Transcript Artemia Enrichment products

Enrichment products
for Artemia
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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
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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
100
mg/g DW
80
60
40
20
0
0
Total n-3
6
12
18
20:5n-3
24
30
hours
22:6n-3
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36
42
48
mg/g DW
Artemia in storage
30
25
20
15
10
5
0
0
20:5n-3 @ 10'C
22:6n-3 @ 10'C
6
hours
12
20:5n-3 @ 25'C
22:6n-3 @ 25'C
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24
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.
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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 6fold 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 transcanthaxanthin.
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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
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