饥饿对食蚊鱼仔鱼摄食、生长和形态的影响

本文研究了饥饿胁迫下食蚊鱼仔鱼的摄食、生长和外部形态的变化规律.结果表明,在水温(28.5±1.2)℃时,仔鱼产出2h后鳔完成充气即建立巡游模式并开始觅食,摄食比率迅速达到100%,其混合营养期仅有4h.实验期间,投喂组仔鱼的摄食比率一直保持在100%;饥饿组仔鱼在饥饿0-3d内初次摄食比率同样可达到或接近100%,但第4天开始下降,第6天初次摄食比率降至0,抵达饥饿不可逆点(PNR)时间为产出后第5.5天左右.投喂组初产仔鱼对1-2龄期库蚊幼虫的摄食强度为(2.9±1.4)ind/individual·h,摄食强度随日龄显著增长;饥饿组仔鱼在饥饿0-5d内其初次摄食强度也随日龄及饥饿时间的延长显著增长,但均显著低于相应日龄的投喂组仔鱼,其初次摄食比率与初次摄食强度之间并无显著相关关系.饥饿仔鱼在PNR前约1.5d时其累计死亡率已超半数,达(64.4±18.1)%,抵达PNR后数小时内残存个体全部死亡.实验结束(6d)时投喂组仔鱼5项生长指标呈不等速增长,其中体重增长最为显著,瞬时增长率达0.0275/d,此时腹鳍发育基本完备,进入幼鱼期.而同期饥饿组仔鱼形态发育停滞,多项生长指标出现负增长,其中体高负增长最为明显,其瞬时增长率为-0.0511/d;体重次之,体长负增长则不甚明显.饥饿仔鱼在接近或处在PNR期时腹部萎缩呈弧形,体长/体高>5,而同期投喂组仔鱼体长/体高<4.5,两者差异显著,可作为鉴别饥饿仔鱼和健康仔鱼较理想的形态数量指标.     

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.     

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.     

中国林蛙继饥饿后的补偿生长研究

本研究在室内环境条件下进行,研究了不同饥饿程度和再投喂后中国林蛙的生长变化,并对中国林蛙饥饿后的补偿生长及其机制进行了分析。结果表明：中国林蛙经饥饿后再投喂,各处理组的体重已经赶上对照组的体重,其体重逐渐增加,经单因素方差分析,对比变化不显著,呈现出完全补偿生长。体重恢复过程中,各饥饿处理组的特殊生长率（SGR）、摄食率（FR）及饵料转化率（CE）均存在不同程度的差异。     

延迟首次投喂对南方鲇（Silurus meridionalis Chen）仔鱼身体含能量、体长及游泳能力的影响

在(22.0±0.5)℃条件下,将人工孵化的南方鲇仔鱼分别于出膜后4、5、6、7天进行首次投喂（其中4d的为对照组）,首次投喂前（出膜后4 d）取样测量体长、体重、身体含能量作为初始值,于出膜后7 d（延迟投喂实验）和21 d（继续喂养实验）分别测定体长、体重、身体所含能量和临界游泳速度。结果显示：延迟投喂实验结束时各处理组的体重、身体含能量和体长随首次投喂时间的延迟均呈下降趋势,相对临界游泳速度随首次投喂时间的延迟表现为先提高后降低的趋势,绝对临界游泳速度在延迟投喂2d以内无显著差异;继续喂养实验结束时处理组各指标逐渐接近对照组水平,两种临界游泳速度表现为同步变化趋势;另外,体长特定生长率相对百分比（SGR_L％）的变化幅度小于身体含能量特定生长率相对百分比（SGR_E％）的变化幅度,而绝对临界游泳速度相对百分比（Ucri_t％）的变化又小于体长特定生长率相对百分比的变化。结果表明：早期食物资源的短缺会导致南方鲇仔鱼体重、身体含能量产生明显变化,体长生长速度的变化则相对较小,而短期饥饿不会显著降低南方鲇仔鱼的游泳能力。     

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.     

投喂水平对长吻 仔稚鱼生长和存活的影响

以长吻(鱼危)仔鱼为实验对象, 探讨不同投喂水平对7-14日龄阶段和21-29日龄阶段的长吻(鱼危)仔稚鱼存活、生长以及鱼体组成的影响。7-14日龄阶段设计6个投喂水平, 分别为: 20、30、40、50、60和70 % IBW/d(IBW: initial body weight); 21-29日龄阶段设计6个投喂水平: 10、20、30、40、50、60 % IBW/d。实验结果表明: (1)投喂水平显著影响长吻(鱼危)仔稚鱼的存活和生长(P0.05)。7-14日龄阶段, 投喂水平为30%-60% IBW/d处理组的仔鱼存活率显著高于20%与70 % IBW/d投喂组(P0.05)。特定生长率随投喂水平的增加显著上升, 以60% IBW/d投喂组最高(P0.05)。21-29日龄期间, 10% IBW/d投喂组存活率显著低于50% IBW/d投喂组(P0.05), 特定生长率(SGR)则显著低于其他各处理组(P0.05); (2)鱼体体长体重变异系数未受投喂水平的显著影响。鱼体产出与饲料投入之比、鱼体水分含量随投喂水平升高显著下降(P0.05), 粗蛋白含量则显著上升(P0.05); 粗脂肪和粗灰分含量无显著差异; (3)分别通过存活率和投喂水平做一元二次回归、特定生长率与投喂水平做折线回归得到7-14日龄阶段的仔鱼最适投喂水平为43 % IBW/d; 通过仔鱼存活率和特定生长率与饲料投喂水平做折线回归得到21-29日龄阶段的仔鱼最适投喂水平分别为30.62% IBW/d和28.41% IBW/d。       

延迟初次投喂对太门哲罗鱼仔鱼生长和存活的影响

在水温为10.4～14.9℃条件下,研究了延迟初次投喂对太门哲罗鱼仔鱼的生长、存活和个体大小差异的影响.该试验共分5组:S0(饥饿0d,对照)、S1(开口9d后投喂)、S2(开口12 d后投喂)、S3(开口15 d后投喂)、S4(开口18d后投喂).结果表明:经过36 d试验,S1组生长率和初次摄食率高于S0组,试验结束时总体的死亡率低于S0组,两组个体大小和体质量均无显著性差异;S2组生长率和初次摄食率高于S0组,两组个体大小差异不显著,但S2组体质量明显低于S0组,且总死亡率和自残死亡率均高于S0组;S3组初次摄食率高于S0组,总死亡率、自残死亡率和个体大小均高于S0组,虽然生长率接近S0组,但体质量明显低于S0组;S4组生长率和体质量均小于S0组,总死亡率和自残死亡率高于S0组.相同条件下延迟9d投喂太门哲罗鱼仔鱼出现了“完全补偿生长”,可应用于太门哲罗鱼初次摄食期仔鱼的培育.     

延迟首次投喂对南方鲇(Silurus meridionalis Chen)仔鱼身体含能量、体长及游泳能力的影响

在（22.0±0.5）℃条件下,将人工孵化的南方鲇仔鱼分别于出膜后4、5、6、7天进行首次投喂（其中4d的为对照组）,首次投喂前（出膜后4d）取样测量体长、体重、身体含能量作为初始值,于出膜后7d（延迟投喂实验）和21d（继续喂养实验）分别测定体长、体重、身体所含能量和临界游泳速度。结果显示：延迟投喂实验结束时各处理组的体重、身体含能量和体长随首次投喂时间的延迟均呈下降趋势,相对临界游泳速度随首次投喂时间的延迟表现为先提高后降低的趋势,绝对临界游泳速度在延迟投喂2d以内无显著差异;继续喂养实验结束时处理组各指标逐渐接近对照组水平,两种临界游泳速度表现为同步变化趋势;另外,体长特定生长率相对百分比（SGRL%）的变化幅度小于身体含能量特定生长率相对百分比（SGRE%）的变化幅度,而绝对临界游泳速度相对百分比（Ucrit%）的变化又小于体长特定生长率相对百分比的变化。结果表明：早期食物资源的短缺会导致南方鲇仔鱼体重、身体含能量产生明显变化,体长生长速度的变化则相对较小,而短期饥饿不会显著降低南方鲇仔鱼的游泳能力。     

周期性饥饿再投喂对长蛸存活、生长以及肌肉脂肪酸和氨基酸的影响

在19.8—22.2℃条件下, 采用周期性饥饿再投喂的方法, 研究不同投喂模式对长蛸[Octopus minor, 初始体重(94.29±9.35) g, 初始胴背长(53.25±5.25) mm]的存活、生长以及脂肪酸和氨基酸的影响。实验分为4个组包括对照组(持续投喂)、S₁F₅组(周期性饥饿1d再投喂5d)、S₂F₄组(周期性饥饿2d再投喂4d)和S₃F₃组(周期性饥饿3d再投喂3d), 持续24d。实验结果如下: 随饥饿时间的延长, 增重率、肝体比、体重变化量以及终末体重四个指标均呈现出先上升后下降的趋势, 其中S₁F₅组的值均显著高于对照组, 而S₃F₃组的值除肝体比外均显著低于对照组。长蛸的成活率随饥饿时间的增长呈现出下降趋势, 但各实验组均与对照组差异不显著; 摄食量随饥饿时间的延长, 表现出上升趋势, 且三个实验组的值均显著高于对照组。在长蛸肌肉脂肪酸中, 饱和脂肪酸(SFA)、不饱和脂肪酸(UFA)、单不饱和脂肪酸(MUFA)以及多不饱和脂肪酸(PUFA)的含量均与对照组差异不显著, 但S₁F₅组的值与对照组相比出现了一定程度的升高; 在氨基酸含量上, 各实验组的必需氨基酸总量(TEAA)、氨基酸总量(TAA)以及必需氨基酸总量/氨基酸总量(TEAA/TAA)的值均与对照组差异不显著。综上所述, S₁F₅组和S₂F₄组长蛸出现了补偿生长现象, 且S₁F₅组长蛸具备超补偿生长能力。因此, 在长蛸的人工养殖过程中, 为保证其养殖效果, 建议采用周期性饥饿1d再投喂5d的投喂模式。     

The effect of starvation on RNA: DNA ratios and growth of larval striped bass, Morone saxatalis

Hatchery reared larval striped bass, Morone saxatilis , 8-days-post-hatching were subjected to various feeding/starvation regimes over a period of 14 days.
Batches of larvae from each treatment were sampled over the 14-day period and subdivided for determination of notochord length and RNA:DNA ratio. The best growth was found in fully fed F1000 larvae (exposed to 1000 Artermia nauplii l⁻¹), which reached 8.2 mm after 11 days and 9.6 mm after 14 days. Starved animals after 11 days had notochord lengths of 4.9 mm. Growth curves from feeding-delayed larvae indicated that animals fed after up to 5 days starvation were capable of complete recovery. F100 larvae (exposed to 100 Anemia nauplii 1^−l) had a slower growth rate than F1000 larvae, reaching a notochord length of 7.3 mm after 14 days. RNA:DNA ratios over time closely followed notochord growth curves, with clear differences between starved, F100 and F1000 larvae being established after only 2 days. Equilibrium RNA:DNA ratios of 3.0 and 2.25 were established in F1000 and F100 larvae, respectively, 6.8 days after the beginning of the experiment. The average lag time between a change from the starved to the fed condition and a change in RNA:DNA ratio as determined by the divergence of the nucleic acid curve from the starved condition was 0.66 days.
In treatments where starvation followed various periods of feeding, larvae regressed in notochord length such that the final length at 14 days reflected the degree of feeding. RNA:DNA ratios in these animals again closely followed growth curves with a lag time of 0.81 days.
It was concluded that RNA:DNA ratios provided very accurate indices of growth in striped bass larvae which were highly sensitive to feeding status.     

Assessment of the nutritional status of field-caught larval Pacific bluefin tuna by RNA/DNA ratio based on a starvation experiment of hatchery-reared fish

RNA/DNA ratio is a useful and reliable indicator of the nutritional status of fish larvae and juveniles. In order to assess the nutritional status of field-caught larval Pacific bluefin tuna Thunnus orientalis (Temminck et Schlegel), starvation experiments of hatchery-reared larvae were conducted and changes in the RNA/DNA ratio of fed and starved larvae were analyzed. Starvation experiments were conducted every 3 days after first feeding. The survival rate of Pacific bluefin tuna larvae ranged 10-50% after 1 day of starved conditions and growth retardation was observed immediately. These results suggest that Pacific bluefin tuna larvae have a very low tolerance to starvation. The RNA/DNA ratios of fed larvae were approximately 2.0-4.0. On the other hand, the value of starved larvae significantly decreased to 1.0-3.0. The nutritional status of 3 cohorts of field-caught tuna larvae collected in the northwestern Pacific Ocean was examined based on the value of the RNA/DNA ratio of the 1 day starved larvae. 4.35-25.77% of the cohorts were regarded as the “starving condition”, which was negatively correlated to the ambient prey densities. These findings suggest that the nutritional condition of larval Pacific bluefin tuna was influenced by the ambient prey density, and starvation itself and starvation-induced predation could greatly contribute to mortality in the larval period of Pacific bluefin tuna.     

Evaluating the nutritional condition of individual whitefish (Coregonus spp.) larvae by the RNA/DNA ratio

Larvae of Coregonus spp. were reared in the laboratory under different temperature (4, 6 and 8°C) and feeding conditions ( ad libitum , limited, with starvation intervals). Their RNA/DNA ratios were determined with a highly sensitive fluorescence technique. After resorption of their yolk reserves (about 2 weeks after hatching), well fed larvae (RNA/DNA >2.5) could be significantly distinguished from larvae reared under limited food supply (RNA/DNA < 2.5), both at the 6 and 8°C levels. At 4°C, no differences due to the feeding regime were found. During a second series of experiments, larvae were affected by an intestinal disease, which was caused by the ingestion of unsuitable copepod plankton. This disease provoked high mortality, decreased growth and RNA/DNA ratios which were almost as low as in temporarily starved larvae from the first series. Coregonid larvae sampled in Lake Constance during spring 1990 showed RNA/DNA ratios which were unexpectedly low when judged on the basis of mean body length and average ambient temperature. It was obvious from macroscopic observations that some of these wild larvae were severely attacked by the intestinal disease. The low RNA/DNA ratios in field samples are, therefore, interpreted as a sublethal result of this disease.     

Changes in RNA/DNA ratio and growth of slime flounder, Microstomus achne, larvae until metamorphosis

Understanding the nutritional condition and survival of fish larvae is of primary importance in mass larva culture because intensive mortality is concentrated during the larval period. In order to estimate growth and nutritional status based on biochemical indices of slime flounder, Microstomus achne, larvae reared under starved and fed conditions in the hatchery for 58 days and the changes of RNA, DNA, and protein contents were described with the progress of growth and developmental. DNA contents increased gradually throughout the experimental period until 12 and 58 days post‐hatching (DPH) in starved and fed groups respectively. Although they fluctuated and decreased around 12 and 46 DPH, the RNA contents of the fed group increased gradually after hatching; however, in the starved group, they decreased after yolk absorption and 7 DPH. Subsequently, the RNA/DNA ratios in the starved group remained constant until 6 DPH and then decreased rapidly. In the fed group, this decreased slightly from hatching to 14 DPH, then increased gradually until the end of the experiment, except at the lower level of around 46 DPH. Namely, temperature shocks (around 14 DPH) and the dramatic changes in body shape (around 46 DPH) were accompanied by the decrease of the RNA/DNA ratios. Total protein/DNA in both groups decreased rapidly during yolk absorption 0–7 DPH, then decreased continuously until death in the starved group; in the fed group total protein/DNA increased again with feeding. It is suggested that the changes in these biochemical values reflect yolk absorption, feeding, morphogenetic changes, growth, and environmental conditions.     

Effects of starvation on larval growth, survival, and metamorphosis of Manila clam Ruditapes philippinarum

The effects of starvation on larval growth, survival, and metamorphosis of Manila clam Ruditapes philippinarum at the temperature of 19.6–21.6 °C, the salinity of 34‰ and pH of 8.0 were investigated from May 18 to July 18, 2006. In this study, the early, middle and late umbo-veliger larvae with the shell lengths of 100, 140, and 190 μm were subject to temporary food deprivation for up to 4.5, 20, and 25d at 0.5, 4, 5d intervals, followed by refeeding for the remaining of a 24, 20, 25d period, respectively. The results suggested that the larvae should have shown considerable tolerance to starvation due to their endogenous and exterior nutrition material, for larvae and time to the point-of-no-return (PNR: the threshold point during starvation after which larvae could no longer metamorphose even if food is provided) were calculated to be 4.25, 17.54, and 22.17d. As the starvation period prolonged, the mean shell length of larvae starved got close to constants at 1.5, 4, and 15d after starvation, which were different for larvae at different stages when starvation began, survival of larvae decreased, and was lower in treatments starved earlier in development than those starved later, for the early, middle and late umbo-veliger larvae, after 4.5, 20 and 25d of starvation period, few larvaes were alive. After starvation period, the alive larvaes were able to metamorphose and had a capability of compensatory growth when refeeding was given. Starvation not only affected metamorphosis rate, but also caused the delay in the time to metamorphosis and the decrease in the metamorphosed sizes. For example, for the continuously-fed larvae, duration to metamorphosis was 20.7d, for larvae with a size of 100-μm starved for up to 4d, larvae with a size of 140-μm starved for up to 16d, larvae with a size of 190-μm starved for up to 20d, duration to metamorphosis were 29.7, 31.7, and 37.7d, the delay in duration to metamorphosis were 9, 11, and 17d, respectively. Furthermore, importance of nutrition material for maintaining larval survival during starvation and the compensatory growth on larvae at the same feeding time were discussed.     

Nutritional condition and vertical distribution of Baltic cod larvae

Newly hatched Baltic cod Gadus morhua larvae are typically found at depths >60 m. This is a region of low light and prey availability, hence generating the hypothesis that larvae have to migrate from hatching depth to the surface layer to avoid starvation and improve their nutritional condition. To test this hypothesis, Baltic cod larvae were sampled during the spawning seasons of 1994 and 1995 with depth-resolving multiple opening/closing nets. Each larva was aged by otolith readings and its RNA/DNA ratio was determined as a measure of nutritional condition. The RNA/DNA ratios of these larvae aged 2-25 days (median 10 days) ranged from 0.4 to 6.2, corresponding to levels exhibited by starving and fast-growing larvae in laboratory calibration studies (starvation, protein growth rate, G_pi= -12.2% day⁻¹; fastgrowing larvae, G_pi=14.1%day⁻¹) respectively. Seventy per cent of the field caught larvae had RNA/DNA ratios between the mean values found for starving and fed laboratory larvae. Only larvae aged 8-11 days had higher mean RNA/DNA ratios above 45 m than below ( t -test, P<0.05). However, the instantaneous protein growth rates were significantly higher for all larval age groups in the surface layers ( t -test, P<0.05). Starving larvae were found in all depths sampled (10-85 m), whereas growing larvae (positive G_pi) were restricted to samples taken shallower than 45 m. These superior growth rates above 45 m corroborate the hypothesis and imply that migration to the shallow water layers is a prerequisite for good nutritional condition, growth and survival of Baltic cod larvae. The frequent occurrence of cod larvae older than 8 days in the deep water in poor condition suggests that a proportion of the larvae will die from Starvation in the deep layers of the Baltic Sea.     

Evaluation of an improved RNA/DNA quantification method in a common carp (Cyprinus carpio Linnaeus 1758) larval feeding trial with Artemia,two nematodes (Panagrellus redivivus Linnaeus 1758, Panagrolaimus sp. Fuchs 1930) and dry feed

The RNA/DNA ratio commonly used as proxy for the nutritional condition of fish larvae is affected by RNA degradation during analysis. For evaluation of two strategies to improve RNA integrity, a three‐week feeding trial was carried out to assess the suitability of two nematode species (fam. Panagrolaimidae) as feed for newly hatched carp larvae (Cyprinus carpio) in comparison to Artemia nauplii (Artemia sp.) and a commercial dry feed. Aiming for an increased reproducibility of RNA/DNA determination, a high‐salt inactivation (RNA later) as well as a targeted approach with a recombinant RNase inhibitor were compared to the classical protocol using lab chip technology. Improved RNA integrity was observed with high‐salt inactivation when compared with a strategy applying a specific RNase inhibitor or the classic protocol. Carp larvae fed Artemia for 2 weeks and then dry feed for 1 week revealed the best overall growth performance as well as survival [83.0 ± 35.2 mg fresh weight (FW), 20.0 ± 2.4 mm total length (TL), 86.6 ± 11.7% survival]. Larvae fed the nematode species Panagrellus redivivus for 1 week and subsequently dry feed for 2 weeks (37.4 ± 29.1 mg FW, 14.7 ± 2.8 mm TL, 76.0 ± 6.0% survival) performed better than larvae fed with dry feed alone (28.2 ± 29.6 mg FW, 14.3 ± 2.9 mm TL, 54.3 ± 14.2% survival) or those receiving Panagrellus for 2 weeks. Between both nematode species, Panagrellus was a better feed with regard to growth performance and survival. RNA/DNA ratios ranged between 0.65 ± 0.27 (8 days post‐hatch) and 1.96 ± 0.63 (22 days post‐hatch) and were in the same treatment order as the other growth parameters. RNA/DNA ratios were significantly correlated with the growth rate, and decreasing RNA/DNA ratios in larger larvae may reflect decreasing growth rates with size rather than decreased nutritional status. Here, an improved RNA/DNA ratio protocol is presented in a feeding trial that reveals the suitability of nematodes as a first feed for common carp larvae.     

饥饿和再投喂对草鱼鱼种生物化学组成的影响

分析了饥饿１５天和再投喂２１天的草鱼鱼种肝脏和肌肉生物化学组成的变化，结果表明：（１）饥饿降低白肌ＲＮＡ／ＤＮＡ比值，蛋白质含量和肝脏ＲＮＡ／ＤＮＡ比值，使肝脏蛋白质含量升高，再投喂后，肝脏ＲＮＡ／ＤＮＡ比值，蛋白质含量和白蛋白质含量均恢复至正常投喂组水平，白肌ＲＮＡ／ＤＮＡ比值升高并显著高于正常投喂组水平；（２）饥饿状态下，肝脏和肌肉的脂类含量降低，水含量升高，再投喂后，肝脏和肌肉的脂类含量升高     

草地贪夜蛾幼虫耐饥力及饥饿对其生长发育和繁殖的影响

本文旨在明确草地贪夜蛾Spodoptera frugiperda(J.E.Smith)幼虫耐饥力及饥饿处理对其生长发育、繁殖力的影响.选取初孵幼虫(幼虫孵化1 h内)、2、4、6、8和10日龄的幼虫进行饥饿处理,测定存活率和存活时间分析其耐饥力;进一步选取8日龄幼虫分别饥饿1、2、3和4d后再复食,分别统计和分析饥饿胁...