盐度对卵形鲳鲹幼鱼生长及能量收支的影响

在水温(28±1)℃,以配合饲料及最大摄食量的条件下,研究卵形鲳鲹(Trachinotus ovatus)幼鱼[初始体重(5.77±0.45)g]在盐度10、15、20、25、30和35下的生长及能量收支。结果表明:在盐度25时,湿重、干重、蛋白质及能量指标的特定生长率均达到最大值,分别为3.21%、2.06%、4.76%和4.66%;干重、蛋白质和能量指标的摄食率也达最大,分别为20.31%、13.57%和12.21%;干重、蛋白质和能量指标的转化效率也达最大,分别为35.61%、46.60%和52.78%。可见,盐度对卵形鲳鲹幼鱼的特定生长率、摄食率、转化效率及能量收支有显著影响。盐度对吸收效率则无显著影响,蛋白质和能量的平均吸收效率分别为94.91%和92.45%;在盐度25,卵形鲳鲹幼鱼得到最佳的能量分配模式,其收支方程为:100.00C=7.30F+10.13U+29.80R+52.77G。     

限食水平与饥饿时间对卵形鲳鲹幼鱼补偿生长的影响

限食水平与饥饿时间对卵形鲳鲹幼鱼生长的影响实验共分7组,其中3个限食处理组日投喂量分别为对照组的20%、40%和60%,限食12 d后饱食投喂28 d;3个饥饿处理组饥饿时间分别为4、8、12 d,分别饱食投喂36、32和28 d;对照组饱食投喂40 d。结果表明:短期限食都能发生完全补偿生长效应,补偿生长效果随饥饿时间延长而减弱,饥饿12 d发生部分补偿生长;各组的摄食率和饲料转化率都有所提高,饥饿程度较大组补偿生长效应主要是通过提高摄食率来实现;在限食或饥饿期间,鱼体肌肉中的水分和粗灰分含量均有所升高,粗蛋白和粗脂肪含量呈现不同程度下降。     

温度、盐度对卵形鲳鲹呼吸代谢的影响

运用间歇流水式呼吸仪研究卵形鲳鲹(Trachinotus ovatus L.)在不同温度、盐度下呼吸代谢的变化。结果表明:在19~33℃内,随温度升高,卵形鲳鲹的耗氧率(RO)、排氨率(RN)、代谢率(REO)、排泄率(REN)均不断增大,差异有统计学意义(P<0.05),氨商(QA)与蛋白质供能比(PEP)则下降,差异有统计学意义(P<0.05),并在28~33℃组达到稳定;温度系数(Q10值)在水温由28℃升至33℃时最小,为1.59;肝糖原(LG)及乳酸(LD)均呈下降趋势,且各组LG差异均具统计学意义(P<0.05)。在盐度15~30时,随盐度增大,卵形鲳鲹RO、RN、REO、REN、QA与PEP均呈U型抛物线变化,并在盐度20~25时有最小值;LG与LD变化均不明显。在19~33℃内,卵形鲳鲹代谢水平与水温呈正相关,主要由氧化蛋白质供能,28~33℃的温度条件更利于卵形鲳鲹生长。在盐度15~30内,卵形鲳鲹代谢水平与盐度呈U型抛物线变化,主要由氧化蛋白质供能,盐度20~25利于机体储备蛋白质,即利于生长。     

卵形鲳鲹结节病病原的分离与鉴定

从湛江港、阳江闸坡海水网箱养殖的患结节病卵形鲳鲹(Trachinotus ovatus)中分离一株细菌,回归感染结果证明该菌是引起卵形鲳鲹结节病的病原,对卵形鲳鲹半致死浓度为45 g-1。该菌株呈革兰阳性,好氧,具有弱抗酸性,菌体呈短杆状或细长分枝状,过氧化氢酶阳性,氧化酶阴性,还原硝酸盐,不水解酪素、黄嘌呤、酪氨酸、淀粉、明胶,以柠檬酸盐为唯一碳源生长。对其16S rDNA序列作Blast分析,构建系统进化树。结果表明,该菌株与诺卡氏菌属的菌株亲缘关系最近,且与鰤鱼诺卡氏菌(Nocardia seriolea JCM 3360T)的16S rDNA序列同源性高达99%。综合患病鱼的症状及病原菌形态、生理生化特性及16S rDNA序列的结果,该菌被鉴定为鰤鱼诺卡氏菌(N.seriolea)。     

禁食暂养对卵形鲳鲹有水保活生理响应的影响

【目的】探究禁食暂养对卵形鲳鲹有水保活生理响应的影响,为卵形鲳鲹的保活运输奠定基础。【方法】通过测定暂养过程中水体的总氨氮和pH值、卵形鲳鲹血液生理生化指标、肌肉氧化应激指标等的变化,分析确定卵形鲳鲹有水保活的禁食暂养条件。【结果与结论】禁食暂养过程中,随着暂养时间的延长,水体总氨氮含量与pH值显著上升,但在禁食暂养时间为6 h时,其总氨氮质量浓度为3.22 mg/L和pH值为7.80;禁食暂养6 h可以降低或减少卵形鲳鲹的应激,使血液中乳酸脱氢酶(LDH)和谷草转氨酶(AST)活性以及皮质醇(Cortisol)、血糖(GLU)、尿素氮(BUN)和总胆固醇(T-CHO)含量处于较低水平,分别为2785.53 U/L、19.04 U/L、158.72 ng/mL、2.98 mmol/L、4.35 mmol/L和4.96 mmol/L;同时减轻了应激带来的肌肉组织氧化损失,使过氧化氢酶(CAT)活性和丙二醛(MDA)含量维持在较低水平,分别为6.34 U/L和5.86 mmol/L;卵形鲳鲹适宜的暂养条件为在鱼水比m鱼∶m水=1∶20和(25±1)℃的洁净海水中暂养6 h。     

热处理温度对卵形鲳鲹品质和肌肉蛋白质理化特性的影响

【目的】揭示不同加热温度对卵形鲳鲹（Trachinotus ovatus）蛋白特性的影响,探究卵形鲳鲹最佳热处理温度,提升热加工处理后卵形鲳鲹的品质。【方法】应用差式扫描量热仪、电泳、显微镜及理化功能特性检测分析在0、40、50、60、70、80、90、100℃加热温度下卵形鲳鲹肌肉的品质（色泽、质构）,蛋白质失重率、总巯基含量、浊度、Ca2+-ATP酶活性、表面疏水性、蛋白降解变性等理化特性指标及微观结构的变化。【结果】热处理温度对肌肉品质和肌肉蛋白理化特性有显著影响（P <0.05）,卵形鲳鲹肌肉的热变性温度为75.1℃。随加热温度升高,肌肉色泽由半透明转为乳白色,咀嚼性、弹性、内聚性先升后降,黏性先降后升,硬度先降后升再下降,在70℃时最大。随着加热温度的升高,肌肉蛋白质逐渐变性,失重率和pH均上升,水分含量呈波动性变化,在0～60℃时随加热温度的升高而下降,在60～80℃随加热温度的升高而增加,在80℃后则随加热温度升高而略有下降;表面疏水性在0～50℃逐渐升高,50～60℃间维持稳定,60～70℃呈下降趋势,70～80℃呈快速上升趋势,80℃后则随加热温度升高呈下降趋势...     

非诺贝特对卵形鲳鲹PPAR α及CPTI基因表达的影响

对卵形鲳鲹(Trachinotus ovatus)腹腔注射20、50、100 mg/kg的激动剂非诺贝特,用RT-PCR检测肝脏、肌肉中PPARα和CPTI基因表达的变化趋势,研究激动剂对卵形鲳鲹PPARα和CPTI基因表达的影响。结果表明,PPARα基因表达量50 mg/kg非诺贝特组高于其他组,差异有统计学意义(P0.05),而CPTI表达量在20 mg/kg组有较高的表达水平(P0.05);50 mg/kg非诺贝特组中PPARα基因表达量随着时间的变化呈现先降低后恢复至初始水平的趋势,CPTI表达量随时间变化先升高后降低,随后又升高的变化趋势,肝脏组织中,CPTI表达量在注射后30 h达到最高(P0.05),而在肌肉组织中18 h时达到最高值(P0.05);非诺贝特组PPARα和CPTI基因的表达量均高于PBS对照组(P0.05)。非诺贝特可诱导PPARα基因的表达,但CPTI与PPARα基因表达无较明显的相关性。     

不同盐度对龙虎斑生长和摄食的影响

在盐度5、10、15、20、25、30条件下,以全人工配合饵料饲喂龙虎斑[鞍带石斑鱼(Epinephelus lanceolatus♂)×棕点石斑鱼(E.fuscoguttatus♀)]60 d,研究不同盐度对龙虎斑生长和摄食的影响。结果表明,不同盐度对龙虎斑生长的影响有统计学意义(P0.05),盐度5~20组增长率、特定生长率均高于盐度25、30组,差异有统计学意义(P0.05),盐度10组的增长率最高,为55.08%,盐度15组的特定生长率最大,为2.30%/d,盐度和龙虎斑生长速率的回归方程为K=0.000 09 S 4-0.006 S 3+0.131 S 2-1.055 S+4.832(R 2=0.984);不同盐度对龙虎斑的摄食率和饵料系数影响有统计学意义(P0.05),盐度15组的摄食率最高,为1.64%/d,其次为盐度10组,为1.60%/d,饵料系数在盐度15组最低,为0.820,其次为盐度10组,为0.827。因此,龙虎斑在低盐度条件下生长比高盐度快,摄食率高,饵料利用率高,最佳生长盐度为10~15。     

卵形鲳鲹肉碱棕榈酰基转移酶Ⅰ全长cDNA序列的克隆及生物信息学分析

采用RACE-PCR克隆卵形鲳鲹(Trachinotus ovatus)肉碱棕榈酰基转移酶Ⅰ(carnitine palmitoyltransferaseⅠ,CPTⅠ)c DNA序列全长,并对其编码氨基酸进行生物信息学分析。结果表明,卵形鲳鲹CPTⅠ基因(Gen Bank登录号KP987456)c DNA序列全长2 841 bp,其开放阅读框(ORF)为2 363 bp,编码787个氨基酸,3'非编码区(URT)335 bp,5'非编码区142 bp;生物信息预测显示CPTⅠ基因编码的蛋白无信号肽序列,脂溶指数高达85.63,亲水性平均值(GRAVY)为-0.213,具有2个跨膜区螺旋,在第312和367氨基酸残基处存在N-糖基化位点,在19个丝氨酸(Ser)、9个苏氨酸(Thr)和14个酪氨酸(Tyr)残基上可能发生磷酸化;二级结构中α螺旋(Alpha helix)占比例最大,为40.66%;该蛋白亚细胞定位预测其主要分布于细胞质和线粒体中;分子系统进化分析显示,卵形鲳鲹CPTⅠ蛋白与花鲈(Lateolabrax japonicas)的同源性最高,达94%,与大黄鱼(Larimichthys crocea)、金鲷(Sparus aurata)的次之,均为93%,与人(Homo sapiens)、鼠(Mus musculus)等的同源性较低(65%)。     

CO2协同低温有水对卵形鲳鲹麻醉保活效果的影响

【目的】探究二氧化碳CO₂麻醉协同低温对卵形鲳鲹有水保活的影响,延长卵形鲳鲹(Trachinotus ovatus)的保活时间。【方法】研究保活过程中CO₂质量浓度、麻醉时间、麻醉温度和鱼质量水比对卵形鲳鲹有水保活时长的影响;在最佳麻醉保活条件下,测定其血清生化指标、肌肉及肝脏氧化应激指标及代谢指标。【结果】卵形鲳鲹在16℃、100 mg/L CO₂水溶液中麻醉3 min其麻醉效果最佳。在15℃低温下进行有水保活,鱼水质量比为2∶1,存活时间最长,为(359±2)min,此条件下复苏率达100%。经过CO₂麻醉协同低温有水保活后的卵形鲳鲹血清谷草转氨酶(GOT)活性显著升高(P<0.05)、尿素氮(BUN)和甘油三酯(TG)含量上升,血糖含量下降。肌肉中的乳酸脱氢酶(LDH)活性显著上升(P<0.05),乳酸(LD)和糖原含量上升,过氧化氢酶(CAT)活性和丙二醛(MDA)含量下降;肝脏中的LDH活性显著上升(P<0.05)、CAT活性和LD的含量上升,MDA和糖原的含量下降。【结论】CO₂协同低温有水对卵形鲳鲹有较好的麻醉效果,有助于保活运输。在保活过程中卵形鲳鲹通过提升能量代谢水平和抗氧化能力应答环境应激,在一定程度上影响卵形鲳鲹保活过程的存活时间。     

The Effect of Temperature on Growth and Energy Budget of the Polychaete,Neanthesjaponica Izuka

Growth and energy budget of the polychaete, Neanthesjaponica, at various temperatures （17, 20, 23, 26 and 29℃） were investigated in this study. The growth, as indicated by final dry weight and specific growth rate （SGR）, increased with increasing temperature, with the maximum level at 26℃, and then decreased significantly at 29℃. A similar trend was observed in feeding rate, food conversion efficiency （FCE） and apparent digestive rate （ADR）. However, no significant differences were detected in ADR among all the temperature treatments. In the pattern of energy allocation, faeces energy was only a small component of energy budget and had little influence on the proportion of food energy allocated to growth. The metabolic energy accounted for a large portion of energy intake for each temperature treatment. The nitrogen excretion was appreciable with changing temperature. The two expenditure terms （respiration energy and excretion energy） in energy budget were the major factors influencing the proportion of food energy allocated to growth. These results revealed that temperature affected the growth of N. japonica mainly by influencing feeding rate and FCE. In addition, regression equations describing the relationship between feeding rate, faecal production, SGR, FCE and temperature were obtained. The optimum temperatures for feeding rate, FCE and SGR were estimated at 25.01 ℃, 24.24℃ and 24.73 ℃, respectively, from the regression equations.     

The Effect of Temperature on Growth and Energy Budget of the Polychaete,Neanthes japonica Izuka

Growth and energy budget of the polychaete, Neanthesjaponica, at various temperatures (17, 20, 23, 26 and 29 ℃) were investigated in this study. The growth, as indicated by final dry weight and specific growth rate (SGR), increased with increasing temperature, with the maximum level at 26℃, and then decreased significantly at 29℃. A similar trend was observed in feeding rate, food conversion efficiency (FCE) and apparent digestive rate (ADR). However, no significant differences were detected in ADR among all the temperature treatments. In the pattern of energy allocation, faeces energy was only a small component of energy budget and had little influence on the proportion of food energy allocated to growth. The metabolic energy accounted for a large portion of energy intake for each temperature treatment. The nitrogen excretion was appreciable with changing temperature. The two expendi-ture terms (respiration energy and excretion energy) in energy budget were the major factors influencing the proportion of food en-ergy allocated to growth. These results revealed that temperature affected the growth of N. japonica mainly by influencing feeding rate and FCE. In addition, regression equations describing the relationship between feeding rate, faecal production, SGR, FCE and temperature were obtained. The optimum temperatures for feeding rate, FCE and SGR were estimated at 25.01 ℃, 24.24℃ and 24.73 ℃, respectively, from the regression equations.     

Comparisons of Salinity Adaptation in Terms of Growth,Body Composition,and Energy Budget in Juveniles of Rainbow and Steelhead Trouts (Oncorhynchus mykiss)

This study examined the effect of different salinities(0, 5, 10, 15, 20, 25 and 30) on the growth performance and energy budget of juveniles of two different ecotypes of Oncorhynchus mykiss, landlocked rainbow trout and anadromous steelhead trout. In the 42 d experiment, fish were cultured in three replicate tanks per salinity treatment(eight fish per tank). At the end of the experiment, the growth of rainbow and steelhead trouts was significantly higher at salinities of 5 and 10, respectively, than at all other salinities. The protein, lipid and energy content of both ecotypes declined with the increase of salinity. Based on their energy budgets, the percentage of energy consumed for growth by rainbow and steelhead trouts were significantly higher at salinities of 5(34.00% ±1.69%) and 10(43.76% ± 1.29%), respectively, than at all other salinities. The percentage of energy consumed for respiration by rainbow and steelhead trouts was lower at salinities of 5(54.90% ± 1.77%) and 10(46.73% ± 0.62%), respectively, than at all other salinities. Our results indicated that the salinity adaptation ability of juvenile steelhead trout was slightly better than that of juvenile rainbow trout, and salinities of 10 and 5, respectively, were most suitable for growth of these two fishes.     

半干旱夏季放牧草地能量收支和地表蒸散量变化特征

以半干旱区域典型夏季放牧草地为研究对象,采用涡动相关法,获取了2012年5月至2013年5月水汽和能量通量观测数据,分析夏季近地层能量收支特征、地表蒸散量变化及其气象控制因子。观测结果显示:生长季有效能量的分配以潜热通量为主,非生长季则以感热通量为主;地表蒸散日总量最大值为3.0mm,日蒸散量大小主要取决于土壤温度、气温和净辐射;降雨量的季节分布是地表蒸散量季节变化的一个重要的影响因子。     

Effects of Dietary Protein Level on Growth and Utilization of Protein and Energy by Juvenile Mangrove Red Snapper (Lutjanus argentimaculatus )

1Introduction The mangrove red snapper,Lutjanus argentimacu-latus(Forsskal,1775)is a carnivorous,warm-watereuryhaline fish that is considerably cultured in South-east Asia,Southern China and the Middle East(Le-ung et al.,1999;Estudillo et at.,2000;Ng et al.,2000;Catacutan et al.,2001).In Pakistan,it isknown for its good quality meat and also for its highconsumption rate.Although it fetches a premiumprice at local markets(Anonymous,2002),the in-creasing demand has generated interest towar…     

西施舌人工育苗及幼虫、稚贝生长研究

对西施舌 (Coelomactraantiquata)室内人工育苗进行了研究。结果表明 ,西施舌在广东的繁殖高峰期为 5～ 6月 ,用阴干加流水刺激的方法诱导亲贝排放精卵 ,其受精率和孵化率可达 98%左右。 1997年和 1999年两次育苗试验结果 :在盐度为 2 6 .0 0～ 32 .0 0、水温为 2 3～ 2 6℃条件下 ,幼虫在培育密度为 1～ 2mL- 1时生长较好 ,经 9～ 10d培育 ,可进入附着变态期 ,其壳长生长速度为14 .1μm·d- 1。稚贝阶段在日流水量为育苗水体的 1.5～ 2 .0倍时取得较好效果 ,其壳长生长速度为 112 .4 μm·d- 1。