A 3×3 factorial feeding trial was conducted to evaluate the production response of juvenile northern snakehead fish(Channa argus). Nine diets containing 3 protein levels(45%, 48% and 51%) and 3 lipid levels(9%,12...A 3×3 factorial feeding trial was conducted to evaluate the production response of juvenile northern snakehead fish(Channa argus). Nine diets containing 3 protein levels(45%, 48% and 51%) and 3 lipid levels(9%,12% and 15%) were formulated and fed to triplicate groups of juvenile northern snakehead(15.78 ± 0.09 g/fish) for 8 weeks. The formulated diets were named as P45 L9, P45 L12, P45 L15, P48 L9,P48 L12, P48 L15, P51 L9, P51 L12 and P51 L15(P-Protein, L-Lipid), respectively. Fish fed diets with the lowest protein and lipid combination(P45 L9) had the lowest growth performance. Weight gains(WG) of fish fed the 4 diets P48 L12, P48 L15, P51 L9, and P51 L12 were not significantly different(P> 0.05), but significantly higher(P < 0.05) than those of fish fed the other diets. Fish fed diets P48 L12 and P48 L15 had significantly lower(P < 0.05) feed conversion ratios(FCR) than the rest of the treatments. Protein retentions(PR) among fish fed the diets P45 L12, P45 L15, P48 L12, P48 L15, P51 L9, and P51 L12 were similar and significantly higher(P < 0.05) than those of fish fed the remaining diets. Protein sparing effect was observed in the treatments when fish was fed diets containing 45% or 48% dietary protein levels with dietary lipid increased from 9% to12%. Fish fed diets with 9% lipid tended to have lower viscerosomatic index(VSI), hepatosomatic index(HSI),and whole-body lipid. Increasing dietary protein level significantly increased(P < 0.05) liver moisture and lipid while dietary lipid level increased liver lipid. Intestinal lipase activity increased significantly(P < 0.05)with increasing dietary lipid and protein levels while intestinal a-amylase and protease activities were not significantly influenced(P > 0.05) by dietary treatments. Based on these results, the diet containing 48%protein with either 12% or 15% lipid is the optimal for supporting growth and feed utilization of juvenile northern snakehead under the current testing conditions.展开更多
A new fully automatic ^40Ar/^39Ar laboratory with a Thermo Scientific ARGUS VI mass spectrometer has been established in China University of Geosciences （Wuhan）. We designed and developed a mini efficient preparatio...A new fully automatic ^40Ar/^39Ar laboratory with a Thermo Scientific ARGUS VI mass spectrometer has been established in China University of Geosciences （Wuhan）. We designed and developed a mini efficient preparation system （80 mL）, a CO2 laser for heating samples, a crusher for extracting fluid inclusions within K-poor minerals and an air reservoir （31 L） and pipette （0.1 mL） system. The ARGUS VI mass spectrometer is operated by the Qtegra Noble Gas software, which can control the peripheral accessories, such as pneumatic valves, CO2 laser and crusher through a PeriCon （peripheral controller）. The experimental procedures of atmospheric argon ana- lyses, ^40Ar/^39Ar dating by laser stepwise heating and by progressive crushing in vacuo, can be fully automatically performed. The weighted mean of atmospheric ^40Ar/^36Ar ratios is 302.22＋0.03 （1σ, MSWD=0.74, n=200）, indicating that air reservoir and pipette system and the whole instrument sys- tem are very stable. This laboratory is a successful pioneer example in China to establish a new no- ble gas laboratory with self-made peripheral accessories expect for the mass spectrometer.展开更多
The teleost Scatophagus argus is a species whose females grows faster than males.Growth hormone(gh)mRNA abundance in females pituitary is higher than that in males;however the mechanism underlining such differential i...The teleost Scatophagus argus is a species whose females grows faster than males.Growth hormone(gh)mRNA abundance in females pituitary is higher than that in males;however the mechanism underlining such differential is still unknown.Growth hormone(GH)is tightly associated with GH-releasing hormone(Ghrh)in vertebrates.In this study,Ghrh gene(ghrh)and its receptor gene,ghrhr,were isolated from S.argus.Tissue expression analysis showed that ghrh and ghrhr were mainly expressed in hypothalamus while ghrhr was expressed in pituitary and gh was predominantly expressed in pituitary.Twenty cultured S.argus individuals were used to compare ghrh,ghrhr and gh mRNA abundances,120 g and 181 g average weight for male(n=11)and female(n=9),respectively.Real-time PCR indicated that the ghrh and ghrhr mRNA abundances in male hypothalamus were significantly higher than those in female hypothalamus while that of gh mRNA abundance was significantly higher in female pituitary than in male pituitary.The ghrh and ghrhr mRNA abundances were significantly up-regulated in female hypothalamus 3 h after injection of 0.1 mg kg^-1 body weight Ghrh while pituitary ghrhr and gh mRNA abundances were not affected.In female hypothalamus,ghrh and ghrhr m RNA abundances were not affected at 6 h post-injection of 4 mg kg^-1 body weight 17α-methyltes-tosterone(17α-MT)or 17β-Estradiol(E2).In female pituitary,ghrhr m RNA abundance was down-regulated by 17α-MT while that of gh m RNA abundance was up-regulated by E2.Our findings indicated that E2,rather than Ghrh,plays an important role in up-regulating the expression of gh in female S.argus,which should aid to understand the sexual dimorphism of teleost growth.展开更多
基金supported by a grant(No.201524) from the Technical Support Group in Aquaculture of Zhejiang Ocean and Fisheries Bureau
文摘A 3×3 factorial feeding trial was conducted to evaluate the production response of juvenile northern snakehead fish(Channa argus). Nine diets containing 3 protein levels(45%, 48% and 51%) and 3 lipid levels(9%,12% and 15%) were formulated and fed to triplicate groups of juvenile northern snakehead(15.78 ± 0.09 g/fish) for 8 weeks. The formulated diets were named as P45 L9, P45 L12, P45 L15, P48 L9,P48 L12, P48 L15, P51 L9, P51 L12 and P51 L15(P-Protein, L-Lipid), respectively. Fish fed diets with the lowest protein and lipid combination(P45 L9) had the lowest growth performance. Weight gains(WG) of fish fed the 4 diets P48 L12, P48 L15, P51 L9, and P51 L12 were not significantly different(P> 0.05), but significantly higher(P < 0.05) than those of fish fed the other diets. Fish fed diets P48 L12 and P48 L15 had significantly lower(P < 0.05) feed conversion ratios(FCR) than the rest of the treatments. Protein retentions(PR) among fish fed the diets P45 L12, P45 L15, P48 L12, P48 L15, P51 L9, and P51 L12 were similar and significantly higher(P < 0.05) than those of fish fed the remaining diets. Protein sparing effect was observed in the treatments when fish was fed diets containing 45% or 48% dietary protein levels with dietary lipid increased from 9% to12%. Fish fed diets with 9% lipid tended to have lower viscerosomatic index(VSI), hepatosomatic index(HSI),and whole-body lipid. Increasing dietary protein level significantly increased(P < 0.05) liver moisture and lipid while dietary lipid level increased liver lipid. Intestinal lipase activity increased significantly(P < 0.05)with increasing dietary lipid and protein levels while intestinal a-amylase and protease activities were not significantly influenced(P > 0.05) by dietary treatments. Based on these results, the diet containing 48%protein with either 12% or 15% lipid is the optimal for supporting growth and feed utilization of juvenile northern snakehead under the current testing conditions.
基金financially supported by the National Natural Science Foundation of China (Nos. 41503053, 41630315, 41688103, and 91128203)
文摘A new fully automatic ^40Ar/^39Ar laboratory with a Thermo Scientific ARGUS VI mass spectrometer has been established in China University of Geosciences （Wuhan）. We designed and developed a mini efficient preparation system （80 mL）, a CO2 laser for heating samples, a crusher for extracting fluid inclusions within K-poor minerals and an air reservoir （31 L） and pipette （0.1 mL） system. The ARGUS VI mass spectrometer is operated by the Qtegra Noble Gas software, which can control the peripheral accessories, such as pneumatic valves, CO2 laser and crusher through a PeriCon （peripheral controller）. The experimental procedures of atmospheric argon ana- lyses, ^40Ar/^39Ar dating by laser stepwise heating and by progressive crushing in vacuo, can be fully automatically performed. The weighted mean of atmospheric ^40Ar/^36Ar ratios is 302.22＋0.03 （1σ, MSWD=0.74, n=200）, indicating that air reservoir and pipette system and the whole instrument sys- tem are very stable. This laboratory is a successful pioneer example in China to establish a new no- ble gas laboratory with self-made peripheral accessories expect for the mass spectrometer.
文摘以乌鳢(Ophiocephalus argus)为研究对象,采用不同日粮饲喂,试验W1组饲喂冰鲜鱼,试验W2组饲喂畜禽内脏。12周后,取肠道内容物,利用16S rDNA技术研究投喂不同饲粮的乌鳢肠道生物群落结构差异和微生物多样性,分别获得W1组和W2组乌鳢肠道细菌有效序列51124和39298条。结果分析表明;W1组和W2组物种注释(operational taxonomic unit,OTU)数目分别为2631和4114条,分类地位明确的细菌种类分别隶属5个属和49个属,W1组和W2组乌鳢肠道细菌种类差异很大。W1组乌鳢肠道细菌的优势类群是邻单胞菌属(Plesiomonas)、狭义梭菌属(Clostridium sensu stricto)、鲸蜡菌属(Cetobacterium);W2组乌鳢肠道细菌的优势类群是狭义梭菌属(Clostridium sensu stricto)、邻单胞菌属(Plesiomonas)、Spartobacteria、甲基副球菌属(Methyloparacoccus)、杆菌属(Alsobacter)、Saccharibacteria、分支杆菌属(Mycobacterium)。W2组乌鳢肠道细菌香农指数高于W1组乌鳢肠道细菌,表明前者肠道细菌多样性大于后者。本实验揭示了畜禽内脏饲喂乌鳢肠道细菌的群落种类多样性、OTU丰富度和物种总数均高于冰鲜鱼饲喂乌鳢;W1组肠道有益菌OTU丰富度大于W2组,且W2组还存在一些潜在致病菌。本研究为乌鳢的健康养殖和后续肠道微生物资源的挖掘提供了理论依据。
基金the Key Project of ‘Blue Granary Science and Technology Innovation’ of the Ministry of Science and Technology (No. SQ2018 YFD090006)the National Natural Science Foundation of China (Nos. 31702326 and 41706174)+8 种基金the Natural Science Foundation of Guangdong Province (Nos. 2016A03 0313743, 2017A030313101 and 2018B030311050)the Department of Education of Guangdong Province (Nos. 2018KTSCX090 and 2018KQNCX106)the Guangdong Provincial Special Fund For Modern Agriculture Industry Technology Innovation Teams (No. 2019KJ149)the Zhanjiang Science and Technology Bureau (No. 2016A03017)Guangdong Ocean University Natural Science Research Program (2015 and 2016)the Project of Provincial Key Platform and Major Scientific Research of Colleges and Universities in Guangdong (No. 2015KTSCX058)the Sail Projects of Guangdong (2014.1)the Marine Fishery Science and Technology Extension Projects of Guangdong (Nos. A201408A06 and A201608B01)the Program for Scientific Research Start-Up Funds of Guangdong Ocean University
文摘The teleost Scatophagus argus is a species whose females grows faster than males.Growth hormone(gh)mRNA abundance in females pituitary is higher than that in males;however the mechanism underlining such differential is still unknown.Growth hormone(GH)is tightly associated with GH-releasing hormone(Ghrh)in vertebrates.In this study,Ghrh gene(ghrh)and its receptor gene,ghrhr,were isolated from S.argus.Tissue expression analysis showed that ghrh and ghrhr were mainly expressed in hypothalamus while ghrhr was expressed in pituitary and gh was predominantly expressed in pituitary.Twenty cultured S.argus individuals were used to compare ghrh,ghrhr and gh mRNA abundances,120 g and 181 g average weight for male(n=11)and female(n=9),respectively.Real-time PCR indicated that the ghrh and ghrhr mRNA abundances in male hypothalamus were significantly higher than those in female hypothalamus while that of gh mRNA abundance was significantly higher in female pituitary than in male pituitary.The ghrh and ghrhr mRNA abundances were significantly up-regulated in female hypothalamus 3 h after injection of 0.1 mg kg^-1 body weight Ghrh while pituitary ghrhr and gh mRNA abundances were not affected.In female hypothalamus,ghrh and ghrhr m RNA abundances were not affected at 6 h post-injection of 4 mg kg^-1 body weight 17α-methyltes-tosterone(17α-MT)or 17β-Estradiol(E2).In female pituitary,ghrhr m RNA abundance was down-regulated by 17α-MT while that of gh m RNA abundance was up-regulated by E2.Our findings indicated that E2,rather than Ghrh,plays an important role in up-regulating the expression of gh in female S.argus,which should aid to understand the sexual dimorphism of teleost growth.
