| Cypris subglobosa is a common species of Ostracoda,Caudoptera,Venus,Venus.Ostracoda are widely distributed in natural water bodies and serve as biological bait for some bottom to middle level fish.It is also a typical predator of organic debris in water bodies,plays an important role in the material cycle and energy flow of ecosystems.There are few practical applications of benthic species as bait organisms.At present,the application of ostracods as live feed organisms in aquaculture production practice is almost blank,and there are also few biological basic experiments related to them.Therefore,this experiment investigated the tolerance of hemispherical adenoids to different temperature and salinity levels,as well as the impact of different temperature and salinity levels on population dynamics and individual morphology,and conducted a preliminary study on their life history,in order to provide basic theoretical data for the future application of hemispheric adenoids in production practice.The experimental results are as follows:1、Tolerance of Cypris subglobosa to temperature and salinity In the temperature acute experiment,set 12℃,14℃,16℃,18℃,20℃,22℃,24℃,26℃,28℃,30℃,and 32℃ in sequence.Using 20℃ as the control group,the survival rates were observed and recorded at 24,48,72,and 96 hours,respectively.And obtain the low temperature and half lethal temperatures of the hemispherical glandular scale insects at four time periods,which are10.07℃,11.58℃,13.33℃,and 14.00℃;The high temperature half lethal concentration is 45.71℃,32.98℃,30.95℃,30.04℃.The 96 hour survival rate of Cypris subglobosa at 12 ℃ is only 3.3%,and large-scale death occurs at 32℃.There was a significant difference in survival rate between the temperature groups from 72 hours onwards and the control group(20 ℃)(P<0.05).In the salinity acute experiment,set 0,2,4,6,8,10,12,14,16,and 18 in sequence.Using salinity 0 as a control,the experiment was conducted at a constant temperature of 20 ℃,and the survival rates were observed and recorded at 24,48,72,and 96 hours,respectively.Using salinity 0 as a control,the experiment was conducted at a constant temperature of 20 ℃.The survival rates were observed and recorded at 24,48,72,and 96 hours,respectively.The semi lethal salinity of the hemispherical gland scale insects at four time periods was determined to be 25.13,18.26,15.86,14.12.There were differences in survival rates at different times in the experimental group after salinity 10;There was a significant difference in the 96 h survival rate between the salinity 14 and salinity 16 groups and the control group(salinity 0)(P<0.05).In the experimental group with a salinity of 18,the survival rate of the hemispheric gland mesozoa after 96 hours was the lowest,only 5±0.8%.2、 The Effect of Different Temperatures on the Population Dynamics and Individual Morphology of Cypris subglobosa Based on the results of the acute temperature experiment,a temperature range of14℃~30 ℃ was set to explore the impact of different temperatures on the population growth of the hemispherical gland scale insect.There was no significant difference in the population size of Cypris subglobosa among different experimental groups at temperatures ranging from 18℃ to26℃(p>0.05).The population variation of Cypris subglobosa reached a maximum of1.46±0.13 ind./m L in each experimental group at a temperature of 18℃~26℃.Atatemperature of 30℃,the population reached a minimum value of 0.03±0.009 ind./mL,and overall showed a trend of first increasing and then decreasing.The population growth rate of the hemispheric gland beetle gradually increases from 18℃ to the highest value at 24℃,reaching 0.136±0.014individuals/d ind.After 24℃,the population growth rate gradually decreases with the increase of temperature.At the end of the experiment,there was no significant difference in shell length and shell height among different temperature groups(P>0.05),and the shell length reached its maximum value at 24 ℃,which was 1.41 ± 0.08mm;The shell height reaches its maximum value at14 ℃,which is 0.57 ± 0.04 mm.3、The Effect of Different Salinities on the Population Dynamics and Individual Morphology of Cypris subglobosa Select a relatively suitable salinity range of 0-8 based on the results of acute salinity to explore the impact of different salinity on the population growth of adenophora.The population of Cypris subglobosa has been increasing in the salinity range of 0-6,but as the salinity increases,the population growth rates of Cypris subglobosa increases more slowly.Therefore,the most suitable salinity for the growth of Cypris subglobosa is 0,The population growth rate reached 0.116±0.032 ind./d ind.,The maximum population is 1.26 ± 0.13 ind./m L.When the salinity reached 8 in the experiment,the population of the hemispheric gland beetle did not increase with time,and the population no longer engaged in reproductive activities.By the end 0.06 mm in the salinity 6 groups,respectively.There was no significantdifference in shell of the experiment,the gland beetle had basically died.The maximum values of shell length and shell height were 1.45 ± 0.25 mm and 0.56 ± length and shell height among the salinity 6 groups(P>0.05).4、A Preliminary Study on the Life History of Cypris subglobosa Select adult worms without eggs and observe their egg formation and egg production after cultivation,and then select the hatching new individuals to observe their growth and development status.It was observed in the experiment that the reproductive mode of Hemispheric gland mesozoa was egg laying,and its reproductive mode was parthenogenesis.At room temperature of20℃,the insect body takes 7~8 days from hatching to hatching,and does not experience the nauplius stage.During development,it molts four times,with shell lengths(mm)of 490.06±11.00,636.59±30.07,1190.31±87.49,1384.52±114.66,respectively.The shell height(mm)is382.03±9.45,461.30±21.96,625.39±21.37,780.0±53.41 in sequence.The shell height(mm)is382.03±9.45,461.30±21.96,625.39±21.37,and 780.0±53.41,respectively.The number of eggs laid by the glandular scale insects is basically between 39.7±14.3 and 62.7±11.3.The hatching rate is relatively low,with a range of 8-14 hatchlings per culture well.The highest hatching rate is only35.9%,and the lowest is 12.9%.Cypris subglobosa mostly lays eggs during the day,and the incubation time is generally around 10-15 days. |
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