饥饿过程鲇鱼幼鱼静止代谢、身体组成及与力竭性运动后过量耗氧的关系

将33尾鲇鱼(Silurus asotus)幼鱼(32.14±1.40)g在(25±1)℃条件下驯化2周后分5组(0、1、2、4、8周)进行饥饿处理;分别测定了各处理组实验鱼的静止耗氧率、力竭性运动后的过量耗氧(EPOC)并对鱼体组成进行了分析。实验结果显示:各处理组实验鱼的静止耗氧率分别为(2.21±0.15)、(1.63±0.04)、(1.64±0.13)、(1.44±0.08)、(0.98±0.09)mgO2/kg min,其中饥饿1、2、4周组之间无显著差异,却都显著低于0组、高于8周组的水平(P2peak)立即(2min)出现,随后逐渐下降至稳定耗氧水平(VO2steady),EPOC总量(Excess VO2)分别为(31.8±6.06)、(76.67±4.34)、(69.2±5.89)、(70.41±3.12)、(38.28±2.72)mgO2/kg,其中饥饿1、2、4周组均显著高于饥饿0和8周组的水平(P<0.05),出现无氧运动功能补偿的"效应期"。通过鲇鱼幼鱼静止代谢"平台期"与其功能补偿"效应期"在时间上完全吻合的现象,揭示鱼类的功能补偿效应与其静止代谢水平之间存在的密切关联。       

力竭追赶训练对两种鲤科鱼类呼吸循环系统参数和力竭运动后代谢特征的影响

为了考察力竭追赶训练对中华倒刺鲃(Spinibarbus sinensis)和岩原鲤(Procypris rabaudi)幼鱼呼吸循环系统和力竭运动后代谢特征的影响, 在(25±0.5)℃条件下, 将2种实验鱼各60尾 [体重分别为(28.36±0.08) g和(19.53±0.13) g]随机等分成对照组和训练组, 训练组进行1次/d共21d的力竭追赶训练。随后测定各组实验鱼的心脏和鳃指数、血液指标以及力竭运动后过量耗氧(Excess post-exercise oxygen consumption, EPOC)。结果发现: 2种鱼心脏指数、鳃指数、血红蛋白含量和红细胞数目在各自对照组和训练组之间都没有显著性差异; 岩原鲤对照组的鳃指数显著低于中华倒刺鲃对照组(P<0.05), 但心脏指数、血红蛋白含量和红细胞数目与中华倒刺鲃对照组无显著性差异。中华倒刺鲃训练组的运动前代谢率、运动代谢峰值、峰值比率、代谢恢复速率与其对照组没有显著差异, 但运动后恢复时间和过量耗氧显著大于对照组(P<0.05); 岩原鲤训练组的运动前代谢率显著低于其对照组(P<0.05), 但运动代谢峰值、峰值比率、运动后恢复时间、过量耗氧、代谢恢复速率与其对照组没有显著性差异。岩原鲤对照组的运动前代谢率、运动代谢峰值、过量耗氧和代谢恢复速率分别显著低于中华倒刺鲃对照组(P<0.05), 但峰值比率和运动后恢复时间与中华倒刺鲃对照组无显著性差异。研究表明: (1)力竭追赶训练对中华倒刺鲃和岩原鲤幼鱼的呼吸和循环系统参数没有产生显著性影响; (2)力竭追赶训练显著提高了中华倒刺鲃幼鱼的无氧代谢能力; (3)中华倒刺鲃幼鱼力竭运动前后代谢率显著高于岩原鲤幼鱼, 这可能与其较为活跃的习性有关。     

饥饿再投喂对大鳞副泥鳅生长性能、肝脏抗氧化能力和肠道消化酶的影响

为探究周期性饥饿再投喂对大鳞副泥鳅(Paramisgurnus dabryanus)生长性能、抗氧化能力和肠道消化酶活性的影响, 实验将初始重一致的大鳞副泥鳅随机分为4组, 每组3个重复, 饲养于12个水箱中, 每箱20尾。采用周期性饥饿2d再投喂4d(S2F4)、周期性饥饿2d再投喂6d(S2F6)、周期性饥饿2d再投喂8d(S2F8)和持续投喂(对照组)4种投喂模式, 投喂30d, 并于第0、第15和第30天收集样本进行检测。结果表明: (1)不同处理对末体长和特定生长率无显著影响(P>0.05), S2F8处理组末体重和增重率显著高于对照组(P<0.05)。(2)周期性饥饿再投喂对肥满度、脏体比和肝体比无显著影响(P>0.05)。(3)随饥饿再投喂处理时间增长, S2F6和S2F8组肝脏SOD、CAT和GSH-PX活性显著升高; 在第15天, S2F8组SOD活性显著高于对照组(P<0.05), S2F6和S2F8组肝脏CAT活性显著高于对照组(P<0.05), S2F6和S2F8组肝脏GSH-PX活性均显著高于对照组(P<0.05)。在第30天, S2F6和S2F8组SOD活性显著高于对照组(P<0.05), S2F6组CAT活性均显著高于对照组(P<0.05), S2F6和S2F8组中GSH-PX活性显著高于对照组(P<0.05)。(4)对肠道消化酶研究发现, 投喂时间对肠道蛋白酶、淀粉酶和脂肪酶活性无显著影响。在第30天时, S2F6和S2F8组肠道脂肪酶显著低于对照组(P<0.05)。综上所述, 周期性饥饿再投喂可激发大鳞副泥鳅补偿生长, 引起肝脏抗氧化酶活性增加, 肠道消化酶活性降低。其中S2F8组补偿生长最显著, 且肠道消化酶活性变化程度较小。因此, 为保证饲养效果, 推荐使用S2F8投喂模式。     

摄食对鲇鱼幼鱼力竭性运动后过量耗氧的影响

为了检验鲇鱼(Silurus asotus Linnaeus)幼鱼力竭性运动(Exhaustive exercise)后过量耗氧(EPOC)是否受到摄食的影响,以阐明其在两种功能状态下的功率配置模式,在(25.0±1.0)℃条件下,分别测定了对照组(摄食前)、摄食组[摄食12 h,摄食水平为(8.74±0.40)%]、摄食代谢恢复组[摄食60 h,摄食水平为(8.84±0.25)%]鲇幼鱼力竭性运动后EPOC及力竭性运动后恢复过程中呼吸频率(Vf)的变化。研究结果显示:对照组、摄食组、摄食代谢恢复组力竭性运动前耗氧率(MO2)显著差异(P<0.05),而Vf差异不显著;力竭性运动后MO2和Vf均立即达到峰值,随后逐渐恢复到稳定状态;摄食组的耗氧率峰值(MO2peak)[(222.47±10.14)mgO2/(kg.h)]显著大于对照组[(180.53±6.79)mgO2/(kg.h)]和摄食代谢恢复组[(181.65±10.94)mgO2/(kg.h)](P<0.05),但三个组之间Vf无显著变化;摄食组的EPOC总量[(42.49±10.13)mgO2]显著小于对照组[(66.58±6.40)mgO2]和摄食代谢恢复组[(53.46±5.80)mgO2](P<0.05)。以上结果表明:(1)无论是摄食还是运动任一生理功能均不能诱导出鲇鱼幼鱼的最大的MO2;(2)当摄食和运动两种生理功能同时存在时,鲇鱼无氧运动能力减弱,同时力竭性运动后的恢复过程加快,可能与消化导致的内环境碱化减缓了运动后的内环境酸化有关。     

运动训练和停训对鲈鲤幼鱼游泳能力的影响

为探讨运动训练和停训对鲈鲤Percocypris pingi幼鱼运动能力的影响,将480尾(体质量为2.18g±0.12g,体长为5.33cm±0.09cm)鲈鲤幼鱼随机分为4组(每组120尾):对照组(C)、无氧训练组(An)、4BL·s^-1组(BL为体长)(H)和2BL·s^-1组(L)(H组和L组每天均训练8h),在15℃±2℃条件下持续训练30d后停训。分别在训练前(T0)、训练30d后(T30)、停训20d后(DT20)和停训50d后(DT50)测定鲈鲤幼鱼的临界游泳速度(Ucrit)和1.5Ucrit条件下的耐受时间。结果显示:(1)持续运动训练显著提高了鲈鲤幼鱼的有氧和无氧运动能力,而力竭运动训练只提高了鲈鲤幼鱼的无氧运动能力;(2)停训20d后,L组的Ucrit显著高于An组和C组,An组、H组和C组间的差异无统计学意义,而An组和H组的耐受时间仍显著高于对照组,L组和C组间的差异无统计学意义;(3)停训50d后,实验组和C组间Ucrit和耐受时间的差异均无统计学意义。因此,运动训练显著提高了鲈鲤幼鱼的有氧和无氧运动能力,但不同训练方式的提升效果及其维持时间不同。     

日本沼虾继饥饿后补偿生长研究

在25.0±1℃条件下,对日本沼虾Macrobrachium nipponense (湿重, 0.52～0.64 g )进行了不同时间的饥饿处理后再供食的恢复生长实验.对照组C连续饱食投喂18 d;处理组S2、S4和S8分别饥饿2、4和8 d后再饱食投喂16、14和10 d.结果 饥饿结束时各处理组的湿重均显著低于对照组;实验结束时S2、S4组与对照组间的湿重差异不显著,而S8组的湿重仍显著低于对照组;恢复生长时各处理组的湿重摄食率、食物转化率和生长率开始显著高于对照组,但随着恢复时间延长又逐步达到对照组水平.随着饥饿时间延长,日本沼虾标准代谢率降低.在恢复投喂后又逐步回升到对照组水平.实验结果表明,日本沼虾继饥饿后再恢复喂食出现完全或部分补偿生长效应不仅是由于增加食欲,提高了摄食水平,同时也改善了食物转化率.因此,补偿生长是这两种生理因素共同作用的结果.     

两种油脂水平下DHA强化对饥饿鲤体重及脂代谢的影响

饥饿是鱼类无法有效获取食物从而使机体呈现能量匮乏的特殊时期, DHA (Docosahexaenoic acid)作为大多数鱼饥饿后得以特别保留的高不饱和脂肪酸, 它对饥饿鱼体可能具有特殊的能量调控作用。为进一步探讨这一问题, 研究设计了以下饲养试验: 先在6%与12%两个油脂水平下分别添加3%DHA制品, 形成基础组、基础-DHA组、高脂组和高脂-DHA组共4组试验饲料。将尾均重为(14.81±0.13) g的鲤360尾随机分为4组, 每组3个重复, 每个重复30尾鱼, 分别用以上4组饲料对进行饲喂, 饲养74d后, 每个养殖缸随机余留6尾鲤(Cyprinus carpio L.)进行饥饿, 36d后检测饥饿鲤体重、生物学性状、体成分、血清生化指标等。结果显示: ①在同一脂肪水平下, DHA添加组饥饿鲤体重减重率均分别显著高于无DHA组(P<0.05); ②在2个油脂水平下DHA添加组饥饿鲤肝细胞直径均分别显著低于无DHA组(P<0.05); 鱼体肥满度、空壳比率等生物学性状在各组饥饿鲤间均无显著差异(P>0.05); ③在2个油脂水平下, DHA添加组饥饿鲤肌肉及肠脂肪含量均分别显著低于无DHA组(P<0.05), 而饥饿鲤肝胰脏脂肪含量在各组间均无显著差异(P>0.05); ④饥饿鲤血清生化指标在各组间均无显著差异(P>0.05)。结果表明, DHA添加组饥饿鲤体重、肝细胞直径以及肌肉及肠脂肪含量均呈显著下降趋势, 显示出DHA的添加未能协助鲤有效抵御饥饿等不良环境的胁迫。     

中华倒刺鲃幼鱼能量代谢特征个体差异及生态关联

为了探讨鱼类能量代谢特征个体变异及其生态关联, 以中华倒刺鲃(Spinibarbus sinensis)幼鱼为实验对象, 在25℃条件下测定44尾实验鱼的静止代谢率(Resting metabolic rate, RMR)、力竭运动后峰值代谢率(Peak metabolic rate, PMR)、力竭运动后过量耗氧(Excess post-exercise oxygen consumption, EPOC)、低氧胁迫后峰值代谢率PMR和低氧胁迫后过量耗氧(Excess post-hypoxia oxygen consumption, EPHOC)。研究发现, 中华倒刺鲃能量代谢特征参数存在较大个体差异, RMR、力竭运动后PMR、EPOC、低氧胁迫后PMR和EPHOC分别为193.62—460.33 [mg O₂/(kg·h)]、617.9—2165.02 [mg O₂/(kg·h)]、28.76—267.20 mg O₂/kg、484.3—1142.97 [mg O₂/(kg·h)]和30.27—211.88 mg O₂/kg。力竭运动后PMR(r=0.348, P=0.010)和低氧胁迫后PMR(r=0.449, P=0.002)与RMR间均呈显著正相关; EPOC与RMR间呈显著负相关(r=–0.426, P=0.004), 而EPHOC与RMR间的关系不显著(r=–0.292, P=0.054); 力竭运动后PMR与EPOC间(r=0.424, P=0.004)和低氧胁迫后PMR与EPHOC间(r=0.391, P=0.009)均呈显著正相关。力竭运动后PMR与低氧胁迫后PMR(r=0.673, P<0.001)和EPOC与EPHOC(r=0.526, P<0.001)在个体差异均显著正相关; 然而力竭运动后PMR和EPOC分别显著高于低氧胁迫后PMR与EPHOC(P<0.05)。研究表明: 维持代谢较高的中华倒刺鲃个体有助于其快速提升有氧功率输出以维持高的游泳运动能力; 而较低维持代谢个体具有相对较高的EPHOC有助于机体在极端环境条件下提升其低氧耐受能力。中华倒刺鲃能量特征的个体变异可能是经长期自然选择适应环境的结果。     

亚硒酸钠、酵母硒和富硒螺旋藻对杂交鲟幼鱼生长、抗氧化能力及组织硒含量的影响

实验旨在研究饲料中不同类型和水平的硒源对杂交鲟(Acipenser baerii♂×Acipenser schrenckii♀)幼鱼生长、抗氧化能力及组织硒含量的影响。不同类型的硒源为亚硒酸钠、酵母硒和富硒螺旋藻,添加水平为0、0.4和1.2 mg/kg,制作对照饲料(C)、亚硒酸钠添加饲料(S1和S2)、酵母硒添加饲料(Y1和Y2)和富硒螺旋藻添加饲料(P1和P2)。使用实验饲料饲喂初始体重为(7.82±0.12) g的杂交鲟幼鱼,养殖62d。结果表明,不同硒源和硒水平对杂交鲟幼鱼的特定生长率和饲料效率无显著影响(P>0.05)。高水平亚硒酸钠显著提高了全鱼和肝脏硒含量(P<0.05),但对肌肉和脊椎骨硒含量无显著影响(P>0.05)。高水平酵母硒和富硒藻螺旋添加组杂交鲟幼鱼的全鱼、肝脏、肌肉及脊椎骨硒含量均显著高于对照组(P<0.05)。酵母硒添加组的血浆总蛋白(TP)和总胆固醇(TC)含量均显著高于对照组(P<0.05)。同时,高水平硒添加组杂交鲟幼鱼的血浆谷胱甘肽过氧化物酶(GSH-Px)活性显著高于对照组和低水平硒添加组(P<0.05)。亚...     

有氧运动训练和摄食对中华倒刺鲃幼鱼力竭运动后代谢特征的影响

为了探讨有氧运动训练和摄食对中华倒刺鲃（Spinibarbus sinensis）幼鱼力竭运动后代谢特征的影响,在（25±0.5）℃条件下,将120尾实验鱼[体重（21.35±0.05）g,体长（10.21±0.03）cm]随机分成4组,即:对照组、1、2和4 BL/s（体长/秒,body length/s）训练组,分别放置于不同流速下处理8周。随后测定各实验组心脏和鳃指数以及禁食或摄食（轻度麻醉灌喂体重1.5%的饵料）状态下的力竭运动后过量耗氧。结果发现:4 BL/s训练组的心脏和鳃指数都显著高于其他实验组（P < 0.05）;无论摄食与否,3个训练组运动前代谢率都显著高于对照组（P=0.001）,而各实验组过量耗氧均没有显著差异;在禁食状态下,仅4 BL/s训练组的运动代谢峰值和代谢率增量显著高于对照组,而在摄食状态下,3个训练组的运动代谢峰值和代谢率增量均显著高于对照组（P < 0.005）。与禁食组相比,摄食导致各处理组的运动前代谢率显著上升（P < 0.001）,但对运动代谢峰值没有显著影响;另外,摄食对照组代谢率增量和力竭运动后过量耗氧显著低于禁食对照组（P < 0.05）。研究表明:（1）有氧运动训练显著提高了中华倒刺鲃幼鱼的有氧代谢能力,这可能与其呼吸和循环系统功能的改善有关;（2）力竭运动能够诱导出中华倒刺鲃幼鱼的最大有氧代谢率;（3）摄食削弱了中华倒刺鲃幼鱼无氧代谢能力。     

Effect of feeding and fasting on excess post-exercise oxygen consumption in juvenile southern catfish (Silurus meridionalis Chen)

The impact of feeding (fed to satiation, 13.85% body mass) on excess post-exercise oxygen consumption (EPOC, chasing for 2.5 min) was investigated in juvenile southern catfish (Silurus meridionalis Chen) (38.62-57.55 g) at 25. Cutlets of freshly killed loach species without viscera, head and tail were used as the test meal, and oxygen consumption (VO(2)) was adjusted to a standard body mass of 1 kg using a mass exponent of 0.75. Resting VO(2) increased significantly above fasting levels (49.89 versus 148.25 mg O(2) h(-)(1)) in 12 h postprandial catfish. VO(2) and ventilation frequency (V(f)) both increased immediately after exhaustive exercise and slowly returned to pre-exercise values in all experimental groups. The times taken for post-exercise VO(2) to return to the pre-exercise value were 20, 25 and 30 min in 12 h, 60 h and 120 h postprandial catfish, respectively. Peak VO(2) levels were 257.36+/-6.06, 219.32+/-6.32 and 200.91+/-5.50 mg O(2) h(-1) in 12 h, 60 h and 120 h postprandial catfish and EPOC values were 13.85+/-4.50, 27.24+/-3.15 and 41.91+/-3.02 mg O(2) in 12 h, 60 h and 120 h postprandial southern catfish, respectively. There were significant differences in both EPOC and peak VO(2) during the post-exercise recovery process among three experimental groups (p<0.05). These results showed that: (1) neither digestive nor exhaustive exercise could elicit maximal VO(2) in southern catfish, (2) both the digestive process and exercise (also the post-exercise recovery process) were curtailed under postprandial exercise, (3) the change of V(f) was smaller than that of VO(2) during the exhaustive exercise recovery process, (4) for a similar increment in VO(2), the change in V(f) was larger during the post-exercise process than during the digestive process.     

5种光周期对锦鲤生长、能量收支及生物钟基因表达的影响

研究不同光照周期(长光照18L﹕6D、短光照8L﹕16D、连续光照24L﹕0D、连续黑暗0L﹕24D和对照组12L﹕12D)条件对锦鲤(Cyprinus carpio)生长、能量收支及生物钟基因相对表达量的影响, 实验周期为90d。结果表明, 在整个试验周期, 各光周期处理组成活率无显著变化(P＞0.05), 24L组和18L﹕6D组饲料系数显著低于12L﹕12D组、8L﹕16D组和24D组(P＜0.05)。终末体重、特定生长率在实验前30d内受光照影响不大(P＞0.05), 而实验30d后出现显著变化, 延长光周期尤其是连续光照会显著增加终末体重和特定生长率(P＜0.05); 对比连续黑暗0L﹕24D组, 其他光周期处理组锦鲤摄食能分配在代谢和生长的比例显著增加(P＜0.05); 4个生物钟相关Clock、Per2、Cry1和Bmal1基因相对表达水平无明显规律。综上所述, 延长光照时间, 尤其是连续光照有利于锦鲤幼鱼的生长和发育。     

哲罗鱼稚鱼最佳投喂策略

为探讨哲罗鱼稚鱼的最佳投喂策略,设置了饥饿再投喂试验、饥饿再投喂恢复试验以及日投喂频率试验.结果表明: 饥饿再投喂试验中,各饥饿组未表现出补偿生长现象.但在饥饿再投喂恢复试验中,各饥饿组表现出不同程度的补偿生长,其中S_1/2组(饥饿1/2 d投喂1/2 d)体质量的增加量与对照组接近,表现出完全补偿生长.表明在哲罗鱼早期稚鱼阶段(体质量0～2 g,水温9～15.3 ℃),S_1/2是可以考虑使用的投喂方法.日投喂频率试验中,T₃组(日投喂3次)体长、体质量的增加量以及特定生长率均最高,饵料转化率也相对较高.表明在哲罗鱼后期稚鱼阶段(体质量2～21 g,水温8.8～15.5 ℃),以日投喂3次为宜.     

Compensatory growth in the gibel carp following feed deprivation: temporal patterns in growth, nutrient deposition, feed intake and body composition

To investigate the nature of compenstory growth in fish, an 8 week study at 28°C was performed on juvenile gibel carp Carassius auratus gibelio weighing 6·6 g. Fish were starved for 0 (control), 1 (S1) or 2 (S2) weeks and then re-fed to satiation for 5 weeks. Weekly changes in weight gain, feed intake and body composition were monitored during re-feeding. No significant difference was found in final body weight between the three groups, indicating complete compensation in the deprived fish. The deprived groups caught up in body weight with that of the control after 2 weeks of re-feeding. Body fat: lean body mass ratio was restored to the control level within 1 week of re-feeding. In the re-feeding period, weekly gains in body weight, protein, lipid, ash and energy in the S1 group were significantly higher than in the controls for 1 week. For the S2 group, weekly gains in body weight, lipid, ash and energy were higher than in the controls for 2 weeks, and gain in protein was higher than in the controls for 3 weeks, though gain in body energy became elevated again during the last 2 weeks of the experiment. Feed intake remained higher than the control level for 3 weeks in the S1 group and 4 weeks in the S2 group. Growth efficiency was not significantly different among the three groups in any of the weeks during re-feeding. Compensatory responses in growth and especially feed intake tended to last longer than the recovery of body composition.     

Effect of meal size on excess post-exercise oxygen consumption in fishes with different locomotive and digestive performance

Effects of feeding on pre-exercise VO₂ and excess post-exercise oxygen consumption (EPOC) after exhaustive exercise were investigated in sedentary southern catfish, active herbivorous grass carp, omnivorous crucian carp, and sluggish omnivorous darkbarbel catfish to test whether feeding had different effects on EPOC and to compare EPOC in fishes with different ecological habits. For fasting fish, the pre-exercise and peak post-exercise VO₂ were higher and recovery rates were faster in crucian carp and grass carp compared to those of darkbarbel catfish and southern catfish. EPOC magnitudes of grass carp and southern catfish were significantly larger than those of crucian carp and darkbarbel catfish. Feeding had no significant effect on peak post-exercise VO₂, recovery rate, and EPOC magnitude in grass carp. Both the pre-exercise and peak post-exercise VO₂ increased with meal size, while the EPOC magnitude and duration decreased significantly in the larger meal size groups of crucian carp and southern catfish. In darkbarbel catfish, both the pre-exercise and peak post-exercise VO₂ increased with meal size, but the VO₂ increment elicited by exercise was larger in feeding groups compared with the fasting group. These results suggest that (1) the characteristics of the post-exercise VO₂ profile, such as peak post-exercise VO₂ and recovery rate, were closely related to the activity of fishes, whereas the EPOC magnitude was not and (2) the effects of feeding on EPOC were more closely related to the postprandial increase in VO₂.     

Effect of starvation and refeeding on digestive enzyme activities in juvenile roach, Rutilus rutilus caspicus

We evaluated the effects of starvation and refeeding on digestive enzyme activities in juvenile roach, Rutilus rutilus caspicus. Fish were divided into four feeding groups (mean mass 1.68 ± 0.12 g). The control group was fed to satiation twice a day throughout the experiment with formulated diet (SFK). The other three groups were deprived of feed for 1(S1), 2(S2), and 3(S3) weeks, respectively, and then fed to satiation during the refeeding period. The results showed that trypsin specific activity was not affected significantly either by starvation or refeeding, in all experimental groups. Chymotrypsin specific activity did not change significantly in S1 fish during the experimental period. In S2 and S3 fish no significant changes were observed during the starvation period. Upon refeeding, the activity increased in S2 fish, while it decreased in S3 fish. Amylase specific activity decreased significantly during the starvation period in all experimental groups. Upon refeeding, the activity increased. Alkaline phosphatase specific activity did not change significantly during the experiment period in S3 fish, while it showed significant changes during the starvation and refeeding period in the S1 and S2 fish. Starvation also had a significant effect on the structure of the intestine.