饥饿对小规格斑点叉尾鮰体重及鱼体生化组成的影响

EFFECTS OF STARVATI ON ON BODY W EIGHT AND BODY COM POSITI ON OF SMALL2SIZED CHANNEL CATFISH ICTALURUS PUNCTATUS

  • 摘要: 将180尾初始体重为(41.9±0.5)g的斑点叉尾鮰放养于18个室内容积为300L的水族箱中进行饥饿处理12周,每箱放10尾,每2周取样一次,研究长期饥饿胁迫下小规格斑点叉尾鮰生长和鱼体生化组成的变化,尤其是肌肉氨基酸和脂肪酸组成的变化.实验结果表明:斑点叉尾鮰的体重、肥满度、脏体比、肝体比和脂体比随着饥饿时间的延长显著降低(pppp>0.05),而6周后显著降低(pppppp>0.05),而总的必需氨基酸和总的非必需氨基酸的比值显著增加(pppp<0.05).以上结果说明:小规格斑点叉尾鮰在饥饿条件下优先动用机体的贮存性物质(脂肪和糖原)作为能源的供给物,而后才被迫动用组织或器官中的功能性物质蛋白质;长期饥饿胁迫下斑点叉尾鮰优先保留必需氨基酸及EPA、DHA等高度不饱和脂肪酸.

     

    Abstract: A decrease in food availability duringwinter forces fish species from temperate regions to undergo a natural but prolonged starvation1To survive these regularly occurring periods of food limitation, fish must subsist bymobilizing the ma-terials present in their tissues1Fish have diverse strategies to dealwith periods of food deprivation, consisting of decreasing locomotor and metabolic activities,modifying tissue metabolic capacities and degradingmuscle protein1The findings of star-vation studies can be used to determine the nutrientsmost critical as energy reserves and accordingly permit a better under-standing of fish physiology and nutrient metabolism1Channel catfish Ictalurus punctatus, amongst other things, originally native to stateswithin theMississippiValley and those along the Gulf ofMexico,were introduced to China in 1984 and now become one of the major freshwater cultured fish species in the country1During overwintering, channel catfish is adapated to mobilize body constituents and survive extensive feed deprivation, leading to considerable fluctuations in energetic sta-tus1The effects of feed restrictions (including starvation) on growth, hepatosomatic index (HSI), visceral fat levels and processing yield of channel catfish have been reported by several authors1However, little is available on effect of long-term starvation on body composition in small-sized channel catfish, especially on both amino acid and fatty acids changes consid-ered together1Thus, the present study investigated the effects of starvation on the growth and compositional changes in small-sized channel catfish Ictalurus punctatus (initial mean weight: 4119 ?015,Mean ?S1D1) starved in indoor circular fiberglass aquarium for 1-weeks,with special emphasis on amino acid and fatty acid changes1Sampleswere collected at an interval of-weeks, and bodyweight,morphometrical parameters, body composition, amino acid and fatty acids composition both in muscle and liver were determined1Starvation significantly reduced body weight, condition factor (CF), visceroso-matic index (VSI), HSI and intraperitoneal index (IPF) (p p p p p p p p protein) as energy; EAA and highly-unsaturated fatty acids (HUFA, especially EPA and DHA) were preferentially restored1The present information provided an indication of impact of starvation on bodyweight and identified the nutrients catabolised and conserved in the face of increasing food starvation, and will assist in the development of the formulated diet for juvenile channel catfish I1punctatus

     

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