【作者】 杨凯；

【导师】 樊启学；

【作者基本信息】 华中农业大学 ， 水产养殖， 2010， 硕士

【摘要】 本研究以黄颡鱼(Pelteobagrus fulvidraco Richardson)为研究对象,采用实验生态和生理学方法,在室内可控条件下,研究了溶氧水平黄颡鱼生长、呼吸代谢、能量代谢及氧化应激的影响。本研究包括三部分,第一部分测定黄颡鱼的瞬时耗氧率与窒息点；第二部分研究溶氧水平对黄颡鱼稚鱼生长及呼吸代谢的影响；第三部分研究溶氧水平对黄颡鱼生长、能量收支及氧化应激的影响。其主要研究结果如下：1.黄颡鱼瞬时耗氧率与窒息点的研究在28±0.5℃下,用封闭静水式装置测定了黄颡鱼的瞬时耗氧率和窒息点,其体长(BL)为1.90～11.03 cm,体重(BW)为0.17～22.99 g。结果表明：在该规格范围内,窒息点(Sp)范围为0.33～0.60 mg/L,瞬时耗氧率(IRO2)范围为0.0119～0.2081 mg/g·h。Sp和IRO2随规格增加而降低,二者与BL、BW的幂函数方程分别为：Sp=0.7795BL-3695(R2=0.9619)、Sp=0.4897BW-0.1323(R2=0.9656),IRO2=0.7290BL-0·5709(R2=0.9580)、IRO2=0.3549BW-0.2036(R2=0.9539)；IRO2随水中溶解氧(DO)的下降相应地下降,二者之间存在明显的线性关系。可见,黄颡鱼是低窒息点鱼类,其呼吸类型可归属于顺应型。在28±0.5℃循环水环境中设置四种溶氧组,分别为低溶氧组(G1,2.92mg/L)、中低溶氧组(G2,4.71mg/L)、饱和溶氧组(G3,6.77mg/L)、过饱和溶氧组(G4,9.68mg/L),研究初始体重为(1.62±0.02)g的黄颡鱼稚鱼的生长、摄食及呼吸代谢规律。结果显示：G3组特定生长率(SGR)、饲料转化效率(FCE)均显著高于其它各试验组(P<0.05)。试验鱼的耗氧率、排氨率与溶氧水平无正相关性,G3组的耗氧率、排氨率始终显著高于其它三组。摄食后1～4h内耗氧率和排氨率均呈现迅速上升,到达最大值后再缓慢下降,二者均在09：00和21：00出现高峰,G3组的耗氧率高峰值分别为0.345 mg/g·h、0.331 mg/g·h,G3组的排氨率高峰值分别为24.194μg/g·h、17.77μg/g·h。上述结果表明,不同溶氧条件下,黄颡鱼稚鱼的耗氧率、排氨率变化过程具有类似的特征,二者在能量代谢机制上相互关联；在饱和溶氧条件下,黄颡鱼稚鱼生长最快、呼吸代谢最为旺盛。研究了溶氧水平对黄颡鱼生长、饲料利用、氮代谢及氧化应激的影响。试验设计4个溶氧组(DO),分别为低溶氧组(D1,2.28 mg/L)、中低溶氧组(D2,4.04 mg/L)、饱和溶氧组(D3,6.51 mg/L)、过饱和溶氧组(D4,9.11 mg/L),每组3个重复。试验在循环水养殖系统持续8周,试验期间水温28℃。结果表明,当DO上升至6.51mg/L时,特定生长率(SGRw)、摄食率(FR)显著升高(P<0.05)；在2.28～9.11mg/L DO范围内,各试验组的FCEd、FCEe、ADCd、ADCe表现出随着DO水平的升高而升高,但D4组与D5组差异不显著(P>0.05)；摄食能(C)、生长能(G)在D3组最高,分别为434.39J/g·d、77.89 J/g·d,在D4组又有所下降；呼吸代谢能(R)的变化趋势与C、G相似。肝脏和血清中丙二醛(MDA)的含量在D3组最低；肝脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性在D3组最高,谷胱甘肽过氧化物酶(GSH-PX)活性在各组间无显著性差异；血清中SOD、GSH-PX、CAT活性在D3组均显著最高。试验表明,饱和溶氧条件对黄颡鱼的生长代谢、氮代谢以及抗氧化物酶活性具有显著促进作用。更多还原

【Abstract】 The present study was conducted to investigate the effects of dissolved oxygen on the growth, metabolism and oxidative stress of yellow catfish with the method of experimental ecology and physiology under indoor controlled condition. This study consists of three parts, the first part investigated instantaneous oxygen consumption rate and suffocation point of yellow catfish; the second part investigated effects of dissolved oxygen on feed intake, growth and respiratory metabolism of juvenile yellow catfish; the third part investigated effects of dissolved oxygen on the growth, energy budget and oxidative stress of yellow catfish. Its main findings as fellows:In this experiment, instantaneous oxygen consumption rate (IRO2) and suffocation point (Sp) of yellow catfish (BL:1.90～11.03 cm, BW:0.17～22.99 g) were investigated by means of sealed-still water at 28±0.5℃. The results showed that the range of Sp and IRO2 was 0.33～0.60 mg/L and 0.0119～0.2081 mg/g·h. Both Sp and IRO2 of yellow catfish decreased with size increasing, and the power function between Sp and size, and IRO2 and size can be described as Sp=0.7795L-0.3695(R2= 0.9619), Sp=0.4897W-0.1323 (R2=0.9656) and IRO2=0.7284L-0.5709 (R2=0.9580), IRO2= 0.3549W -0.2036(R2= 0.9539), respectively. IRO2 of yellow catfish decreased with decreasing dissolved oxygen (DO) and there were linear correlations between IRO2 and DO. This study suggests that yellow catfish has low suffocation point and its breath relegates to compliant style.A 6-week feeding experiment was conducted to investigate the effects of dissolved oxygen (DO) levels on feed intake, growth and respiratory metabolism of juvenile yellow catfish (initial weight:1.62±0.02 g per fish) reared in 300-L indoor flow-through circular fiberglass tanks in 28±0.5℃. Four DO levels were hypoxia (G1,2.92 mg/L), moderate hypoxia (G2,4.71 mg/L), saturation (G3,6.77 mg/L) and super-saturation (G4,9.68 mg/L), respectively. The results showed that specific growth rate and feed conversion efficiency were significantly higher in the normoxic group (G3) than in the other groups (P< 0.05). The oxygen consumption and ammonia excretion rate of experimental fish had no direct correlation with dissolved oxygen, which was significantly higher in the saturation than in the hypoxia and super-saturation. The experiment showed that after the tested fish ate its food in 4 hours the both rates increased drastically at 09:00 and 21:00, and reached their maximum levels, then decreased slowly towards to their nomal levels. The highest oxygen consumption rate were 0.345 mg/g·h and 0.331 mg/g·h and ammonia excretion rate were 24.194μg/g·h and 17.770μg/g·h in the saturated group (G3). This study suggests that response in the rate of ammonia excretion in juvenile yellow catfish should be relative closely to response in the oxygen consumption and saturation was considered to be highest for growth and respiratory metabolism.A 8-weeks feeding experiment was conducted to investigate the effects of dissolved oxygen levels (DO) on growth performance, feed utilization, nitrogen metabolism and oxidative stress of yellow catfish. Four dissolved oxygen levels were formulated. Experimental fish were reared at oxygen levels of hypoxia (D1,2.28 mg/L), moderate hypoxia (D2,4.04 mg/L), saturation (D3,6.51 mg/L) and super-saturation (D4,9.11 mg/L). During the experiment, the experimental fish was reared in re-circulating system and water temperature was 28℃. The results showed that the specific growth rate in wet weight (SGRw) and feeding rate (FR) increased significantly, when DO be above 6.51 mg/L. Feed conversion efficiency of dry weight (FCEd) and energy (FCEe), apparent digestibility coefficient of dry matter (ADCd) and gross energy (ADCe) increased with the increasing with DO increment within the range of 2.28～9.11mg/L, but no significant difference was found among D3 and D4 groups (P>0.05). The highest gross energy intake (C) and growth energy (G) were 434.39 J/g·d and 77.89 J/g·d in the D3 group, then decreased slowly in D4 group. The general direction in the value of energy of respiratory metabolism (R) was similar closely to C and G. The contents of malondialdehyde (MDA) in liver and serum were the lowest in the D3 group. Activities of superoxide dismutase (SOD) and catalase (CAT) were the highest and activities of glutathione peroxidase (GSH-PX) were no significantly affected in the liver of yellow catfish exposed to 6.51 mg/L DO. Activities of SOD、GSH-PX、CAT in the serum were the highest in the D3 group. The results indicated that metabolism of growth and nitrogen and activities of the antioxidant defense were promoted in yellow catfish exposed to saturated DO level.更多还原