amplitude（y）and the concentration of amino aci d stimulation solution（x）satisfies the equation:log（y）=a+b×log（x）,a,b are constants.The reaction threshold conce ntrations are 10^{-1 0}～10^-7mol/L（largemouth bass）and 10^{-1 0}～10^-6mol/L（hybrid grouper）,respectively.In this experi ment,10^-2mol/L Cysteine stimulation solution was the strongest（RSE=179.02±26.24%）to largemouth bass,and 10^-6mol/L Proline stimulation solution was the weakest（RSE=21.24±4.08%）to largemouth bass.10^-2mol/L Methionine stimulation solution had the strong est irritation to hybrid grouper（RSE=187.18±2.38%）,and 10^-6mol/L Proline stimulation solution had the weakest irritation to hybrid grouper（RSE=28.73±0.26%）.The olfactory electrophysiological res ponse patterns of largemouth bass and hybrid grouper had a strong correlation to monomer amino acids（r=0.82）.Experiment 2:behavioral response of largemouth bass to 5 monomer amino acidsIn this experiment,the feeding effect of some monomer amino acids screened by EOG was studied by behavioral method.The f eeding effect of different concentrations of Cysteine on largemouth bass was stronger than that of the control,and the difference was signi ficant.With the increase of Cysteine concentration,the stro nger the feeding effect was,and 10^-2mol/L Cysteine was the most attractive to largemouth bass.The feeding effect of Methionine on largemouth bass was stronger than that of the control,and the re was significant difference at low concentration（P<0.05）,but there was no significant difference at high concentr ation（P>0.05）,and decreased with the increase of Methionine concentration.The feeding effect of each concentration of Alanine was stronger than that of the control,and there was significant differ ence at low concentration（P<0.05）,but there was no sig nificant difference at high concentration（P>0.05）,and with the increase of Alanine concentration,the feeding effect was almost unchanged and reached the plateau stage.There was no difference betwe en the low concentration of Glutamate and the control,t hat is,there was no fo od attraction,and there w as no significant difference between the low concentration of glutamate and the control（P>0.05）.The inhibitory effect at high concentration was weake r than that of the control（P<0.05）,and the difference was significant（P<0.05）.And with the increase of concentration,the inhibition was stronger.The feeding balls with different concentrations of Proline were not attractive to largemouth bass.Only the appropriate type and concentration of monomer amino a cids can achieve a better food attraction effect,high concentration will lead to the decline of food attraction effect or produce inhibitory effect.