Enrichment products for Artemia

1. Enrichment productsfor Artemia Live food aquaculture training course www.aquatrain.org

2. Essential Fatty Acids • Eicosapentaenoic acid (EPA 20:5n-3), improves survival • Docosahexaenoic acid (DHA 22:6n-3) accumulating in the brain of larval fish, improves pigmentation of flat fish, improves growth and development. • Arachidonic acid (ARA 20:4n-6) substrate for producing eicosanoids • 16:0n-9 and 18:1n-9 promote growth Live food aquaculture training course www.aquatrain.org

3. HUFAs In Artemia, levels of EPA vary tremendously from strain to strain and even from batch to batch. Commercial quantities of Artemia cysts naturally containing high EPA levels are limited and consequently, these cysts are very expensive. Therefore, high-EPA cysts are used for feeding of unenriched nauplii. Live food aquaculture training course www.aquatrain.org

4. Enrichment with HUFAs Artemia are non selective for feed uptake but are selective for catabolism so although DHA and ARA are ingested they are selectively catabolised. Artemia require a relatively long time to enrich with HUFAs. Live food aquaculture training course www.aquatrain.org

5. Artemia enrichment with super selco Live food aquaculture training course www.aquatrain.org

6. Artemia in storage Live food aquaculture training course www.aquatrain.org

7. Proteins • Protein content of rotifers vary between 28 and 67% of dry weight. • Variability is dependant on nutritional status • Protein:lipid ratio is positively correlated to SGR with fast growing rotifers (high protein to lipid ratios) giving better larval growth and survival (Turbot). • Protein and has great affect on early larval production success. Live food aquaculture training course www.aquatrain.org

8. Amino acids The amino acid composition of Artemia nauplii seems to be remarkably similar from strain to strain, suggesting that it is not environmentally determined. The levels of essential amino acids in Artemia are generally not a major problem in view of its nutritional value, but sulphur amino acids, like methionine, are the first limiting amino acids Live food aquaculture training course www.aquatrain.org

9. Vitamins Artemia cysts (San Francisco Bay) were analysed for the content of various vitamins and were found to contain high levels of • Thiamin (7-13 mg.g-1) • Niacin (68-108 mg.g-1) • Riboflavin (15-23 mg.g-1) • Pantothenic acid (56-72mg.g-1) • Retinol (10-48 mg.g-1). Live food aquaculture training course www.aquatrain.org

10. Vitamin C In Artemia cysts, Vitamin C is found as ascorbic acid 2-sulfate (AAS) which is a very stable form but with low bio-availability. During the hatching process the AAS is hydrolyzed into free ascorbic acid, a more unstable form, but directly available in the nauplii for the predator. Ascorbic acid levels in Artemia nauplii vary between 300 and 550 mg g-1 DW. Live food aquaculture training course www.aquatrain.org

11. Vitamin C Vitamin C can assist with stress tolerance and reduce deformity (opercular plate for bream) High levels of free ascorbic acid (AA) can be incorporated into Artemia. A 10%-AP inclusion enhances the natural levels by 50%, however, a 20 or 30% addition increases AA levels in Artemia respectively 3-fold and 6-fold after 24 h enrichment at 270C. These AA concentrations do not drop when the enriched nauplii are stored. Live food aquaculture training course www.aquatrain.org

12. Other Vitamins Fat soluble vitamins (especially vitamin A and vitamin E) can accumulate in Artemia during a short-term (9 h) enrichment period. Vitamin A levels can increase from below 1 IU.g-1 (WW basis) to over 16 IU.g-1 Vitamin E levels can increase from below 20 mg.g-1 to about 250 mg.g-1. Live food aquaculture training course www.aquatrain.org

13. Carotenoids In Artemia cysts and nauplii, there are qualitative differences in carotenoid pattern, and more specifically the canthaxanthin content. In Artemia cysts, the unusual cis-configuration is found, whereas in developing nauplii it is converted into the more stable trans-canthaxanthin. Live food aquaculture training course www.aquatrain.org

14. Enzymes The presence of several proteolytic enzymes in developing Artemia embryos and Artemia nauplii indicates that those exogenous enzymes play a significant role in the breakdown of the Artemia nauplii in the digestive tract of the predator larvae. This is important in view of the relatively low levels of digestive enzymes in many first-feeding larvae and the poor performance of prepared feeds versus live prey. Live food aquaculture training course www.aquatrain.org

15. Minerals The mineral requirements of marine larvae are poorly known but may be met by the seawater that they drink. The main concern about Artemia mineral composition is whether they meet the requirements of freshwater organisms in culture particularly the levels of selenium. Live food aquaculture training course www.aquatrain.org

16. Phospolipids • used for the formation of cell components particularly during rapid growth periods • during rapid growth phospholipids probably not produced fast enough to meet requirements • found to reduce malformation in larvae Live food aquaculture training course www.aquatrain.org

17. Standardisation It is necessary to try and standardise the bioencapsulation technique (e.g. using disinfected cysts, applying standard aeration methods) as there can be high variability in the essential fatty acid composition of Artemia nauplii when enriched by the same person or by various people. Average (n-3) HUFA levels in enriched Artemia meta-nauplii vary among hatcheries from 2.8 to 4.7% on DW basis. Live food aquaculture training course www.aquatrain.org

18. Disinfection during enrichment Enrichments that contain bacteriostats giving continuous disinfection during the enrichment process have been developed. The DC Selco or Micro control concept ensures enriched Artemia nauplii that contain much less Vibrio. The most recent development is the "all-in-one" concept which makes it possible to hatch and enrich decapsulated cysts in the same tank without problems of mortalities and/or bacterial blooming Live food aquaculture training course www.aquatrain.org

19. DC Effect on Vibrio Live food aquaculture training course www.aquatrain.org