Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experi...Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experiment are: Fish Flesh (FF), Shrimp Flesh (SF), Clam Foot (CF), Polychaete Worm (PW), and Formulated Diet (FD). No significant differ- ences of attractability exist between any two different diets when every two natural diets or all five diets are provided simul- taneously. On the other hand, significant differences of attractability exist between FD and every single natural diet when they are provided simultaneously. Results of behavioral observation indicate that natural diets are more attractive than FD. In feeding experiment, Chinese shrimp has distinct selectivity on different diets. It positively selects CF and PW, negatively selects FF and SF, and excludes FD absolutely. The results of the present studies indicate that the dietary selectivity of shrimp was based not only on the attractabilities of the diets, but also on the responses such as growth and food conversion.展开更多
In order to study the food consumption, preference and day-night predatorydifference of Asterias amurensis on Scapharca broughtonii, the experiments werecarried out at the temperatures ranging from 16 ℃ to 20 ℃, sal...In order to study the food consumption, preference and day-night predatorydifference of Asterias amurensis on Scapharca broughtonii, the experiments werecarried out at the temperatures ranging from 16 ℃ to 20 ℃, salinity of 28.2 ± 2.1,dissolved oxygen of 7.5±0.7 mg/L and pH of 8.0 ± 0.3.The results provided basic datafor promoting steady and healthy development of the multiplication and cultivation of S.broughtonii. The results of food consumption suggested that the food intake of starfishincreased with the density of S. broughtonii at all conditions. The food consumption ofstarfish in different sizes on S. broughtonii in the same size had no significant difference(p>0.05), but it was significantly different among S. broughtonii in different sizes. Thestarfish had the highest feeding rate on the smallest S. broughtonii. Our findings alsoverified the positive relation between the weight of food intake of starfish in differentsizes on the density and size of S. broughtonii. The feeding rhythm of starfish onS. broughtonii in different sizes showed a certain day-night difference, higher at nightthan in the day. The maximum food consumption occurred when the size of S.broughtonii became larger. The results showed that 30 ind/m2 was the suitable seabottom sowing density for S. broughtonii. Our data indicated that the ability to avoidpredators and rivals increased as the shell length rose. Based on prey selectivity,bivalves that have a lower commercial value may be used to clear away A. amurensis.展开更多
The study was conducted for the detection of Listeria monocytogenes bacteria from different sources （CSF and blood） obtained from patients in Pediatric hospital and from food sources like （yogurt, raw vegetables an...The study was conducted for the detection of Listeria monocytogenes bacteria from different sources （CSF and blood） obtained from patients in Pediatric hospital and from food sources like （yogurt, raw vegetables and raw milk, sausage）. Ten isolates were isolated from 150 specimens one of them from CSF and one isolate isolated from blood samples the others isolated from food specimens 6 isolates isolated from sausage and 2 from raw vegetables. Isolates were identified traditionally involved culture methods based on selective enrichment and plating followed by the characterization of Listeria spp. based on colony morphology, sugar fermentation and haemolytic properties, identification by Api listeria was done. Determine the isolates that produce biofilm by tissue culture plate method. The highest biofilm forming strains ofListeria monocytogenes isolates appear in No. （D10, El, E5 and E7） OD reading each of them is （0.13, 0.09, 0.11 and 0.19） respectively, the lowest or poor biofilm forming strains appear in No. （D11, D12, E2, E3, E4 and E6） that optical density （OD） reading are （0.04, 0.03, 0.05, 0.04, 0.05 and 0.03） respectively by comparing with control prepared in well （A12） that stained by crystal violate without putting any isolates and the OD reading is （0.003）. Confirmation by PCR was done only for four isolates that produce biofilm （D10 and El） that obtained from CSF and blood sample and for （E5 and E7） that obtained from food samples.展开更多
基金the Major State Basic Research of China(Grant No.G1999012011)the State Agriculture Program(Grant No.K2002-16) the Initializing Fund for Teachers of Ocean University of China.
文摘Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experiment are: Fish Flesh (FF), Shrimp Flesh (SF), Clam Foot (CF), Polychaete Worm (PW), and Formulated Diet (FD). No significant differ- ences of attractability exist between any two different diets when every two natural diets or all five diets are provided simul- taneously. On the other hand, significant differences of attractability exist between FD and every single natural diet when they are provided simultaneously. Results of behavioral observation indicate that natural diets are more attractive than FD. In feeding experiment, Chinese shrimp has distinct selectivity on different diets. It positively selects CF and PW, negatively selects FF and SF, and excludes FD absolutely. The results of the present studies indicate that the dietary selectivity of shrimp was based not only on the attractabilities of the diets, but also on the responses such as growth and food conversion.
基金supported by the National Sea Welfare Project(201205023)China Agriculture Research System(CARS-48)the earmarked fund for Modern Agro-industry Technology Research System in Shandong Province(SDAIT-14)
文摘In order to study the food consumption, preference and day-night predatorydifference of Asterias amurensis on Scapharca broughtonii, the experiments werecarried out at the temperatures ranging from 16 ℃ to 20 ℃, salinity of 28.2 ± 2.1,dissolved oxygen of 7.5±0.7 mg/L and pH of 8.0 ± 0.3.The results provided basic datafor promoting steady and healthy development of the multiplication and cultivation of S.broughtonii. The results of food consumption suggested that the food intake of starfishincreased with the density of S. broughtonii at all conditions. The food consumption ofstarfish in different sizes on S. broughtonii in the same size had no significant difference(p>0.05), but it was significantly different among S. broughtonii in different sizes. Thestarfish had the highest feeding rate on the smallest S. broughtonii. Our findings alsoverified the positive relation between the weight of food intake of starfish in differentsizes on the density and size of S. broughtonii. The feeding rhythm of starfish onS. broughtonii in different sizes showed a certain day-night difference, higher at nightthan in the day. The maximum food consumption occurred when the size of S.broughtonii became larger. The results showed that 30 ind/m2 was the suitable seabottom sowing density for S. broughtonii. Our data indicated that the ability to avoidpredators and rivals increased as the shell length rose. Based on prey selectivity,bivalves that have a lower commercial value may be used to clear away A. amurensis.
文摘The study was conducted for the detection of Listeria monocytogenes bacteria from different sources （CSF and blood） obtained from patients in Pediatric hospital and from food sources like （yogurt, raw vegetables and raw milk, sausage）. Ten isolates were isolated from 150 specimens one of them from CSF and one isolate isolated from blood samples the others isolated from food specimens 6 isolates isolated from sausage and 2 from raw vegetables. Isolates were identified traditionally involved culture methods based on selective enrichment and plating followed by the characterization of Listeria spp. based on colony morphology, sugar fermentation and haemolytic properties, identification by Api listeria was done. Determine the isolates that produce biofilm by tissue culture plate method. The highest biofilm forming strains ofListeria monocytogenes isolates appear in No. （D10, El, E5 and E7） OD reading each of them is （0.13, 0.09, 0.11 and 0.19） respectively, the lowest or poor biofilm forming strains appear in No. （D11, D12, E2, E3, E4 and E6） that optical density （OD） reading are （0.04, 0.03, 0.05, 0.04, 0.05 and 0.03） respectively by comparing with control prepared in well （A12） that stained by crystal violate without putting any isolates and the OD reading is （0.003）. Confirmation by PCR was done only for four isolates that produce biofilm （D10 and El） that obtained from CSF and blood sample and for （E5 and E7） that obtained from food samples.
