This study was conducted to evaluate the effects of dietary lipid sources on the growth performance and fatty acid composition of the swimming crab, P ortunus trituberculatus. Four isonitrogenous and isoenergetic expe...This study was conducted to evaluate the effects of dietary lipid sources on the growth performance and fatty acid composition of the swimming crab, P ortunus trituberculatus. Four isonitrogenous and isoenergetic experimental diets were formulated to contain four separate lipid sources, including fish, soybean, rapeseed, and linseed oils(FO, SO, RO, and LO, respectively). With three replicates of 18 crabs each for each diet, crabs(initial body weight, 17.00 ±0.09 g) were fed twice daily for 8 weeks. There were no significant differences among these groups in terms of weight gain, specific growth rate, and hepatosomatic index. However, the RO groups' survival rate was significantly lower than FO groups. The feed conversion and protein efficiency ratios of RO groups were poorer than other groups. The proximate compositions of whole body and hepatopancreas were significantly affected by these dietary treatments. Tissue fatty acid composition mainly reflected dietary fatty acid compositions. Crabs fed FO diets exhibited significantly higher arachidonic, eicosapentaenoic, and docosahexaenoic acid contents in muscle and hepatopancreas compared with VO crabs. Linoleic, oleic, and linolenic acids in muscle and hepatopancreas were the highest in the SO, RO, and LO groups, respectively. The present study suggested that SO and LO could substitute for FO in fishmeal-based diets for swimming crabs, without affecting growth performance and survival.展开更多
Effect of salinity on survival,feeding behavior and growth of juvenile swimming crab P ortunus trituberculatus was investigated under 5 salinity levels of 5,10,20,30 and 40. The results show that the crab juveniles fe...Effect of salinity on survival,feeding behavior and growth of juvenile swimming crab P ortunus trituberculatus was investigated under 5 salinity levels of 5,10,20,30 and 40. The results show that the crab juveniles fed 2 or 3 times at the salinity 20 and 30,each lasted for about 25 minutes,for a total feeding time of 73.2±22.65 minutes per day. At these salinities,there were significantly higher in the frequency of feeding and in total feeding time than those at lower salinities of 5 and 10. All crab juveniles moulted when reared at a salinity of 20 during the 5 days duration of the experiment,which is significantly higher than those at other salinities. All juveniles survived at salinity 20,and the survivorship was not significantly different from that at 30,but was signif icantly higher than those at other salinities. The crab juveniles reared at a salinity of 20 had the highest value of food ration of 0.190 8±0.011 3 g/g BW,average body weight gain of 0.796±0.128 g,gain rate of 87%–96%,and food conversion ratio of 1.20±0.09. There was no significant difference in the values found between 20 and 30 but these values were significantly lower than that at the other salinities( P> 0.05). Highest activities of digestive enzymes(Amylase,Protease,Lipase) and lowest activities of protective enzymes(SOD,PO,CAT) were also obtained on crab juveniles reared at salinity of 20.展开更多
The sound stimulus has a signifi cant impact on marine animals.However,many studies have focused on the negative impacts of sound on marine vertebrates.The positive impacts of sound on marine animals,especially on mar...The sound stimulus has a signifi cant impact on marine animals.However,many studies have focused on the negative impacts of sound on marine vertebrates.The positive impacts of sound on marine animals,especially on marine invertebrates,were rarely studied.In the present study,we evaluated the eff ects of music on the survival and development of an economically important marine invertebrate,swimming crab Portunus trituberculatus.Three pieces of classical music and a control group,i.e.,Eine Kleine Nachtmusik by Mozart(EK),Bach-Violin Concerto No.1(BV),Anonymous Romanza by Anonymous(AR),and environmental sound(EN)were used.The sound pressure received were 163-dB root mean square(RMS)re 1μPa for EK,166-dB RMS re 1μPa for BV,165-dB RMS re 1μPa for AR,44-dB RMS re 1μPa for EN,respectively.The larvae were subject to 3-h classical music transmission every day during the entire larval development period.The result showed that BV and AR signifi cantly elevated the cumulative survival rate of the larva from 3.42%±1.77%(EN)to 10.65%±1.69%(BV)and 7.12%±1.37%(AR)respectively(P<0.05).Though music did not aff ect the cumulative development time of larvae from ZoeaⅠto ZoeaⅣ,it signifi cantly increased the molting rate of megalopa from 24.00%±11.78%(EN)to 44.00%±13.06%(AR)and 46.67%±10.50%(BV)(P<0.05).Musical exposure during critical growth intervals may contribute to the survival and development of larval crustaceans.From an application point of view,music intervention is much economically feasible.The observed music eff ects imply that music could further enhance growth,welfare,and production.展开更多
This study attempted to compare the performance of local polynomial interpolation,inverse distance weighted interpolation,and ordinary kriging in studying distribution patterns of swimming crabs.Cross-validation was u...This study attempted to compare the performance of local polynomial interpolation,inverse distance weighted interpolation,and ordinary kriging in studying distribution patterns of swimming crabs.Cross-validation was used to select the optimum method to get distribution results,and kriging was used for making spatial variability analysis.Data were collected from 87 sampling stations in November of 2015(autumn)and February(winter),May(spring)and August(summer)of 2016.Results indicate that swimming crabs widely distributed in autumn and summer:in the summer,they were more spatially independent,and resources in each sampling station varied a lot;in the winter and spring,the abundance of crabs was much lower,but the individual crab size was bigger,and they showed the patchy and more concentrative distribution pattern,which means they were more spatially dependent.Distribution patterns were in accordance with ecological migration features of swimming crabs,which were affected by the changing marine environment.This study could infer that it is applicable to study crab fishery or even other crustacean species using geostatistical analysis.It not only helps practitioners have a better understanding of how swimming crabs migrate from season to season,but also assists researchers in carrying out a more comprehensive assessment of the fishery.Therefore,it may facilitate advancing the implementation in the pilot quota management program of swimming crabs in northern Zhejiang fishing grounds.展开更多
基金Supported by the Agriculture Science Technology Achievement Transformation Fund(No.2014GB2C22015)the Public Projects of Zhejiang Province(Nos.2013C32037,2013C31032)+3 种基金the Zhejiang Major Special Program of Breeding(No.2012C12907-3)the Ningbo Innovation and Entrepreneurship Project(No.2014C92011)the Zhejiang Provincial Oceanic and Fishery Bureau ProjectZhoushan Science and Technology Bureau Project(No.2013C41007)
文摘This study was conducted to evaluate the effects of dietary lipid sources on the growth performance and fatty acid composition of the swimming crab, P ortunus trituberculatus. Four isonitrogenous and isoenergetic experimental diets were formulated to contain four separate lipid sources, including fish, soybean, rapeseed, and linseed oils(FO, SO, RO, and LO, respectively). With three replicates of 18 crabs each for each diet, crabs(initial body weight, 17.00 ±0.09 g) were fed twice daily for 8 weeks. There were no significant differences among these groups in terms of weight gain, specific growth rate, and hepatosomatic index. However, the RO groups' survival rate was significantly lower than FO groups. The feed conversion and protein efficiency ratios of RO groups were poorer than other groups. The proximate compositions of whole body and hepatopancreas were significantly affected by these dietary treatments. Tissue fatty acid composition mainly reflected dietary fatty acid compositions. Crabs fed FO diets exhibited significantly higher arachidonic, eicosapentaenoic, and docosahexaenoic acid contents in muscle and hepatopancreas compared with VO crabs. Linoleic, oleic, and linolenic acids in muscle and hepatopancreas were the highest in the SO, RO, and LO groups, respectively. The present study suggested that SO and LO could substitute for FO in fishmeal-based diets for swimming crabs, without affecting growth performance and survival.
基金Supported by the Science and Technology Innovation Team of Marine Crab Industry in Ningbo City(No.2011B81003)the National Natural Science Foundation of China(No.41276123)+2 种基金the National Spark Plan Program of China(No.2012GA701048)the Key Project of Ministry of Education,Science and Technology(No.212070)the K C Wong Magana Fund in Ningbo University
文摘Effect of salinity on survival,feeding behavior and growth of juvenile swimming crab P ortunus trituberculatus was investigated under 5 salinity levels of 5,10,20,30 and 40. The results show that the crab juveniles fed 2 or 3 times at the salinity 20 and 30,each lasted for about 25 minutes,for a total feeding time of 73.2±22.65 minutes per day. At these salinities,there were significantly higher in the frequency of feeding and in total feeding time than those at lower salinities of 5 and 10. All crab juveniles moulted when reared at a salinity of 20 during the 5 days duration of the experiment,which is significantly higher than those at other salinities. All juveniles survived at salinity 20,and the survivorship was not significantly different from that at 30,but was signif icantly higher than those at other salinities. The crab juveniles reared at a salinity of 20 had the highest value of food ration of 0.190 8±0.011 3 g/g BW,average body weight gain of 0.796±0.128 g,gain rate of 87%–96%,and food conversion ratio of 1.20±0.09. There was no significant difference in the values found between 20 and 30 but these values were significantly lower than that at the other salinities( P> 0.05). Highest activities of digestive enzymes(Amylase,Protease,Lipase) and lowest activities of protective enzymes(SOD,PO,CAT) were also obtained on crab juveniles reared at salinity of 20.
基金Supported by the National Natural Science Foundation of China(Nos.41776164,31972783)the Public Welfare Applied Research Project of Zhejiang Province(No.LGN19C190008)+2 种基金the Ministry of Agriculture of China&China Agriculture Research System(No.CARS-48)the Major Agriculture Program of Ningbo(No.2017C110007)the K.C.Wong Magna Fund in Ningbo University。
文摘The sound stimulus has a signifi cant impact on marine animals.However,many studies have focused on the negative impacts of sound on marine vertebrates.The positive impacts of sound on marine animals,especially on marine invertebrates,were rarely studied.In the present study,we evaluated the eff ects of music on the survival and development of an economically important marine invertebrate,swimming crab Portunus trituberculatus.Three pieces of classical music and a control group,i.e.,Eine Kleine Nachtmusik by Mozart(EK),Bach-Violin Concerto No.1(BV),Anonymous Romanza by Anonymous(AR),and environmental sound(EN)were used.The sound pressure received were 163-dB root mean square(RMS)re 1μPa for EK,166-dB RMS re 1μPa for BV,165-dB RMS re 1μPa for AR,44-dB RMS re 1μPa for EN,respectively.The larvae were subject to 3-h classical music transmission every day during the entire larval development period.The result showed that BV and AR signifi cantly elevated the cumulative survival rate of the larva from 3.42%±1.77%(EN)to 10.65%±1.69%(BV)and 7.12%±1.37%(AR)respectively(P<0.05).Though music did not aff ect the cumulative development time of larvae from ZoeaⅠto ZoeaⅣ,it signifi cantly increased the molting rate of megalopa from 24.00%±11.78%(EN)to 44.00%±13.06%(AR)and 46.67%±10.50%(BV)(P<0.05).Musical exposure during critical growth intervals may contribute to the survival and development of larval crustaceans.From an application point of view,music intervention is much economically feasible.The observed music eff ects imply that music could further enhance growth,welfare,and production.
文摘This study attempted to compare the performance of local polynomial interpolation,inverse distance weighted interpolation,and ordinary kriging in studying distribution patterns of swimming crabs.Cross-validation was used to select the optimum method to get distribution results,and kriging was used for making spatial variability analysis.Data were collected from 87 sampling stations in November of 2015(autumn)and February(winter),May(spring)and August(summer)of 2016.Results indicate that swimming crabs widely distributed in autumn and summer:in the summer,they were more spatially independent,and resources in each sampling station varied a lot;in the winter and spring,the abundance of crabs was much lower,but the individual crab size was bigger,and they showed the patchy and more concentrative distribution pattern,which means they were more spatially dependent.Distribution patterns were in accordance with ecological migration features of swimming crabs,which were affected by the changing marine environment.This study could infer that it is applicable to study crab fishery or even other crustacean species using geostatistical analysis.It not only helps practitioners have a better understanding of how swimming crabs migrate from season to season,but also assists researchers in carrying out a more comprehensive assessment of the fishery.Therefore,it may facilitate advancing the implementation in the pilot quota management program of swimming crabs in northern Zhejiang fishing grounds.
