水流速率对全缘马尾藻幼孢子体生长和生理活性的影响

在0、0.5、1、2、4、8 cm/s 等5 种不同水流速率下培养全缘马尾藻（Sargassum integerrimum）幼孢子体,研究水流速率对幼孢子体质量、叶绿素a 含量、SOD 活力、CAT 活力和蛋白质浓度等生理指标的影响.结果表明,以1、2、4 cm/s 流速的幼孢子体质量增长最快,3 种流速的增长差异不具统计学意义（P〉0.05）.在生理指标方面：叶绿素a 含量以1、2、4 cm/s 流速最高,3 种流速的含量差异不具统计学意义（P〉0.05）;SOD 比活性以流速0.5、1、2 cm/s 的活力最低,各组间差异不具统计学意义（P〉0.05）;CAT 比活性以流速1、2 cm/s 的活力最低,组间差异不具统计学意义（P〉0.05）;蛋白质含量以1、2、4 cm/s 流速最大,组间差异具统计学意义（P〈0.05）.水流速率对体质量增长和各生化指标均产生显著的影响,以流速1～4 cm/s 培育全缘马尾藻培幼孢子体较合适.     

黑暗条件下连续性干出对全缘马尾藻幼孢子体生长和生化成分的影响

在黑暗条件下对全缘马尾藻(Sargassum integerrimum)幼孢子分别进行0.5、1、2、4 h干出处理,研究干出处理对幼孢子体生长、幼孢子体体内叶绿素a、叶绿素c、类胡萝卜素、脯氨酸以及可溶性糖含量的影响。结果表明:相比于未进行干出处理的对照组,0.5 h、1 h组的短暂干出可促进幼孢子体生长(P0.05),幼孢子体体内两种叶绿素、类胡萝卜素、脯氨酸以及可溶性糖含量差异均无统计学意义(P0.05);2 h、4 h组的长时间干出可抑制幼孢子体生长(P0.05),幼孢子体体内两种叶绿素含量均降低(P0.05),类胡萝卜素、脯氨酸以及可溶性糖的含量升高(P0.05)并保持较高水平。在人工育苗过程中每天在黑暗条件下对幼孢子体进行短时间(0.5~1 h)干出处理,可促进幼孢子体生长,并适当提高其抗逆性以及对干旱的适应性。     

硇洲马尾藻Sargassum naozhouense幼孢子体附着及原生态恢复

【目的】探究硇洲马尾藻(Sargassum naozhouense)幼孢子体附着的选择性及原生态位点固着人工藻礁对马尾藻海藻资源恢复效果。【方法】选用混凝土、黄泥砖、牡蛎壳、聚丙烯板、橡皮条、沥青等6种废弃物材质对硇洲马尾藻幼孢子体附着效果进行比较;将硇洲马尾藻于徐闻南山进行原生态位点投放,周年观察比较人工藻礁与自然藻礁生长差异,探究硇洲马尾藻资源恢复效果。【结果】(1)不同材质藻礁对硇洲马尾藻幼孢子体附着差异显著,附着效果依次为混凝土>黄泥砖>牡蛎壳>聚丙烯板>橡皮条,沥青完全没有幼孢子附着。(2)当年人工藻礁苗有性生殖苗较自然生态苗生长慢,第二年假根再生苗生长与自然苗生长无显著性差异。(3)人工藻礁苗成活率为29.2%,此后不出现消退死亡,并以假根再生维持种群的繁衍。【结论】混凝土是马尾藻原生态藻床恢复较理想的人工附着基,黄泥砖、牡蛎壳、聚丙烯板等废弃物也可用于天然硇洲马尾藻以及室内有性苗源的附着基。假根再生是马尾藻种群繁衍的主要方式,利用有性繁殖的幼孢子体附着于混凝土块上进行硇洲马尾藻原生态位点投放是短时间增加马尾藻资源的有效措施,可为硇洲马尾藻海藻资源恢复提供可行的方法。     

温度对马尾藻及其油页岩混合物热解产气特性的影响

【目的】研究马尾藻及其油页岩混合物在不同温度下的热解产气特性。【方法】利用燃烧烟气污染物测试实验台,测量马尾藻及其油页岩混合物在温度区间400℃至800℃下CO和H_2的排放特性,包括峰值浓度、峰值时间和平均浓度。【结果】马尾藻以及其油页岩混合物的热解过程可分为慢速析出、快速析出和降速三个阶段。马尾藻单独热解实验中,排放的CO体积分数峰值达到10 367×10~(-6)。温度的升高有利于马尾藻在热解中CO和H_2的析出,反应的开始时间和完成时间均有所提前。在马尾藻与油页岩混合物的热解中,H2的析出在700℃时达到最高(体积分数峰值为1 254×10~(-6))。油页岩的加入迟滞了CO和H_2的排放时间。【结论】油页岩的加入有效减少马尾藻热解过程中CO的排放并缩短反应时间,提高效率节省能源,马尾藻与油页岩的混合热解具有良好的应用前景。     

盐度对半叶马尾藻幼苗生长及光合色素合成的影响

在温度22±0.5℃、光照强度100μmol·m-2·s-1的光照培养箱中,以8组不同盐度培养半叶马尾藻(Sargassum hemiphyllum)幼苗(2~3 g/株),研究不同盐度对其生长发育和光合色素合成的影响。结果表明:半叶马尾藻幼苗适合存活和生长的盐度为24.84~35.28,在该盐度范围内幼苗均可正常存活和生长;幼苗最适生长盐度为30.06,质量增长率达到最大,光合色素含量达到最高;24.84~35.28中,幼苗更适合于在高盐端生长。     

3种环境因子对围氏马尾藻受精卵生长发育的影响

为探索围氏马尾藻(Sargassum withgii)受精卵生长发育的最适条件,研究不同温度(18、21、24、27、30℃)、照度(1 000、2 000、3 000、4 000 lx)和盐度(15、20、25、30、35、40)对围氏马尾藻受精卵成活率和幼孢子体生长的影响。结果表明:围氏马尾藻受精卵在21℃下成活率最高(89.3%),与其他温度组差异有统计学意义(P0.05);受精卵在1 000 lx下的成活率最高,为89.3%,与其他照度组差异有统计学意义(P0.05);受精卵对于盐度的适应范围较广,15~30的盐度组成活率均较高(86.3%)。培养前10 d,21℃组的幼孢子体平均长度最大(P0.05),15 d时24℃组平均长度超过其他温度组(P0.05);在培养前15 d,1 000 lx照度组幼孢子体生长速度最快(P0.05),20 d后3 000 lx组孢子体平均长度超过其他照度组(P0.05);在15~30盐度范围内,幼孢子体均生长较好,且各盐度组间平均长度差异无统计学意义(P0.05)。     

温度、光照对小环藻生长和叶绿素a含量的影响

用单因子和正交实验方法研究了温度和光照对小环藻生长和叶绿素a含量的影响。结果表明,温度对小环藻生长和叶绿素a含量有极显著影响(P<0.01),当温度在30~40℃时比增长率和叶绿素a含量分别为0.37~0.38 d-1和1 084.4~1 214.2μg.L-1,均显著高于其他温度组。光照对小环藻生长和叶绿素a含量有极显著影响(P<0.01),当光照强度从29.25~146.26μmol.m-2.s-1时比增长率最高,为0.30~0.32 d-1;而叶绿素a含量则在9.75~58.50μmol.m-2.s-1时最高,达709.7~731.8μg.L-1,极显著高于其他照度组。正交实验结果表明:在35℃、87.75μmol.m-2.s-1条件下种群增长最快,比增长率为0.4402 d-1;在30℃、29.25μmol.m-2.s-1时,叶绿素a含量最高,为1 746.6μg.L-1。     

不同光合光子照度LED蓝光对湛江等鞭金藻生长及色素含量的影响

在实验室水温26℃、盐度31条件下,研究LED蓝光(波长450 nm)不同光合光子照度对湛江等鞭金藻(Isochrysis zhanjiangensis)细胞生长速率及色素含量的影响,结果表明,不同光合光子照度的梯度实验组藻细胞生长速率及色素含量差异具统计学意义(P0.05),在66~171μmol·m~(-2)·s~(-1)范围内,细胞相对生长速率随光子照度的增加而加快,在171μmol·m~(-2)·s~(-1)时达到最大值0.48个·d~(-1),在192μmol·m~(-2)·s~(-1)时出现下降;藻细胞的7 d色素累积量在171μmol·m~(-2)·s~(-1)下其叶绿素a、叶绿素c、类胡萝卜素及总色素的累积量均达到最大,分别是3 340.16、1 176.23、1 566.43及6 082.82μg·L-1,与其他组差异具统计学意义(P0.05)。蓝光LED下湛江等鞭金藻细胞光合作用的最佳光合光子照度约为171μmol·m~(-2)·s~(-1)。     

Effects of Temperature and Light on Growth Rate and Photosynthetic Characteristics of Sargassum horneri

The changing environmental factors exerted great influences on coastal macroalgal communities.To study the responses of the brown seaweed Sargassum horneri to temperature and light,S.horneri was cultured under three temperatures(20,25 and 30℃)and three light intensities(30,60,and 120μmol photons m-2 s-1)for seven days.The growth rate,chlorophyll a(Chl a)and carotenoids(Car)contents,chlorophyll fluorescence,and photosynthetic oxygen evolution rate were measured.The results show that the highest relative growth rate(RGR),maximal electron transport rate(rETRmax);the net photosynthetic rate(Pn)were observed at the lowest temperature(20℃)and highest light intensity(120μmol photons m-2 s-1);and the RGR and Pn were significantly inhibited by the highest temperature(30℃),especially at the lowest light intensity(30μmol photons m-2 s-1)(P<0.05).Additionally,the highest light intensity enhanced the non-photochemical quenching(NPQ)even under the highest temperature(30℃),indicating that the higher light intensity could induce photo-protection reaction of thalli.These results suggest that the higher temperature and lower light intensity exerted negative influences on S.horneri.     

不同饵料对方斑东风螺幼螺生长的影响

在盐度29.5~30,p H 7.6~7.8、水温29~29.5℃条件下,投喂凡纳滨对虾、小黄鱼、太平洋牡蛎3种饵料30 d,研究不同饵料对方斑东风螺幼螺生长的影响。研究表明,投喂凡纳滨对虾的方斑东风螺幼螺生长最快,壳宽(9.41±0.72)mm,壳高(15.08±1.18)mm,体质量(0.61±0.13)g,特定生长率5.153%·d-1,均优于投喂小黄鱼和太平洋牡蛎处理组。     

Effects of Salinity and Temperature on Growth and Survival of Juvenile Iwagaki Oyster Crassostrea nippona

Iwagaki oyster Crassostrea nippona occurs naturally along the coasts of Japan and Korea. Because of its unique flavor, delicious taste, edibility during the summer and high commercial value, it has been identified as a potential aquaculture species. To determine the optimum aquaculture conditions and provide necessary information for mass production of the juvenile, the effects of six salinities(15, 20, 25, 30, 35 and 40) and five temperatures(16, 20, 24, 28 and 32℃) on growth and survival of juvenile C. nippona were examined in this study. In the salinity experiment, the largest values of mean shell height and growth rate were observed at salinity 25(20.96 ± 0.36 mm and 172.0 μm d~(-1), respectively), which were significantly different(P 0.05) with those of other treatments, except at salinity 30(20.56 ± 1.05 mm and 160.3 μm d~(-1), respectively)(P 0.05). The maximum survival rate 84.44% was always observed at salinity 20, and there was no significant difference(P 0.05) in survival rate among salinities varying between 15 and 35. In the temperature-related experiments, the highest growth and survival rates of juvenile were observed at 24℃(180.8 μm d~(-1) and 84.4%) and 28℃(190.7 μm d~(-1) and 83.3%), respectively, on day 20, and showed significantly(P 0.05) larger size and higher survival rate than any other groups. Both juvenile survival and growth were significantly depressed at extreme salinities(15, 40) and temperatures(16℃, 32℃). Based on the results of the present study, a salinity range from 25 to 30 and a temperature range from 24℃ to 28℃ are considered optimal conditions for survival and growth of juvenile C. nippona.     

Effect of Dietary Phosphorus on the Growth and Body Components of Juvenile Synechogobius hasta

The effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta was determined. Different percentages of dietary phosphorus (0.63, 0.77, 0.93, 1.06, 1.22 and 1.36) were tested by feeding the fish (body weight, 15.81 g ± 0.32 g; 20 individuals each group; 3 groups each percentage) at a surplus of 5%–10% above satiation for 35 d. Dietary phosphorus did not significantly affect the specific growth rate, feed intake, feed conversion ratio and protein efficiency rate. Nitrogen ...     

Effects of Starving and Re-feeding Strategies on the Growth Performance and Physiological Characteristics of the Juvenile Tongue Sole(Cynoglossus semilaevis)

Starving and re-feeding trials were conducted to evaluate the effects of starvation duration and recovery times on the growth performance and physiological characteristics of juvenile tongue sole Cynoglossus semilaevis, which included growth, body composition, intestinal morphology and digestive enzymes activities. The fish starved for one(D1), two(D2) and four(D4) days, respectively, were recovered for three(R3, R6, R12), seven(R7, R14, R28) and eleven(R11, R22, R44) folds of starvation days while the control fish were fed constantly. The experiment was conducted for 96 days. The fish individuals in D1R11, D2R14 and D2R22 caught up in weight with the control, indicating that complete compensatory growth existed in these fish individuals. The highest body weight gain and total specific growth rates were observed in D2R22. Food intake increased significantly in most treatments in comparison with that of the control except for D1R7 and D2R22(P 0.05). Food conversion efficiency and apparent digest coefficient in D2R22 were significantly promoted, being higher than that of the control(P 0.05). The activities of trypsin and lipase were found to be closely related to the growth performance. The activities of liver and hindgut trypsin, also midgut and hindgut lipase in D2R22 were significantly higher than those of the control(P 0.05). The fold height(HF) of foregut and midgut increased significantly in D2R22, and HF decreased significantly in D1R3, D2R6 and D4R12(P 0.05). On our findings, we may conclude that the optimum starving and re-feeding strategy is starving for 2 days and re-feeding for 22 days. And in this starving and re-feeding strategy, the compensatory growth could be mostly attributed to the promotion of food conversion efficiency and digestibility coefficiency.     

Compensatory Growth of Juvenile Brown Flounder Paralichthys olivaceus Following Low Temperature Treatment for Different Periods

We investigated the effects of low temperature(8.5℃) on the growth and feeding rates and feed conversion efficiency of juvenile P.olivaceus with an average initial weight of 3.87 ± 0.06 g(mean ± SE).Fish were exposed to 8.5℃ for 0(control),1,2,3 and 4 weeks,and then to 20℃ for 10,9,8,7 and 6 weeks,respectively.Low temperature clearly led to growth depression.The weight of fish exposed to low temperature for 1 week was restored to that of control,while that of fish exposed to low temperature longer was significantly decreased(P 0.05).During the entire low-temperature period,specific growth rate,feeding rate and feed conversion efficiency of the fish were significantly lower(P 0.05) than those of control,while in the whole recovery period,specific growth and average feeding rate were markedly higher(P 0.05) than those of control.At the end of experiment,only the feeding rate of the fish exposed to low temperature for 1 week was not significantly different from that of control(P 0.05).Feeding rate and feed conversion efficiency were reduced at low temperature in juvenile P.olivaceus.The compensatory growth of juvenile P.olivaceus may therefore be attributed to the improvement of feeding rate.Our results suggested that growth depression occurs when juvenile P.olivaceus are exposed to low temperature for more than one week.     

不同饲料蛋白水平下L-肉碱对新吉富品系尼罗罗非鱼生长和饲料利用的影响

研究了三个蛋白水平(22%、25%、28%)和五个L-肉碱水平(0、200、400、600、800mg/kg)下尼罗罗非鱼生长和饲料利用率。结果表明,随着饲料中蛋白水平的提高,罗非鱼幼鱼的终体重、增重率(WGR)和特定生长率(SGR)呈上升趋势,而饲料系数(FCR)和蛋白质效率(PER)均随饲料蛋白水平的升高而显著下降(P<0.05);同等蛋白水平下,终体重、WGR和SGR均在L-肉碱添加量为200mg/kg时最高,不添加L-肉碱组最小;在添加400mg/kgL-肉碱时FCR最小,而PER最大,与不添加L-肉碱组比较,差异均显著(P<0.05)。说明饲料中蛋白含量和L-肉碱添加量能显著影响罗非鱼幼鱼的生长和饲料利用,而外源性L-肉碱可明显促进罗非鱼生长,提高饲料转化效率。