首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 718 毫秒
1.
Three different life stages of spiny lobster larvae (phyllosoma) of Panulirus homarus were fed A1‐Selco‐enriched Artemia in two culture treatments, one with the microalgae Nannochloropsis salina (green water) and the other without the microalgae (clear water) to assess the ability to manipulate their fatty acid composition. Phyllosoma fed with 3‐h A1‐Selco‐enriched Artemia salina attained Stage VIII (5.3 mm) and Stage V (3.4 mm) in 42 days in the green and clear water treatments respectively. The higher content of the essential fatty acids in N. salina (eicosapentaenoic acid, 25.8%; arachidonic acid, 9.5%; and docosahexaenoic acid, 4.2%) in the green water system increased the fatty acid content of the live food Artemia, and ultimately the phyllosoma. In spite of phyllosoma being fed with enriched Artemia in the clear water system, the total polyunsaturated fatty acid content of the early (Stages I–III) and mid stage (Stages IV–V) phyllosoma were significantly smaller (18.8% and 14.6% respectively) (P<0.05) than in the green water system (25.3% and 21.2% respectively). These results indicate the positive role of the microalgae in boosting the essential fatty acid content of lobster larvae.  相似文献   

2.
Newly hatched Jasus edwardsii phyllosoma were fed unenriched Artemia [endogenous ascorbic acid (AA) concentration of 166 μg g?1 dry weight (dw)], Artemia supplemented with algae (AA concentration 594 μg g?1 dw) or with ascorbyl‐2‐polyphosphate (A2P) (AA concentration 11 737 μg g?1 dw) to examine possible benefits of AA enhancement on culture. Plain or algal‐enriched Artemia were fed continuously for 28 days in two treatments during the study. Four other treatments received A2P‐enriched Artemia on a progressive basis starting from the commencement of the trial (D‐0), the third (D‐3), sixth (D‐6) or ninth day (D‐9) of Stage I (14 days) and similarly during Stage II (14 days). Prior to the commencement of A2P supplementation, plain Artemia were supplied to these animals. By Stage III (28 days feeding), algal, D‐0 and D‐3 phyllosoma had attained the largest size. The uptake and retention of AA by Stage III phyllosoma appeared to be dose‐dependent with the highest concentration of AA incorporation evident in D‐0 phyllosoma (1816 μg g?1 dw), while algal and plain phyllosoma contained the lowest concentrations (600 and 300 μg g?1 dw, respectively). Survival at Stage III was highest in D‐0 phyllosoma (89%) and lowest in plain phyllosoma (51%). There was a positive relationship between phyllosoma AA concentration and larval survival (R2 = 0.8328, P < 0.0001). D‐0 phyllosoma had the lowest stress index when subjected to an osmotic/temperature activity test, indicative of better survival in culture compared to plain, algal and D‐9 phyllosoma, which had consistently higher indices. A negative relationship existed between phyllosoma AA concentration and stress indices at Stage III (R2 = 0.9263, P < 0.0001), suggesting that AA from the Artemia diet conferred stress resistance.  相似文献   

3.
Western rock lobster, Panulirus cygnus, phyllosoma were grown from hatching to stage IV. Larvae were fed with Artemia enriched with a (i) base enrichment (Base) containing 520 g kg?1 squid oil or tailor made enrichments in which oils high in polyunsaturated fatty acid (PUFA) have been added at the expense of squid oil. These treatments were (ii) base enrichment supplemented with docosahexaenoic acid (DHA) rich oil, (iii) base enrichment supplemented with arachidonic acid (AA) rich oil, or (iv) base enrichment supplemented with DHA and AA (D + A) rich oils. Total survival of phyllosoma to stage IV was high, with no significant difference between treatments (range 12.3–17.5%). By stage IV, the larvae fed the DHA or AA enriched Artemia were significantly larger (3.33 mm length) than larvae fed the Base or D + A enriched Artemia (3.18–3.24 mm length). Phyllosoma were sampled at stages II and III for biochemical analysis. The major lipid class (LC) in all phyllosoma was polar lipid (PL) (88.9–92.4%), followed by sterol (ST) (6.2–9.7%). Triacylglycerol (TAG), free fatty acid (FFA) and hydrocarbon/wax ester were minor components (≤1%) in all phyllosoma samples. In contrast, the major LC in all enrichments and enriched Artemia was TAG (76.3–85.1% and 53.4–60.2%, respectively), followed by PL (11.4–14.8% and 30.6–38.1% respectively). The main fatty acids (FA) in phyllosoma were 16:0, 18:1n‐9, 18:1n‐7, 18:0, AA, eicosapentaenoic acid (EPA) and DHA. Addition of AA, and to a lesser extent DHA, to enrichments resulted in increased levels of those FA in Artemia and phyllosoma compared with the Base enrichment. This was particularly evident for stage III larvae. Comparatively, elevated growth for phyllosoma to stage IV was achieved with DHA and AA enriched diets. Our findings highlight the importance of lipids and in particular essential long‐chain PUFA, as nutritional components for phyllosoma diets.  相似文献   

4.
The arachidonic acid (20:4n-6,AA) requirements of larval summer flounder weredetermined for the rotifer- and Artemia-feeding stages. Experimental emulsionscontained adequate n-3 highly unsaturated fattyacid (HUFA) ratios and emulsion levels of AAwere set at 0, 3, 6, 9, and 12% (AA0, AA3,AA6, AA9, and AA12). Examination of fatty acidlevels in live feeds and larval tissuesconfirmed the physiological incorporation offatty acids relative to dietary levels. In thefirst experiment, survival, growth, andsalinity tolerance (2-h in 70) were measuredat 18 days after hatch (dah) after feeding thelarvae the various levels of AA. Larvae fedAA6-enriched rotifers were better able tosurvive the salinity tolerance test. AAenrichment up to 12% had no effect on growthand survival. In the second experiment, larvaewere fed AA0- or AA6-enriched rotifers until 23dah, followed by unenriched 24- and 48-h Artemia nauplii until 32 dah. These larvaethen were subdivided and fed AA-enriched Artemia from 33-45 dah. At the end of thisexperiment, larvae fed AA6-enriched rotifershad higher survival, increased growth, andsurvived better in the salinity tolerance test(2-h in 80). The enrichment of Artemiadid not have any effect on these variables.Thus, the provision of AA6-enriched rotifers(10 mg AA g–1 DW) early in larvaldevelopment may serve to enhance larval stresstolerance at the rotifer stage while alsoincreasing larval survival, growth, and stresstolerance later in the Artemia stage.  相似文献   

5.
Fatty acid analyses were conducted on newly hatched and 8‐day‐old‐starved and fed Stage I phyllosoma larvae of the spiny lobster, Jasus edwardsii. Fed animals were offered excess 1.5 mm juvenile Artemia (enriched using the alga Isochrysis galbana, Tahitian isolate, T. iso.). After 8 days, there were significant increases in larval dry weight and the proportion of lipid in fed phyllosoma, whereas these parameters decreased in starved phyllosoma. The abundance of the saturated fatty acids 16 : 0 and 18 : 0 increased in both starved and fed phyllosoma, whereas the main monounsaturated fatty acids 16 : 1n‐7, 18 : 1n‐9 and 18 : 1n‐7 increased with feeding but decreased with starvation. There were no significant differences in the relative proportions of the highly unsaturated fatty acids (HUFAs) arachidonic (AA, 20 : 4n‐6), eicosapentaenoic (EPA, 20 : 5n‐3) and docosahexanoic (DHA, 22 : 6n‐3) acids between newly hatched and starved animals, whereas quantitatively DHA decreased with starvation and feeding. The DHA/EPA ratio was significantly lower in the starved and fed phyllosoma (0.5) compared with that found in the newly hatched phyllosoma (0.9). The lipid profiles of the newly hatched, starved and fed phyllosoma contained large amounts of n‐6 fatty acids resulting in low n‐3 : n‐6 ratios (2.8, 2.7 and 1.6 respectively). The importance of these results and the ability of enriched Artemia to provide a suitable fatty acid profile for this species are discussed.  相似文献   

6.
To determine the optimum time at which to wean Scylla serrata larvae from rotifers onto Artemia two experiments were conducted, approximately 1 month apart, using larvae from two different female crabs. In the first experiment, the larvae in three treatment groups, with nine replicates each, were fed rotifers for the first 8 days after hatching. Artemia were introduced on days after hatch (DAH) 0 – during the first zoeal instar (treatment R + A); on DAH 4 – during the second zoeal instar (treatment R4A); on DAH 8 – during the third zoeal instar (treatment R8A). In a control (ROT) larvae were fed with rotifers exclusively for 18 days until the completion of metamorphosis to megalopa. In the second experiment, the same four feeding schedules as in experiment 1 were used with an additional group of larvae (treatment AC) that were fed only on Artemia throughout the rearing period. Similar results were recorded in the two experiments. Larvae in treatments R + A and R4A performed significantly better than those in treatments R8A, ROT and AC. This was particularly evident when examining the proportion of zoeae which successfully completed metamorphosis to megalopa. Poor performance of larvae in treatments AC and ROT implied that rotifers are needed as a first food, but that rotifers alone do not fill the nutritional requirements of S. serrata larvae. Poor performance of larvae in treatment R8A suggested that the diet should be supplemented with Artemia before the end of the zoea 3 stage.  相似文献   

7.
The use of dried Artemia biomass meal as an exclusive feed for postlarval white shrimp (Litopenaeus vannamei) was compared with four commercial feeds and three crustacean meals in a series of trials. Postlarvae (PL1–PL6) were stocked at a density of 1.5–2.5/litres in 16 tanks (100 litres volume) and fed, ad libidum, five times a day, over 23–29 days. Feeding postlarval shrimp with dried Artemia biomass resulted in a significantly larger size than feeding with three of the commercial feeds, and the crustacean meals. There was no significant size difference observed in animals fed with Artemia biomass and the commercial 'Golden Pearls' feed for postlarvae, however the coefficient of variation among the size of the 'Golden Pearls' fed animals was significantly higher. The weight increase of animals fed with Artemia biomass was higher than in animals fed with all the tested feeds. The survival rate was not significantly different in animals fed with Artemia flakes from 'Salt Creek', 'Bio-Marine', 'Golden Pearls' and Artemia biomass, however the survival rate was significantly larger in animals fed with Artemia biomass than in animals fed with the crustacean meals and 'Artemac.' Results suggest that dried Artemia biomass is a well-suited feed for postlarval L. vannamei.  相似文献   

8.
The suitability of the harpacticoid copepodTisbe holothuriae as a diet for larval and juvenile Dover sole (Solea solea) was assessed by rearing groups of sole for 42 days under a range of dietary regimes. Larval sole, approximately 1 week old, were reared onTisbe, Artemia, or a mixedTisbe-Artemia diet for 13 days. No significant differences in length between sole larvae from any diet were found after this time, but larvae offeredArtemia alone showed a significantly higher frequency of malpigmentation than those offered the other diets. After metamorphosis (day 16), survivors of this experiment were reared for a further 29 days on various diets to give the following dietary sequences:Tisbe-fed larvae, fed onArtemia as juveniles (Tis.-Art.);Artemia-fed larvae, fed onArtemia as juveniles (Art.-Art.);Artemia-fed larvae, fed onTisbe as juveniles (Art.-Tis.) and mixed diet fed larvae, fed on a mixed diet as juveniles (AT-AT). At the end of this period AT-AT and Tis.-Art.-fed juveniles were significantly larger than those on the Art.-Art. dietary regime. Juveniles from the Tis.-Art. dietary regime consumed more prey items than the Art.-Art group. AT-AT juveniles consumed similar amounts of food to Art.-Art. juveniles but were significantly larger after 29 days culture. This was attributed to the presence ofTisbe in their diet. Overall, the best larval and juvenile diet appeared to be a mixed diet throughout the culture period.  相似文献   

9.
High mortality frequently occurs in larval mass production of Korean rockfish, Sebastes schlegeli Hilgendorf. Nutritional deficiencies in live feeds, rotifers and Artemia nauplii, fed to larvae could be a reason. A series of experiments was carried out to evaluate the effect of nutritional enrichment of live feeds by ω‐yeast, Spirulina powder and Super SelcoTM on survival and growth rates in rockfish larvae. Preference of rockfish larvae for the live feeds was determined by analysis of stomach contents. In addition, the effect of green water produced by the use of Chlorella ellipsoidea and Spirulina powder on the growth performance of larvae was evaluated. Larvae fed rotifers nutritionally enriched with Super Selco showed significantly higher survival rates than those fed rotifers enriched with ω‐yeast. Larvae fed rotifers that were nutritionally enriched with both Super Selco and Spirulina together exhibited improved growth and survival rates. Larvae fed Artemia nauplii nutritionally enriched with Spirulina powder showed significantly higher survival than larvae fed Artemia nauplii without enrichment. When larvae were fed rotifers, Artemia nauplii or the mixture of rotifers and Artemia nauplii, the second and last group showed significantly higher survival than the first group. Fatty acid composition in live feeds was improved by enrichment of ω‐yeast and larvae fed this feed showed higher survival and growth rates compared with larvae fed non‐enriched feeds. No positive effect of green water in the tank produced with C. ellipsoidea or Spirulina powder was observed on survival and growth rates for larvae fed nutritionally enriched rotifers with Super Selco and Spirulina powder. However, when the larvae were fed Artemia nauplii that were nutritionally enriched with ω‐yeast and Spirulina powder, green water obtained by adding Spirulina powder to the tanks resulted in significantly higher growth rates of larvae than was obtained by adding C. ellipsoidea.  相似文献   

10.
The effect of high levels of ascorbic acid (AA) delivered through enriched live food has been verified through the successful culture of larval giant freshwater prawn, Macrobrachium rosenbergii. Two successive feeding trials were set up using a control (550 g AA g–1 DW) and two different AA-enrichment levels in Artemia (1300 and 2750 g AA g–1 DW). Under standard culture conditions, no differences in growth nor survival could be observed demonstrating that the nutritional requirements are below 550 g AA g–1 DW, which is the normal level occurring in freshly-hatched Artemia. However, a significantly positive effect could be demonstrated on the physiological condition of the postlarvae, measured by means of a salinity stress test, when vitamin C-boosted live food was administered. Since the AA levels in the predator larvae are linked with the enrichment levels in the live prey, it may be assumed that a positive influence on stress resistance was caused by feeding vitamin C-enriched Artemia. It is expected that under suboptimal conditions, supplementation of high vitamin C levels might also enhance production characteristics.  相似文献   

11.
Results from three larval Senegalese sole (Solea senegalensis) feeding trials using non-enriched Artemia and Artemia enriched with Super HUFA®, Arasco®, sunflower oil and microalgae are presented and the effects on larval survival, growth and fatty acid (FA) composition are reported. The FA profile of Senegalese sole eggs was analysed to gather information about the nutritional requirements of the early larval stages and a quite high DHA/EPA ratio (4.3) was found. However, there was no evidence of a high dietary demand for DHA or EPA, given that no relationship was found between dietary HUFA concentration and larval growth and survival. When larvae were fed non-enriched Artemia a significantly better growth and comparable survival were obtained than with Artemia enriched with Super HUFA® (containing the highest HUFA level and DHA/EPA ratio). The FA profiles of the larvae generally reflected those of their diets. DHA was an exception, as it was present in high proportions, even in larvae fed DHA-deficient prey. Total FAME concentration decreased during larval development, with SFA, MUFA and PUFA being equally consumed; HUFA appeared to be less used, with its relative concentration being either kept constant (particularly EPA and ARA) or increased (DHA). A specific requirement for ARA in the first larval stages could not be confirmed but it was always present in considerable amounts, even in larvae fed an ARA poor diet.  相似文献   

12.
Three commercially available fatty acid enrichment emulsions (DC Selco, DC DHA Selco and DC Super Selco) were used to enrich Artemia nauplii fed to seahorse, Hippocampus sp. fry. The emulsions varied in their n-3 highly unsaturated fatty acid (HUFA) composition. Total n-3 HUFA content ranged from 200 to 450mgg-1 between the three emulsions while levels of eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) ranged between 47–220 and 80–190mgg-1, respectively. Survival and growth of seahorses at the end of the 30 day growth trial were greater in treatments receiving enriched Artemia. Seahorses receiving Artemia enriched with DC DHA Selco and DC Super Selco showed significantly (p < 0.05) greater mean survival (71.6 ± 6.0% and 78.3 ± 6.0%, respectively) than those receiving unenriched Artemia (48.3 ± 6.0%). Mean standard length was also significantly greater (p < 0.05) in fry fed DC DHA Selco and DC Super Selco enriched Artemia (20.2 ± 0.3 and 19.7 ± 0.3mm, respectively) compared to those fed unenriched Artemia (18.1 ± 0.3mm). The results show that dietary n-3 HUFA are essential for optimal growth and survival of Hippocampus sp. and, based on the fatty acid compositions of the enriched Artemia used in this study, indicate that the level of dietary DHA supporting optimal growth and survival is greater than 9.3mgDHAg-1 dry weight.  相似文献   

13.
To improve the nutritional quality of live foods and dry feeds ordinarily used for the seed production of amberjack Seriola dumerili, the nutrient contents of rotifers, Artemia nauplii and commercial feeds used in two larval production stations were evaluated. For comparison of the nutrient contents, artificially produced larvae, wild-caught juveniles and wild zooplankton samples were also analyzed. The proportions of 22∶6n-3 in the polar lipid of the cultured larvae increased by feeding the dry feeds. The taurine contents of the cultured larvae reflected the contents of their foods (rotifers<dry feed<Artemia nauplii). The taurine content and the proportion of 22∶6n-3 in Acartia spp. were higher than in foods fed to the larvae. These parameters in the wild juveniles were higher than the cultured ones. The A/E ratios [(each essential amino acid/total essential amino acids)×1000] of the total amino acids of the live foods and dry feeds were similar to those of the cultured larvae, except for the lower ratios of histidine, arginine, threonine and lysine in the live foods. The mucosal folds of the intestine of the cultured larvae did not show typical signs of dietary phospholipid deficiency. These results suggest that requirements of nutrients such as 22∶6n-3 and taurine should be determined for mass production of amberjack seeds.  相似文献   

14.
Mass seed production depends a great deal on the development of adequate artificial diets, which in turn depends on the development of methods to speedily and reliably assess the nutritional value of experimental diets. This study examined the sensitivity of light histological and ultrastructural criteria to detect differences in the nutritional value of diets for the Japanese spiny lobster, Panulirus japonicus (V. Siebold), phyllosoma larvae. The acceptability of diets, the apparent absorption of lipids and carbohydrates by the midgut gland cells, and the characteristics of various cell types were determined in 43-, 106- and 143-day-old intermoult phyllosoma fed diets of Mytilus edulis (L.) ovary alone (MO) or in combination with Anemia (MO+AR), which so far have given the best results in terms of growth and percentage of metamorphosis into puerulus, and two other diets considered less efficient, viz. Mytilus edulis testis (MT) and Artemia (AR). Acceptability of all diets attained 100% within 10 min of feeding as revealed by observation through the semitransparent cuticle of the larvae. Histological examination of larvae that ingested comparable amounts of food revealed pronounced variation in the absorption of lipids and carbohydrates by the midgut gland cells (AR相似文献   

15.
Because of high costs and labour requirements along with the highly variable nutritional value of live feeds, we investigated the possibility of early weaning for barramundi (Lates calcarifer Bloch) larvae aimed at reducing the use of Artemia. Two commercial microdiets, Gemma Micro (Skretting, Australia) and Proton (INVE, Belgium) were compared for growth and survival of larvae using three weaning protocols, until 33 days posthatch (dph). Enriched rotifers were fed to larvae in all protocols through mouth opening until 21, 18 and 30 dph (protocols 1, 2 and 3, respectively). At 13 dph, enriched Artemia metanauplii were introduced to weaning protocols 1 and 2, and continued until 29 and 24 dph, respectively, whereas protocol 3 did not receive Artemia. Microdiet was initiated at 20, 16 and 13 dph in protocols 1, 2 and 3, respectively. Barramundi larvae grew successfully to 33 dph when co‐fed rotifers and microdiet, and significantly larger larvae resulted from feeding Gemma Micro rather than Proton, when Artemia were not used. However, larvae weaned onto Proton using a longer period of Artemia provision were significantly larger than larvae reared according to all other protocols. Survival was significantly higher in all Gemma Micro protocols when compared with Proton protocols. This was in part due to higher cannibalism when using Proton compared with Gemma Micro (22.8 ± 0.9% and 9.2 ± 0.6%, respectively). Cannibalism became more noticeable in all protocols when the larvae reached 7–8 mm standard length and further increased after the cessation of live feed. Tank biomass production was the highest when larvae were weaned onto Gemma Micro including a short period of Artemia provision as a result of a combination of high growth and survival. However, similar biomass production resulted when larvae were weaned directly from rotifers onto Gemma Micro and/or from a prolonged Artemia period onto proton. The success of weaning barramundi larvae directly to microdiet from rotifers, thus eliminating the need for Artemia, was influenced by the microdiet. Relatively higher levels of free amino acids and lipids were believed to contribute to increasing larval growth and survival. Larvae that were fed Gemma Micro showed higher growth when Artemia were utilized for a shorter period, while Proton‐fed larvae benefited from an extended Artemia feeding period.  相似文献   

16.
The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 103 to 3.76 × 105 cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 105 cfu/g). This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

17.
Two experiments were carried out to test microparticulate diets forweaning hatchery-produced larvae and juveniles of bullseye pufferSphoeroides annulatus. The diets were formulated with differentprotein sources: diet 1 with a combination of decapsulated cysts ofArtemia and fishmeal, and diet 2 with a combination offishmeal, squid, tuna gonad and shrimp meal. In the first experiment60-days-old fish were weaned with the microdiets over five days. Fishsurvival after 11 weeks of feeding was 92% for diet 1, 85%for diet 2, and 95% for the control fish fed Artemianauplii. Once it was determined that bullseye puffer can be adequatelyreared with artificial dry diets, diet 1 was used to test earlier timesfor weaning to reduce the period of Artemia feeding. In thesecond experiment, three different times were tested for initiation ofweaning in sibling fish larvae, i.e., at 29, 34, and 39 days post-hatch.Small differences in weight, length and survival were found amongweaning treatments after 23 days of feeding. When weaned at day 29post-hatch, fish larvae grew from an initial weight of 38.4 mg andlength of 11.1 mm to a final weight and length of 405.7 mg and 25.1 mmrespectively. Final survival in this treatment was 49.3%. Thereduced period of Artemia feeding would provide an economicalalternative for the species to take into consideration for its cultureat commercial scale.  相似文献   

18.
It is not known whether rotifers or Artemia nauplii are the best first food for South African mud crab Scylla serrata larvae. In order to test this, larvae were fed with five different test diets. These were rotifers for the first 8 days and newly hatched EG® type Artemia nauplii (San Francisco Bay) from day 6 onwards (treatment R6A); newly hatched EG® type Artemia nauplii throughout the rearing period (treatment EG); newly hatched Vinh-Chau strain (Vietnam) Artemia nauplii throughout the rearing period (treatment VC); decapsulated cysts of EG® type Artemia throughout the rearing period (treatment DECAP); or decapsulated cysts supplemented with low densities of Artemia EG type Artemia nauplii (treatment MIX). Two experiments were conducted approximately 1 month apart using larvae from two different female crabs. Although results showed it is possible to rear S. serrata larvae through metamorphosis on Artemia nauplii exclusively, larval performance (development, survival and successful metamorphosis) was enhanced by the inclusion of rotifers as a first feed.No significant difference in performance was recorded between larvae fed on the two strains of Artemia nauplii. Larvae fed on decapsulated cysts in treatments DECAP and MIX performed poorly, but there were indications that decapsulated cysts and other inert diets may have potential as supplements to live food in the rearing of S. serrata larvae.  相似文献   

19.
The giant freshwater prawn, Macrobrachium rosenbergii, is cultured widely in the Mekong Delta region of Vietnam but it is often difficult or expensive for hatchery operators to purchase commercial diets used as a feeding supplement to Artemia nauplii. Therefore, in the present study, the effects of lipid sources and lecithin on the growth and survival rate of M. rosenbergii larvae were examined in order to develop suitable hand-prepared larval diets for seed production of M. rosenbergii in this area. Six egg custard diets consisting of various ratios of lipid (originating from soybean oil and squid oil) and lecithin were used for rearing Macrobrachium rosenbergii larvae. Treatments in which larvae were fed diets containing squid oil exhibited the highest body length and survival rates (7.14–7.43 mm and 51.1–68.1%, respectively), and differed significantly from other treatments (P<0.05). Use of dietary soybean oil yielded the lowest body length and survival rates (6.29–6.75 mm and 22.0–48.7%), respectively). The supplementation of dietary lecithin did not increase final body weight but did improve larval survival rates. The n-3 HUFA content of prawns fed dietary squid oil was higher than those of animals provided with other diets. These results indicated that the most appropriate diet for rearing M. rosenbergii larvae is the diet containing 3% squid oil and 1.5% lecithin.  相似文献   

20.
One of the major problems in the shrimp culture industry is the difficulty in producing high-quality shrimp larvae. In larviculture, quality feeds containing a high content of highly unsaturated fatty acids (HUFA) and ingredients that stimulate stress and disease resistance are essential to produce healthy shrimp larvae. In the present study, Penaeus monodon postlarvae (PL15) were fed for 25 days on an unenriched Artemia diet (control; A) or on a diet of Artemia enriched with either HUFA-rich liver oil of the trash fish Odonus niger (B), probionts [Lactobacillus acidophilus (C1) or yeast-Saccharomyces cerevisiae (C2)] or biomedicinal herbal products (D) that have anti-stress, growth-promoting and anti-microbial characteristics. P. monodon postlarvae fed unenriched Artemia exhibited the lowest weight gain (227.9 ± 8.30 mg) and specific growth rate (9.95 ± 0.05%), while those fed the HUFA-enriched Artemia (B) exhibited the highest weight gain and specific growth rate (362.34 ± 12.56 mg and 11.77 ± 0.08%, respectively). At the end of the 25-day rearing experiment, the shrimp postlarvae (PL40) were subjected to a salinity stress study. At both low and high (0 and 50‰) salinities, the group fed the control diet (A) experienced the highest cumulative mortality indices (CMI) 935.7 ± 2.1 and 1270.7 ± 3.1, respectively. Those fed diet D showed the lowest stress-induced mortality, and CMI were reduced by 31.1 and 32.3% under conditions of low and high salinity stress, respectively. A 10-day disease challenge test was conducted with the P. monodon postlarvae (PL40–PL50) by inoculating the shrimp with the pathogen Vibrio harveyi at the rate of 105–107 CFU/ml in all rearing tanks. P. monodon postlarvae fed probiont-encapsulated Artemia diets (C1 and C2) exhibited the highest survival (94.3 and 82.3%, respectively) and lowest pathogen load (V. harveyi) in hepatopancreas (5.2 × 102 ± 9.0 × 10 and 4.6 × 102 ± 9.0 × 10 CFU g−1, respectively) and muscle (2.0 × 102 ± 6 × 10 and 1.7 × 102 ± 8.6 × 10 CFU g−1, respectively) tissues. The shrimp that were fed the unenriched Artemia (Control; A) showed the lowest survival (26.33%) and highest bacterial load in the hepatopancreas (1.0 × 105 ± 5 × 103 CFU g−1) and muscle (3.6 × 104 ± 6 × 102 CFU g−1). The shrimp fed the herbal product (D)-enriched Artemia also exhibited enhanced survival and reduced V. harveyi load in the tissues tested compared to the control diet (A) group. The results are discussed in terms of developing a quality larval feed to produce healthy shrimp larvae.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号