Enriched Artemia Research Articles

Effects of PUFA-enriched Artemia on the early growth and fatty acid composition of Murray cod larvae

The Murray cod (Maccullochella peelii peelii), an iconic Australian freshwater fish, is subject to a small but growing aquaculture sector in Australia. Optimal larviculture techniques for this species have yet to be established, particularly with regard to the nutritional quality of starter diets. As such, optimisation of current Murray cod hatchery practices and feeding regimes is essential to maximize the production of high quality larvae and expand commercial aquaculture prospects. The aim of this investigation was to assess the effects of Artemia nauplii enriched with high levels of long-chain polyunsaturated fatty acids (LC-PUFA; ENR treatment), on the growth and fatty acid composition of larval Murray cod. Using untreated Artemia nauplii as a control treatment (CTL), larvae were fed either treatment to apparent satiation twice daily in triplicate groups of 700 fish with initial mean weights of 0.012 ± 0.06 g for 21 days at 19.85 °C. Survival was not significantly different between treatments (P > .05). Final mean weight and length, as well as specific growth rate, were significantly higher for ENR compared to CTL. Enriched larvae also contained significantly higher total lipid contents and across all three of the major fatty acid groups. Of the individual fatty acids, increases in ARA (20:4n-6) and DHA (22:6n-3) were recorded in the ENR fish, while CTL fish contained high concentrations of 18:4n-3, 20:4n-3 and 22:5n-3, which are intermediate fatty acids along the n-3 conversion pathway, suggesting desaturation and elongation toward EPA (20:5n-3) and DHA. Results demonstrate that enriched Artemia nauplii are vastly superior to untreated Artemia as a starter diet for optimal growth and fatty acid composition of Murray cod larvae. Thus, despite the clear ability of Murray cod larvae to undergo elongation and desaturation of ALA (18:3n-3), the present study demonstrates that this is not sufficient to sustain growth or LC-PUFA tissue levels akin to those possible through high dietary LC-PUFA intake.

β-Carotene-enriched Artemia as a natural carotenoid improved skin pigmentation and enhanced the mucus immune responses of platyfish Xiphophorus maculatus

The present study investigated the effects of enriched Artemia franciscana with β-carotene of Dunaliella salina on color, skin carotenoid, and mucosal immune responses of platyfish, Xiphophorus maculatus. To this end, one hundred and eighty platyfish with an initial weight of 0.9 ± 0.03 g were randomly assigned into four groups in triple and were daily fed on three times. The first and second groups were fed with commercial food (control) and unenriched A. franciscana (Un-EA), respectively. In addition, the third and fourth groups were fed with enriched A. franciscana with castor oil (oil-EA) and enriched A. franciscana with β-carotene (β-carotene EA) for 8 weeks, respectively. Based on results, the highest amount of carotenoids (112.4 ± 22.79 μg g−1) was significantly observed in the group fed with β-carotene EA while the lowest amount (24.31 ± 2.36 μg g−1) was found in the group fed Un-EA. As regards lysozyme, total immunoglobulin, and alkaline phosphatase activity of the mucus, the highest amounts were detected in fish with β-carotene EA as 84.5 ± 19.09 mg dL−1, 6.4 ± 0.41 mg dL−1, and 477 ± 39.59 U L−1, respectively. Based on skin colorization results, the group fed with β-carotene EA had no significant difference regarding the transparency, yellow color, and opacity, while a* index significantly increased in this group in comparison with the control group. However, the Hue index significantly decreased in the β-carotene EA group compared with the control group. In conclusion, A. franciscana enriched with β-carotene of D. salina enhanced the mucosal immune responses and improved the skin carotenoids as well as a* index in platyfish X. maculatus.

Effects of enriched Artemia with n–3 long-chain polyunsaturated fatty acids on growth performance, stress resistance and fatty acid profile of Litopenaeus vannamei postlarvae

A 15-day study was conducted to evaluate the effects of Artemia metanauplii enriched with two commercial supplements (Easy DHA-Selco and S. presso) which contained high levels of n–3 long chain polyunsaturated fatty acids (n–3 LC-PUFA) on growth performance, stress resistance and fatty acid profile of Litopenaeus vannamei post larvae (PL). In this regard, PL were fed with three different types of Artemia including: (1) newly hatched Artemia franciscana nauplii as the control group; (2) Artemia metanauplii enriched with Easy DHA-Selco; and (3) Artemia metanauplii enriched with S. presso. Survival rates did not change among different groups. PL fed Artemia enriched with the S. presso and the Easy DHA-Selco showed the highest wet and dry weight, respectively (p<0.05). Moreover, PL fed Artemia enriched with the commercial emulsions had higher survival rate (~ 10 %) than treatments fed newly hatched Artemia (p<0.05).The concentration of n–3 PUFA especially DHA and also n-3 / n-6 PUFA ratios were higher in PL fed with Artemia enriched with the commercial emulsions than the control group. Feeding enriched Artemia with n–3 LC-PUFA is recommended to improve growth performance in larval stages of L. vannamei.

Feeding Artemia nauplii enriched with the probiotic bacterium Bacillus subtilis improved growth performance, survival and digestive enzyme activity of Clarias batrachus (Linnaeus, 1758) larvae

Clarias batrachus (Linnaeus, 1758) larvae were subjected to different modes of probiotic (Bacillus subtilis) administration such as: T1: feeding Artemia nauplii enriched with B. subtilis; T2: feeding enriched Artemianauplii + addition of B. subtilis in water and T3: addition of B. subtilis in water alone, for a period of 14 days. A control group (T0) with no probiotic administration was also maintained. On termination of the experiment, probiotic supplemented through enriched Artemia nauplii along with addition in water (T2) yielded significantly (p&lt;0.05) higher length, weight, weight gain, specific growth rate and survival compared to control (T0) and T3 groups. All these parameters did not differ significantly (p&gt;0.05) between T1 and T2. Similar trend was observed in the case of total gut bacterial count and digestive enzyme activity. The highest (p&lt;0.05) digestive enzyme activity of protease, lipase and amylase were recorded in T2, while no significant (p&gt;0.05) difference was observed between T2 and T1. The present study reiterated the advantage of B. subtilis, and its administration through enriched Artemia nauplii which could be a promising supplementation mode during C. batrachus larval rearing.

Growth response, digestive enzyme activity and stress enzyme status in early stages of an endangered fish, Notopterus chitala (Hamilton, 1822) fed with live feed and formulated diet

A 60 days experimental trial was conducted to study the effect of different diets on growth and survival of near threatened species, Notopterus chitala fry. A total of 450 numbers of fry (0.88 ± 0.01 g) were randomly stocked in 6 treatments in triplicates. The experimental fishes were fed with various live feeds viz., live Tubifex (TF), un-enriched Artemia (UA), enriched Artemia (EA), un-enriched Moina (UM), enriched Moina (EM) and commercial feed (CF). Live feed based treatments showed significantly higher growth rate, digestive enzyme activity and survival than commercial feed. Among the live feeds, enriched live feeds contributed better growth performance with the highest average body weight (4.59 ± 0.17 g) and survival (72.66 ± 2.90%) observed in enriched Artemia fed fishes. The digestive enzyme analysis revealed that there was no significant difference in the intestinal amylase activity among the treatment groups whereas, the highest protease (4.22 ± 0.16 U mg protein−1 min−1) and lipase activity (1.13 ± 0.02 U mg protein−1 min−1) was observed in EM fed treatment group. The reduced level of SOD, catalase, AST and ALT activity was recorded in liver tissue of EA and EM fed group which indicates a lower level of stress in experimental fishes when fed with enriched diet. The study found that the enriched live feed is having a positive impact on growth and survival as compared to its un-enriched counterpart and further Artemia is the most preferred live feed for N. chitala fry.

Short-term lecithin enrichments can enhance the phospholipid and DHA contents of the polar lipid fraction of Artemia nauplii

Wild copepods are the main natural diet of marine finfish and they meet the larvae's requirements in phospholipids and essential fatty acids (EFA). While Artemia nauplii are an easier and more reliable live feed to produce in hatcheries for marine fish larvae than wild zooplankton, enrichment products commercially used lack phospholipids and essential long-chain polyunsaturated fatty acids (LC-PUFA). This is particularly true for docosahexaenoic acid (DHA) within their polar lipid fraction (PLDHA), which is critical to the survival and good development of the larvae. In this study, we showed that it is possible to increase the levels of phospholipids and DHA within the PL fraction of Artemia nauplii using marine lecithin through a process referred to as “boosting”. A cheaper alternative to marine lecithin, soya lecithin, was also tested but resulted only in a significant increase of the phospholipid content of the nauplii with no positive effect on the essential LC-PUFA levels, due to the absence of LC-PUFA in the soya lecithin. This study also showed that the levels of PLDHA in the Artemia boosted with marine lecithin did not reflect the levels of PLDHA in the lecithin, highlighting there the complexity of the boosting process. Finally, chilling enriched Artemia nauplii at 5 °C for up to 10 h did not impact on their nutritional quality post-enrichment. Ultimately, this study proposes innovative and sound enrichment strategies to produce Artemia nauplii rich in EFA and/or PL, similarly to that of the wild copepods' lipid profile.

A comparison with Tribulus terrestris extract fish immersion and bioincapsulation of enriched artemia on sex reversing of fighter fish (Betta splendens)

A comparison with Tribulus terrestris extract fish immersion and bioincapsulation of enriched artemia on sex reversing of fighter fish (Betta splendens)

Improving co-feeding strategies for Neotropical green terror cichlid (Aequidens rivulatus ) larvae with lecithin-enriched Artemia franciscana nauplii: Effects on survival, growth performance and body composition

The effects of feeding on a commercial diet and lecithin‐enriched (EN) Artemia franciscana nauplii for improving co‐feeding strategies of Neotropical green terror cichlid (Aequidens rivulatus) larvae were conducted. For this purpose, eight groups of fish in triplicates were assigned with two different diets (unenriched Artemia [UN] and EN Artemia) and four feeding regimes (1, 5, 10 and 25 days feeding with UN and EN diets and then a 10% daily replacement Artemia nauplii with commercial diet). The crude lipid (21.4%) and total polar lipid (12.96% of total crud lipid) levels significantly increased in enriched Artemia nauplii (p < 0.05). The highest amount of saturated fatty acids (SFA) were in enriched and UN Artemia nauplii (41.74% and 49.64% respectively) but the highest level of monounsaturated fatty acids (MUFA) (25.69%) and polyunsaturated fatty acids (PUFA) (49.11%) were obtained in commercial diet. Growth performance of fish fed 10 EN and 5 EN had significantly higher values of total weight (120.67, 120.31 mg), %WG (584.48, 580.50%) and SGR (7.69, 7.67%) respectively (p < 0.05). Nevertheless, fish fed 25 EN had significantly higher FCE (190.4%), PER (3.95) and NPU (202.5), in comparison with other groups. In terms of body composition, the EN Artemia nauplii led to increased lipid contents in 25 EN, 10 EN and 5 EN treatments. In conclusion, the results of this study revealed that feeding regimes of 10 EN and 5 EN could improves survival and growth performance of Neotropical green terror cichlid, A. rivulatus larvae.

Effect of increasing n-3 HUFA content in enriched Artemia on growth, survival and skeleton anomalies occurrence of greater amberjack Seriola dumerili larvae

Elevated mortality during early stages and high occurrence of skeletal anomalies are major concerns in Greater amberjack (Seriola dumerili) juvenile's production. Identification of nutritional requirements during live prey feeding stages, particularly those related with n-3 HUFA would help to formulate specific diets for this species improving larval survival and reducing skeleton anomalies. In this study S. dumerili larvae were reared from 17 to 35 days post hatching (dph). Larvae were fed Artemia sp. containing five different n-3 HUFA levels from 2.7 to 20.5% TFA. Growth, survival, skeletal anomalies occurrence and larval biochemical composition were determined. Best growth, final survival and survival after air stress test were achieved in the range of dietary n-3 HUFA concentrations, between 5 and 20%TFA. The lowest occurrence of skeletal anomalies was achieved in fish fed 12% n-3 HUFA content in Artemia, and the occurrence of cranial anomalies was correlated to increased dietary n-3 HUFA levels. Besides, whole body larval fatty acid profiles showed a positive correlation with dietary n-3 HUFA. Based on the overall results the recommended n-3 HUFA dietary level during Artemia feeding for larval S. dumerili was suggested between 12 and 17%TFA.

Effects of thermal disinfection and autoclave sterilisation on the quality of microalgae concentrates

Microalgae concentrates are important for hatchery operations but have been found to contain high concentrations of bacteria. Therefore, this study investigated the effects of four thermal disinfection and sterilisation treatments, low-temperature long-time (LTLT; 62–65°C, 30 min), high-temperature short-time (HTST; 72–75°C, 15 s), ultra-high-temperature (UHT; 120–150°C, 1–3 s) and high-temperature high-pressure (HTHP; 121°C, 0.2 MPa, 15 min), on concentrates of the microalgae, Chaetoceros gracilis, Chlorella vulgaris (fortified with eicosapentaenoic acid and docosahexaenoic acid) and Nannochloropsis oculata. The concentrates had reduced bacterial counts following LTLT, HTST and UHT and were completely sterilised by HTHP. Furthermore, cell dispersibility was retained in all treatment groups except HTHP-treated C. gracilis. Rotifers that were cultured with HTHP-treated C. vulgaris and N. oculata experienced significant population increases, whereas the survival rate and growth of Artemia nauplii significantly improved when supplied with HTHP-treated N. oculata, indicating that HTHP enhances the digestibility of this microalga. HTHP did not affect the total lipid content and fatty acid composition of the microalgae. These results suggest that HTHP-treated C. vulgaris and N. oculata could be used for the nutritional enrichment of rotifers and Artemia, while avoiding the risk of bacterial contamination, and would have an increased shelf life at room temperature.

Evaluation of the Impacts of Long-Term Enriched Artemia with Bacillus subtilis on Growth Performance, Reproduction, Intestinal Microflora, and Resistance to Aeromonas hydrophila of Ornamental Fish Poecilia latipinna.

The present study investigated the effect of enriched Artemia with Bacillus subtilis on growth performance, reproductive factors, proximate composition, intestinal microflora, and resistance to Aeromonas hydrophila of ornamental fish, Poecilia latipinna. Using a completely randomized design, the experiment included three groups. The first group was fed with commercial food without any probiotic. The second group was fed with unenriched Artemia, and the last group consumed long-time enriched Artemia with Bacillus subtilis. The bacteria B. subtilis with a density of 1 × 105CFUmL-1 was added daily to Artemia culture medium. The total microflora and Bacillus subtilis counts were significantly increased in enriched Artemia compared to the unenriched group (P < 0.05). In fish fed groups, growth factors did not show any significant difference (P > 0.05). The maximum relative fecundity (28.65 ± 2.52egg numberg-1), fry production (62.93 ± 4.6 individual per female), and fry survival (70.97 ± 1.56%) obtained in the third group were found to be significantly more than those in the first and the second groups. Moreover, intestinal bacterial count for Bacillus revealed that the higher concentration of bacteria was significantly related to the third group (6.24 ± 0.11logCFUg-1) (P < 0.05). Maximum protein and fat contents were observed in fish fed with Bacillus-enriched Artemia; however, no significant difference was found between control and unenriched Artemia groups (P > 0.05). The highest amount of ash was observed in fish fed with commercial food without any probiotic (P < 0.05). At the end of the feeding period, each of the three groups along with positive group (oxytetracycline 100mgkg-1 of commercial food) was exposed to A. hydrophila (BCCM5/LMG3770) bacteria intraperitoneally. Based on the results, the lowest cumulative mortality was significantly found in group three (68.75 ± 3.6%) and positive group (62.5 ± 7.0%) compared to control and unenriched Artemia groups (P < 0.05). Hence, B. subtilis with a concentration of 1 × 105CFUmL-1 during the period of Artemia culturing can improve the reproductive parameters, intestinal microflora, and resistance to pathogenic bacteria of Poecilia latipinna.

Aurantiochytrium limacinum BCC52274 improves growth, hypo-salinity tolerance and swimming strength of Penaeus vannamei post larvae

Long-chain polyunsaturated fatty acids (LC-PUFAs) have been shown to promote growth and health of many larval marine animals. Producing high amounts of LC-PUFAs, thraustochytrids are potential alternatives to fish oil as feed supplement for marine larviculture. Their applications have been assessed in many larval aquatic species but not yet in larval and post-larval (PL) shrimp. Here, growth performance and health of Penaeus vannamei PL were evaluated when fed with a thraustochytrid, Aurantiochytrium limacinum BCC52274 (AL), via enrichment in instar-II Artemia. Instar-II Artemia was enriched with AL for 4 h at the ratio of 400,000 individuals: 600 mg of freeze-dried AL per 1l of 30-ppt water. The feeding experiment consisted of treatment groups fed with varied proportions (from 0 to 100%) of the number of meals offering the non-enriched and enriched instar-II Artemia. Additionally, a reference group was included, in which PL were fed only with instar-I Artemia, the stage commonly used in commercial practice. AL enrichment replenished DHA deficiency in Artemia and increased LC-PUFA content in the fed PL. Increased feeding amounts of the enriched Artemia yielded positive effects on increased biomass gain, longer average length and decreased length variation coefficient of the PL (P < 0.05). The highest growth performance was from the group fed with the highest amount of the enriched Artemia and comparable to that of the instar-I reference group. The supplement resulted in an evident effect on hypo-salinity tolerance of the PL. PL fed with AL were more tolerant to hypo-salinity than those fed with no AL (P < 0.05). From our standardized swimming test, PL fed only with the enriched Artemia also exhibited no negative-rheotaxis swimming, different from the other groups (P < 0.05). AL had no effect on immunology of the PL when evaluated via Vibrio harveyi challenge, phenoloxidase and superoxide dismutase activities (P > 0.05). These findings suggest benefits of AL on growth performance, increasing hypo-salinity tolerance and swimming strength of shrimp PL.

Green Synthesis of Chromium Nanoparticles and Their Effects on the Growth of the Prawn Macrobrachium rosenbergii Post-larvae.

This study deals with synthesis of chromium nanoparticles (CrNPs) from potassium dichromate using the aqueous extract of Allium sativum. They were characterized through UV-VIS light, FE-SEM, EDX, XRD, and FT-IR, which revealed uniform, mono-dispersive, and highly stable CrNPs of 31-64-nm size. The Artemia nauplii was enriched with 4.94mg/L of CrNPs (24-h LC50) at different durations (½, 1, 2, and 4h) and then fed to Macrobrachium rosenbegii post-larvae (PL) for 30days as live feed. The results showed that ½- and 1-h enriched Artemia nauplii led to significant improvements in nutritional indices including growth and survival, and concentrations of tissue biochemical constituents, such as total protein, amino acid, carbohydrate, and lipid of M. rosenbergii PL (P < 0.05), which suggests that this concentration of CrNPs was non-toxic to M. rosenbergii PL. This was confirmed by the insignificant alterations recorded in activities of SOD and CAT (P > 0.05) in M. rosenbergii PL fed with ½- and 1-h enriched Artemia nauplii as live feed. After that, SOD and CAT activities started to increase. Therefore, this optimized concentration of CrNPs (4.94mg/L) is recommended for enrichment of Artemia nauplii for ½-1-h duration as a sustainable material in the nursery of M. rosenbergii.

An attempt to improve the proximate composition of local Artemia strain (Wadi El Natrun, Egypt)

BackgroundComparative analysis of essential amino acids and fatty acid of enriched and unenriched Artemia spp. collected from Wadi El Natrun, Elbeheira, Egypt, was investigated.ResultsThe obtained results indicated that Leucine recorded the highest concentration (17.22%, 11.4%) in unenrichment A. tunisiana and A. franciscana, respectively followed by arginine (10.31%, 9.6%); however, glutamic acid recorded the lowest concentration (0.05%) in A. tunisiana. Statistical analysis showed no significant differences in some amino acid concentrations (P < 0.001) in both A. tunisiana and A. franciscana as arginine, valine, proline, and aspartic acid. Other amino acids were highly significantly fluctuated as glycine, leucine, histidine, phenylalanine, glutamic, and tyrosine; they were high in A. franciscana. Aspartic acid was significantly higher in unenrichment nauplii. Regarding the comparison between A. franciscana and enrichment A. tunisiana, the data showed non-significant improvement for the majority of the recorded amino acids. The analysis of unsaturated fatty acids n-3 and n-6 families after 18 and 24 h of enrichment Artemia was achieved. The composition of unsaturated fatty acids was significantly increased after enrichment to 79.7 mg/g DW instead of 46.5 in newly hatched nauplii. Saturated fatty acids were also significantly increased from 20 to 25.28 mg/g DW. The enrichment process was significant (P < 0.001) in nauplii enriched with fatty acids for 18 h. The more pronounced effect of duration was the amount of energy as it was 33.17 kJ/g after 18 h, while it was 45.693 kJ/g after 24 h incubation. The ratio of ascorbic acid, due to Artemia enrichment by vitamin C for 24 h, was increased from 853 to 3227 μg/g dry weight after enrichment.ConclusionTo conclude, enrichment with cod liver oil and vitamin C obviously affected the chemical composition of local Egyptian Artemia (A. tunisiana).

Fatty acid profile, proteolytic activity and survival of Octopus bimaculatus paralarvae fed with enriched Artemia franciscana

ABSTRACTOctopus bimaculatus is an economically important food resource and a potential candidate for aquaculture diversification in the Pacific coast of Mexico; knowledge of its nutritional requirements is nil. For this reason, the composition of fatty acids of the newly hatched paralarvae was determined, as a criterion to define their requirements for essential fatty acids. We also evaluated the nutritional effect of live Artemia franciscana (8.2 ± 1.20 mm total length) enriched with tuna orbit oil (the TOO group) on the proteolytic activity and survival of the O. bimaculatus paralarvae in one experiment. The experimental cultivation of paralarvae fed with the TOO group was ended 17 days after hatching (DAH) with a survival of 1.93% and an increase of suckers per arm from five at hatching to nine, while those fed with the non-enriched A. franciscana (the control group) finished with only six suckers at 11 DAH and a 1.77% survival. Acid and alkaline proteolytic activity was detected at hatching, which increased in accordance with the age of the paralarvae. The TOO group had a significant influence on acid proteolytic activity of the paralarvae only at eight DAH; however, the final survival rate obtained in this treatment was slightly higher compared with those fed with the control group.

Assessing the role of vitamin C and iron in early larvae stages of Solea senegalensis fed enriched Artemia

The effect of dietary iron (Fe) and vitamin C (Ascorbic acid, AA) supplementation on development, gene expression and antioxidant status of Senegalese sole (Solea senegalensis Kaup, 1858) larvae was investigated. Larvae were reared from 7 to 28 days post hatching (dph) in triplicate using a recirculation system. Three experimental groups were established: The control group was fed Artemia enriched with the microalgae Tisochrysis lutea (T. lutea), the F group, T. lutea supplemented with Fe and the FP group, T. lutea supplemented with Fe and ascorbyl palmitate (AP). Enriched Artemia of F and FP groups displayed a significantly higher content of Fe than the control (850 μg Fe g−1 DW and 350 μg Fe g−1 DW, respectively). In addition, enriched Artemia of the FP group also showed a significantly higher content of AA than the control (3.5 μg AA mg−1 DW and 0.8 μg AA mg−1 DW, respectively). At 28 dph, Fe content in larvae from F and FP groups was 1.4- and 1.7-fold higher than the control, respectively. Moreover, larvae from FP group showed the highest AA content throughout the whole experiment (p < 0.05). Larvae from FP group grew faster and completed metamorphosis earlier than the other groups (p < 0.05). Moreover, antioxidant enzymatic activities, lipid peroxidation and total antioxidant content (TAC) at the end of the experiment (p < 0.05) indicated a positive iron-vitamin C interaction with better antioxidant status in FP group. Similar skeletal typology and histological pattern in the development of tissues was observed at 28 dph for larvae under all feeding regimes assayed. Nevertheless, an increasing collagen fibre was evidenced in larvae of FP group The gene expression pattern during the experimental period revealed that different levels of iron and vitamin C modified the expression levels of genes involved in stress (crh, pomca2 and hsc70-4l), glycolytic pathway (pkm), antioxidative defence (slc23a1), osmoregulation (aqp3a, aqp12 and nppc1) and iron homeostasis (hamp1, fpn, tf). The present study is the first report about the potential effect of iron and vitamin C during the first stages of development in S. senegalensis larvae.

Study of the bacteriostatic activity of an Artemia enrichment compound based on plant extracts from Angelica sp.

The bacteriostatic ability of a commercial product was assessed against Vibrio alginolyticus and V anguillarum at concentations 1,3,4,6.5 and 15ppm. The best concentration for short term (48hrs) arrestment of the nonpathogenic bacteria was found l-3ppm whereas for longer effect (72hrs) the best concentration for both species was 6,5ppm. Higher concentrations did not show any advantages.

Phyllanthus amarus enriched Artemia nauplii enhanced survival, growth and nutritional quality of early post-larvae of the prawn Macrobrachium rosenbergii

Phyllanthus amarus enriched Artemia nauplii enhanced survival, growth and nutritional quality of early post-larvae of the prawn Macrobrachium rosenbergii

Effects of thyroxine, cod liver oil and potassium iodide on growth and survival of juvenile seahorse,Hippocampus barbouri

Low survival at early stage is the bottleneck in seahorse aquaculture, particularly in the feeding aspect since newborn seahorses must feed immediately upon birth to sustain themselves. Seahorses are visual predator, therefore preferred live feed such as zooplankton. In aquaculture, the most common live feed used is Artemia. In this study, two experiments were conducted to determine the effect of different Artemia enrichment on the growth and survival of newborn Hippocampus barbouri. In the first experiment, six treatments using Artemia enriched with Culture Selco Plus™ (SELCO), thyroxine (T4), potassium iodide (KI), cod liver oil (CLO), cod liver oil in combination with thyroxine (CLO + T4) and potassium iodide (CLO+KI) were fed to newborn H. barbouri. Newly hatched Artemia were used as control. At the end of first experiment, treatments using CLO + T4 produced juvenile H. barbouri with the best (p < .05) wet weight (0.142 ± 0.000 g), while juvenile in treatment CLO+KI recorded the highest (p < .05) standard length (3.947 ± 0.014 cm). Subsequently, a second experiment was carried out using the two best enrichment (CLO + T4 and CLO + KI) from the first experiment, but given at different frequency (daily, twice a week, once a week, once in 2 weeks). Daily enrichment using both CLO + T4 and CLO + KI showed no significant (p > .05) difference in growth performance and survival of juvenile of H. barbouri. Interestingly, juvenile fed CLO + T4 enriched Artemia at frequency of twice a week also has no significant difference (p > .05) in survival and growth performance (except for final standard length) when compared with treatment CLO + T4 at daily frequency.

Effectiveness of dietary vitamin supplementation to the performance of common carp (Cyprinus carpio L.) larvae in intensive rearing condition

Study of enrichment of different vitamins (C, B1, B6 and E) in common carp larvae through 4 weeks feeding in recirculation system was carried out. For this purpose, procedure for enrichment of Artemia nauplii with different vitamins was developed and investigated the effectiveness in larvae nutrition. The habituation of larvae to dry feeds was done using supplemented dry diets with the same vitamins. To study the effect of vitamins in young fish, the most common stress situation was planned for carp nursed fries, which occurs during transportation. Levels of vitamins and parameters of immune response in mucus were monitored before and after stress situation. At the end of the feeding trials using enriched Artemia nauplii, level of vitamin B1, B6 and C were increased in the body of fish, but remained on similar level or decreased after dry feeding period. Therefore, we concluded that Artemia is a good delivery vector of these vitamins. While handling stress, vitamin C and E concentration was decreased and sparing effect of antioxidant vitamins was confirmed in groups supplemented with both vitamins. Vitamin B1 was consumed intensively during the stress, vigorously in groups without supplementation. Contrary to this, vitamin B6 level increased in stress condition in group without supplementations. The levels of immunoglobulins in mucus were increased in all treated groups independently of treatment. Our results confirm that carp larvae reared in tank condition needs sufficient amount of vitamins C, B1 and B6 supplements to protect them from the mild handling stress.