Live food aquaculture training course

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Enrichment productsfor Artemia
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Essential Fatty Acids

• Eicosapentaenoic acid (EPA 205n-3), improves
  survival
• Docosahexaenoic acid (DHA 226n-3)
• accumulating in the brain of larval fish,
  improves pigmentation of flat fish, improves
  growth and development.
• Arachidonic acid (ARA 204n-6)
• substrate for producing eicosanoids
• 160n-9 and 181n-9 promote growth

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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.

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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.

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Artemia enrichment with super selco
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Artemia in storage
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Proteins

• Protein content of rotifers vary between 28 and
  67 of dry weight.
• Variability is dependant on nutritional status
• Proteinlipid 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.

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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

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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 (56-72 mg.g-1)
• Retinol (10-48 mg.g-1).

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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.

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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.

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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.

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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
  .

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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.

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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.

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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

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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.

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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

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DC Effect on Vibrio