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1.
Juvenile white sturgeon (Acipenser transmontanus, Richardson) were fed or starved for 4 weeks, and their whole body amino acid composition determined at the beginning and the end of the study. The amino acid compositions of muscle, liver, gill and gastrointestinal tract, and the free amino acids in plasma of fed and starved fish were also determined. Very little variation was observed in the amino acid compositions of all the tissues examined after starvation. However, the plasma free amino acids were significantly (P < 0.05) decreased following starvation. On the basis of the amino acid composition and nitrogen retention values of the whole fish, daily indispensable amino acid requirements for protein accretion and obligatory nitrogen losses (mg amino acid 100 g body weighr?1 day?1) were estimated. The pattern of indispensable amino acids required for each of these is different, with the pattern for protein accretion containing much higher levels of lysine, but lower levels of tryptophan and sulfur amino acids. Individual amino acid retention rates varied from 33.3% of dietary tryptophan to 80.2% for arginine. The estimated dietary indispensable amino acid pattern for young growing white sturgeon (expressed as a percentage of total indispensable amino acids plus cystine and tyrosine) is: arginine, 14.0; histidine, 6.6; isoleucine, 8.8; leucine, 12.5; lysine, 15.8; methionine (plus cystine), 6.6; phenylalanine (plus tyrosine), 15.5; threonine, 9.7; tryptophan, 0.8; and valine, 9.7.  相似文献   

2.
Abstract –  We measured growth of pike larvae ( Esox lucius ) fed with freshwater and brackish-water zooplankton by monitoring larval wet weight during 18 days. The fish food was analysed for species composition, carbon, nitrogen and fatty acids. Further, we analysed fish larval faecal pellet production. Larval weight was significantly higher in fresh water than in brackish water with natural zooplankton as food. Growth, given as wet weight, showed a significant relationship with zooplankton (>100  μ m) food carbon and highly unsaturated fatty acids, 20:5ω3, 22:6ω3, ω6 fatty acids and the ω3/ω6 fatty acid ratio. Phytoplankton fatty acids (10–50  μ m), such as polyunsaturated fatty acids, 20:5ω3, 22:6ω3 and the ω3 fatty acids also correlated strongly with the wet weight of pike larvae. We demonstrated that several factors impact on pike larval growth.  相似文献   

3.
Amino acids are the building blocks for growth and the major energy source during fish larval stages. Deficient amino acids can be supplemented in the diets, overcoming problems such as low growth rates and skeletal deformities. In this study, three experimental diets were tested: a balance diet supplemented with lysine, a balance diet supplemented with tryptophan and a control with no supplementation. Trials were conducted with Diplodus sargus larvae from 1 to 25 days after hatching (DAH). A microencapsulated diet was introduced at 15 DAH in co-feeding with live feed and from 20 DAH larvae were fed only this diet. The effect of the supplemented diets was assessed in terms of survival, growth rate, skeletal deformities, ammonia excretion and activity of amino acid catabolism enzymes. The results showed a similar survival in all treatments. However, larvae given tryptophan supplementation had a lower weight on 25 DAH. No significant differences were found in ammonia excretion, frequency or type of deformities or enzymatic activity. Tryptophan and lysine supplementation failed to improve larval growth, survival or larval quality.  相似文献   

4.
The requirements of juvenile prawn, Marsupenaeus japonicus (Bate), 0.79 g initial body weight, for essential amino acids (EAA) were evaluated based on the daily increase of each EAA in the whole body when the prawn was maintained on a diet with a high nutritive value (a casein‐squid protein‐based diet). The quantities of each EAA needed daily for growth and maintenance of prawn are conceived to correspond to the daily requirements of this prawn species for EAA. Therefore, these requirement values of respective EAA should be supplied from dietary proteins. To determine these values, protein and amino acids of the whole body of the prawn were quantified before and after feeding experiments, and the quantities of respective EAA needed to meet the requirements were estimated based on the EAA profile of the whole body protein of prawn. As a result, the contents of EAA in dietary proteins (%) needed to meet the requirements of the prawn for EAA were assessed to be: threonine (2.3), methionine (1.3), valine (2.4), isoleucine (2.3), leucine (3.4), phenylalanine (2.6), lysine (3.2), histidine (1.1), arginine (2.9) and tryptophan (0.6), respectively, when the prawn are fed 50% protein diet with 90% protein digestibility at a ration size of 2% (% of body weight).  相似文献   

5.
Nutritional efficacy of fairy shrimp (Streptocephalus sirindhornae) nauplii, as a live food, was studied for growth performance and survival rate of giant freshwater prawn (Macrobrachium rosenbergii) postlarvae. A feeding experiment was designed with four different feeds: dry commercial feed, fairy shrimp nauplii, Artemia sp. nauplii and adult Moina macrocopa. Results from the nutritional composition revealed that fairy shrimp nauplii had protein and lipid contents of 54.58 ± 2.8 g kg?1 and 255 ± 2.8 g kg?1, respectively. The highest value for an individual amino acid in fairy shrimp was lysine (140.7 ± 1.6 g kg?1). The essential amino acids content in the whole body of the larval prawns was in the range of 66.7–67.5 g kg?1. Fairy shrimp nauplii had the highest essential amino acid ratio (A/E) of lysine, similarly, in musculature of prawn larvae. Weight gain and specific growth rate of the postlarvae fed with fairy shrimp nauplii were significantly higher than those fed with Artemia nauplii, adult Moina and dry commercial feed. The presented results suggest that S. sirindhornae nauplii can be used as a nutritionally adequate food for freshwater prawn M. rosenbergii postlarvae.  相似文献   

6.
Metamorphosing leptocephalous larvae of the bonefish (Albula sp.) were analyzed for total ninhydrinpositive substances (NPS) and free amino acids. Total NPS content showed little change during metamorphosis. The average NPS value (±S.E.) for 16 larvae was 1.8 (±0.1) mg×larva–1, which represents approximately 4% and 8% of the total dry weight of early and advanced larvae, respectively. Taurine was the most abundant free amino acid in whole-larva extracts, accounting for 36% and 59% of the total by weight in early and advanced larvae, respectively. The essential amino acids, leucine, isoleucine, phenylalanine, histidine, valine, methionine, lysine and arginine, accounted for about half (47%) of the total in early larvae but were reduced to about 23% of the total in advanced larvae. All of the component essential amino acids decreased during metamorphosis, but the greatest effect was seen with the first five. The remaining non-essential amino acids comprised less than 20% of the total in early larvae and, although the overall value changed little during metamorphosis, certain components such as glycine and glutamic acid showed large increases whereas others such as tyrosine and serine were reduced. Increases in amino acid content after acid hydrolysis of whole-larva extracts indicated that trichloroacetic acid-soluble, low molecular weight peptides were present in both early and advanced leptocephali.  相似文献   

7.
摘要:为了给华鲮种质资源的开发利用及人工养殖提供依据,对在池塘人工养殖的华鲮含肉率及肌肉营养成分进行测定,结果表明:含肉率为60.65％;肌肉中蛋白质、脂肪和灰分含量分别为19.99％、5.10％、1.51％;肌肉中18种常见氨基酸总含量(占肌肉干重)为75.23％。其中必需氨基酸含量为33.36％,占氨基酸总量的44.34％。必需氨基酸与非必需氨基酸含量的比值为0.80。鲜昧氨基酸含量为30.07％,占氨基酸总量的37.40％。必需氨基酸指数（WH0／FAO标准为参照）为82.34。色氨酸为第1限制性氨基酸,蛋氨酸+胱氨酸为第2限制性氨基酸。  相似文献   

8.
Abstract.— Quantitative changes in the protein, lipid and carbohydrate were studied in the early larval stages of developing freshwater prawn Macrobrachium rosenbergii reared under fed and starved conditions to understand the relative importance of these nutrients in energy metabolism of the growing larvae. Larvae obtained from several females were stocked into three 250-L tanks at a density of 30 larvae/L. The feeding regime consisted of newly hatched Artemia nauplii. Protein was always the major organic constituent followed by lipids and then carbohydrates of both fed and starved larvae. Protein levels of both fed and starved larvae increased during development, suggesting an important role in morphogenesis. The decline of lipid during the larval growth that was more rapid for starved larvae, suggests a probable utilization of lipid as the major metabolic source of energy. Carbohydrates formed less than 5 and 2.4% of the larval dry weight of fed and starved larvae, respectively, suggesting their limited role in larval metabolism.  相似文献   

9.
克氏原螯虾幼体发育时期消化酶活力及氨基酸含量研究   总被引：3，自引：1，他引：2  
采用生物化学方法对克氏原螯虾各期幼体消化酶活力与氨基酸组成进行了分析。实验结果显示,在克氏原螯虾幼体发育过程中,五种消化酶活力(胃蛋白酶、类胰蛋白酶、淀粉酶、纤维素酶和脂肪酶)表现出两种变化模式:胃蛋白酶和类胰蛋白酶在幼体发育Ⅱ龄幼体期和Ⅳ龄幼体期活力较高,其中Ⅳ龄幼体期该两种酶活力最高;淀粉酶、纤维素酶和脂肪酶活力为先增高后降低,在Ⅲ龄幼体期,三种酶的活力达到最高,但与Ⅳ龄幼体期的酶活力比较无显著差异。总氨基酸含量在幼体发育早期逐渐降低,幼体发育至Ⅲ龄幼体期,其氨基酸含量最低,Ⅳ龄幼体期又有所增加。在测定的所有氨基酸中谷氨酸含量最高,必需氨基酸中赖氨酸含量最高,单个必需氨基酸含量与必需氨基酸总量的比值(A/E)在整个胚胎发育过程中的变化趋于一致。  相似文献   

10.
Content of total and free amino acids in zooplanktonic food of fish larvae   总被引：3，自引：0，他引：3  
The content of total and free amino acids in freshwater planktonic rotifers (Brachionus sp.), copepods (Eudiaptomus zachariasi) and groups of Daphnia pulex, Ceriodaphnia sp. and copepodites (Cyclops strenuus) of different sizes was determined. The amino acid content of Artemia salina nauplii on hatching and during fasting was also determined.

Amino acid content was lowest in rotifers and highest in stage III–IV copepodites. The major free amino acids in Cyclops strenuus dry matter were 1.43% arginine, 0.22% histidine, 0.20% alanine, 0.15% glutamic acid and 0.11% lysine. Free arginine content decreased in the daphnids as they increased in size. The content of all free amino acids in fasting Artemia nauplii was lower than in the freshwater zooplankters. The major free amino acids in nauplii were 0.55% proline, 0.41% alanine, 0.34% glycine and 0.37% serine. The content of most free amino acids in nauplii decreased during fasting. The significance of the results are discussed in relation to essential amino acid requirements of fish, and nutrition of fish larvae without fully developed gastrointestinal systems.  相似文献   


11.
The indispensable AA profile of fish carcass has been commonly used as a good indicator of fish amino acids requirements. Amino acid composition of the whole body tissue of Diplodus sargus was determined for the larval ages of 0, 2, 5, 8, 12, 17, 25, 35 and 45 days after hatching (DAH). No significant differences were found during this species ontogeny, except for phenylalanine. A comparative analysis of amino acid profiles from larvae and respective diet was performed. Low correlation was found to rotifers (R2 approximately 0.5), while higher correlations were found for Artemia nauplli, metanauplii (R2 approximately 0.8) as well as for the dry feed. These results suggest that D. sargus are subjected to higher nutritional imbalances during the first 10 days of feeding when larvae are fed on rotifers alone. Arginine, threonine, lysine, cysteine and histidine appeared to be limiting amino acids at 2, 12, 25 and 45 DAH, respectively. Similar results were reported in literature for Sparus aurata and Solea senegalensis, although D. sargus diets seem to have more amino acids in deficiency as well as more severe differences between larval and diet amino acid profiles. To solve these apparent nutritional imbalances, amino acid supplementation should be considered. The use of inert diets in early larvae ages seems to be most adequate as live feed supplementation appears to be more difficult.  相似文献   

12.
Live hatchery feeds were assayed for fatty acids (FA), amino acids (AA), and their ability to support growth and survival of larval and postlarval mahimahi Coryphaena hippurus at two different hatchery stages. Euterpina acuritrons copepods (C), mahimahi yolk-sac larvae (YSL), Artemia parthenogenica brine shrimp nauplii (BSn), A. parthenogenica juveniles (BSj), and Brachionus plicatilis rotifers (R) were assayed, using several enrichment media. There was little difference in AAs among feeds.
Levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were about 10 times higher in YSL than in their feeds. This explains previous findings where first stage larval survival (0–9 days) was not affected by feed HUFA levels. Second stage survival was significantly higher when larvae were fed copepods. Enrichment with 100 ppm SuperSelco greatly improved the survival of larvae that were fed brine shrimp. The even higher omega-3 fatty acids found in copepods appear to be important for survival of larvae under more stressful conditions.
Brine shrimp juveniles enriched with SuperSelco are a good food for postlarval mahimahi. Yolksac larvae of mahimahi are an even better food, promoting faster growth at less cost, for large scale mahimahi aquaculturists. Different batches of yolksac mahimahi larvae varied by a factor of 10 in their concentration of DHA, but always had the highest level of DHA as much as 40% of total fatty acids (FAs). These "high HUFA" batches of YSL also had the highest levels of EPA and total fatty acids. The data suggest that climate and broodstock age may have considerable influence on larval nutrition.  相似文献   

13.
We sought the source of gram-negative bacteria associated with giant freshwater prawns in a hatchery that was previously observed with severe mortality of prawn larvae during the sixth to seventh zoea stages. After thorough disinfection, the gram-negative bacterial microflora of broodstock, larvae, larval rearing tank (LRT) water, and other intake systems were examined for bacteria. Enterobacteriaceae and Vibrio were the major bacteria isolated from the larvae. The present study suggests that Enterobacteriaceae may be introduced via the broodstock and Vibrio via the LRT water.  相似文献   

14.
Free amino acids (FAA) are used principally as substrate in protein synthesis and the source of energy in aerobic catabolism. In marine fish, embryo and larvae FAA are used to maintain body fluid osmolality during fish early development. However, there is essentially no information about FAA concentrations in early ontogeny of freshwater neotropical species in comparison to marine fishes. Therefore, the aim of this study was to evaluate the FAA concentrations in pacu, Piaractus mesopotamicus, eggs and larvae. Broodstock fish were induced to spawn and ovulated females were stripped of their eggs and immediately sampled for analysis. Larvae were sampled right after hatching (HL) and after the completion of the yolk‐sac absorption (YSA). The wet weight of the HL and YSA larvae amounted to 0.5 ± 0.1 mg and 1.1 ± 0.3 mg, respectively. HL larvae showed higher levels of most of the indispensable amino acids (IAA) in comparison to eggs and YSA larvae. Exceptions were observed with His and Trp that showed higher or similar levels, respectively, in YSA larvae. The FAA Orn, Tau, Glu, Gln, Gly, and Tyr increased concentrations in both larval stages while that of Tau was found in higher concentration in all analyzed stages. Also, the concentrations of Asn, Ala, Pro, Ser, and Asp were higher in HL larvae. Both larval stages displayed a rise in total free IAA/total free DAA (dispensable amino acids) ratio. The authors conclude that the highest level of FAA in HL pacu larvae is indicative of active proteolysis of yolk reserves and a probable catabolism regulation of some FAA through spare‐effect. In addition, Tau is one of the major FAA occurring during pacu ontogeny and may be performing regulation on body fluid osmolality regulation .  相似文献   

15.
Lipid Nutrition and Feeding of Cobia Rachycentron canadum Larvae   总被引：3，自引：0，他引：3  
This study examined the fatty acid composition of cobia Rachycentron canadum eggs and yolksac larvae, as well as the ovaries of wild caught females as an initial guide to lipid nutritional requirements. A 2-wk feeding study also was conducted to investigate the effectiveness of four dietary treatments on the growth and survival of cobia larvae. Cobia eggs in the tailbud stage contained 31.4 ± 1.3 μg lipid/egg. After hatching, the amount of lipid decreased significantly (P < 0.05) from 28.3 ± 0.3 to 23.2 ± 0.1 μg lipid/larvae during the yolksac larval stage (days 1 to 3 after hatching). Ovaries from wild caught adults and captive spawned eggs and yolksac larvae contained high levels of PUFAs with docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA) accounting for approximately 80% of the total suggesting that cobia larvae may have a high dietary requirement for these fatty acids. For the feeding study, larvae were fed: 1) Artemia only; 2) enriched rotifers for 1 d only + microparticulate diet (day 313); 3) enriched rotifers for 3 d (day 3–5) + Artemia (day 3–13); and 4) enriched rotifers for 6 d (day 3–8) + Artemia (day 3–13). Cobia larvae began feeding on rotifers 3 d after hatching and on newly hatched Artemia nauplii by the fifth day following the onset of exogenous feeding (day 7). On day 7, no differences in larval growth were found among larvae fed rotifers for 3 versus 6 d, whereas larvae fed only Artemia or rotifers for I d followed by microparticulate diet were significantly smaller (P < 0.05) and did not survive beyond day 9 and 13, respectively. The results of the feeding study indicate that cobia larvae require rotifers for a minimum of 4 d following the onset of exogenous feeding.  相似文献   

16.
为研究杂交青虾"太湖1号"在滨海型盐碱水域养殖条件下的营养特点,采用常规生化成分测定法测定了该杂交青虾肌肉中的营养成分,并与野生青虾的肌肉营养成分进行比较。结果显示:杂交青虾肌肉(鲜重)中蛋白质、脂肪、灰分、水分的含量分别为16.774%、0.927%、1.173%、81.367%;肌肉中共检测出18种氨基酸(总量为85.680%,干重),其中8种必需氨基酸占31.024%;肌肉中含12种脂肪酸,其中二十碳五烯酸(EPA)与二十二碳六烯酸(DHA)含量较高,两者含量之和为1.247%,多不饱和脂肪酸(PUFA)含量为1.753%;矿物元素种类丰富,常量元素中,钾含量最高(12.420 mg/g),微量元素中,锌含量最高(59.673μg/g)。研究发现,杂交青虾"太湖1号"蛋白含量显著低于野生青虾(P0.05),脂肪、EPA+DHA含量极显著高于野生青虾(P0.01),氨基酸总量、非必需氨基酸总量、鲜味氨基酸总量与野生青虾无显著差异(P0.05),必需氨基酸总量显著低于野生青虾(P0.05),但两者氨基酸结构均符合FAO/WHO的标准要求。研究表明:滨海型盐碱水域养殖条件下的杂交青虾"太湖1号"氨基酸组成平衡,微量元素丰富,具有较高的营养价值。  相似文献   

17.
The effects of increasing levels of dietaryphospholipids (PL) on the reproductive performance,egg and larval quality, and lipid composition offemales of the freshwater prawn Macrobrachiumrosenbergii were investigated. Three isolipidic dietscontaining similar amounts of highly unsaturated fattyacids but varying levels of PL (0.8, 2.4 and 4.6%)were fed during 180 days to three groups of eightfemales originating from Thai ponds. No significantdifferences were observed for fecundity, egg size andhatchability, starved larvae size, and size, survivaland tolerance to stress of 8 day-old larvae.Similarly, no major differences in the lipidcomposition of the midgut gland, ovaries and muscletissue of females could be detected. Results indicatethe lack of need of dietary supplementation of PL forM. rosenbergii broodstock, as previouslyreported for earlier life stages. It is suggested thatthe basal level of 0.8% dietary PL was sufficient tomeet the dietary demands of the prawn broodstock. ThePL requirements of M. rosenbergii broodstock, ifany, may be satisfied in commercial feeds through theinclusion of ingredients containing some phospholipidsendogenously.  相似文献   

18.
Abstract— The purpose of this study was to examine the effect of varying dietary levels of highly unsaturated fatty acids (HUFA) in Live prey on the standard length, specific growth rate, survival, and fatty acid composition of yellowtail snapper Ocyurus chrysurus larvae. Two experiments were conducted utilizing rotifers and Artemiu enriched with live algae ( Isochrysis galbana or Nannochloris oculata ) or commercial preparations (Aquagrow Advantage, Aquagrow Advantage plus Aquagrow arachidonic acid, and Algarnac 2000). Larval growth and fatty acid composition were evaluated during the rotifer, B rachionus plicatilis , and Artemia feeding periods and survival rates were calculated at the termination of each trial (18 or 20 d after hatching). In general, prey enriched with the commercial products contained higher levels of docosahexaenoic acid, eicosapentaenoic acid, n-3 HUFA, and × HUFA than those enriched with live algae. The addition of arachidonic acid to the Aquagrow Advantage enrichment medium significantly increased the amount of this fatty acid in rotifers but not in Artemia . At the end of the growth trials, larval standard length was highest when larvae were fed prey enriched with I. galbanu (6.4 mm) or commercial preparations (6.7–7.1 mm) versus N. oculatu (5.2 mm). Furthermore, larvae fed prey enriched with commercial preparations had significantly ( P < 0.05) higher survival rates (2.2-5.9%) than those fed prey enriched with live algae (1.1-1.4%). These results suggest that yellowtail snapper larvae require dietary levels of HUFA beyond those achieved by enriching prey with live N. oculata or I. galbana  相似文献   

19.
Use of egg custard augmented with cod liver oil (CLO) fed during the day, and of an overnight feed with Moina micrura, were evaluated in terms of its effects on production of freshwater prawn (Macrobrachium rosenbergii) postlarvae (PL). Four levels of CLO (0, 1,3 and 5%) were tested. Significantly higher mean (sd) productions, ranging from 11.27 (1.16) to 13.02 (1.70) PL l–1, were obtained for larvae fed egg custard enriched with CLO compared with that of 7.83 (1.58) PLl–1 for larvae fed egg custard without CLO. The development and survival of larval stages were also higher for the CLO diets. The -3 highly unsaturated fatty acid (HUFA) in egg custard increased with increasing CLO level (0–5%). The fatty acid composition of postlarvae reflected the composition of the diet.  相似文献   

20.
This study was performed to assess the nutritional value of Streptocephalus dichotomus nauplii and compared with standard larval diet and parthenogenetic strain of Artemia nauplii. The effectiveness of live feed was determined by feeding freshwater prawn Macrobrachium rosenbergii postlarvae. Results on the growth rate, weight gain, survival, fatty acid and amino acid composition show a significant variation between the dietary treatments. Mean larval growth was significantly different ( P  < 0.001) between control diet (13.5 ± 0.5 mm) and live feeds ( Streptocephalus nauplii; 18.4 ± 0.5 mm and Artemia nauplii 18.7 ± 0.2 mm). The weight of larvae-fed Streptocephalus (41.1 ± 1.44 mg) and Artemia nauplii (41.7 ± 0.2 mg) was not significantly different; however, treatment with live feeds was significantly higher than the control (16.3 ± 0.5 mg) ( P  < 0.001). Proximate composition on the fairy shrimp reveals that they are rich in protein, lipid, essential amino acids (EAA) and essential fatty acids (EFA). The polyenoic unsaturated fatty acid (18 : 2 n-6 and 18 : 3 n-3) and highly unsaturated fatty acid (20 : 4 n-3 and 20 : 5 n-3) show a dramatic increase in larval tissue relative to its proportional composition in the live diets. Amino acid composition in the live feeds, Streptocephalus and Artemia nauplii, perfectly reflects on the amino acid proportions in the larvae-fed diets which confirm its utilization.  相似文献   

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