【作者】 房景辉；

【导师】 董双林； 田相利；

【作者基本信息】 中国海洋大学 ， 水产养殖， 2010， 博士

【摘要】 大多数鱼类在自然或养殖环境中均不可避免地会受到一些胁迫因子的影响,这些胁迫因子包括温度、盐度、光照和食物的变化等。而在不适宜的环境中,鱼类正常的生长往往会受到一定的抑制,从而导致其生长速度减慢。补偿生长就是鱼类在经历一段时间的生长抑制后,当恢复有利条件时,在一定时间内出现的一种生长加速的现象。从现有的研究结果看,鱼类的补偿生长主要分为三个类型,即部分补偿生长,完全补偿生长和超补偿生长。鱼类补偿生长研究一直是国际鱼类生物学研究的热点之一。尽管很多种类都发现了补偿生长现象,但不同种类反应不一,诱发鱼类补偿生长的生理生态学机制也一直有所分歧。由于鱼类的这种补偿生长现象能抵消生长抑制,因此对减少个体差异、渔业养殖管理和研究鱼类生活史具有重要的意义。半滑舌鳎(Cynolossus semilaevis Gunther),为近海名贵经济鱼类。它是我国黄渤海海区的原产鱼种,属东北亚特有种,主要产自黄渤海区,我国的东海以及朝鲜、日本沿海也有一定的分布。半滑舌鳎营养级低、生长速度快、个体大、出肉率高、肉味鲜美,深受人们的喜爱,近年来日益受到国内外市场的青睐,具有较高的经济价值。伴随该鱼人工繁殖手段的成熟,其商品鱼养成已渐成为产业化的主题,适宜的养殖环境条件和投喂技术是该鱼养殖的重点之一。目前对半滑舌鳎的进行的研究主要包括生活史、食性、卵及胚胎发育观察、染色体和遗传多样性、人工繁殖和养殖技术等。关于半滑舌鳎对温度和营养胁迫的生长响应及其生理生态学机制还尚未见报道。开展本项研究,不仅有助于揭示重要种类的生物能量学特征,丰富鱼类的生理生态学研究内容,还可以为进一步发展半滑舌鳎的人工增养殖实践、改进养殖和投饲技术提供理论依据,因而具有重要的理论和实际意义。本研究获得的主要结果如下：1研究了不同温度(16、19、22、25、28和31℃)对半滑舌鳎幼鱼的生长、体成分组成和能量收支的影响。结果表明,随温度的升高,半滑舌鳎幼鱼生长率总体呈现先升高后降低的趋势。其中,在19-25℃温度范围内,半滑舌鳎幼鱼的特定生长率相对较高,在16和28℃下则有所降低,而在31℃下,半滑舌鳎幼鱼特定生长率则显著降低。本研究表明半滑舌鳎幼鱼特定生长率与温度符合二次曲线模型。半滑舌鳎摄食量随温度升高而逐渐增大,但在31℃时显著减小,饵料转化率则随温度的升高而降低。鱼体脂肪与能值均随温度升高而降低,蛋白质含量受温度影响不显著。温度对半滑舌鳎的能量收支影响显著,其中,生长能和代谢能主导半滑舌鳎的能量分配,生长能占摄食能比例则随温度的升高而降低,呼吸能占摄食能比例则随温度的升高而升高。本研究表明,半滑舌鳎幼鱼(13-37g)适宜生长温度范围为19-25℃,而不同温度导致的半滑舌鳎摄食量和能量收支的差异可能是温度影响其生长的主要生理生态学机制。2研究了不同温度(16,22和28℃)和日粮水平(饥饿,25%,50%,75%和100%饱食)对半滑舌鳎幼鱼生长、体成分组成和能量收支的影响。结果表明,特定生长率随日粮水平的增加而增加,在22℃、100%日粮条件下的幼鱼生长最佳。回归分析表明,SGRw.SGRe、RLw和RLe的回归方程：SGRw=20.778 log(RLw+5)-0.0767T-13.628,SGRe=11.016 log(RLe+5)-0.152T- 6.730.由此得出16、22和28℃下以体重表示的维持日粮水平为0.19%、0.46%和0.74%,以能量表示的维持日粮水平分别为1.79%、3.21%和4.94%。50%-100%日粮水平对饵料转化率影响不显著(P>0.05)。75%和100%日粮水平条件下的消化率没有显著差异(P>0.05)。脂肪含量随日粮水平的升高而增加,而随温度的升高而下降。蛋白含量在16℃时,随日粮水平的升高而下降,在22和28℃时,随日粮水平的升高而升高。生长能和呼吸能占摄食能的比例决定半滑舌鳎幼鱼能量收支的类型。在本研究的温度范围内,生长能占摄食能的比例随温度的升高而降低,并且受50%-100%日粮水平的影响不显著(P>0.05)。而呼吸能占摄食能的比例随日粮水平的升高而下降,随温度的升高而升高。22℃时,半滑舌鳎幼鱼的特定生长率最高,这意味着将其养殖在22℃、100%日粮水平下可以获得更快的生长速度。3研究了饥饿后恢复投喂对半滑舌鳎幼鱼的补偿生长、体成分组成、代谢和能量收支的影响。实验设置C(对照)、S1(饥饿4天)、S2(饥饿8天)、S3(饥饿16天)、S4(饥饿32天)、S0(持续饥饿)六个处理,饥饿后恢复饱食投喂,每个处理5个重复,在22℃下进行实验并按时测定呼吸强度,共进行64天。实验结束时,S1组鱼体重最大但是与对照组没有显著差异(P>0.05),表明S1组鱼产生完全补偿生长现象。虽然,S2、S3和S4组鱼的特定生长率在恢复投喂后均高于对照组,但到实验结束时,其体重均小于对照组,所以这三组的半滑舌鳎幼鱼产生部分补偿生长现象。S1组半滑舌鳎的饵料转化率显著高于对照组(P<0.05)。S2、S3和S4组的摄食率和表观消化率均显著高于对照组,但S1组与对照组无显著差异。实验结束时,S1、S2和对照组的主要体成分组成和体能值没有显著差异(P>0.05)。恢复投喂后的实验各组代谢率迅速升高,只有S4组的排氨率在延迟了一段时间后才显著升高。并且饥饿时间越长,代谢率的峰值越高。在能量收支中,S1组生长能占摄食能的比例显著高于对照组,而呼吸能比例显著低于对照组(P<0.05)。基于本研究结果,半滑舌鳎幼鱼补偿生长的机制可归结为恢复投喂期间其代谢降低,从而能量效率提高所致。4研究了2周不同程度的食物限制之后恢复饱食投喂对半滑舌鳎幼鱼的生长、体成分组成、代谢和能量收支的影响。实验包括5个处理：饥饿组(R0)、25%饱食组(R25)、50%饱食组(R50)、75%饱食组(R75)和持续饱食组(对照组,C),实验时间56天。结果表明,R25、R50和R75与对照组的体重在实验第六周直至实验结束没有显著差异(P>0.05)。恢复饱食后,各处理的特定生长率随饱食程度的增加逐渐降低,摄食率(FR)随限食程度的增加而增加,对照组的饵料转化率较低,而饥饿组在第4周到第7周饵料转化率一直高于对照组(P<0.05),在实验的第4-8周,各处理的消化率没有显著差异(P>0.05)。R0组和R25组的耗氧率在恢复饱食后均出现峰值,而后又恢复到与对照组没有差异的水平,而R50组和R75组的耗氧率与对照组变化相似没有出现较大波动。体成分组成中,水分含量和灰分含量变化相似,随饱食程度的增加而逐渐降低,蛋白含量随时间没有显著的变化规律。对照组的能量收支各组分能值均是各处理中最高的,但是在能量收支式中此种优势却没有体现出来。研究表明,半滑舌鳎幼鱼在限食投喂2周后,25%、50%和75%饱食组均具有完全补偿生长能力,而饥饿组具有部分补偿生长能力；由于营养胁迫程度不同,半滑舌鳎幼鱼可能采取不同的补偿生长策略。5研究了不同循环投喂模式对半滑舌鳎幼鱼的生长、体成分组成、代谢和能量收支的影响。其中包括5个处理：C(对照组,实验过程中持续投喂)；S2F4组(饥饿2天,投喂4天)；S4F8组(饥饿4天,投喂8天)；S8F16组(饥饿8天,投喂16天)；S12F24组(饥饿12天,投喂24天),实验时间72天。结果表明,对照组的特定生长率(SGRw和SGRe)显著高于循环投喂各组(P<0.05)。对照组和S2F4组半滑舌鳎幼鱼的末体重没有显著差异(P>0.05)并且均显著高于其它各组(P<0.05)。对照组半滑舌鳎幼鱼的消化率显著低于其它各组(P<0.05),而能量消化率与S12F24组没有显著差异(P>0.05),但显著低于其它三个处理组(P<0.05)。S4F8组半滑舌鳎幼鱼饵料转化率显著低于S12F24组(P<0.05),对照组饵料转化率低于S2F4组和S12F24组但没有显著差异(P>0.05)。对照组半滑舌鳎幼鱼的摄食率显著低于其它各组(P<0.05)。体成分中,蛋白含量随饥饿投喂周期的延长而下降,S2F4组和对照组半滑舌鳎的蛋白含量没有显著差异(P>0.05)。S2F4组的耗氧率和排氨率均较低。对照组的摄食能显著高于其它各组(P<0.05),S2F4组的呼吸能占摄食能的比例显著高于对照组(P<0.05)。研究表明,半滑舌鳎在循环投喂模式下,具有较强的补偿生长能力,S2F4组具有完全补偿生长能力；其在较长的周期性饥饿条件下,首先利用蛋白质作为能量来源。6研究了高温和低温胁迫对半滑舌鳎幼鱼的生长、体成分组成、血液生理和能量收支的影响。实验包括7个处理,其中1个处理在22℃下持续投喂,设为对照组(C),另外6个处理分别在16℃(A)和28℃(B)下养殖1、2、3周,再恢复到22℃至实验结束,处理编号依次为：A1、A2、A3、B1、B2、B3。每个处理5个重复,实验时间56天。结果表明,A1组和B1组半滑舌鳎在实验结束时,体重显著大于对照组(P<0.05),A1组和B1组的SGRw显著高于其它各处理(P<0.05)。在温度胁迫后各胁迫组的食物转化率均出现了先升高后降低的现象,到实验结束时除B3组外,其它各组的食物转化率与对照组无显著差异(P>0.05)。表观消化率在温度胁迫之后随着时间的延长,胁迫组表现出比对照组更明显的优势。到实验结束时,对照组的蛋白含量最低,各处理的水分、脂肪、灰分含量和体能值无显著差异(P>0.05)。在能量收支式中,对照组和B3组生长能占摄食能的比例与B2组无显著差异(P>0.05),但显著低于其它各处理(P<0.05)。对照组粪能和排泄能占摄食能的比例均最高。血清中的游离三碘甲状腺原氨酸(FT3)含量在16℃和28℃时均高于对照组；而血清中游离甲状腺素(FT4)低温处理时间越长,FT4的含量越高,高温组仅有B3组在处理结束时,FT4含量显著升高。在温度恢复到22℃后各处理的FT3、FT4水平很快恢复到与对照组相仿的水平。研究表明,半滑舌鳎幼鱼在温度胁迫一周后表现出超补偿生长现象。温度胁迫条件下半滑舌鳎幼鱼通过降低代谢,提高饵料转化率实现补偿生长。7比较研究了温度和限食胁迫对半滑舌鳎幼鱼的生长、体成分组成和能量收支的影响。实验包括7个处理,其中1个处理在22℃下持续投喂,设为对照组(C),另外6个处理分别在28-C(B)和25%饱食(R)条件下养殖1、2、3周,再恢复到22℃饱食投喂至实验结束,处理编号依次为：B1、B2、B3、R1、R2、R3。每个处理5个重复,实验时间56天。结果表明,B1组半滑舌鳎在实验结束时,体重显著大于对照组(P<0.05),而R1组体重与对照组没有显著差异(P>0.05),B1组的SGRw显著高于其它各处理(P<0.05)。在温度胁迫后各组的饵料转化率均出现了先升高后降低的现象,到实验结束时除B3组外,其它各组的饵料转化率与对照组无显著差异(P>0.05),而营养胁迫组的饵料转化率在恢复投喂期间的1-2周显著高于对照组(P<0.05)。表观消化率在恢复正常条件之后随着时间的延长,胁迫组表现出比对照组更明显的优势。到实验结束时,各处理的水分、脂肪、蛋白、灰分含量和体能值无显著差异(P>0.05)。在能量收支式中,B1组的生长能占摄食能的比例显著高于B3组和对照组(P<0.05),除B1组,其它各组生长能占摄食能的比例无显著差异(P>0.05)；对照组粪能占摄食能的比例显著高于其它各处理(P<0.05),其中R1组最低(P<0.05)；排泄能占摄食能的比例在B1组最低(P<0.05),其它各组没有显著差异(P>0.05)；实验各处理间呼吸能占摄食能的比例没有显著差异(P>0.05)。研究表明,半滑舌鳎幼鱼在高温胁迫一周后表现出超补偿生长现象,而在25%饱食胁迫一周后出现完全补偿生长现象。温度胁迫条件下半滑舌鳎幼鱼通过降低代谢,提高饵料转化率实现补偿生长,而营养胁迫条件下,通过降低代谢,提高饵料转化率和摄食率实现补偿生长。更多还原

【Abstract】 Compensatory growth is a phase of accelerated growth when favourable conditions are restored after a period of growth depression. It reduces variance in size by causing growth trajectories to converge and is important to fisheries management, aquaculture and life history analysis because it can offset the effects of growth arrests. Compensatory growth has been demonstrated in both individually housed and grouped fish, typically after growth depression has been induced by complete or partial food deprivation. Partial, full and over-compensation have all been evoked in fish. But the studies on compensatory growth are far from enough. There is so much work to do to make the phenomenon of the compensatory growth clear. Effects and mechanism of temperature and nutrition stress on tongue sole, Cynolossus semilaevis Giinther were investigated in this study. The main results are as followings:1. The influence of temperature (16,19,22,25,28 and 31℃) on growth, biochemical composition and energy budget was investigated in juvenile tongue sole. The results showed that the specific growth rate of tongue sole increased with the increase of temperature from 16-25℃and then decrease at 28-31℃. The relationship between specific growth rate of juvenile tongue sole and temperatures was described as quadratic graph. Lipid and energy contents of dry body decreased with the increasing temperatures, while crude protein content was not significantly affected by temperature. The effects of temperatures on the energy budget of juvenile tongue sole were significant. Energy assimilated in growth and those consumed in respiration dominated the mode of the energy allocation of juvenile tongue sole. The proportion of food energy allocated to respiration increased with the increasing temperature. However, those assimilated to growth decreased with the increasing temperature. The present study revealed that the suitable temperature of juvenile tongue sole was 19-25℃. The mechanism of effects of temperature on the growth of tongue sole may be ascribed to the differences of food consumption and energy budget resulted from different temperatures.2. The influence of water temperatures (16,22 and 28℃) and ration levels (0%,25%, 50%,75% and 100% of satiation) on the growth, body composition and energy budget in juvenile tongue sole were investigated over 60 days. The specific growth rates of fish increased with increasing ration levels. Fish fed to 100% satiation at 22℃exhibited better growth than other treatments. The relationship among SGRW, SGRe, temperature (T) and ration (RLw, in weight and RLe, in energy) could be described by the regression equations:SGRW=20.778 log(RLw+5)-0.0767T-13.628, SGRe= 11.016 log(RLe+5)-0.152T-6.730. The maintenance ration levels were 0.19%, 0.46% and 0.74% of body weight, while 1.79%,3.21% and 4.94% of body energy at 16,22 and 28℃, respectively. Ration level from 50%-100% satiation did not influence food conversion efficiency. There is no significant difference in apparent digestion rate between fish fed to 75% and 100% satiation. The content of lipid in fish tended to increase with increasing ration levels, while tend to decrease with increasing water temperature. The crude protein content in fish tended to decrease with increasing ration levels at low temperature (16℃), while tended to increase at high temperature (22 and 28℃). The proportion of food energy assimilated in growth and the proportion consumed for respiration dominated the mode of the energy allocation of juvenile tongue sole. In the temperature range of this experiment, the proportion of food energy allocated to growth decreased with increasing temperature, and was not affected significantly ration level from 50%-100% satiation at the same temperature. The proportion of food energy consumed for respiration decreased with increasing ration, while increased with increasing temperature. The maximum of specific growth rate occurred in fish fed to satiation at 22℃, which suggested that commercial farmers could feed juvenile tongue sole to satiation at 22℃to obtain higher growth rate.3. The effects of starvation and re-feeding on compensatory growth, body composition, metabolism and energy budget were examined in juvenile tongue sole at 22℃for 64 days. Fish were divided into six groups including control group (continuously fed ad libitum group, C), starvation group (SO) and other four groups with food deprivation for 4 days (S1),8 days (S2),16 days (S3) and 32 days (S4), respectively. Fish in S1, S2, S3 and S4 resumed feeding after the corresponding starvation period. At the end of the experiment, the weight of S1 fish was highest but not significantly different with that of the control fish (P>0.05), indicating complete compensatory growth occurred. Although the specific growth rate in S2, S3 and S4 fish was greater than that in the control fish after re-feeding, S2, S3 and S4 fish did not reach the same body weight of the control fish at the end. Food conversion efficiency of tongue sole was significantly higher in S1 than in the control fish (P< 0.05). The feeding rate and apparent digestion in S2, S3 and S4 fish were significantly higher than those in the control fish, while no significant difference was found between S1 and the control fish. There was no significant difference among S1, S2 and C in the content of moisture, lipid, protein, ash and energy (P>0.05) at the end of the experiment. Upon re-feeding, metabolic rates of juvenile tongue sole increased rapidly except that there was a time lag appeared in nitrogen excretion for the fish starved for 32 days, and the peaks of these increases were directly proportional to the length of the starvation period. Estimated form energy budget during the period of the experiment, S1 fish exhibited significantly higher proportion of food energy assimilated in growth and significantly lower proportion consumed for respiration than the control fish (P<0.05). Based on the result of the present study, the underlying mechanisms for complete compensatory growth in juvenile tongue sole could be attributed to an improved energetic efficiency resulted from reduced metabolic expenditure during the period of recovery.4. The effects of previous food restriction on compensatory growth, body composition, metabolism and energy budget were examined in juvenile tongue sole at 22℃for 56 days. Fish were divided into five groups including control group (continuously fed ad libitum group, C), and the other four groups expressed as Group R0 (starvation group), R25, R50 and R75 were first fed at 0%,25%,50% and 75% of satiation, respectively for 14 days, and were then fed ad libitum for a recovery period of 42 days. There was no significant difference in body weight among R25, R50, R75 and the control group at the 6th,7th and 8th week. After re-feeding, the specific growth rate decreased with the increasing ration, but feeding rate increased with increasing ration. Food conversion efficiency of R0 fish was significantly higher than the control group in the 4th week to the 7th week(P<0.05). In the 4th week to the end of the experiment, there was no significant difference in the apparent digestion rate among all groups (P> 0.05). The oxygen consumption of R0 and R25 fish peaked after re-feeding, and then recovered to the level of the control group. The oxygen consumption of R50 and R75 fish were similar with that of the control fish. The moisture content of fish decreased with the increasing ration, which was similar with the ash content. The energy parameters in the control group were highest among all groups, but the proportions of food energy were not. It showed that the R25, R50 and R75 fish showed complete compensatory growth and the R0 fish showed incomplete compensatory growth. The growth compensation is mainly dependent on the different food restriction.5. A feeding experiment was conducted to examine the effects of repetitive periods of fasting and satiation feeding on the growth, body composition, metabolism and energy budget of juvenile tongue sole at 22℃for 72 days. There were five groups:the control fed ad libitum throughout the experiment (C); the treatment groups were subjected to repetitive periods of fasting and satiation feeding (2:4,4:8,8:16 and 12:24 days for group S2F4, S4F8, S8F16 and S12F24). The specific growth (SGR including SGRw, in terms of weight, and SGRe, in terms of energy) of C fish was significantly higher than those of other groups (P<0.05). There was no significant difference in body weight between S2F4 and C fish (P>0.05), and both of them were significantly higher than that of other groups. The apparent digestion rate of C fish was significantly lower than that of other groups (P<0.05). The energy digestion rate of C fish was not significantly different with S12F24 fish (P>0.05), but was significantly lower than the other three groups (P<0.05). The food conversion efficiency of S4F8 fish was significantly lower than that of S12F24 fish (P< 0.05). The feeding rate of control fish was the lowest (P<0.05). The protein content of fish decreased with the increasing cycle period. There was no significant difference in protein content between S2F4 and C fish (P>0.05). The oxygen consumption and ammonia excretion were lower in S2F4. The food energy of the control group was the highest (P<0.05). The food energy assimilated to metabolism in S2F4 fish was higher than that in C fish (P<0.05). It showed that the juvenile tongue sole of S2F4 showed complete compensatory growth. During the repetitive periods of fasting and satiation feeding, the juvenile tongue sole used protein as the first energy source.6. The effects of high and low water temperatures stress on the growth, body composition, blood physiology and energy budget of juvenile tongue sole was detected during 56 d experiment. There were seven groups:the control fed ad libitum throughout the experiment at 22℃(C); the other six treatments were reared at 16℃and 28℃for 1,2 and 3 weeks, respectively. Recorded as:A1, A2, A3, B1, B2, B3. The body weight of A1 and B1 were significantly higher than that of the control group (P<0.05). The SGRw of Al and B1 were significantly higher than those of other groups (P<0.05). The food conversion efficiency of fish underwent temperature stress increased and then decreased during compensatory growth. At the end of the experiment, there was no significant difference among treatments involved. Apparent digestion rate of fish suffered stress was higher than that of C fish at the later period of the experiment. At the end of the experiment, the moisture, lipid, ash and the body energy content of the fish was not significantly different with each other (P>0.05) except for the protein content. There was no significant difference of the food energy allocated to growth among C, B3 and B2 fish (P>0.05) which were significantly lower than that in other treatments (P<0.05). The food energy allocated to exertion and feces were highest in C. There were more FT3 at 16℃and 28℃in serum than at 22℃. In the fish at 16℃, the FT4 increased with the progress of the experiment. When the temperature returned to 22℃, the levels of the FT3 and FT4 in the serum clamed down to the level of the control group soon. It suggested that the fish in A1 and B1 showed over compensatory growth. The fish underwent temperature stress had reduced the metabolism and lifted the food conversion efficiency to complete their compensatory growth.7. The effects of high water temperatures and 25% ration stress on the growth, body composition and energy budget of juvenile tongue sole was detected during 56 d experiment. There were seven groups:the control fed ad libitum throughout the experiment at 22℃(C); the other six treatments were reared at 28℃and 25% ration for 1,2 and 3 weeks, respectively. Recorded as:B1, B2, B3, R1, R2, R3. The body weight of B1 was significantly higher than that of the control group (P<0.05) which was not significant with that of R1 (P>0.05). The SGRW of B1 were significantly higher than those of other groups (P<0.05). The food conversion efficiency of fish underwent temperature stress was superior to that of fish underwent food restriction. Apparent digestion rate of fish suffered stress was higher than that of C fish at the later period of the experiment. At the end of the experiment, the moisture, lipid, protein, ash and the body energy content of the fish were not significantly different with each other (P>0.05). There was no significant difference of the food energy allocated to growth among all treatments (P<0.05) except for B1 which was significantly higher than that of B3 and C. The energy lost in feces was higher in C than that in other treatments (P<0.05). There was no significant difference among all treatments of food energy allocated to exertion which was lowest in B1 (P<0.05). There was no significant difference among all treatments of food energy allocated respiration (P>0.05). It suggested that the fish suffered high temperature for 1 week showed over compensatory growth. And the fish in R1 showed complete compensatory growth. The fish underwent temperature stress had reduced the metabolism and lifted the food conversion efficiency to complete their compensatory growth. But the fish underwent food restriction lifted the feeding rate and food conversion efficiency more to achieve the compensatory growth.更多还原