Organs Identification Of Chinese Sturgeon (Acipenser Sinensis) Using Ultrasound Imaging

Chinese sturgeon(Acipenser sinensis Gray),an anadromous fish,distributes in the most south place among the world sturgeon species.Since 1970s,as a result of the construction of Gezhouba hydroelectric Dam and Three Gorges Project,in addition to the effect of environment degradation,the nature population serious threat.Chinese sturgeon was listed in categoryⅠof the National Protected Animals in 1988.Surgical operation is usually used to inspect the parent fish of Chinese sturgeon,but it has high fatality. Establishing safe and non-injured technology to inspect the parent fish is apparently important.The application of ultrasonic diagnosis in the fish tends to mature in the foreign,but not in China.Ultrasonic diagnosis that uses in the internal organs of Chinese sturgeon was studied in this issue.The result show:1.The first turning point of esophagus corresponded to the fifth and sixth scute of right abdomen,the second one corresponded to or was anterior to the first scute.The heart of ultrasound image showed that blood no echo,the wall was smooth with clear interface. The right hepar corresponded to the sixth and seventh scute of right abdomen.The left hepar corresponded to the foth and fifth scute.Ultrasound image of hepar parenchyma was composed of tiny and weak echoes,and ultrasound image of hepar wall was smooth and homogeneous.Pyloric caecum corresponded to the second and third scute. Abdominal muscular layer had strong echo images of pale colour;gallbladder contour was clear,and the wall of it had brighter echoes than hepar parenchyma;the protuberance d epartment of ileum had bright echo;and the concave department had no echo;the ultrasound images of esophagus,ventriculus,pyloric caecum and bladder were not obvious.2.It was a positive linear relationship(p＜0.01) between body length(x) and the cross-section circumferece of hear(y),y=1.689x+10.118(R~2=0.825,n=42).Gills moving frequency rate and heart rate had a negative linear relationship with age.Gills moving frequency of one year-old sturgeon was the highest with,104.6±8.9 times/min,and that of the matured wild parent fish was the lowest with 50.5±3.6 times/min(n=8).It was a negative linear relationship(p＜0.01) between body length(x) and gills moving frequency (y) with,y=-0.5078x+130.59(R~2=0.8161,n=35).Gills moving frequency and heart rate had a positive linear relationship with water temperature.At water temperature of 13℃gills moving frequency was 74.5±6.2 times/min(n=5),and heart rate was 26.9±3.2 times/min(n=5);at 28℃gills moving frequency was 106.1±6.4 times/min(n=5),and heart rate was 43.4±8.44 times/min(n=5).Results showed that gills moving frequency and heart rate of Chinese sturgeon were stable when developing to certain age.3.It was not sigificant difference in the head exterior characteristics of male and female of 1,2,3,4 year-old Chinese sturgeon.The characteristics of 9,11 years-old and wild Chinese sturgeon were significant different.StageⅠgonad did not be indentified through ultrasound imaging,the image of stageⅡgonad was not plump in the abdominal cavity and had some fat,and male and female of this stage can not identified,the image of testis of stageⅣandⅤwere large,full and density were uniform,the image density of stageⅥtestis were not uniform.there were clear and bright eggs in the image of the ovary of stageⅣandⅤ;the image of stageⅥovary showed that the gland were stratiform and the surface were not smooth.