以聚乙烯醇为基膜材料,分别加入2 g/100 m L壳聚糖季铵盐、0.5 g/100 m L茶多酚、2.5 g/100 m L丙酸钙、0.5 g/100 m L对羟基苯甲酸乙酯联合1.5 g/100 m L丙酸钙做为抗菌剂,制得的聚乙烯醇抗菌包装薄膜,在冷藏(4±1)℃条件下对鳊鱼...以聚乙烯醇为基膜材料,分别加入2 g/100 m L壳聚糖季铵盐、0.5 g/100 m L茶多酚、2.5 g/100 m L丙酸钙、0.5 g/100 m L对羟基苯甲酸乙酯联合1.5 g/100 m L丙酸钙做为抗菌剂,制得的聚乙烯醇抗菌包装薄膜,在冷藏(4±1)℃条件下对鳊鱼肉进行包装保鲜。以持水率、p H值、白度、硫代巴比妥酸值、挥发性盐基氮值、菌落总数、质构指标、感官评定对保鲜效果进行评价。结果表明:添加0.5 g/100 m L茶多酚和添加0.5 g/100 m L对羟基苯甲酸乙酯联合1.5 g/100 m L丙酸钙的聚乙烯醇抗菌保鲜薄膜对(4±1)℃鳊鱼具有最佳的保鲜效果。展开更多
Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid （DHA） on lipegen...Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid （DHA） on lipegenic and lipelysis enzymes, one-year fish were roared on a casein-based purified diet and a DHA fortified diet （ 1.5% DHA ethyl ester/kg diet） for 60 d, followed with a period of 55 d for starvation. Dietary DHA was effectively incorporated into the fish body. Fortification of DHA depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancroas and intraperitoneal fat body. Carnitine palmitoyltransferase as lipolysis enzyme in the hepatopancreas was active in the DHA fortified fish. Starvation after feeding experiment induced increased carnitine palmitoyltransferase activity in both control and DHA fortified fish and the activity remained higher in the DHA fortified fish, while the monoenes were selectively consumed prior to highly unsaturated fatty acids. These results indicated that dietary DHA depressed lipogenesis and activated lipolysis.展开更多
In terms of taxonomic status,common carp(Cyprinus carpio,Cyprininae)and crucian carp(Carassius auratus,Cyprininae)are different species;however,in this study,a newborn homodiploid crucian carp-like fish(2n=100)(2nNCRC...In terms of taxonomic status,common carp(Cyprinus carpio,Cyprininae)and crucian carp(Carassius auratus,Cyprininae)are different species;however,in this study,a newborn homodiploid crucian carp-like fish(2n=100)(2nNCRC)lineage(F1–F3)was established from the interspecific hybridization of female common carp(2n=100)×male blunt snout bream(Megalobrama amblycephala,Cultrinae,2n=48).The phenotypes and genotypes of 2 n NCRC differed from those of its parents but were closely related to those of the existing diploid crucian carp.We further sequenced the whole mitochondrial(mt)genomes of the 2n NCRC lineage from F1 to F3.The paternal mt DNA fragments were stably embedded in the mt-genomes of F1–F3 generations of 2n NCRC to form chimeric DNA fragments.Along with this chimeric process,numerous base sites of F1–F3 generations of 2 n NCRC underwent mutations.Most of these mutation sites were consistent with the existing diploid crucian carp.Moreover,the mt DNA organization and nucleotide composition of 2n NCRC were more similar to those of the existing diploid crucian carp than those of the parents.The inheritable chimeric DNA fragments and mutant loci in the mt-genomes of different generations of 2nNCRC provided important evidence of the mt DNA change process in the newborn lineage derived from hybridization of different species.Our findings demonstrated for the first time that the paternal mt DNA were transmitted into the mt-genomes of homodiploid lineage,which provided new insights into the existence of paternal mt DNA in the mt DNA inheritance.展开更多
The insulin-like growth factor Ⅰ(IGF-Ⅰ) gene of triangular bream (Megalobrama terminalis)(GenBank No.AY247412)(Tb)was cloned for the first time from liver by RT-PCR. Thenucleotide sequence analysis showed the Tb IGF...The insulin-like growth factor Ⅰ(IGF-Ⅰ) gene of triangular bream (Megalobrama terminalis)(GenBank No.AY247412)(Tb)was cloned for the first time from liver by RT-PCR. Thenucleotide sequence analysis showed the Tb IGF-ⅠcDNA consisted of 486 nucleotides andencoded 117 amino acids including B, C, A, D and E five domains. Analysis of E-domainindicated that cloned Tb IGF-Ⅰbelonged to IGF-ⅠEa-2 subtype. Identity analysis showedthe IGF-Ⅰnucleotide sequence shared 99.8% homology with bluntnose bream, 88.8% withgrass carp, 85.8% with common carp; the pre-IGF-Ⅰamine acid sequence shared 99.4% withbluntnose bream, 88.8% with grass carp, 85.4% homology with common carp. In the CyprinusCarpio, the higher homology of nucleotide sequence and amino acid sequence in IGF-Ⅰshowed that the closer relationship the fishes have. These results could provide basicdata for the research on Tb germplasm and the development and utilization of biologicalfeed additives.展开更多
Recently,the use of natural immunopotentiators,such as plant extracts,is predicted to offer high disease-prevention potential in aquaculture.However,few reports on the immunomodulatory impacts of olive extract(OE)on t...Recently,the use of natural immunopotentiators,such as plant extracts,is predicted to offer high disease-prevention potential in aquaculture.However,few reports on the immunomodulatory impacts of olive extract(OE)on teleost are available.Therefore,the effects of dietary intake of triterpene-enriched OE on black sea bream(Acanthopagrus schlegelii)were investigated in this study.Our data showed that total blood cell counts,in vivo content of lysozyme,activities of antiprotease and myeloperoxidase,and contents of IL-4 and IL-6 were significantly up-regulated by dietary intake of triterpene-enriched OE.Additionally,the hampered immune response induced by cadmium exposure was significantly mitigated by the administration of OE as were indicated by partially or completely rescued immune-relating parameters.Furthermore,the expressions of immune-related genes encoding NF-κB inhibitor alpha(IkBα),tumor necrosis factorα(TNFα),cyclooxygenase-2(COX-2),and proto-oncogene protein c-fos(FOS)were found to be significantly up-regulated by the dietary intake of OE.In general,the results suggested that the dietary intake of triterpene-enriched OE has immune enhancing effect in black sea bream.Such effect may be realized by 1)increasing the total counts of diverse blood cells;2)activating nonspecific immune biomolecules;and 3)affecting signaling pathways such as IKK and ERK and subsequently inducing IL-4 and IL-6 biosyntheses.展开更多
In one trial 360 gilthead bream fingerlings received two different feed mixtures containing two different levels of protein (diet A 400 and B 360 g?kg<sup>?1</sup>). The average initial live weight was abo...In one trial 360 gilthead bream fingerlings received two different feed mixtures containing two different levels of protein (diet A 400 and B 360 g?kg<sup>?1</sup>). The average initial live weight was about 2.2 ± 0.1 g fish<sup>?1</sup> in each replicate of all treatments. Sixty fish per tank were stocked randomly in 6 fiberglass tanks (1 m<sup>3</sup> each). Fish were fed with experimental diets at rate 8% of the body weight daily. The Amino Acids (AA) content was analyzed in the diets, whole fish and muscle at the end of the growth period (60 days). The results indicated that at the end of experiment gilthead bream fingerlings had reached an average live weight 18.5 and 16.2 g fish<sup>?1</sup> for fish fed diet A and B respectively. Also the increase of protein levels in the feed to 40% caused a significant increase in the content of Indispensable Amino Acid (IAA) and dispensable amino acid (as %v of whole fish and muscle of wet weight). Two methods were subsequently used to estimate the quantitative IAA requirements of gilthead bream fry based on the hypothesis that (a) the dietary requirement pattern of IAA reflected the tissue pattern and (b) the rate of daily deposition in the fish could be equated with the dietary requirement as percentage of 100 g<sup>?1</sup> diet. The quantitative IAA requirement (%) of gilthead bream (Sparus aurata) diets was as follow: Lysine 2.27, Methionine 1.09, Therionine 0.61, Leucine 2.4, Isoleucine 0.47, Histidine1.6, Arginine 1.39, Phenylalanine 1.43, Valine 1.22 and Tryptophane 0.42.展开更多
In the present study, the genetic diversity of one selected strain （Pujiang No. 1）, two domesticated populations （GA and HX） and four wild populations （LZ, YN, SS and JL） of blunt snout bream （Megalobrama ambly...In the present study, the genetic diversity of one selected strain （Pujiang No. 1）, two domesticated populations （GA and HX） and four wild populations （LZ, YN, SS and JL） of blunt snout bream （Megalobrama amblycephala） was analyzed using 17 microsatellite markers. The results showed that an average of 4.88-7.65 number of alleles （A）; an average of 3.20-5.33 effective alleles （Ne）; average observed beterozygosity （Ho） of 0.6985-0.9044; average expected beterozygosity （He） of 0.6501--0.7805; and the average polymorphism information content （PIC） at 0.5706-0.7226. Pairwise FST value between populations ranged from 0.0307-0.1451, and Nei＇s standard genetic distance between populations was 0.0938-0.4524. The expected heterozygosities in the domesticated populations （GA and HX） were significantly lower than those found in three wild populations （LZ, SS and JL）, but no difference was detected when compared with the wild YN population. Likewise, no difference was found between the four wild populations or two domesticated populations. The expected heterozygosity in Pujiang No. 1 was higher than the two domesticated populations and lower than the four wild populations. Regarding pairwise Fsr value between populations, permutation test P-values were significant between the GA, HX and PJ populations, but not between the four wild populations. These results showed that the expected beterozygosity in the selected strain of blunt snout bream, after seven generations of selective breeding, was lower than that of wild populations, but this strain retains higher levels of genetic diversity than domesticated populations. The genetic differences and differentiation amongst wild populations, domesticated populations and the genetically improved strain of blunt snout bream will provide important conservation criteria and guide the utilization of germplasm resources.展开更多
The effects of recombinant eel growth hormone (reGH).methyltestosterone (MT)and L-thyroxine (T4)on the growth of red sea bream. Pagrosomus major.were investigated.Administration of reGH to fry by immersion at 2 mg 1 f...The effects of recombinant eel growth hormone (reGH).methyltestosterone (MT)and L-thyroxine (T4)on the growth of red sea bream. Pagrosomus major.were investigated.Administration of reGH to fry by immersion at 2 mg 1 for 2 hevery 5 dsys resulted in significant increase in both weight and length.but the condition factor (CF) diminished relative to that of similarly treated controls over the 37day treatment period.Immersion in 0.1 mg:1 T4 also resulted in significant increase in both weight and length and higher survival rate of test fry compared to the controls. Immersion in MT had less effect on growth and high-dose resulted in high mortality.In the second study.injection of 2 μg reGH(gwk)caused a significant increase in the specific growth rate (SGR) of test red sea bream fingerlings relative to that of the controls during the 4-week treatment period and maintained the increasing trend over the post-treatment period (weeks 4-6).Injection of MT at a dosage of 1μg (gwk) resulted in a significant展开更多
An experiment on the phosphorus requirement and the proper Ca/P ratio in the diet of the black sea bream using the phosphorus gradient method (with casein as basic diet, sodium dihydrogen phosphate as source of phosph...An experiment on the phosphorus requirement and the proper Ca/P ratio in the diet of the black sea bream using the phosphorus gradient method (with casein as basic diet, sodium dihydrogen phosphate as source of phosphorus, and calcium lactate as source of calcium) showed that growth was greatly affected by the diet’s phosphorus content and Ca/P ratio. Inadequate phosphorus in the diet resulted in slow growth and poor food conversion ratio (FCR). Analyses of the fish body showed it contained a high level of lipid but a low level of moisture, ash, calcium and phosphorus. The optimal values of phosphorus and Ca/P ratio in the black sea bream diet are 0.68% and 1:2 respectively. Phosphorus in excess of this optimum value resulted in slow growth or even death. The results of this experiment clearly indicated that phosphorus is the principal mineral additive affecting black sea bream growth.展开更多
This study attempted to culture red sea bream lymphocytes using artificial medium supplemented with mitogens and a cytokine. Growth of the lymphocytes was compared between cultures with mitogens phytohemagglutinin (PH...This study attempted to culture red sea bream lymphocytes using artificial medium supplemented with mitogens and a cytokine. Growth of the lymphocytes was compared between cultures with mitogens phytohemagglutinin (PHA), lipopolysaccharide (LPS), concanavalin A(Con A) and a cytokine mouse interleukin 2(IL 2) in a basal medium at various combinations. Addition of PHA or LPS enhanced growth of the lymphocytes, Con A did not enhance growth so much. Large colonies were formed when PA was added. Con A induced scattered single cell proliferation of the lymphocytes. IL 2 supported the actions of PHA and LPS. Combined addition of PHA and IL 2 maintained proliferation for 30 d.展开更多
STUDIES on the nutrition requirement of larval fish have made some progress abroad, but therehave been no reports on such studies in China. It was determined recently that n-3 HUFA (es-pecially 22: 6(n-3) (DHA) and 20...STUDIES on the nutrition requirement of larval fish have made some progress abroad, but therehave been no reports on such studies in China. It was determined recently that n-3 HUFA (es-pecially 22: 6(n-3) (DHA) and 20:5 (n-3) (EPA)) is essential for larval seafish growth. Thehigh content of DHA in seafish eggs and the low content of DHA in rotifers show that rotifersas live food cannot satisfy the n-3 HUFA requirement of larval seafish. Some scientists ob-展开更多
Rock bream (Oplegnathus fasciatus) is one of the most economically valuable fish in Korea. In recent years, artificial breeding techniques with molecular and microsatellite markers have been developed to enhance rock ...Rock bream (Oplegnathus fasciatus) is one of the most economically valuable fish in Korea. In recent years, artificial breeding techniques with molecular and microsatellite markers have been developed to enhance rock bream resources. Microsatellite loci to define genetic diversity were screened in rock bream (n = 30) from Jeju areas of Korea and fifteen polymorphic microsatellite loci were newly identified and analyzed. The number of alleles per locus ranged from 9 to 34 while observed and expected heterozygosity ranged from 0.600 to 1.000 and from 0.772 to 0.977, respectively. These markers will serve as a foundation for future population genetic studies and the selective breeding technology of rock bream farming.展开更多
An experiment on the optimum dietary protein content for the black sea bream using semi-purified dietsshowed the optimum content is 50.19% by weight as inferred from the growth rate and food consumptionof the fish. A...An experiment on the optimum dietary protein content for the black sea bream using semi-purified dietsshowed the optimum content is 50.19% by weight as inferred from the growth rate and food consumptionof the fish. Another experiment on the proper ratio of animal to plant protein in its diet using sandeel as theanimal protein source and peanut cake meal as plant protein source showed that the ratio had great ef-fect on its growth and should be 1.00:0.89—0.96 as judged from the growth rate and food consumptionof the fish.展开更多
文摘以聚乙烯醇为基膜材料,分别加入2 g/100 m L壳聚糖季铵盐、0.5 g/100 m L茶多酚、2.5 g/100 m L丙酸钙、0.5 g/100 m L对羟基苯甲酸乙酯联合1.5 g/100 m L丙酸钙做为抗菌剂,制得的聚乙烯醇抗菌包装薄膜,在冷藏(4±1)℃条件下对鳊鱼肉进行包装保鲜。以持水率、p H值、白度、硫代巴比妥酸值、挥发性盐基氮值、菌落总数、质构指标、感官评定对保鲜效果进行评价。结果表明:添加0.5 g/100 m L茶多酚和添加0.5 g/100 m L对羟基苯甲酸乙酯联合1.5 g/100 m L丙酸钙的聚乙烯醇抗菌保鲜薄膜对(4±1)℃鳊鱼具有最佳的保鲜效果。
文摘Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid （DHA） on lipegenic and lipelysis enzymes, one-year fish were roared on a casein-based purified diet and a DHA fortified diet （ 1.5% DHA ethyl ester/kg diet） for 60 d, followed with a period of 55 d for starvation. Dietary DHA was effectively incorporated into the fish body. Fortification of DHA depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancroas and intraperitoneal fat body. Carnitine palmitoyltransferase as lipolysis enzyme in the hepatopancreas was active in the DHA fortified fish. Starvation after feeding experiment induced increased carnitine palmitoyltransferase activity in both control and DHA fortified fish and the activity remained higher in the DHA fortified fish, while the monoenes were selectively consumed prior to highly unsaturated fatty acids. These results indicated that dietary DHA depressed lipogenesis and activated lipolysis.
基金supported by the National Natural Science Foundation of China(31802287,31730098,31430088)the China Postdoctoral Science Foundation(2018M632969)+3 种基金the earmarked fund for China Agriculture Research System(CARS-45)the Key Research and Development Program of Hunan Province(2018NK2072)Hunan Provincial Natural Science and Technology Major Project(2017NK1031)the Cooperative Innovation Center of Engineering and New Products for Developmental Biology of Hunan Province(20134486)
文摘In terms of taxonomic status,common carp(Cyprinus carpio,Cyprininae)and crucian carp(Carassius auratus,Cyprininae)are different species;however,in this study,a newborn homodiploid crucian carp-like fish(2n=100)(2nNCRC)lineage(F1–F3)was established from the interspecific hybridization of female common carp(2n=100)×male blunt snout bream(Megalobrama amblycephala,Cultrinae,2n=48).The phenotypes and genotypes of 2 n NCRC differed from those of its parents but were closely related to those of the existing diploid crucian carp.We further sequenced the whole mitochondrial(mt)genomes of the 2n NCRC lineage from F1 to F3.The paternal mt DNA fragments were stably embedded in the mt-genomes of F1–F3 generations of 2n NCRC to form chimeric DNA fragments.Along with this chimeric process,numerous base sites of F1–F3 generations of 2 n NCRC underwent mutations.Most of these mutation sites were consistent with the existing diploid crucian carp.Moreover,the mt DNA organization and nucleotide composition of 2n NCRC were more similar to those of the existing diploid crucian carp than those of the parents.The inheritable chimeric DNA fragments and mutant loci in the mt-genomes of different generations of 2nNCRC provided important evidence of the mt DNA change process in the newborn lineage derived from hybridization of different species.Our findings demonstrated for the first time that the paternal mt DNA were transmitted into the mt-genomes of homodiploid lineage,which provided new insights into the existence of paternal mt DNA in the mt DNA inheritance.
文摘The insulin-like growth factor Ⅰ(IGF-Ⅰ) gene of triangular bream (Megalobrama terminalis)(GenBank No.AY247412)(Tb)was cloned for the first time from liver by RT-PCR. Thenucleotide sequence analysis showed the Tb IGF-ⅠcDNA consisted of 486 nucleotides andencoded 117 amino acids including B, C, A, D and E five domains. Analysis of E-domainindicated that cloned Tb IGF-Ⅰbelonged to IGF-ⅠEa-2 subtype. Identity analysis showedthe IGF-Ⅰnucleotide sequence shared 99.8% homology with bluntnose bream, 88.8% withgrass carp, 85.8% with common carp; the pre-IGF-Ⅰamine acid sequence shared 99.4% withbluntnose bream, 88.8% with grass carp, 85.4% homology with common carp. In the CyprinusCarpio, the higher homology of nucleotide sequence and amino acid sequence in IGF-Ⅰshowed that the closer relationship the fishes have. These results could provide basicdata for the research on Tb germplasm and the development and utilization of biologicalfeed additives.
基金supported by the National Key R&D Pro-gram of China(No.2018YFD0900603)the National Na-tural Science Foundation of China(No.31672634)the research funding from Innovation Division,Lucta(Guangzhou)Flavours Co.,Ltd
文摘Recently,the use of natural immunopotentiators,such as plant extracts,is predicted to offer high disease-prevention potential in aquaculture.However,few reports on the immunomodulatory impacts of olive extract(OE)on teleost are available.Therefore,the effects of dietary intake of triterpene-enriched OE on black sea bream(Acanthopagrus schlegelii)were investigated in this study.Our data showed that total blood cell counts,in vivo content of lysozyme,activities of antiprotease and myeloperoxidase,and contents of IL-4 and IL-6 were significantly up-regulated by dietary intake of triterpene-enriched OE.Additionally,the hampered immune response induced by cadmium exposure was significantly mitigated by the administration of OE as were indicated by partially or completely rescued immune-relating parameters.Furthermore,the expressions of immune-related genes encoding NF-κB inhibitor alpha(IkBα),tumor necrosis factorα(TNFα),cyclooxygenase-2(COX-2),and proto-oncogene protein c-fos(FOS)were found to be significantly up-regulated by the dietary intake of OE.In general,the results suggested that the dietary intake of triterpene-enriched OE has immune enhancing effect in black sea bream.Such effect may be realized by 1)increasing the total counts of diverse blood cells;2)activating nonspecific immune biomolecules;and 3)affecting signaling pathways such as IKK and ERK and subsequently inducing IL-4 and IL-6 biosyntheses.
文摘In one trial 360 gilthead bream fingerlings received two different feed mixtures containing two different levels of protein (diet A 400 and B 360 g?kg<sup>?1</sup>). The average initial live weight was about 2.2 ± 0.1 g fish<sup>?1</sup> in each replicate of all treatments. Sixty fish per tank were stocked randomly in 6 fiberglass tanks (1 m<sup>3</sup> each). Fish were fed with experimental diets at rate 8% of the body weight daily. The Amino Acids (AA) content was analyzed in the diets, whole fish and muscle at the end of the growth period (60 days). The results indicated that at the end of experiment gilthead bream fingerlings had reached an average live weight 18.5 and 16.2 g fish<sup>?1</sup> for fish fed diet A and B respectively. Also the increase of protein levels in the feed to 40% caused a significant increase in the content of Indispensable Amino Acid (IAA) and dispensable amino acid (as %v of whole fish and muscle of wet weight). Two methods were subsequently used to estimate the quantitative IAA requirements of gilthead bream fry based on the hypothesis that (a) the dietary requirement pattern of IAA reflected the tissue pattern and (b) the rate of daily deposition in the fish could be equated with the dietary requirement as percentage of 100 g<sup>?1</sup> diet. The quantitative IAA requirement (%) of gilthead bream (Sparus aurata) diets was as follow: Lysine 2.27, Methionine 1.09, Therionine 0.61, Leucine 2.4, Isoleucine 0.47, Histidine1.6, Arginine 1.39, Phenylalanine 1.43, Valine 1.22 and Tryptophane 0.42.
基金supported by the National Natural Science Foundation of China(30630051)Doctoral Research Initial Funding from Shanghai Ocean University(A-2400-11-0186)
文摘In the present study, the genetic diversity of one selected strain （Pujiang No. 1）, two domesticated populations （GA and HX） and four wild populations （LZ, YN, SS and JL） of blunt snout bream （Megalobrama amblycephala） was analyzed using 17 microsatellite markers. The results showed that an average of 4.88-7.65 number of alleles （A）; an average of 3.20-5.33 effective alleles （Ne）; average observed beterozygosity （Ho） of 0.6985-0.9044; average expected beterozygosity （He） of 0.6501--0.7805; and the average polymorphism information content （PIC） at 0.5706-0.7226. Pairwise FST value between populations ranged from 0.0307-0.1451, and Nei＇s standard genetic distance between populations was 0.0938-0.4524. The expected heterozygosities in the domesticated populations （GA and HX） were significantly lower than those found in three wild populations （LZ, SS and JL）, but no difference was detected when compared with the wild YN population. Likewise, no difference was found between the four wild populations or two domesticated populations. The expected heterozygosity in Pujiang No. 1 was higher than the two domesticated populations and lower than the four wild populations. Regarding pairwise Fsr value between populations, permutation test P-values were significant between the GA, HX and PJ populations, but not between the four wild populations. These results showed that the expected beterozygosity in the selected strain of blunt snout bream, after seven generations of selective breeding, was lower than that of wild populations, but this strain retains higher levels of genetic diversity than domesticated populations. The genetic differences and differentiation amongst wild populations, domesticated populations and the genetically improved strain of blunt snout bream will provide important conservation criteria and guide the utilization of germplasm resources.
文摘The effects of recombinant eel growth hormone (reGH).methyltestosterone (MT)and L-thyroxine (T4)on the growth of red sea bream. Pagrosomus major.were investigated.Administration of reGH to fry by immersion at 2 mg 1 for 2 hevery 5 dsys resulted in significant increase in both weight and length.but the condition factor (CF) diminished relative to that of similarly treated controls over the 37day treatment period.Immersion in 0.1 mg:1 T4 also resulted in significant increase in both weight and length and higher survival rate of test fry compared to the controls. Immersion in MT had less effect on growth and high-dose resulted in high mortality.In the second study.injection of 2 μg reGH(gwk)caused a significant increase in the specific growth rate (SGR) of test red sea bream fingerlings relative to that of the controls during the 4-week treatment period and maintained the increasing trend over the post-treatment period (weeks 4-6).Injection of MT at a dosage of 1μg (gwk) resulted in a significant
文摘An experiment on the phosphorus requirement and the proper Ca/P ratio in the diet of the black sea bream using the phosphorus gradient method (with casein as basic diet, sodium dihydrogen phosphate as source of phosphorus, and calcium lactate as source of calcium) showed that growth was greatly affected by the diet’s phosphorus content and Ca/P ratio. Inadequate phosphorus in the diet resulted in slow growth and poor food conversion ratio (FCR). Analyses of the fish body showed it contained a high level of lipid but a low level of moisture, ash, calcium and phosphorus. The optimal values of phosphorus and Ca/P ratio in the black sea bream diet are 0.68% and 1:2 respectively. Phosphorus in excess of this optimum value resulted in slow growth or even death. The results of this experiment clearly indicated that phosphorus is the principal mineral additive affecting black sea bream growth.
文摘This study attempted to culture red sea bream lymphocytes using artificial medium supplemented with mitogens and a cytokine. Growth of the lymphocytes was compared between cultures with mitogens phytohemagglutinin (PHA), lipopolysaccharide (LPS), concanavalin A(Con A) and a cytokine mouse interleukin 2(IL 2) in a basal medium at various combinations. Addition of PHA or LPS enhanced growth of the lymphocytes, Con A did not enhance growth so much. Large colonies were formed when PA was added. Con A induced scattered single cell proliferation of the lymphocytes. IL 2 supported the actions of PHA and LPS. Combined addition of PHA and IL 2 maintained proliferation for 30 d.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39470562).
文摘STUDIES on the nutrition requirement of larval fish have made some progress abroad, but therehave been no reports on such studies in China. It was determined recently that n-3 HUFA (es-pecially 22: 6(n-3) (DHA) and 20:5 (n-3) (EPA)) is essential for larval seafish growth. Thehigh content of DHA in seafish eggs and the low content of DHA in rotifers show that rotifersas live food cannot satisfy the n-3 HUFA requirement of larval seafish. Some scientists ob-
文摘Rock bream (Oplegnathus fasciatus) is one of the most economically valuable fish in Korea. In recent years, artificial breeding techniques with molecular and microsatellite markers have been developed to enhance rock bream resources. Microsatellite loci to define genetic diversity were screened in rock bream (n = 30) from Jeju areas of Korea and fifteen polymorphic microsatellite loci were newly identified and analyzed. The number of alleles per locus ranged from 9 to 34 while observed and expected heterozygosity ranged from 0.600 to 1.000 and from 0.772 to 0.977, respectively. These markers will serve as a foundation for future population genetic studies and the selective breeding technology of rock bream farming.
文摘An experiment on the optimum dietary protein content for the black sea bream using semi-purified dietsshowed the optimum content is 50.19% by weight as inferred from the growth rate and food consumptionof the fish. Another experiment on the proper ratio of animal to plant protein in its diet using sandeel as theanimal protein source and peanut cake meal as plant protein source showed that the ratio had great ef-fect on its growth and should be 1.00:0.89—0.96 as judged from the growth rate and food consumptionof the fish.
