The effects of algal concentration and initial density on the population growth of the estuarine cladocera, Diaphanosoma celebensis Stingelin, were evaluated in an indoor experiment. A 2 × 4 layout that included ...The effects of algal concentration and initial density on the population growth of the estuarine cladocera, Diaphanosoma celebensis Stingelin, were evaluated in an indoor experiment. A 2 × 4 layout that included two algal concentrations （Chlorella pyrenoidosa, 1 × 10^6 and 3 ×10^6 cell/mL） and four inoculation densities （100, 200, 300 and 400 ind./L） were established. Diaphanosoma celebensis were reared in 150 mL flasks containing 50 mL of algal medium at 22℃, under salinity of 10 and a photoperiod of 12 h L： 12 h D. The lag phase required to initiate continuous population growth following inoculation was shorter for D. celebensis fed 1 × 10^6 cell/mL and inoculated at 300 or 400 ind./L than that for D. celebensis fed 3 × 10^6 cell/mL and inoculated at 100 or 200 ind./L. However, D. celebensis fed 3 × 10^6 cell/mL and inoculated at 100 or 200 ind./L exhibited longer periods of positive population growth The maximum population densities were 5 875 ± 324, 6 690 ± 691, 7 735 ± 1,121 and 6 365 ± 691 ind./L for D. celebensis fed 1 × 10^6 cell/mL and inoculated at 100, 200, 300 and 400 ind./L, respectively, and 15 070 ± 379, 12 215 ± 648, 11 960±2,551 and 16 130 ± 880 ind./L for D. celebensis fed 3 ×10^6 cell/mL and inoculated at 100, 200, 300 and 400 ind./L, respectively. The average daily increasing rates of population were 0.076 ± 0.001, 0.065 ± 0.002, 0.055 ±0.002 and 0.048 ± 0.003 for D. celebensis fed 1×10^6 cell/mL and inoculated at 100, 200, 300 and 400 ind./L, respectively, and 0.098± 0.001, 0.078 ± 0.002, 0.072 ± 0.003 and 0.067 ± 0.003 forD. celebensis fed 3 × 10^6 cell/mL and inoculated at 100, 200, 300 and 400 ind./L, respectively. The maximum population density and average daily increasing rate of population increased as the algal concentration increased, whereas an increase in the inoculation density led to a linear decrease in the daily increasing rate of population under both algal concentrations. The results of the present experiment indicate that the algal concentration and inoculation density significantly affect population growth of D. celebensis, Furthermore, the results suggest that the optimal algal concentration and inoculation density for the mass culture ofD. celebensis should be 3 × 10^6 cell/mL and 100 ind./L.展开更多
Oryzias celebensis is determined by an XX-XY system,however,its sex-related genes have not been confirmed.The genes foxl2 and sox9b are important for gonadal development in vertebrates.In the present study,the foxl2 a...Oryzias celebensis is determined by an XX-XY system,however,its sex-related genes have not been confirmed.The genes foxl2 and sox9b are important for gonadal development in vertebrates.In the present study,the foxl2 and sox9b cDNAs were cloned and their expression patterns were analyzed.The cDNA sequence of foxl2 and sox9b were obtained by rapid amplification of cDNA ends(RACEs).Reverse transcription polymerase chain reaction(RT-PCR)showed that O.celebensis foxl2(Ocfoxl2)transcript was predominately expressed in the ovary while O.celebensis sox9b(Ocsox9b)transcript was mainly expressed in the testis.In embryos,Ocfoxl2 transcript was first detected in gastrula.In contrast,Ocsox9b transcript was of maternal origin as expression was detected at the two cell stage.By chromogenic and fluorescent in situ hybridization(ISH),Ocfoxl2 mRNA in the ovary was highly expressed in early oocytes and weakly expressed in the granulosa cells and thecal cells in the later oocytes.In contrast,Ocsox9b mRNA was mainly found in Sertoli cells surrounding spermatogonia and in spermatids and sperm in the testis.In summary,Ocfoxl2 identified somatic cells and differentiating oocytes in the ovary,indicating it is involved in ovarian development.Ocsox9b is identified in Sertoli cells and late developing male germ cells indicating it is involved in testicular development.展开更多
基金Supported by the National Natural Science Foundation of China (No 30471340)
文摘The effects of algal concentration and initial density on the population growth of the estuarine cladocera, Diaphanosoma celebensis Stingelin, were evaluated in an indoor experiment. A 2 × 4 layout that included two algal concentrations （Chlorella pyrenoidosa, 1 × 10^6 and 3 ×10^6 cell/mL） and four inoculation densities （100, 200, 300 and 400 ind./L） were established. Diaphanosoma celebensis were reared in 150 mL flasks containing 50 mL of algal medium at 22℃, under salinity of 10 and a photoperiod of 12 h L： 12 h D. The lag phase required to initiate continuous population growth following inoculation was shorter for D. celebensis fed 1 × 10^6 cell/mL and inoculated at 300 or 400 ind./L than that for D. celebensis fed 3 × 10^6 cell/mL and inoculated at 100 or 200 ind./L. However, D. celebensis fed 3 × 10^6 cell/mL and inoculated at 100 or 200 ind./L exhibited longer periods of positive population growth The maximum population densities were 5 875 ± 324, 6 690 ± 691, 7 735 ± 1,121 and 6 365 ± 691 ind./L for D. celebensis fed 1 × 10^6 cell/mL and inoculated at 100, 200, 300 and 400 ind./L, respectively, and 15 070 ± 379, 12 215 ± 648, 11 960±2,551 and 16 130 ± 880 ind./L for D. celebensis fed 3 ×10^6 cell/mL and inoculated at 100, 200, 300 and 400 ind./L, respectively. The average daily increasing rates of population were 0.076 ± 0.001, 0.065 ± 0.002, 0.055 ±0.002 and 0.048 ± 0.003 for D. celebensis fed 1×10^6 cell/mL and inoculated at 100, 200, 300 and 400 ind./L, respectively, and 0.098± 0.001, 0.078 ± 0.002, 0.072 ± 0.003 and 0.067 ± 0.003 forD. celebensis fed 3 × 10^6 cell/mL and inoculated at 100, 200, 300 and 400 ind./L, respectively. The maximum population density and average daily increasing rate of population increased as the algal concentration increased, whereas an increase in the inoculation density led to a linear decrease in the daily increasing rate of population under both algal concentrations. The results of the present experiment indicate that the algal concentration and inoculation density significantly affect population growth of D. celebensis, Furthermore, the results suggest that the optimal algal concentration and inoculation density for the mass culture ofD. celebensis should be 3 × 10^6 cell/mL and 100 ind./L.
基金This work was supported by National Key R&D Program of China(2018YFD0901205)National Natural Science Foundation of China(31672700,31372520).
文摘Oryzias celebensis is determined by an XX-XY system,however,its sex-related genes have not been confirmed.The genes foxl2 and sox9b are important for gonadal development in vertebrates.In the present study,the foxl2 and sox9b cDNAs were cloned and their expression patterns were analyzed.The cDNA sequence of foxl2 and sox9b were obtained by rapid amplification of cDNA ends(RACEs).Reverse transcription polymerase chain reaction(RT-PCR)showed that O.celebensis foxl2(Ocfoxl2)transcript was predominately expressed in the ovary while O.celebensis sox9b(Ocsox9b)transcript was mainly expressed in the testis.In embryos,Ocfoxl2 transcript was first detected in gastrula.In contrast,Ocsox9b transcript was of maternal origin as expression was detected at the two cell stage.By chromogenic and fluorescent in situ hybridization(ISH),Ocfoxl2 mRNA in the ovary was highly expressed in early oocytes and weakly expressed in the granulosa cells and thecal cells in the later oocytes.In contrast,Ocsox9b mRNA was mainly found in Sertoli cells surrounding spermatogonia and in spermatids and sperm in the testis.In summary,Ocfoxl2 identified somatic cells and differentiating oocytes in the ovary,indicating it is involved in ovarian development.Ocsox9b is identified in Sertoli cells and late developing male germ cells indicating it is involved in testicular development.
