· Timing
· Day 1 - filter + disinfect seawater 1 h + aerate
· Day 2
9:00 start cysts disinfection
9:30 start hatching
· Day 3
9:30 harvest and start enrichment
18:00 add second enrichment
· Day 4 - 9:30 harvest

4.4. Tank production and use of ongrown
Artemia

4.4.1. Nutritional properties of ongrown Artemia
4.4.2. Tank production
4.4.3. Literature of interest
4.4.4. WorksheetsJean Dhont and Patrick Lavens
Laboratory of Aquaculture & Artemia Reference Center
University of Gent, Belgium
4.4.1. Nutritional properties of ongrown Artemia
The nutritional quality of Artemia biomass produced in semi-intensive or super-intensive
systems is analogous to natural produced biomass except for the lipid content. The
protein content of ongrown Artemia, independent of its rearing conditions or food, is
appreciably higher than for instar I-nauplii (Table 4.4.1.) and is especially richer in
essential amino acids (Table 4.4.2.).

Table 4.4.2. Profile of fatty acids (in mg.g
-1
DW) and amino acids (ing. 100g
-1
DW) in
Great Salt Lake preadults cultured under flow-through conditions on a diet of corn
and soybean powder compared to nauplii (After Léger et al., and Abelin, unpubl.
data).
Fatty acids preadults Amino acids preadults nauplii
Saturated 16.20 Essential 26.94 55,7
14:0 0.70 tryptophan - -
15:0 .50 lysine 4.23 7.8
16:0 9.10 histidine 1.30 2.3
17:0 0.70 arginine 2.69 8.2
18:0 5.20 threonine 2.42 4.0
19:0 - valine 3.20 4.4
20:0 - methionine 0.71 3.1
24:0 - isoleucine 2.96 5.7
Unsaturated 46.70 leucine 4.52 8.4
14:1 1.20 tyrosine 2.16 5.6
14:2 - phenylalanine 2.75 7.2
15:0 0.30 Non-essential 25.71 39.6
16:1n-7 + 16:1n-9 4.30 asparagine 5.82 9.5
16:2 - serine 2.63 4.5
16:3 0.30 glutamine 7.64 11.4
14:1 - proline 3.29 5.0
18:1n-7 + 18:1n-9 18.30 glycine 2.68 5.1
18:2 15.90 alanine 3.61 4.1
18:4 0.10 cysteine 0.14 -
19:4 -

in this sector are sold frozen since they are harvested from a restricted number of natural
sources and live transportation to other continents is cost prohibitive. Singapore, for
example, already experiences a bottleneck where the local tropical aquarium industry is
threatened by a shortage of live foods.
4.4.2. Tank production

4.4.2.1. Advantages of tank production and tank produced biomass
4.4.2.2. Physico-chemical conditions
4.4.2.3. Artemia
4.4.2.4. Feeding

4.4.2.5. Infrastructure

4.4.2.6. Culture techniques

4.4.2.7. Enrichment of ongrown Artemia
4.4.2.8. Control of infections
4.4.2.9. Harvesting and processing techniques

4.4.2.10. Production figures and production costs

4.4.2.1. Advantages of tank production and tank produced biomass
Although tank-produced Artemia biomass is far more expensive than pond-produced
brine shrimp, its advantages for application are manifold:
· year-round availability of ongrown Artemia, independent of climate or season;
· specific stages (juveniles, preadult, adults) or prey with uniform size can be harvested as
a function of the size preferences of the predator; and
· quality of the Artemia can be better controlled (i.e. nutritionally, free from diseases).
Super-intensive culture techniques offer two main advantages compared to pond
production techniques. Firstly, there is no restriction with regard to production site or

* selection of suitable diets
· infrastructure
* tank and aeration design
* filter design
* recirculation unit
* heating
* feeding apparatus
· culture techniques
* open flow-through system
* recirculation type
* stagnant culture
4.4.2.2. Physico-chemical conditions
SALINITY AND IONIC COMPOSITION OF THE CULTURE MEDIA
Although Artemia in its natural environment is only occurring in high-salinity waters
(mostly above 100 g.l
-1
), brine shrimp do thrive in natural seawater. In fact, as outlined
earlier (see under 4.1.), the lower limit of salinity at which they are found in nature is
defined by the upper limit of salinity tolerance of local predators. Nonetheless their best
physiological performance, in terms of growth rate and food conversion efficiency is at
much lower salinity levels, (i.e. from 32 g.l
-1
up to 65 g.l
-1
).
For culturing Artemia, the use of natural seawater of 35 g.l
-1
is the most practical. Small
adjustments of salinity can be carried out by adding brine or diluting with tap water free
from high levels of chlorine. However, one should avoid direct addition of sea salt to the

follows that temperature must be maintained between the specific optimal levels of the
selected Artemia strain. Several methods for heating seawater are discussed below
(4.4.2.4 Heating).
According to published information, it is generally accepted that the pH tolerance for
Artemia ranges from 6.5 to 8. The pH tends to decrease during the culture period as a
result of denitrification processes. However, when the pH falls below 7.5 small amounts
of NaHCO
3
(technical grade) should be added in order to increase the buffer capacity of
the culture water. The pH is commonly measured using a calibrated electrode or with
simple analytic lab kits. In the latter case read the instructions carefully in order to make
sure whether the employed reaction is compatible with seawater.
With regard to oxygen, only very low concentrations of less than 2 mg O
2
.l
-1
will limit
the production of biomass. For optimal production, however, O
2
-concentrations higher
than 2.5 mg.l
-1
are suggested. Maintaining oxygen levels continuously higher than 5 mg.l
-
1
, on the other hand, will result in the production of pale animals (low in the respiratory
pigment: haemoglobin), possibly with a lower individual dry weight, which may
therefore be less perceptible and attractive for the predators.
Table 4.4.3. Artificial seawater formulations used for tank production of Artemia
(ing.l

.6H
2
O 0.004 Mg
2+
1.238 KCl 0.97
KCl 0.682 K
+
0.39 MgSO
4
7.74
KBr 0.099 Ca
2+
0.37 NaHCO
3
1.80
HCO
3-
0.142
H
2
O 856 H
2
O 1000 H
2
O 1000
Solution B

NaSO
4
.10H

d,e
0.456
e
0.448
f
n.a.
Food conversion
c
3.89 3.35
d
3.64
e
3.87
e
4.15
f
n.a.
Great Salt Lake, Utah, USA
Survival (%) 77 85 89 89 87 88
Biomass production
a
(%) 69 104 122 128 135 78
Specific growth rate
b
0.392
b
0.437
f
0.454
e

d,e
0.459
d
0.456
d
0.437
e,f
n.a.
Food conversion
c
3.42
e
3.00
d
3.03
d
3.11
d
3.72
d
n.a.
Tanggu, PR China
Survival (%) 95 94 91 93 84 54
Biomass production
a
(%) 41 61 80 92 85 16
Specific growth rate
b
0.299
f

- W
0
).T-1 where T = duration of experiment in days(=9)
W
t
= µg dry weight Artemia biomass after 9 days culturing
W
0
= µg dry weight Artemia biomass at start of experiment
c:
food conversion = F.(Wt - W0)
where F = µg dry weight Dunaliella offered as food
d
to
g:
means with the same superscript are not significantly different at the P<0.05 level
n.a.: not analyzed
A dark red colouration (high haemoglobin content) is easily obtained by applying regular
but short (few minutes) oxygen stresses (by switching off the aeration) a few days before
harvesting. Oxygen levels should be checked regularly as they may drop significantly,
especially after feeding. Oxygen is conveniently measured with a portable oxygen
electrode. When oxygen occasionally drops below 30% saturation (i.e. 2.5 mg O
2
.l
-1
in
seawater of 32 g.l
-1
salinity at 27°C), aeration intensity should be increased temporarily
or air stones added. If oxygen levels remain low, the aeration capacity should be

concentrations up to 1000 mg.l
-1
NH
4
+
, respectively 320 mg.l
-1
NO
2
-
N. It is therefore
very unlikely that N-components will interfere directly with the Artemia cultures.
Nevertheless the presence of soluble substances should be restricted as much as possible
since they are an ideal substrate for bacteria.
Excess soluble waste products can only be eliminated by diluting the culture water with
clean water, be it new or recycled. Methods to evacuate loaded culture water are
discussed below.
4.4.2.3. Artemia
STRAIN SELECTION
Based on laboratory results (Table 4.4.4.), guidelines are provided for strain selection as a
function of optimal temperature and culture performance. The most suitable strain should
be selected according to local culture conditions, such as temperature range, ionic
composition of culture water, etc ...
CULTURE DENSITY OF ARTEMIA
Unlike other crustaceans, Artemia can be cultured at high to very high densities without
affecting survival. Depending on the applied culture technique, inoculation densities up
to 5,000 larvae per litre for batch culture, 10,000 for closed flow-through culture, and
18,000 for open flow-through culture can be maintained without interference on survival
(Table 4.4.5.). Maximum densities cause no real interference on behaviour. Of course,
each culture has its maximum carrying capacity: above these densities, culture conditions

and/or assimilation: including the quality and quantity of the food offered, the
developmental stage of the larvae, and the culture conditions. More detailed information
concerning these processes are given in Coutteau & Sorgeloos (1989).
SELECTION OF A SUITABLE DIET
Artemia can take up and digest exogenous microflora as part of the diet. Bacteria and
protozoans which develop easily in the Artemia cultures are able to biosynthesize
essential nutrients as they use the supplied brine shrimp food as a substrate; in this way
they compensate for any possible deficiencies in the diet’s composition.
The interference by bacteria makes it a hard task to identify nutritionally adequate diets
as such, since growth tests are difficult to run under axenic conditions. As a consequence
the nutritional composition of the diet does not play the most critical role in the selection
of diets suitable for high density culture of brine shrimp. Other more important criteria
include:
· availability and cost
· particle size composition (preferentially <50µm)
· digestibility
· consistency in composition among different batches and storage capacity
· solubility (minimal)
· food conversion efficiency (FCE)
· buoyancy
Commonly used food sources include:
Micro-algae: undoubtedly yield best culture results but rarely available in sufficient
amounts at a reasonable cost. As such the mass culture of suitable algae for Artemia is
not economically realistic, so their use can only be considered in those places where the
algal production is an additional feature of the main activity. Moreover, not all species of
unicellular algae are considered suitable for sustaining Artemia growth (d’Agostino,
1980). For example, Chlorella and Stichococcus have a thick cell wall that cannot be
digested by Artemia, Coccochloris produces gelatinous substances that interfere with
food uptake, and some dinoflagellates produce toxic substances.
Normally, a constant supply of a rather concentrated algal effluent is required to sustain

Waste products from the food industry: non-soluble waste products from agricultural
crops or from the food-processing industry (e.g. rice bran, corn bran, soybean pellets,
lactoserum) appear to be a very suitable feed source for the high-density culture of
Artemia (Dobbeleir et al., 1980). The main advantages of these products are their low
cost and universal global availability. Equally important in the evaluation of dry food is
the consistency of the food quality and supply, and the possibility for storage without loss
of quality. It follows therefore that bulk products must be stored in a dry and
preferentially cool place.
In most cases, commercially available feeds do not meet the particle size requirements
and further treatment is needed. When man-power is cheap a manual preparation can be
used to obtain feed particles in the 50-60 µm size range. It consists of a wet
homogenization in seawater (using an electrical blender) followed by the squeezing of the
suspension through a 50 µm filter bag. Since the feed suspension obtained cannot be
stored, this manual method can only be used on a day-to-day basis for feed processing.
Furthermore, this manual processing method is not very effective with products high in
fibre such as e.g. rice bran, where as much as 90% of the product may be discarded.
In order to reduce the manual labour required in preparing the food, mechanical
techniques for dry grinding and processing need to be used. In several cases,
sophisticated and therefore expensive equipment is required, (i.e. micronisation grinding)
which restricts its practical use and cost-effectiveness.
Soluble material is not taken up by Artemia and will be decomposed in the culture
medium by bacteria, thereby deteriorating water quality via a gradual build up of toxic
substances such as ammonia and nitrite. Hence feeds which contain high amounts of
soluble proteins (e.g. soybean meal) should be treated prior to their use in order to reduce
the soluble fraction. This can easily be achieved by strongly aerating the feed suspension
with airstones for 1-2 h and then allowing the feed particles to settle by cutting off the
aeration for another half an hour. Dissolved materials will foam off or remain in the water
fraction which can be drained off from the sedimented particles. This washing procedure
can be repeated until most soluble matter is removed.
FEEDING STRATEGY