Effect of vitamin E and highly unsaturated fatty acid-enriched Artemia urmiana on growth performance, survival and stress resistance of Beluga (Huso huso) larvae

A 44-day rearing trial was conducted to examine the enrichment of Artemia urmiana nauplii with vitamin E and highly unsaturated fatty acid (HUFA) and its effects on the growth performance, survival and stress resistance of great sturgeon, Huso huso , larvae. Cod liver oil (EPA 18% and DHA 12%) and α-tocopherol acetate were used as lipid and vitamin E sources. Beluga larvae at the first exogenous feeding with 69±5.9 mg body weight were randomly distributed into four treatments and three tanks were assigned to each diet. The test treatments were as follows: larvae fed with HUFA+20% and HUFA+50% (w/w) vitamin E-enriched Artemia nauplii (E1 and E2 groups, respectively), HUFA without vitamin E (HUFA group) and non-enriched Artemia (control group). All treatments fed non-enriched Artemia for the initial 5 days after first feeding and then fed enriched Artemia for 7 days. After the period of enrichment, larvae were fed with daphnia from the 13th to the 40th day. At day 40, submersion in salt water (6 ppt for 4 days and 12 ppt for 2 days) and warm water (33 °C for 2 days) was performed to evaluate larvae resistance to salinity and temperature stress. Final weight, daily growth rate, specific growth rate and weight gain were higher in beluga fed with enriched Artemia . The highest growth rates were observed in E1, whereas survival was not significantly different between groups. Use of vitamin E and HUFA significantly increased fish resistance to a salinity of 12 ppt and the lowest stress resistance was observed in the control group. Stress tolerance was not significantly different at 6 ppt and 33 °C between groups. There was no comparable difference in the haematocrit index under stress conditions. These results indicated that the enrichment of Artemia with essential fatty acids and vitamin E can affect some growth and stress tolerance factors in great sturgeon, Huso huso , larvae.     

Bioencapsulation of erythromycin using adult brine shrimp, Artemia franciscana (Latreille)

Live adult brine shrimp, Artemia franciscana (Latreille), were enriched with erythromycin to determine if Artemia could accumulate therapeutic levels for subsequent feeding to young fish. Three trials were conducted to determine the erythromycin incorporation and survival rates of enriched Artemia when fed either liposomes containing erythromycin or various erythromycin suspensions. Erythromycin concentration in Artemia fed a liposome suspension was low (∼ 5 μg mL⁻¹) relative to Artemia fed the direct suspension (> 100 μg mL⁻¹) over the same time period. When enriched with suspensions up to 1 g erythromycin L⁻¹ sea water for 14 h, Artemia survival was not significantly affected ( P > 0.05) relative to controls. Using a suspension of 1 g L⁻¹, tissue erythromycin concentrations of 109 ± 16 μg erythromycin mL⁻¹  Artemia homogenate (mean ± SEM) were achieved after 12 h. Concentrations above 170 μg mL⁻¹ were obtained using suspensions of 2–5 g L⁻¹, but Artemia survival significantly ( P < 0.05) decreased.     

营养强化的轮虫、卤虫对牙鲆仔鱼的成活、生长及体脂肪酸组成的影响

用3种营养强化剂强化的轮虫和卤虫无节幼体投喂牙鲆仔鱼,研究牙鲆仔鱼的生长、成活、体脂肪酸的组成。结果表明:用强化的轮虫和卤虫无节幼体投喂牙鲆仔鱼,成活率、增重均显著高于对照组(p<0 01),其中V号强化剂的效果最好,成活率为29 34%,比对照组提高100%;增重倍数为217 90,比对照组提高68 61%;这是由于V号强化剂强化的卤虫无节幼体体内含有较多的AA的缘故,饵料中AA含量的提高,可以提高牙鲆仔鱼的成活率、促进其生长。牙鲆摄食强化过的轮虫、卤虫无节幼体后,其EPA、DHA、n-3HUFA、PUFA的含量随着饵料中含量的升高而升高,这也是牙鲆仔鱼生长速度和成活率提高的重要因素之一。     

Survival and Growth Improvement of Palm Ruff,Seriolella violacea,Larvae Fed Artemia Nauplii Enriched with an Experimental Emulsion

The palm ruff, Seriolella violacea (Cojinoba), is a potential new species for Chilean aquaculture. To approach Cojinoba larviculture, an experimental Artemia enrichment emulsion, containing docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) = 2.5, supplemented with vitamin E, astaxanthin, and β‐glucan, was evaluated in both Artemia and Cojinoba larvae, 30–50 d.a.h. This study tested an experimental enrichment emulsion versus a commercial emulsion, with an integral approach of multicompound emulsions. After 23 h enrichment, experimental emulsion (EE)‐enriched nauplii reached DHA and EPA concentrations of 23.8 and 18.7 mg/g dry weight (dwt), respectively, while in Cojinoba larvae they were 18.4 and 19.7 mg/g dwt. Control emulsion (CE)‐enriched nauplii exhibited lower DHA and EPA (6.1 and 7.7 mg/g dwt), while only DHA decreased in the control larvae (12.6 mg/g dwt). Vitamin E was higher in EE‐enriched nauplii (29.2 mg/100 g dwt) than in the control (8.4 mg/100 g dwt). Larvae fed EE‐enriched Artemia exhibited 8% increase in survival and 19% in growth compared with the control. Astaxanthin was detected only in larvae fed EE‐enriched nauplii. The tumor necrosis factor‐α concentration was not significantly different between larvae fed EE‐ and CE‐enriched nauplii. EE looks promising as an Artemia enrichment and experimental diet to assess palm ruff larval requirements, and has a positive impact on fish larvae performance.     

Rhodovulum sulfidophilum,a phototrophic bacterium,grown in palm oil mill effluent improves the larval survival of marble goby Oxyeleotris marmorata (Bleeker)

Survival of marble goby larvae fed either Rhodovulum sulfidophilum, a phototrophic bacterium cultured from palm oil mill effluent (pPB), or microalgae ( Nannochloropsis sp.) was evaluated at two salinities. Larvae directly fed pPB had survival of 0–29% at 5 g L^?1 salinity and 0–19% at 10 g L^?1 salinity, whereas larvae directly fed microalgae suffered complete mortality after 20 days of culture at both salinities. However, larvae indirectly fed pPB or microalgae, i.e. via rotifers (Days 1–30) and Artemia nauplii (Days 21–30) cultured solely from pPB or microalgae, showed improved survival of 35–55% or 44–49% at 5 g L^?1 salinity respectively. In all experiments, fish larvae reared at 5 g L^?1 salinity showed significantly higher (P < 0.01) mean survival than those reared at 10 g L^?1 salinity. The survival of larvae fed the bacterial‐based diet was higher compared with microalgal diet used in previous studies. The pPB had higher total polyunsaturated fatty acids and docosahexaenoic acid (DHA) than the microalgae, which had very high eicosapentaenoic acid (EPA). Larvae with very high ratios of DHA/EPA (>11) or/and ARA (arachidonic acid)/EPA (>5), attributable to their given diet, however suffered the highest mortality.     

Effects of Artemia enriched with eicosapentaenoic and docosahexaenoic acid on survival and occurrence of molting failure in megalop larvae of the mud crab Scylla serrata

ABSTRACT:   The present study was conducted to investigate the effect of eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) on the survival and the occurrence of molting failure to megalops of mud crab Scylla serrata larvae fed enriched Artemia . Survival rate, intermolt period, carapace width at the first crab stage, ratio of chela to carapace length at the fifth zoeal stage and the occurrence of molting failure to megalops were observed. Mud crab larvae were reared in 1-L plastic beakers and fed with Artemia enriched at five different levels of EPA (0.31% to 1.36% EPA; referred to as E25, E50, E75 and E100) or four different levels of DHA (0.75–0.95% EPA and 0.49–1.38% DHA; referred to as D25, D50, D75 and D100). As a negative control, larvae were fed Artemia enriched with oleic acid (OA). Mud crab larvae fed Artemia containing low (0.41–0.45% EPA and trace DHA) or high (1.36% and 0.95% EPA and 0.16% and 1.38% DHA) amounts of EPA and DHA showed a significantly lower survival rate and prolonged intermolt period ( P  < 0.05). Moreover, a high frequency of molting failure to the megalops stage (34 and 33%) occurs coincident with a high chela to carapace length ratio (43 and 44%) in mud crab larvae fed high amounts of EPA and DHA (E100 and D100), suggesting that both of these treatments contain EPA and DHA in excess. These results indicate that during Artemia feeding, EPA and DHA content should be adjusted to 0.71–0.87% and 0.49–0.72% for maintaining a high survival, accelerating the intermolt period, and producing larger carapace width in the first crab stage.     

Assessment of marine thraustochytrid <Emphasis Type="Italic">Schizochytrium limacinum</Emphasis> OUC88 for mariculture by enriched feeds

ABSTRACT:   In the present study, Schizochytrium limacinum OUC88, a thraustochytrid with high content of docosahexaenoic acid (DHA, 22:6 n −3), was used as feed for rotifer Brachionus plicatilis and Artemia franciscana . The rotifer and Artemia were harvested at 3, 6, 9, 12, 18, and 24-h intervals, analyzed for fatty acid composition, and compared with the control which fed on yeast only. The highest DHA content resulted from an enrichment period of 12 h for both fed organisms, reached 13.4 and 10.9% of the total fatty acids (TFAs) in rotifers and Artemia nauplii, respectively, and the DHA level reduced sharply if enrichment time was longer than 12 h. The pseudoalbinism rate of turbot Scophthalmus maximus juveniles fed enriched rotifers and Artemia nauplii reduced greatly (40% lower than in control group). Thus, enrichment of rotifers and Artemia nauplii by DHA-rich Schizochytrium limacinum OUC88 may provide a practical strategy for feeding fish juveniles in aquaculture.     

Effect of different diets on larval production, quality and fatty acid profile of the marine ornamental shrimp Lysmata amboinensis (de Man, 1888), using wild larvae as a standard

The present work evaluates the influence of broodstock diets [Marine Cuisine^®– MC, MC supplemented with highly unsaturated fatty acid- (HUFA) enriched Artemia biomass – MC + AB, and MC supplemented with squid – MC + S] on larval production, newly hatched and early zoeal stage survival and fatty acid profile of newly hatched larvae of Lysmata amboinensis . These parameters are compared with those from larvae hatched from embryos spawned in the wild. The number (±SE) of larvae produced with MC and MC + S (1077 ± 219 and 1103 ± 184, respectively) was similar to that in broodstock carrying embryos spawned in the wild (1224 ± 111), while those fed MC + AB displayed significantly lower values (1044 ± 161). Larvae produced with MC + AB displayed lower survival for all starvation periods, while larvae spawned in the wild displayed the highest survival. No larvae resisted 144 h of starvation and none moulted to zoea II. The fatty acid comparison revealed that larvae from embryos spawned in the wild displayed the highest levels of DHA, as well as higher DHA/EPA and n -3/ n -6 ratios. These results suggest that broodstock diets commonly used to promote ornamental shrimp's maturation (based on mixed frozen components) are far from being optimal.     

Effect of artemia nauplii enriched with vitamin A palmitate on hypermelanosis on the blind side in juvenile Japanese flounder Paralichthys olivaceus

ABSTRACT:   The effect of Artemia nauplii enriched with different level of vitamin A (VA) palmitate (1 µg = 1 IU) on the occurrence of hypermelanosis on the blind side of Japanese flounder Paralichthys olivaceus was determined. Artemia were enriched with 0, 1, 2, 5 or 10 mg VA palmitate/L (control group, and 1-, 2-, 5-, and 10-mg groups). The enriched Artemia were fed to the larvae from 27 to 31 days post hatching (dph) corresponding to the F–G stage. VA palmitate, retinol and retinoic acid (RA) contents of Artemia were correlatively elevated with increasing VA palmitate in the culture medium. RA was detected in Artemia enriched with 5 mg and 10 mg, and a significantly high frequency of hypermelanosis on the blind side was observed in these groups at 65 dph ( P  < 0.05). These results suggest that RA synthesized from VA palmitate in Artemia could induce hypermelanosis on blind side of flounder when Artemia are enriched with more than 5 mg VA palmitate/L.     

A formulated diet for Atlantic halibut (Hippoglossus hippoglossus, L.) larvae

A diet for Atlantic halibut-larvae was formulated taking into account the fact that marine-fish larvae have a limited ability to assimilate protein and lipid. Dietary protein consisted of a free amino-acid premix (7.2% of crude protein), predigested-squid mantle (7.2%), squid mantle (8.6%) and cod-muscle mince (77.0%). Lipid sources were soyabean lecithin (33% of crude lipids), crude phospholipids extracted from cod roe (10%) and sardine oil (57%). Larvae were weaned onto the experimental diet at wet-body weights of 0.07, 0.10 or 0.16 g, respectively. The experimental diet was fed for 31, 25 or 17 days, respectively, and the experiment was terminated on the same calendar day for all groups. A control group was fed with Artemia nauplii enriched with DHA Selco™ from 0.07 g. Survivals ranged from 78% in larvae transferred at 0.10 g to 96% in those transferred at 0.16 g and in the control group. Daily specific-growth rates (SGR) were 3.1 ± 0.07, 3.3 ± 0.11 and 2.2 ± 0.01% day⁻¹ in larvae transferred at 0.07, 0.10 and 0.16 g, respectively, while growth in the control group was 5.1% day⁻¹. It was concluded that weaning of Atlantic-halibut larvae is feasible from 0.7 g (approximately 20 days post first-feeding) when the formulated diet contains predigested protein and ample amounts of phospholipids.