A numerical model of flatfish cage is built based on the lumped mass method and the principle of rigid body kinematics. To validate the numerical model, a series of physical model tests are conducted in the wave flume...A numerical model of flatfish cage is built based on the lumped mass method and the principle of rigid body kinematics. To validate the numerical model, a series of physical model tests are conducted in the wave flume. The numerical results correspond well with the data sets from physical model test. The effect of weight of bottom frame, height of fish net and net shape on motion responses of fish cage and tension force on mooring lines is then analyzed. The results indicate that the vertical displacements of float collar and bottom frame decrease with the increase in the weight of bottom frame; the maximum tension force on mooring lines increases with the increasing weight of bottom frame. The inclination angles of float collar and bottom frame decrease with the increasing net height; the maximum tension force increases obviously with the increase of net height.展开更多
This paper presents a simulation model based on the finite element method. The method is used to analyze the motion response and mooring line tension of the flatfish cage system in waves. The cage system consists of t...This paper presents a simulation model based on the finite element method. The method is used to analyze the motion response and mooring line tension of the flatfish cage system in waves. The cage system consists of top frames, netting, mooring lines, bottom frames, and floats. A series of scaled physical model tests in regular waves are conducted to verify the numerical model. The comparison results show that the simulated and the experimental results agree well under the wave conditions, and the maximum pitch of the bottom frame with two orientations is about 12o. The motion process of the whole cage system in the wave can be described with the computer visualized technology. Then, the mooring line tensions and the motion of the bottom frame with three kinds of weight are calculated under different wave conditions. According to the numerical results, the differences in mooring line tensions of flatfish cages with three weight modes are indistinct. The maximum pitch of the bottom frame decreases with the increase of the bottom weight.展开更多
Insulin-like growth factors(IGFs)are key regulators of development and growth.Here,we characterized the igf2 gene from olive flounder(Paralichthys olivaceus)and determined its temporal and spatial expression.We set up...Insulin-like growth factors(IGFs)are key regulators of development and growth.Here,we characterized the igf2 gene from olive flounder(Paralichthys olivaceus)and determined its temporal and spatial expression.We set up an in-vitro protein expression system in eukaryotic human embryonic kidney(HEK293 T)cells and explored its effects on cell proliferation.The flounder igf2 cDNA contained a 648-bp open reading frame(ORF)encoding a protein of 215 amino acids(aa),which spanned the complete signal peptide(47 aa),mature peptide(70 aa),and E domain(98 aa).In adult flounder,igf2 mRNA was detected in all selected tissues.In early development,igf2 mRNA was detected throughout development from unfertilized eggs to hatching-stage embryos.In-situ hybridization analysis indicated that igf2 mRNA was specially expressed in the brain region,floor plate,hypochord,otic vesicle,and pectoral fin during embryogenesis.Western blotting analysis indicated that the soluble recombinant flounder IGF2 protein was successfully produced through eukaryotic expression in HEK293T cells.In addition,the recombinant IGF2 protein significantly promoted the proliferation of human cervical carcinoma(HeLa)and HEK293T cells.These results provide new information about the structural and functional conservation,expression patterns,and biological activity of the igf2 in teleosts.展开更多
Response surface method （RSM）, based on Box-Behnken design, was used to optimize the enzymatic hydrolysis conditions of flatfish skin protein hydrolysates （FSPH）. Among the tested proteases, the combination of nut...Response surface method （RSM）, based on Box-Behnken design, was used to optimize the enzymatic hydrolysis conditions of flatfish skin protein hydrolysates （FSPH）. Among the tested proteases, the combination of nutrase and trypsin was selected. The optimal hydrolysis conditions were as follows： pH 7.3, temperature 51.8℃, and the enzyme/substrate （E/S） ratio 2.5; under these conditions, the maximum peptide yield （PY） was 69.41 =1：0.43%. The physiochemical analysis showed that the amino acids （His, Asp and Glu） of FSPH accounted for 18.15%, and FSPH was a mixture of polypeptides mostly distributed among 900-2000 Da. FSPH could exhibit a 93% chelating effect on ferrous ion at a concentration of 400 gg/mL, and also a notable reducing power. This study showed bioprocess for the production of FSPH for the first time, which had a good potential for valuable ingredients in the food, cosmetic and medicine industries.展开更多
Objective:To investigate the surface architecture of the asymmetrical buccal cavity of Solea solea which are considered one of the most important predators in benthic communities.Methods:Adult Solea solea were obtaine...Objective:To investigate the surface architecture of the asymmetrical buccal cavity of Solea solea which are considered one of the most important predators in benthic communities.Methods:Adult Solea solea were obtained from Mediterranean Sea near Damielta.The heads were removed and processed for scanning electron microscopy.Its buccal cavity is asymmetrical and divided into roof and floor and the tongue for histological studies.Results:The buccal cavity roof is formed from upper jaw,velum and the palate.The upper jaw has several wing like processes with teeth arranged in several rows which may help in cutting and pushing the food to the entrance of the digestive canal while the floor is formed from the lower jaw and the tongue.The tongue is divided into apex,body and root.There is a gradual decrease of goblet cells in the tongue from anterior to posterior.These goblet cells function in protection of the epithelium.CoDctusions:Teeth in the floor of the buccal cavity and taste buds can be considered adaptive changes of the oral cavity related to the feeding habits and was a source to identify new and better methods of nutrition in aquaculture of Solea solea.展开更多
Ontogenetic changes in digestive enzyme activities and the amino acid(AA) profile of starry flounder,Platichthys stellatus,were investigated and limiting amino acids were estimated compared with the essential AA profi...Ontogenetic changes in digestive enzyme activities and the amino acid(AA) profile of starry flounder,Platichthys stellatus,were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements.Larvae were collected at the egg stage and 0,2,4,7,12,17,24 days after hatching(DAH)for analysis.Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH.Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH.Pepsin activity increased sharply beginning 17 DAH.Lipase activity increased significantly 4 DAH and increased progressively with larval growth.Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease.High free amino acid(FAA) content was detected in starry flounder eggs(110.72mg/g dry weight).Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae.Most FAAs(except lysine and methionine) decreased >50%in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae.Changes in the protein amino acid(PAA) profile were much milder than those observed for FAAs.Most PAAs increased gradually during larval development,except lysine and phenylalanine.The percentages of free threonine,valine,isoleucine,and leucine decreased until the end of the trial,whereas the protein forms of these four AAs followed the opposite trend.A comparison of the essential AA composition of live food(rotifers,Artemia nauplii,and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA.These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food.Moreover,the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51109187,51239002 and 51221961the Project form Zhoushan Science and Technology Bureau(Grant No.2013C41002)
文摘A numerical model of flatfish cage is built based on the lumped mass method and the principle of rigid body kinematics. To validate the numerical model, a series of physical model tests are conducted in the wave flume. The numerical results correspond well with the data sets from physical model test. The effect of weight of bottom frame, height of fish net and net shape on motion responses of fish cage and tension force on mooring lines is then analyzed. The results indicate that the vertical displacements of float collar and bottom frame decrease with the increase in the weight of bottom frame; the maximum tension force on mooring lines increases with the increasing weight of bottom frame. The inclination angles of float collar and bottom frame decrease with the increasing net height; the maximum tension force increases obviously with the increase of net height.
基金financially supported by the Earmarked Fund for Modern Agro-industry Technology Research System(Grant No.CARS-50-G05)the National Natural Science Foundation of China(Grant Nos.31101938+1 种基金30972256 and 51239002)Science and Technology Development Project of Shandong Province(Grant No.2009GG10005005)
文摘This paper presents a simulation model based on the finite element method. The method is used to analyze the motion response and mooring line tension of the flatfish cage system in waves. The cage system consists of top frames, netting, mooring lines, bottom frames, and floats. A series of scaled physical model tests in regular waves are conducted to verify the numerical model. The comparison results show that the simulated and the experimental results agree well under the wave conditions, and the maximum pitch of the bottom frame with two orientations is about 12o. The motion process of the whole cage system in the wave can be described with the computer visualized technology. Then, the mooring line tensions and the motion of the bottom frame with three kinds of weight are calculated under different wave conditions. According to the numerical results, the differences in mooring line tensions of flatfish cages with three weight modes are indistinct. The maximum pitch of the bottom frame decreases with the increase of the bottom weight.
基金Supported by the National Natural Science Foundation of China(No.31972774)the National Natural Science Foundation of China(No.31672636)the Key Research and Development Program of Shandong Province,China(No.2019GHY112007)。
文摘Insulin-like growth factors(IGFs)are key regulators of development and growth.Here,we characterized the igf2 gene from olive flounder(Paralichthys olivaceus)and determined its temporal and spatial expression.We set up an in-vitro protein expression system in eukaryotic human embryonic kidney(HEK293 T)cells and explored its effects on cell proliferation.The flounder igf2 cDNA contained a 648-bp open reading frame(ORF)encoding a protein of 215 amino acids(aa),which spanned the complete signal peptide(47 aa),mature peptide(70 aa),and E domain(98 aa).In adult flounder,igf2 mRNA was detected in all selected tissues.In early development,igf2 mRNA was detected throughout development from unfertilized eggs to hatching-stage embryos.In-situ hybridization analysis indicated that igf2 mRNA was specially expressed in the brain region,floor plate,hypochord,otic vesicle,and pectoral fin during embryogenesis.Western blotting analysis indicated that the soluble recombinant flounder IGF2 protein was successfully produced through eukaryotic expression in HEK293T cells.In addition,the recombinant IGF2 protein significantly promoted the proliferation of human cervical carcinoma(HeLa)and HEK293T cells.These results provide new information about the structural and functional conservation,expression patterns,and biological activity of the igf2 in teleosts.
文摘Response surface method （RSM）, based on Box-Behnken design, was used to optimize the enzymatic hydrolysis conditions of flatfish skin protein hydrolysates （FSPH）. Among the tested proteases, the combination of nutrase and trypsin was selected. The optimal hydrolysis conditions were as follows： pH 7.3, temperature 51.8℃, and the enzyme/substrate （E/S） ratio 2.5; under these conditions, the maximum peptide yield （PY） was 69.41 =1：0.43%. The physiochemical analysis showed that the amino acids （His, Asp and Glu） of FSPH accounted for 18.15%, and FSPH was a mixture of polypeptides mostly distributed among 900-2000 Da. FSPH could exhibit a 93% chelating effect on ferrous ion at a concentration of 400 gg/mL, and also a notable reducing power. This study showed bioprocess for the production of FSPH for the first time, which had a good potential for valuable ingredients in the food, cosmetic and medicine industries.
基金funded by Damietta University-Faculty of Science-Zoology Department(Crant No.541113)
文摘Objective:To investigate the surface architecture of the asymmetrical buccal cavity of Solea solea which are considered one of the most important predators in benthic communities.Methods:Adult Solea solea were obtained from Mediterranean Sea near Damielta.The heads were removed and processed for scanning electron microscopy.Its buccal cavity is asymmetrical and divided into roof and floor and the tongue for histological studies.Results:The buccal cavity roof is formed from upper jaw,velum and the palate.The upper jaw has several wing like processes with teeth arranged in several rows which may help in cutting and pushing the food to the entrance of the digestive canal while the floor is formed from the lower jaw and the tongue.The tongue is divided into apex,body and root.There is a gradual decrease of goblet cells in the tongue from anterior to posterior.These goblet cells function in protection of the epithelium.CoDctusions:Teeth in the floor of the buccal cavity and taste buds can be considered adaptive changes of the oral cavity related to the feeding habits and was a source to identify new and better methods of nutrition in aquaculture of Solea solea.
基金Supported by the Scientific and Technological Development Plan Project of Yantai City(No.2013ZH348)the Aquatic Animal Nutrition and Feed Research and Innovation Demonstration Platform(No.201301001)the National Special Research Fund for Non-Profit Marine Sector(No.1205025)
文摘Ontogenetic changes in digestive enzyme activities and the amino acid(AA) profile of starry flounder,Platichthys stellatus,were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements.Larvae were collected at the egg stage and 0,2,4,7,12,17,24 days after hatching(DAH)for analysis.Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH.Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH.Pepsin activity increased sharply beginning 17 DAH.Lipase activity increased significantly 4 DAH and increased progressively with larval growth.Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease.High free amino acid(FAA) content was detected in starry flounder eggs(110.72mg/g dry weight).Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae.Most FAAs(except lysine and methionine) decreased >50%in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae.Changes in the protein amino acid(PAA) profile were much milder than those observed for FAAs.Most PAAs increased gradually during larval development,except lysine and phenylalanine.The percentages of free threonine,valine,isoleucine,and leucine decreased until the end of the trial,whereas the protein forms of these four AAs followed the opposite trend.A comparison of the essential AA composition of live food(rotifers,Artemia nauplii,and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA.These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food.Moreover,the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.
