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1.
This study assessed the effect of starvation on survival and nutritional status of newborn juveniles H. erectus (<10 days) to optimize rearing protocols, thereby helping to reduce wildlife exploitation. Maximum starvation time (MST) was estimated through the survival of juveniles continuously starved from birth. Resistance to starvation and the effect of food re‐introduction after 1, 2, 4 and 6 days of starvation on survival and metabolite concentrations (total proteins, total lipids, acylglycerides, cholesterol, glucose) were also determined. Survival amongst continuously starved animals decreased from 6.6 ± 0.5 to 0% from days 9 to 10 of starvation. Seahorses under different starvation–refeeding treatments all had 100% survival up to day 5 of experiments. After 10 days, however, a 4‐day starvation period followed by refeeding showed negative effects with <50% survival. During continuous starvation, lipids were the first energy reserve used to maintain basal metabolism, followed by proteins. Except for cholesterol, all metabolite concentrations differed between continuous starvations and feeding. Despite high seahorse survival after 5 days in the absence of food, the recovery of the metabolic status is possible after a starvation period of no more than 2 days, since irreversible physiological changes compromising the ultimate survival of the organisms take place after this time.  相似文献   

2.
This study aimed at evaluating the effects of two starvation modes (fasting‐feeding mode and feeding‐fasting mode) on survival, growth and development of mysis larvae of Exopalaemon carinicauda. It showed that food restriction significantly affected the survival, growth and development in both starvation modes. With the extension of initial starvation period, a significantly reduced survival rate during metamorphosis was observed. In the fasting‐feeding mode, the duration of metamorphosis was extended and the body lengths of the individuals, which experienced successful metamorphosis to the post‐larval stage 1, were much shorter. In the feeding‐fasting mode, the extension of initial feeding period led to dramatically increased survival rate and body lengths, while there was no significant difference in duration of metamorphosis of those groups that reached to post‐larval stage. The 50% point‐of‐no‐return and the 50% point‐of‐reserve‐saturation were 3.85 days and 4.81 days respectively. The results of this study indicate that E. carinicauda mysis have the ability to withstand or recover from relatively extended starvation, but to ensure the success of commercial seedling, timely and adequate feeding is necessary. The information obtained from this study could provide a basis to optimize the feeding schedule of artificial seedling of E. carinicauda.  相似文献   

3.
This study investigated the effect of starvation (78 days) and refeeding (33 days) on the oxidative stress [malondialdehyde (MDA)] and the non‐enzymatic antioxidants [vitamin E (VE), vitamin C (VC), vitamin A (VA), beta carotene (βC) and reduced glutathione (GSH)] in the hepatopancreas, muscle and gill tissues of freshwater crayfish (Astacus leptodactylus). Crayfish were divided into three experimental groups: control (fed), starved (not fed) crayfish for 78 days and refeeding crayfish for 33 days after 78 days of starvation. The biochemical analysis of the tissues was conducted at 3, 18, 33, 48, 63 and 78 days of starvation and feeding and at 3, 18 and 33 days of refeeding. It was determined that crayfish can withstand starvation period of 78 days. In all of the periods, the MDA levels were significantly higher in the tissues of starved crayfish when compared with the control. The findings of this study demonstrate that starvation has a negative effect on the VE, VC, VA, βC and GSH levels in the crayfish. The measured parameters returned to control values after 33 days of the refeeding. Additionally, the starvation resulted in decreased levels of VE, VA and βC in the abdomen muscle of crayfish consumed by humans.  相似文献   

4.
探讨了饥饿及恢复投饵过程中花鲈（Lateolabrax japonicus）（196±38g）肌肉组成分及鱼体非特异免疫水平的变化。实验设S0组（对照组，持续正常投喂），S5组（饥饿5d后恢复正常投喂），S10组（饥饿10d后恢复正常投喂），S15组（饥饿15d后恢复正常投喂）。S0组每隔5d取样，S5，S10和S15组分别在结束饥饿及恢复投饵后每隔5d取样测定。结果显示：饥饿程度对花鲈肌肉组成有显著影响。与对照组相比，S10组饥饿结束时肌肉的总脂含量显著降低；S15组饥饿结束时肌肉的总脂含量和粗蛋白含量都显著降，同时显著增加了肌肉的水分含量。表明饥饿过程中花鲈先动用肌肉脂肪，后动用肌肉蛋白。在恢复投饵过程中，S10和S15组总脂含量表现出先降后升的规律，而S15组蛋白表现为逐步回升的趋势。表明花鲈在饥饿后恢复投饵的过程中，先恢复肌肉蛋白含量，后恢复肌肉脂肪含量。饥饿15d时花鲈血清蛋白浓度显著降低。与对照组相比，S5组血清、脾脏和头肾溶菌酶活性均无显著变化；S10组头肾溶菌酶活性在恢复投饵10d时补偿性升高。S15组在饥饿结束时显著降低了花鲈头肾溶菌酶活性，但在恢复投饵5d时恢复到对照组水平。花鲈白细胞的吞噬活性也受饥饿程度及恢复投饵的影响。饥饿会降低花鲈血液白细胞的吞噬活性。在恢复投饵过程中,饥饿（5d）后恢复投饵会引起白细胞吞噬百分率和吞噬指数的补偿性升高。表明饥饿及恢复投饵也影响花鲈的非特异免疫水平。  相似文献   

5.
To increase the current knowledge about the relationship between nutritional status and the digestive capacity of Siberian sturgeon (Acipenser baerii), we addressed the effect of starvation‐refeeding and macronutrient composition on growth parameters and key digestive enzyme activities in A. baerii. Acipenser baerii juveniles were fed four different diets for 3 weeks, then starved for 2 weeks and allowed to refed for 5 weeks with the same diets. Another group of fish were fed 10 weeks with the corresponding diets. Among 10‐week fed fish, high‐protein diets promoted higher body weight values, while the lowest specific growth rate was observed in fish fed a low‐protein, medium‐carbohydrate, high‐lipid diet (p < .05). At the end of the experiment, in fish refed for 5 weeks following a feeding‐starvation cycle and in 10‐week fed animals, the higher levels of blood glucose, triglycerides and cholesterol were found in fish fed low‐protein diets (p < .05). In all treatments, 2 weeks of starvation decreased α‐amylase activity in the intestine (p < .05), while 4 days of refeeding increased lipase (p > .05) and α‐amylase activity in the intestine as well as pepsin in the stomach (p < .05). Our findings suggest that A. baerii maintains a high capacity to digest proteins and lipids after 2 weeks of starvation and that α‐amylase can be used as an indicator of the nutritional status in fish submitted to starvation‐refeeding cycles. Indeed, refeeding with high‐protein and CHO:L ratio diets after starvation could improve the growth rate of A. baerii in culture.  相似文献   

6.
Many fish species can withstand long period of food deprivation and consequently compensate for any weight loss by undergoing rapid growth during resumption of feeding. There is an interest in taking advantage of compensatory growth to reduce feed cost. In this present study, we attempted to compare the changes in hepatic mitochondrial proteome of zebrafish undergoing starvation and refeeding. Two‐dimensional gel separation and image analysis revealed a total of 65 spots that showed changes in expression after 15 days of starvation followed by 7 days of refeeding. A total of 35 proteins were selected for mass spectrometry analysis, resulting in the positive identification of 18 proteins. Identified proteins indicated that starvation resulted in reduction in glycolysis and increase in gluconeogenesis, while refeeding caused these activities to return to normal levels. Expression pattern of several proteins related to fatty acid and amino acid metabolism also suggested the utilization of non‐carbohydrate resources for energy during starving conditions. Proteins with chaperoning and antioxidative roles such as glucose‐regulated protein, paraxonase and heat‐shock protein were also upregulated in starved conditions.  相似文献   

7.
In this study, we assessed the effects of Radix Rehmanniae Preparata polysaccharides (RRPP) on the digestive enzymes, morphology, microbial communities and mucosal barrier function of the intestine of Luciobarbus capito. Fish were fed different amounts of RRPP (0, 0.05, 0.1, 0.2 and 0.4%) for 60 days. The results revealed that intestinal amylase and trypsin activities significantly increased after the 0.2% RRPP treatment (p < .05). Increases in intestinal fold height, wall thickness and fold density were observed in Luciobarbus capito fed an RRPP‐supplemented diet, and the best effect was observed in the proximal intestine. Sequencing of the bacterial 16S rRNA V4 region showed that dietary RRPP reduced intestinal microbial community richness and species diversity. Fusobacteria, Proteobacteria, Firmicutes and Verrucomicrobia were the dominant bacterial phyla in the intestine of Luciobarbus capito. Dietary RRPP affected the overall microbial community and increased the abundance of the genus Cetobacterium. Moreover, RRPP significantly upregulated the expression of occludin, zonula occludens (ZO)‐1 and claudin‐c in the intestine (p < .05). In summary, supplementing the diet of Luciobarbus capito with RRPP can improve digestive enzymes activities and intestinal morphology, modulate the microbial composition and enhance intestinal mucosal barrier function.  相似文献   

8.
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9.
This study was performed to determine the effect of starvation and delayed feeding on activities of digestive enzymes and alkaline phosphatase (ALP) of larval red swamp crayfish (Procambarus clarkii), so as to reveal the tolerance to prolonged starvation and the recovery of digestive enzymes after delayed feeding in larval and juvenile P. clarkii. In the control group, activities of trypsin and ALP increased significantly (p < .05) with day‐age and then kept constant at 24 days after hatching (DAH) and 10 DAH, respectively, whereas the activities of amylase and pepsin increased firstly then decreased with day‐age, and the activity of lipase increased firstly then decreased and then increased again during the development period of juvenile P. clarkii (1–31 DAH). In the group with continuous starvation (CS), activities of pepsin and lipase both decreased (p < .05) after fasting, and the activities of pepsin, lipase and trypsin in the groups with delayed feeding all increased (p < .05) and recover to the levels of the control group after food supply. However, the activity of amylase increased (p < .05) in the CS group, and it decreased to normal level after food supply. The ALP activity did not significantly (p > .05) vary after starvation, whereas it decreased in the groups with delayed feeding after 1 day of food supply, and then increased back to the level similar with the control group. Results from this study could provide information for diet preparation and feeding regime in larval and juvenile red swamp crayfish culture.  相似文献   

10.
We evaluated whether body fat content affects the energetic metabolism and growth in pacu submitted to daily feeding, fasting and refeeding. For 15 days, fish were fed different diets to obtain lean and fat conditions, and then subjected, for 20 days to: (1) continuously feeding (control), or (2) fasting for 15 days and refeeding for 5 days. Blood (glucose, triglycerides, cholesterol, non‐esterified fatty acids and total protein) and tissue (liver lipid and glycogen, muscle lipid and mesenteric fat) metabolic indicators, and growth performance parameters (weight gain, specific growth rate, daily feed intake and feed conversion ratio) were measured. Fasting led both lean and fat pacu to make notable use of their energy reserves, through glycogenolysis and lipolysis, reflected in reduced blood glucose and triglycerides, liver glycogen and muscle lipid levels. Lipolysis was confirmed by the high levels of non‐esterified fatty acids, especially in fat pacu. Refeeding led to higher plasma glucose and liver lipid in lean fish. Muscle fat increased in fat fish but was not restored in lean fish, while mesenteric fat index (MFI) remained the same in fat fish and increased in lean fish. Although refeeding occurred only for 5 days, lean fish grew more and were more efficient at utilizing food (higher weight gain and better feed conversion ratio). In conclusion, our results suggest that fat pacu have higher glycogenic and lipogenic abilities, and the higher deposition of lipids in fish does not mean higher availability of energy for growth when compensatory growth is stimulated by refeeding after fasting.  相似文献   

11.
饥饿与再投喂对中华倒刺鲃幼鱼生长和消化酶活性的影响   总被引：1，自引：0，他引：1  
周兴华  向枭  向桢  欧仁建  陈俊  冉龙虎 《淡水渔业》2012,42(3):50-54,73
在室内水温23～26℃的条件下,将中华倒刺鲃(Spinibarbus sinensis)幼鱼分装于6个饲养桶中,试验设计分为两组,每组3个平行,并依次编号为A、B、C、D、E、F,将两组同时饥饿20 d,分别在饥饿0、3、5、10、15、20 d对A、B、C取样。而D、E、F饥饿20 d后进行16 d的恢复投喂,并在再投喂3、7、12、16 d进行取样,分别测定其体质量、肥满度、肝脏指数以及肝胰脏、前后肠消化酶(胰蛋白酶、脂肪酶、淀粉酶)活性的变化。结果表明:(1)在饥饿过程中,中华倒刺鲃幼鱼体质量、肥满度、肝脏指数均呈下降趋势;恢复投喂后,三者均有不同程度的恢复。(2)肝胰脏蛋白酶活性在饥饿过程中呈下降趋势,并在20 d降到最低,恢复投喂后其活性逐步回升到正常水平;而肠蛋白酶活性饥饿过程中先升高,并在5 d达到最高值而后呈下降趋势,恢复投喂后达到正常水平。(3)饥饿过程中,肝胰脏和前后肠脂肪酶活性迅速升高,在10 d达到最值,并显著高于饥饿前的水平,而后逐步下降,恢复投喂后脂肪酶活性仍持续维持在较高的水平。(4)肝胰脏和前后肠淀粉酶活性在饥饿过程中逐步下降,恢复投喂后其活性恢复至正常水平。  相似文献   

12.
饥饿对大口黑鲈消化器官、蛋白酶和淀粉酶活力的影响   总被引：5，自引：0，他引：5  
对饥饿和饥饿后投喂的大口黑鲈(Micropterus salmoides)蛋白酶和淀粉酶活力及消化组织的变化进行了研究,饥饿周期为30d。饥饿对大口黑鲈消化道指数的影响为肝体比从试验的第3天开始明显下降(P<0.05),第20天开始保持稳定水平(P>0.05);幽门盲囊重与体重比先上升后下降;胃重与体重比始终呈上升趋势(P<0.05);肠重与体重比在第10天开始保持稳定水平(P>0.05);肠长与体长比呈上升趋势(P<0.05)。饥饿对蛋白酶活力影响为从开始到第3天胃蛋白酶活力上升,第10天开始下降;幽门盲囊蛋白酶活力在第10天之后持续下降(P<0.05);肠道蛋白酶活力一直呈下降趋势。饥饿对淀粉酶活力影响为肝脏淀粉酶活力、胃淀粉酶活力和幽门盲囊淀粉酶活力均呈下降趋势(P<0.05);肠道淀粉酶活力第10天之后即稳定在低水平(P>0.05)。饥饿后摄食对蛋白酶活力和淀粉酶活力的影响为饥饿后摄食蛋白酶活力和淀粉酶活力均呈上升趋势,上升的速度在不同组织有差异,在恢复摄食后的第10天基本达到正常水平。  相似文献   

13.
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14.
Different fasting and re‐feeding cycles were tested in a 60‐day trial in sobaity sea bream (Sparidentex hasta) juveniles to evaluate their effects on growth, physiological and biochemical parameters. Fish were exposed in triplicate to the following feeding regimes: control (fed everyday); F‐RF1+1 (1 day of starvation followed by 1 day of re‐feeding); F‐RF2+2 (2 days of starvation followed by 2 days of re‐feeding); F‐RF3+3 (3 days of starvation followed by 3 days of re‐feeding); F‐RF6+6 (6 days of starvation followed by 6 days of re‐feeding); and F‐RF1+2 (1 day of starvation followed by 2 days of re‐feeding). A reduction in body mass between 10.0% (F‐RF1+1) and 24.3% (F‐RF6+6) was found in comparison with the control group after 60 days. As the length of fasting increased, the compensation coefficients in feed intake and weight gain decreased. Body lipid content decreased as fasting cycles increased. Haemoglobin, plasma protein, lysozyme and alkaline phosphatase activities were the most reliable biomarkers for assessing the nutritional condition in sobaity sea bream. A feeding strategy based on 1 day of starvation followed by 2 days of re‐feeding (F‐RF1+2 group) may be advisable for on‐growing sobaity sea bream without reduction in growth and alteration of their haematological and physiological parameters.  相似文献   

15.
We investigated the effect of dietary supplementation with a branched‐chain amino acid (BCAA) mixture (valine, leucine and isoleucine) on juvenile yellowtail (Seriola quinqueradiata) growth and hepatic insulin‐like growth factor (IGF) gene expression. Total dietary BCAA content was 8.1, 8.5, 9.0 and 9.8 g   kg?1 for the control, 0.4%, 1.0% and 2.0% BCAA experimental groups, respectively. Body weight was measured on day 77, after which fish were fasted for 3 days and refed; the livers were then removed 3 or 9 h later for analysis of hepatic gene expression. Body weight significantly increased in the BCAA‐supplemented groups. Hepatic expression of IGF1 and IGF2 significantly increased in the 2% BCAA group at 3 and 9 h after refeeding. In the 1% BCAA group, hepatic IGF1 expression tended to be higher at 9 h than in the control group after refeeding. Also, hepatic IGF2 significantly increased at only 9 h after refeeding in the 1% BCAA group. In conclusion, dietary supplementation with crystalline BCAAs increased growth and hepatic expression of IGF1 and IGF2. These results suggest that dietary crystalline BCAA supplementation would be a valuable addition to yellowtail aquaculture practices.  相似文献   

16.
Under normal farming conditions, shrimp can experience starvation periods attributable to disease outbreaks or adverse environmental conditions. Starvation leads to significant morphological changes in the hepatopancreas (HP), being the main organ for absorption and storage of nutrients. In the literature, limited research has described the effect on the HP of periods of starvation followed by refeeding and none in whiteleg shrimp (Penaeus vannamei) using computer‐assisted image analysis (CAIA). This study describes the effect of starvation and starvation followed by refeeding on the HP of whiteleg shrimp using CAIA. Visiopharm® software was used to quantify the following morphological parameters, measured as ratio to the total tissue area (TLA): total lumen area (TLA:TTA), haemocytic infiltration area in the intertubular spaces (HIA:TTA), B‐cell vacuole area (VBA:TTA), lipid droplet area within R cells (LDA:TTA) and F‐cell area (FCA:TTA). Significant changes were measured for HIA:TTA and LDA:TTA during starvation (increase in HIA:TTA associated with decrease in LDA:TTA) and starvation followed by refeeding (decrease in HIA:TTA associated with increase in LDA:TTA). In the future, HIA:TTA and LDA:TTA have the potential to be used in a pre‐emptive manner to monitor the health of the HP, facilitate early diagnosis of diseases and study the pathophysiology of the organ.  相似文献   

17.
在水温22~26℃条件下,研究了在不同饥饿时间处理后再投喂对白斑狗鱼(Esox lucius)生长性能的影响,试验设置饥饿14、21、28、35、42 d组和正常投喂对照组,各组饥饿结束后恢复正常投饵,在投喂后以7 d为一个生长阶段,比较各处理组的增重率、特定生长率、摄食率、饲料系数,试验周期为56 d。结果显示,随着饥饿时间的延长,白斑狗鱼的总体重损失率呈逐渐升高的趋势,而各饥饿阶段体重损失率呈下降的趋势;各饥饿处理组恢复投喂后的增重率和特定生长率均显著高于对照组(P<0.05),且随饥饿时间的延长而逐渐升高,但在恢复投喂后的第35天,S14组(饥饿14 d组)与对照组无显著性差异(P>0.05);各饥饿处理组恢复投喂后的摄食率随饥饿时间的延长而显著性升高(P<0.05);饵料系数随饥饿时间的延长而逐渐下降,其中在第14天时,S42组(饥饿42 d组)的饵料系数显著高于其他饥饿处理组(P<0.05),与对照组无显著性差异(P>0.05)。在同一饥饿处理组,随着投喂时间的延长,增重率、特定生长率和摄食率均呈显著性下降的趋势(P<0.05),饵料系数呈升高的趋势,其中S14组在第35天时恢复到对照组水平。结果表明:摄食率升高和饵料系数下降是饥饿再投喂白斑狗鱼增重率显著上升的原因,且这种生长倾向随着恢复投喂时间的延长而不断减弱。  相似文献   

18.
朱艺峰  林霞  关文静  陈芝丹 《水产科学》2007,26(11):597-600
试验设3个饥饿处理组和1个对照组,研究花鲈在短期周期性饥饿下的补偿生长。试验结果表明,不同饥饿处理下的花鲈具有部分补偿生长能力,再投喂下的干物质摄食率(FR)显著高于对照组(P<0.0001),但饲料效率(FE)与对照组相比差异不显著(P<0.05),表明花鲈在短期周期性饥饿下的补偿生长通过提高摄食率实现。花鲈在补偿生长期间的生长效率大幅度提高,在投喂时间为对照组50%的条件下,周期性饥饿7 d(SR77)和周期性饥饿2 d(SR22)组平均特定生长率达到对照组的70.0%。  相似文献   

19.
Here, we aimed to study the slow muscle of the fish Piaractus mesopotamicus submitted to 30 days of fasting (D30) followed by 1 day (D31) or 30 days of refeeding (D60). Histological analysis of fibre diameter was performed in D30 and D60. The gene expression of parvalbumin (pvalb), atrogenes (murf1a, murf1b, mafbx) and anabolic genes (igf‐1, mtor) was analysed using RT‐qPCR in D30, D31 and D60. The proteome was obtained by shotgun proteomics at D30 and D60, and the set of differentially expressed proteins was analysed by bioinformatics. In all experiments, the control was regularly fed fish. The histological analysis showed no changes in muscle fibre diameter. The expression of catabolic and anabolic genes was not changed, except for the downregulation of igf‐1 in D30 and of mafbx in D31. The expression of pvalb was not changed in D30 and D60 but was decreased in D31. The proteomic analysis identified 169 proteins in D30 (24 upregulated and 18 downregulated) and 170 proteins in D60 (17 upregulated and 21 downregulated); many of them were related to energetic metabolism and intracellular Ca2+ homoeostasis. Overall, our results indicate that the slow‐twitch muscle presented few changes upon prolonged fasting and refeeding condition.  相似文献   

20.
The synthesis of vitellogenin (Vg) is induced by conspecific Vg (Vg1 and Vg2) and estradiol‐17β (E2) as demonstrated by the pattern of 3H‐serine incorporation in the liver and plasma proteins. The incorporation studies indicated that the label was first incorporated into the liver after which it appeared in the blood in both E2‐ and Vg‐treated male catfish. Since Vg was capable of inducing its own synthesis, experiments were conducted in females during preparatory–prespawning period (March–May) to make them gravid by implanting Vg pellets. Two implantations of 4 mg Vg1 pellets into female catfish with an interval of 15 days, followed by laboratory maintenance for 45 days of initial implantation showed a significant increment in ovarian weight with concomitant formation of yolky oocytes through synthesis and incorporation of Vg, whereas Vg2 implantation was not effective in this regard. Histological observation of yolky oocytes in Vg1‐treated group showed the peripheral migration of germinal vesicle (eccentric germinal vesicle), which indicates the onset of maturation. On 45th day, third implantation with 2 mg Vg pellets was performed and after 15 days, fish were hormonally induced with a single injection of hCG (2,000 IU/kg fish). Six groups were considered such as initial control, BSA‐implanted control, Vg1‐implanted, Vg2‐implanted, catfish collected from the field on the last day of the experiment and catfish collected during spawning period in this experiment with 3–7 fish in each group. Each of the experimental fish was sexually mature and the body weight was between 100 and 125 g. The percentage of ovulation and fertilization in the eggs of Vg1‐implanted group was 91% and 78%, respectively, which was almost similar to that of gravid female catfish collected during breeding period (July). The breeding performance in BSA‐ and Vg2‐treated females was very poor. The fertilized eggs were hatched in the laboratory conditions. Thus, in the female catfish, Vg1 not only induces vitellogenesis but also makes the oocytes viable for fertilization.  相似文献   

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