In order to investigate the effect of temperature on hatching result of fertilized peacock eggs, they were hatched under conditions of varying temperature and constant temperature respectively. The result shows that t...In order to investigate the effect of temperature on hatching result of fertilized peacock eggs, they were hatched under conditions of varying temperature and constant temperature respectively. The result shows that the hatching rate in the varying temperature treatment group (Group Ⅰ) is higher than that in the constant temperature treatment group (Group Ⅱ). It suggests that the varying temperature treatment (high temperature in the early period, medium temperature in the middle period, slightly lower temperature in the late period, and slightly higher temperature in the hulling period) is in line with the optimum temperature variation in the hatching of fertilized peacock eggs, contributing the hatching of fertilized peacock eggs.展开更多
[Objective] Aim to know the whole process of embryonic development of loach. [Method] DOM + LHRH-A2 was used to induce spawning of loach,then after fertilization,the embryos were cultured into freshwater water with te...[Objective] Aim to know the whole process of embryonic development of loach. [Method] DOM + LHRH-A2 was used to induce spawning of loach,then after fertilization,the embryos were cultured into freshwater water with temperature from 24 to 26 ℃ and pH from 7.0 to 7.5. The embryonic development of loach was observed and 27 concrete morphological characteristics and development time of loach from fertilized egg to newly hatched larval period were described in detail. [Result] The embryonic development of loach could be divided into cleavage stage,blastocyst stage,gastrula stage,neurula stage and organogenesis stage. The loach embryo from fertilized egg to out membrane period was 30 h 45 min in fresh water from 24 to 26 ℃ and pH from 7.0 to 7.5. [Conclusion] It provided important reference for studying artificial propagation and genetic breeding of loach.展开更多
[Objective] The paper aimed to explore influence of different factors on eggs hatching of Cryptotympana atrata,and optimize technical parameters in practice.[Method] By using hatching rate as index,L16(44)orthogonal...[Objective] The paper aimed to explore influence of different factors on eggs hatching of Cryptotympana atrata,and optimize technical parameters in practice.[Method] By using hatching rate as index,L16(44)orthogonal design was employed to determine the effects of the four factors including temperature,salinity,photoperiod and pH.[Result] Photoperiod had obviously effects on hatchability of Cryptotympana atrata eggs.The optimal conditions for hatching were temperature 30 ℃,salinity 25%,photoperiod L12∶D12,and pH 6.[Conclusion]The research provided some scientific basis for indoor artificial incubation.展开更多
We studied the effect of pH (pH 5, 6, 7 and 8) on the hatching percentage, survival and reproduction of Artemia strains in Bohai Bay salt ponds. Strains included parthenogenetic Artemia from Bohai Bay (BHB), Artem...We studied the effect of pH (pH 5, 6, 7 and 8) on the hatching percentage, survival and reproduction of Artemia strains in Bohai Bay salt ponds. Strains included parthenogenetic Artemia from Bohai Bay (BHB), Artemiafranciscana from San Francisco Bay, and A. franciscana artificially produced in salt ponds in Vietnam. The latter was included as a potential inoculum for biological management of salt ponds. The hatching percentage of cysts after 24 h and the survival rate of the tested Artemia strains were significantly reduced when exposed to a culture medium at pH 5 for 18 d (P〈0.05). The tolerance of Artemia to 48 h acid exposure varied with developmental stage, increasing in the following order: juvenile, nauplii, pre-adult, with maximum tolerance in adults. All strains of Artemia tested could not reproduce at pH 5. At pH levels from pH 6-8, a higher pH generally resulted in a shorter brood interval and enhanced ovoviviparity. Hence, we suggest that brine acidification has a negative impact on Artemia populations in the Bohai Bay saltworks. Inoculation of Artemia with either local parthenogenetic Artemia or exotic A. franeiscana should be feasible at pH 7-8.展开更多
The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power ...The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power model was estimated for the length-weight relationship during the early life stages. Positive allometric growth for the head segment, trunk length, tail length and eye diameter was also found in the early life stages, while body depth, tail depth, tail fi n length, pectoral fi n length and barbel length displayed a negative coeffi cient. During the subsequent early developmental stage, the growth coeffi cients showed a clear and common tendency towards isometry for all measured body ratios. The allometric growth changes in Chinese loach during the early stage are possibly the result of selective organogenesis directed towards survival priorities.展开更多
The major population of the veined rapa whelk Rapana venosa (Valenciennes, 1846), which is an important fishery resource, is facing a large decline in China. We studied the effects of incubation temperature (16-34...The major population of the veined rapa whelk Rapana venosa (Valenciennes, 1846), which is an important fishery resource, is facing a large decline in China. We studied the effects of incubation temperature (16-34℃ at salinity 30) and salinity (5-45 at 25℃) on the incubation period and subsequent larval development. In the temperature experiment, the shortest incubation period was 12 days at 34℃, the lower temperature limit was 16~C, the longest mean shell length (1 193+17 pan) occurred at 25℃ and the highest survival rate 72.28%+5.62% was observed at 28℃. In the salinity experiment, the shortest incubation period was 15 days at 25. The salinity tolerance range was 15-40, the longest mean shell length (855-4-9 μm) and the highest survival rate 72.93%~4.85% were both observed at 35. This study demonstrated that, during the egg-mass stage, temperature and salinity regimes influence later growth and survival of larvae. These observations deepen our understanding of the ecology and conservation of natural populations of Rapana venosa.展开更多
Benthic diatoms constitute the primary diet of abalone during their early stages of development. To evaluate the dietary preferences of early post-larval abalone, Haliotis diversicolor supertexta, we analyzed the gut ...Benthic diatoms constitute the primary diet of abalone during their early stages of development. To evaluate the dietary preferences of early post-larval abalone, Haliotis diversicolor supertexta, we analyzed the gut contents of post-larvae that settled on diatom films. We compared the abundance and species diversity of diatom assemblages in the gut to those of the epiphytic diatom assemblages on the attachment films, and identified 40 benthic diatom species in the gut contents of post-larvae 12 to 24 d after settlement. The most abtmdant taxa in the gut contents were Navicula spp., Amphora copulate, and Amphora coffeaeformis. Navicula spp. accounted for 64.0% of the cell density. In the attachment films, we identified 110 diatom species belonging to 38 genera. Pennate diatoms were the dominant members including the species Amphiprora alata, Cocconeis placentula var. euglypta, Cylindrotheca closterium, Navicula sp. 2, and A. coffeaeformis. Nano-diatoms (〈20 pm in length) accounted for a considerable proportion of the total species number and cell density of the diatom assemblages in the gut contents and on the films. This suggests that nano-diatoms are important to the efficient production of abalone seed. The difference of the composition and abundance of diatoms between in the guts and on the biofilms suggests that early post-larval grazing was selective. An early post-larval abalone preferred nano-diatoms and the genera Navicula and Amphora during the month after settlement.展开更多
The ef fects of salinity on the copepod, A cartia tonsa in terms of daily egg production rate(EPR), hatching success, fecal pellet production rate(FPR), naupliar development time and survival, sex ratio, and total lif...The ef fects of salinity on the copepod, A cartia tonsa in terms of daily egg production rate(EPR), hatching success, fecal pellet production rate(FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods(seven consecutive days). Results show EPR was aff ected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females(long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages(56.7% and 52.2%, respectively) were signifi cantly observed at two salinities of 13 and 20 compared to that at 35(25%). Total longevity of females was not af fected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.展开更多
基金Supported by Scientific and Technological Development General Program of Beijing Municipal Education Commission(KM201412448004)~~
文摘In order to investigate the effect of temperature on hatching result of fertilized peacock eggs, they were hatched under conditions of varying temperature and constant temperature respectively. The result shows that the hatching rate in the varying temperature treatment group (Group Ⅰ) is higher than that in the constant temperature treatment group (Group Ⅱ). It suggests that the varying temperature treatment (high temperature in the early period, medium temperature in the middle period, slightly lower temperature in the late period, and slightly higher temperature in the hulling period) is in line with the optimum temperature variation in the hatching of fertilized peacock eggs, contributing the hatching of fertilized peacock eggs.
文摘[Objective] Aim to know the whole process of embryonic development of loach. [Method] DOM + LHRH-A2 was used to induce spawning of loach,then after fertilization,the embryos were cultured into freshwater water with temperature from 24 to 26 ℃ and pH from 7.0 to 7.5. The embryonic development of loach was observed and 27 concrete morphological characteristics and development time of loach from fertilized egg to newly hatched larval period were described in detail. [Result] The embryonic development of loach could be divided into cleavage stage,blastocyst stage,gastrula stage,neurula stage and organogenesis stage. The loach embryo from fertilized egg to out membrane period was 30 h 45 min in fresh water from 24 to 26 ℃ and pH from 7.0 to 7.5. [Conclusion] It provided important reference for studying artificial propagation and genetic breeding of loach.
基金Supported by National Trades(Agriculture)Scientific Research Foundation(200803005)~~
文摘[Objective] The paper aimed to explore influence of different factors on eggs hatching of Cryptotympana atrata,and optimize technical parameters in practice.[Method] By using hatching rate as index,L16(44)orthogonal design was employed to determine the effects of the four factors including temperature,salinity,photoperiod and pH.[Result] Photoperiod had obviously effects on hatchability of Cryptotympana atrata eggs.The optimal conditions for hatching were temperature 30 ℃,salinity 25%,photoperiod L12∶D12,and pH 6.[Conclusion]The research provided some scientific basis for indoor artificial incubation.
基金Supported by the International Cooperation Research Program of the Ministry of Science&Technology of China(No.2010DFA32300)the Pilot Project for International Cooperation"Aquaculture in Hebei and Shandong Provinces"funded by the Province of East-Flanders,Belgiumthe Nature Science Foundation of Tianjin(No.13JCZDJC28700)
文摘We studied the effect of pH (pH 5, 6, 7 and 8) on the hatching percentage, survival and reproduction of Artemia strains in Bohai Bay salt ponds. Strains included parthenogenetic Artemia from Bohai Bay (BHB), Artemiafranciscana from San Francisco Bay, and A. franciscana artificially produced in salt ponds in Vietnam. The latter was included as a potential inoculum for biological management of salt ponds. The hatching percentage of cysts after 24 h and the survival rate of the tested Artemia strains were significantly reduced when exposed to a culture medium at pH 5 for 18 d (P〈0.05). The tolerance of Artemia to 48 h acid exposure varied with developmental stage, increasing in the following order: juvenile, nauplii, pre-adult, with maximum tolerance in adults. All strains of Artemia tested could not reproduce at pH 5. At pH levels from pH 6-8, a higher pH generally resulted in a shorter brood interval and enhanced ovoviviparity. Hence, we suggest that brine acidification has a negative impact on Artemia populations in the Bohai Bay saltworks. Inoculation of Artemia with either local parthenogenetic Artemia or exotic A. franeiscana should be feasible at pH 7-8.
基金Supported by the National Key Technology Research and Development Program of China(Nos.2012BAD25B08,2012BAD25B00)
文摘The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power model was estimated for the length-weight relationship during the early life stages. Positive allometric growth for the head segment, trunk length, tail length and eye diameter was also found in the early life stages, while body depth, tail depth, tail fi n length, pectoral fi n length and barbel length displayed a negative coeffi cient. During the subsequent early developmental stage, the growth coeffi cients showed a clear and common tendency towards isometry for all measured body ratios. The allometric growth changes in Chinese loach during the early stage are possibly the result of selective organogenesis directed towards survival priorities.
基金Supported by the National Key Technology Research and Development Program of China(Nos.2011BAD13B01,2011BAD45B01)the Chinese Academy of Science and Government Cooperation Program(No.Y12319101L)the National Marine Public Welfare Research Program of China(No.201305043)
文摘The major population of the veined rapa whelk Rapana venosa (Valenciennes, 1846), which is an important fishery resource, is facing a large decline in China. We studied the effects of incubation temperature (16-34℃ at salinity 30) and salinity (5-45 at 25℃) on the incubation period and subsequent larval development. In the temperature experiment, the shortest incubation period was 12 days at 34℃, the lower temperature limit was 16~C, the longest mean shell length (1 193+17 pan) occurred at 25℃ and the highest survival rate 72.28%+5.62% was observed at 28℃. In the salinity experiment, the shortest incubation period was 15 days at 25. The salinity tolerance range was 15-40, the longest mean shell length (855-4-9 μm) and the highest survival rate 72.93%~4.85% were both observed at 35. This study demonstrated that, during the egg-mass stage, temperature and salinity regimes influence later growth and survival of larvae. These observations deepen our understanding of the ecology and conservation of natural populations of Rapana venosa.
基金Supported by Special Project on Basic Research of China,Ministry of Science and Technology (No 2006FY120100)Natural Science Foundation of Fujian Province (No B05100052005YZ1024)
文摘Benthic diatoms constitute the primary diet of abalone during their early stages of development. To evaluate the dietary preferences of early post-larval abalone, Haliotis diversicolor supertexta, we analyzed the gut contents of post-larvae that settled on diatom films. We compared the abundance and species diversity of diatom assemblages in the gut to those of the epiphytic diatom assemblages on the attachment films, and identified 40 benthic diatom species in the gut contents of post-larvae 12 to 24 d after settlement. The most abtmdant taxa in the gut contents were Navicula spp., Amphora copulate, and Amphora coffeaeformis. Navicula spp. accounted for 64.0% of the cell density. In the attachment films, we identified 110 diatom species belonging to 38 genera. Pennate diatoms were the dominant members including the species Amphiprora alata, Cocconeis placentula var. euglypta, Cylindrotheca closterium, Navicula sp. 2, and A. coffeaeformis. Nano-diatoms (〈20 pm in length) accounted for a considerable proportion of the total species number and cell density of the diatom assemblages in the gut contents and on the films. This suggests that nano-diatoms are important to the efficient production of abalone seed. The difference of the composition and abundance of diatoms between in the guts and on the biofilms suggests that early post-larval grazing was selective. An early post-larval abalone preferred nano-diatoms and the genera Navicula and Amphora during the month after settlement.
文摘The ef fects of salinity on the copepod, A cartia tonsa in terms of daily egg production rate(EPR), hatching success, fecal pellet production rate(FPR), naupliar development time and survival, sex ratio, and total life span were determined in laboratory conditions through three experiments. In experiment 1, EPR, hatching success, and FPR of individual females were monitored at salinities of 13, 20, 35 and 45 during short-periods(seven consecutive days). Results show EPR was aff ected by salinity with the highest outputs recorded at 20 and 35, respectively, which were considerably higher than those at 13 and 45. Mean FPR was also higher in 35 and 20. In experiment 2, the same parameters were evaluated over total life span of females(long-term study). The best EPR and FPR were observed in 35, which was statistically higher than at 13 and 20. In experiment 3, survival rates of early nauplii until adult stage were lowest at a salinity of 13. The development time increased with increasing of salinity. Female percentage clearly decreased with increasing salinity. Higher female percentages(56.7% and 52.2%, respectively) were signifi cantly observed at two salinities of 13 and 20 compared to that at 35(25%). Total longevity of females was not af fected by salinity increment. Based on our results, for mass culture we recommend that a salinity of 35 be adopted due to higher reproductive performances, better feeding, and faster development of A. tonsa.