Aquaculture Research, 2014, 45, 1591–1599
doi:10.1111/are.12105
Mass selection for small-sized cysts in Artemia
franciscana produced in Vinh Chau salt ponds,
Vietnam
Nguyen Thi Hong Van1,2, Nguyen Van Hoa2, Peter Bossier1, Patrick Sorgeloos1 &
Gilbert Van Stappen1
1
Laboratory of Aquaculture & Artemia Reference Center, Faculty of Bioscience Engineering - Department of Animal
Production, Ghent University, Ghent, Belgium
2
College of Aquaculture and Fisheries, Cantho University, Cantho, Vietnam
Correspondence: N T H Van, Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Rozier 44, 9000 Ghent,
Belgium. E-mails: nthvan@ctu.edu.vn or Van.NguyenThiHong@Ugent.be
Abstract
Unidirectional mass truncation selection for smallsized cysts was carried out on brine shrimp
(Artemia franciscana Kellogg 1906), Vinh Chau
strain, Vietnam, through cyst sieving and then
culturing the selected individuals (<5% of the population) under field and laboratory conditions over
two successive generations (F1 and F2). The results
showed that at both culture scales, the cyst size of
the selected line was smaller (P < 0.05) compared
with the control (non-selected) line, illustrating
that there was a response to selection. The cyst
size decreased about 3% per generation and the
accumulated gain on the target trait was in the
range 5.82–6.07% at the end of the selection process compared with the base population. The realized heritability estimation (h2) for cyst size was
0.23 0.06 and 0.74 0.19 in the field trials
and 0.34 and 0.51 in the laboratory test for the
F1 and F2 generation respectively. The variations
found between the respective trials may be
explained as the result of environmental interaction with the selection process, but the results
show that a selection program for small-sized cysts
in Artemia by mass selection is possible.
Keywords: Artemia franciscana, mass selection,
small-sized cysts, response, heritability
Introduction
The brine shrimp Artemia, together with rotifers, is
the most widely used live prey in aquaculture
© 2012 John Wiley & Sons Ltd
(Leger, Bengtson, Simpson & Sorgeloos 1986;
Lavens & Sorgeloos 2000; Conceicßao, Yufera,
Makridis, Morais & Dinis 2010). The main advantage of Artemia is its ability to produce dormant
cysts that are highly resistant to adverse environmental conditions and that can easily be stored for
years. This is convenient for transporting and marketing, and eliminates the need to maintain live
cultures, such as in rotifers Brachionus plicatilis
(Lavens & Sorgeloos 2000).
Artemia cyst diameter and the corresponding
instar I nauplius length can largely differ, e.g.
around 500–515 lm for the nauplii of parthenogenetic strains from China versus 400–418 lm
for the San Francisco Bay (SFB) type Artemia
franciscana Kellogg 1906 strain from Vinh Chau,
Vietnam (Vanhaecke & Sorgeloos 1980). Cyst size
is one of the parameters determining the price of
the cyst product on the market. However, even
the smallest Artemia instar I nauplii, such as in
the Vinh Chau strain, are considerably bigger than
the biggest rotifers (130–340 lm, average length
239 lm), which is a problem for ingestion by
small-sized marine fish larvae (Baylon, Ma-Eugenie
& Maningo 2004). Recently, a lot of efforts have
been made to replace rotifers by Artemia nauplii at
first feeding of shrimp, marine fish and crab. However, prey size limitations resulting in reduced larval survival are still the main challenge (Faleiro &
Narciso 2009; Nhu, Dierckens, Nguyen, Tran &
Sorgeloos 2009; Galley, Green, Watkins & Le Vay
2011). Consequently, there is a high potential for
small-sized Artemia cysts on the world market.
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Artemia small-sized cyst selection N T H Van et al.
Aquaculture Research, 2014, 45, 1591–1599
Scientists working on heritable traits in
Artemia indicated that heritability values can be
used to formulate a selective breeding program
and to develop suitable lines with the specific
aim to alter desirable traits in Artemia as live
food for a specific group of aquatic animals
(Browne, Moller, Forbes & Depledge 2002; Shirdhankar, Thomas & Barve 2004). Although
selection is common in many other aquatic animals, such as crustaceans, shellfish, Tilapia, salmon and catfish (Rezk, Smitherman, Williams,
Nichols, Kucuktas & Dunham 2003; Kenway,
Macbeth, Salmon, McPhee, Benzie, Wilson &
Knibb 2006; Li, He, Hu, Cai, Deng & Zhou
2006; Zheng, Zhang, Liu & Guo 2006; Rezk,
Ponzoni, Khaw, Kamel, Dawood & John 2009),
up to date very little work on Artemia selection
has been reported. So far the genetic basis of
cyst size as well as of selective breeding in
Artemia cysts has remained unexplored. Initial
work has been carried out by Shirdhankar and
Thomas (2003) who realized substantial genetic
gain from bi-directional selection for naupliar
length of A. franciscana. However, this study was
based on laboratory culture tests using a limited
number of animals and did not consider large
scale or field applications. The objective of our
study was therefore to verify if the principle of
unidirectional mass truncation selection, applied
over successive generations, would result in a
heritable smaller Artemia cyst size as compared
with the original population. To assess the
practical feasibility of the technique in view of
mass production, the selection experiment was
run both under pond conditions and laboratory
conditions where more stable environmental
conditions can be maintained.
Material and methods
Parental cyst material
Artemia franciscana, Vinh Chau strain, Vietnam,
was utilized as parental material in the laboratory
and in two field selection experiments run in
2008 and 2010. Parental material in the first and
second field tests originated from a cyst batch
harvested inVinh Chau ponds in 2007 and 2008
respectively. The cysts used in the laboratory test
were produced in a laboratory mass culture
started with nauplii hatched from 2007 Vinh
Chau pond cysts.
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Experimental set-up and selection procedure
Based on the frequency distribution of the Vinh
Chau cyst diameter, a cyst diameter below
210 lm, corresponding to about 5% of the population, was set as targeted selection truncation
point. The parental cyst material (P) was sieved
and hydrated for 1 h in 30 g Ll seawater over a
nylon filter bag with mesh size 212 lm. The
parental cysts were gently shaken on the mesh
under a seawater flow until no cysts passed
through the filter bag anymore. The fraction passing through the mesh was used as inoculation
material Ps (Fig. 1). Nauplii hatched from Ps and
non-sieved control cysts were each inoculated in
three replicate ponds (in the field) or tanks (in the
laboratory), producing F1s and F1c cysts respectively. F1s cysts were pooled and diapause was
broken by oven drying to have sufficient inoculation material to produce a next generation after
selection. To increase the selection pressure, as
compared with the previous generation, the pooled
F1s cysts were sieved over 200-lm mesh size targeting a truncation point of 1% based on the cyst
size frequency distribution. The cysts passing
through the mesh (F1ss) were hatched and inoculated in three replicate ponds and tanks to produce
F2s cysts. In parallel, non-sieved pooled F1s cysts
were used to produce the F2 control line (F2c) in
three replicate ponds (Fig. 1).
Laboratory test
Production of parental generation
Three gram of cysts from the 2007 Vinh Chau
harvest were hatched according to standard procedures (Lavens & Sorgeloos 1996). The nauplii
were stocked at 200 individuals L1 in a semiraceway 4 m3 polyethylene tank with brine water
of salinity 80 g Ll collected from the salt ponds,
and cultured for 35 days without water renewal.
Faeces and other organic deposits were siphoned
weekly. The culture was kept at room temperature
(in the range 24–29°C) and fed twice a day with
spray dried algae (Spirulina pacifica; Cyanotech-Kailua-Kona, HI, USA) combined with Lansy® PZ
shrimp feed (INVE, Baasrode, Belgium) according
to the feeding rate used by Hoa (2002).
Cysts appearing on the water surface were collected daily using a small 200 lm scoop net,
rinsed and stored in NaCl-saturated brine water
for 2 weeks (P generation). To maximize diapause
© 2012 John Wiley & Sons Ltd, Aquaculture Research, 45, 1591–1599
Artemia small-sized cyst selection N T H Van et al.
Aquaculture Research, 2014, 45, 1591–1599
P (parental material)
Selected line Ps
(screening over 212 µm)
Control line
Inoculation in three replicate ponds or
tanks and cultured to maturity
F1s 1
F1s2
Inoculation in three replicate ponds or
tanks and cultured to maturity
F1s3
F1c1
F1c2
F1c3
F1s cysts pooled and dried
Selected line F1ss
(screening over 204 µm)
Inoculation in three replicate ponds or
tanks and cultured to maturity
F2s1
F2s2
Control line
Inoculation in three replicate ponds or
tanks and cultured to maturity
F2s3
F2c1
F2c2
F2c3
Figure 1 Schematic overview of selection experiments.
deactivation, cysts were then rinsed with tap
water and dried in an oven at 40°C during 7 h
before being used for selection using the standard
procedure described above.
material available, the culture was run in 4 L
plastic cones.
F1 and F2 culture conditions
Experimental field site
Parental cysts were hatched according to standard procedures (Lavens & Sorgeloos 1996). The
selected and control lines of the F1 generation
were cultured in three replicate 50 L conical
polyethylene tanks with pond water of 80 g Ll
salinity and moderate aeration, using a stocking
density of 400 nauplii L1. The feeding procedure
was the same as used for the parental generation,
but food quantity was adjusted every 3 days by
examining the densities and population composition. Temperature was maintained at room conditions (24–29°C). Water exchange was carried out
weekly after cyst collection. The culture lasted for
45 days and was ended before the ovoviviparously produced F2 generation approached maturation. Culture conditions for the oviparously
produced F2 generation were the same as for F1.
However, due to the smaller amounts of F1 cyst
Two experimental runs were carried out during
two dry seasons in the solar salt ponds of Vinh
Chau, Soc Trang province, Mekong delta, Vietnam
(106º05′–106º42′E and 9º22′–9º24′N; January–
April 2008 and 2010).
Field tests
Pond management and data collection
All experimental ponds used for production of F1
cysts had a surface area of 800 m² each
(20 9 40 m), whereas those for F2 had 260 m²
(13 9 20 m), as less inoculation material was available. In terms of production of green water, fertilization scheme, control of water level and salinity, the
ponds were managed according to the standard culture procedures described by Anh, Hoa, Van Stappen
and Sorgeloos (2009). Conditions in selected and
control ponds were kept as identical as practically
possible. The stocking density was 100 nauplii L1.
© 2012 John Wiley & Sons Ltd, Aquaculture Research, 45, 1591–1599
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Artemia small-sized cyst selection N T H Van et al.
Aquaculture Research, 2014, 45, 1591–1599
When the cysts started to appear on the pond surface
(generally about 2 weeks after inoculation), they
were daily collected by a scoop net, cleaned and
stored in NaCl-saturated brine for further analysis
and utilization. The culture period lasted around
3–4 weeks, and was terminated before the ovoviviparously produced nauplii became adult.
Data collection and analysis
Abiotic parameters
Both in the laboratory and in the field tests
temperature (mercury thermometer), salinity (temperature-corrected refractometer; Atago, Tokyo,
Japan) and pH (WinLab® Data Line pH meter;
Windaus, Clausthal-Zellerfeld, Germany) were monitored daily at 07:00 hours and 14:00 hours by
direct measurement. The nutritional parameters,
total ammonia nitrogen (TAN) and nitrite (NO2),
were sampled every week and analysed in the laboratory using standard methods (Eaton, Clesceri &
Greenberg 1995).
S ¼selection differential; the difference in
mean phenotype between the selected
parents ðls Þ and the entire parental
population ðlÞ : S ¼ ls l
Genetic gain is the amount of increase in proportional phenotype that can be achieved through
artificial genetic improvement programs. In this
study, it is used to refer to the percentage reduction in cyst diameter between selected and nonselected lines after one generation, known as current genetic gain (GGc) or estimated response; it
was calculated according to Zheng et al. (2006):
GGC ¼ ððlselected lcontrol Þ=lcontrol Þ
100 where
lselected ¼mean phenotype of the progeny in
the selected line
lcontrol ¼mean phenotype of the progeny in
the non-selected line
Cyst biometrical analysis
Cysts produced both in ponds and tanks were sampled
and measured, after that data from replicates were
pooled for analysis of heritability. Cyst biometry of
field samples (P, Ps, F1s, F1c, F1ss, F2s and F2c) was
determined using Clemex® image analysis software at
INVE Tech Company (INVE, Baasrode, Belgium). The
cyst samples were first hydrated in sea water, after
which they were put in vials followed by adding a few
drops of lugol solution as staining agent and as prevention for possible hatching. The samples were then
transferred into a sample holder using a micropipette
and placed on a motorized stage with camera focusing
from above. The individual cyst diameter (in lm) of at
least 500 cysts per sample was determined, and the
average value and standard deviation was calculated.
Biometry of laboratory samples was determined
manually by analysing at least 500 cysts per sample under a microscope equipped with a graduated
ocular (Olympus SZ51, Tokyo, Japan).
Calculation of heritability value and genetic gain
The realized
expressed as
heritability
h²
(Lutz
2001)
R ¼response; the difference in mean
phenotype between the progeny
generation ðl0 Þ and the previous
generation ðlÞ : R ¼ l0 l
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is
The realized response, or difference in mean
phenotype between selected line and parental generation, expressed as percentage of the value of
the parental generation, was calculated and
reported as SR (size reduction).
Statistical analysis
Mean value and standard deviation of cyst diameter of the P, Ps, F1s, F1c, F1ss, F2s and F2c samples
was determined using the Descriptive Statistics tool
in Statistica version 7.0. One-way ANOVA and posthoc comparison (Fisher LSD test) was used to
detect significance of differences at P = 0.05
between P, F1s, F1c, F2s and F2c samples.
Results
Abiotic culture conditions
During the laboratory test, the salinity was kept
stable at 80 g Ll; pH showed little variation
(7.5 0.3) and temperature was 26.2 2.7°C.
TAN and NO2 measurements were in the
range 0.09–0.33 mg L1 and 0.25–0.60 mg L1,
respectively, which is below the harmful levels for
Artemia.
In the field trials, the culture conditions were
more unstable compared with the laboratory test.
© 2012 John Wiley & Sons Ltd, Aquaculture Research, 45, 1591–1599
Artemia small-sized cyst selection N T H Van et al.
Aquaculture Research, 2014, 45, 1591–1599
The salinity was initially maintained at the
optimal level for Artemia culture (80–95 g Ll).
However, heavy rain at the end of the dry season
in the first run lead to a strong decline in salinity
(with a final value below 50 g Ll). The temperature fluctuated in the wide ranging 23–40°C
during daytime and pH was 7.8–8.4 (Table 1).
Concerning to the nutritional value during the
culture, TAN were recorded in the range 0.110–
0.980 and 0.028–0.950 mg L1; meanwhile
NO2 0.001–0.071 and 0.008–0.376 mg L1, for
F1 and F2 respectively. No obvious differences were
found in these parameters between the selected
and non-selected lines (Table 1).
Cyst diameter
The hatching percentage of all cyst samples in the
control and selected lines used for inoculation and
production of a subsequent generation was at least
89.4%. Ps cysts obtained after sieving accounted
for 4.2 0.4% wet weight (mean value for laboratory and both field runs) of the non-sieved P
material. During the second selection round, the
cysts passing through the mesh (F1ss), accounted
for 12.3 1.1% wet weight of the non-sieved F1s.
As the P material used in the laboratory test and
two field tests did not come from the same batch,
different cyst diameter values were found. Consequently, different values were obtained as well for
the respective Ps fractions in laboratory and field
tests (Table 2).
In general, the offspring (F1, F2) in the field and
laboratory tests showed a tendency of decreasing
cyst diameter over the successive generations
for both control and selected lines. However, a
significant difference (P < 0.05) with the parental
generation (P) was found for the selected F1s in
the laboratory test and in the second field run,
whereas it was not significant for the control F1c
in any of the three tests (Table 2). All F2 samples
(both control and selected lines) were significantly
smaller as compared with their respective P-values, but the F2s of all three tests (laboratory and
two field runs) were significantly smaller
(P < 0.05) than their corresponding control F2c
and than the corresponding F1 samples of both
control and selected lines (Table 2).
Response and heritability
In laboratory conditions, the cyst size reduction
through selection was almost similar in each generation (7.4 lm in F1 and 7.0 lm in F2), whereas
in field conditions, this response was found higher
in F2 than in F1 (8.1–10.0 lm versus 3.3–4.3 lm
respectively) because of the cumulative selection
pressure over the two generations.
The percentage reduction in cyst diameter (SR),
obtained on average per generation, was very similar in both the laboratory and field experiment
(3.09% and 2.87 1.47%). However, the estimated response (GGc) was smaller than the corresponding SR value, except in the second run of
the field test. Nevertheless, values from both calculations were generally not dissimilar (Table 2).
The heritability value (h²) in the laboratory test
was lower in F1 than in F2 (Table 2). This was
also observed in the field tests, although the range
of variation between F1 and F2 heritability values
was larger than in the laboratory test (0.19 and
0.27 in F1 versus 0.60 and 0.87 in F2 for the first
Table 1 Abiotic factors in culture ponds during the field experiment (mean standard deviation of all observations
throughout culture period)
Temperature (°C)
Treatment
F1 (R1)
F2 (R1)
F1 (R2)
F2 (R2)
Selected
Control
Selected
Control
Selected
Control
Selected
Control
1
Salinity (g L )
93.6
94.2
63.4
60.8
81.2
81.0
92.7
94.3
6.2
4.9
14.8
15.2
5.9
6.6
6.4
5.5
07:00 hours
26.8
26.5
27.3
27.3
23.4
23.4
26.6
26.7
1.1
1.0
0.9
0.9
1.3
1.3
1.3
1.2
14:00 hours
36.3
36.4
31.5
31.3
31.9
31.9
34.7
34.7
1.7
1.8
2.6
2.7
2.2
2.2
2.3
2.3
TAN
(mg L1)
pH
8.2
8.3
7.8
7.8
8.2
8.2
8.1
8.4
0.3
0.3
0.1
.2
0.3
0.3
0.3
0.2
0.620
0.558
0.305
0.316
0.579
0.563
0.380
0.390
0.259
0.238
0.162
0.171
0.091
0.067
0.291
0.175
NO2
(mg L1)
0.006
0.004
0.017
0.015
0.012
0.010
0.082
0.114
0.004
0.002
0.011
0.009
0.005
0.006
0.046
0.049
R1, R2: first run and second run respectively.
© 2012 John Wiley & Sons Ltd, Aquaculture Research, 45, 1591–1599
1595
1596
204.0 10.5 (1639)
1.69
1.51
0.27
215.5b 9.6 (752)
F(R2)
206.5 12.7 (603)
219.2a 8.6 (1939)
218.7 10.3 (1755)
1.44
1.82
0.19
235.7a 10.5 (4082)
232.3ab 10.8 (3353)
214.1 11.5 (1150)
Mean values sharing the same superscript in the same row are not significantly different at P = 0.05; the sieved cysts (Ps and F1ss) were not involved in the statistical analysis; F(R1), F(R2): first
and second field run, respectively. For abbreviations of heritability parameters, see Material and methods.
5.26
4.64
0.87
2.05
3.49
0.60
2.79
3.05
229.8b 17.3 (943)
215.6 16.0 (700)
Lab
test
F(R1)
237.2a 15.5
(654)
236.6a 12.3
(769)
218.8a 10.6
(563)
234.9a 17.2 (949)
0.34
3.12
2.17
216.1 17.0 (750)
222.8c 13.0
(521)
224.2c 11.4
(5576)
205.5c 10.6
(1068)
227.2b 13.4
(547)
230.0b 11.9
(3361)
216.9b 9.8
(1079)
0.51
GGC
(%)
SR
(%)
h2
F 2c
F2s
F1s
Ps
P
F 1c
h2
SR
(%)
GGC
(%)
F1ss
Second selection
First selection
Table 2 Cyst diameter (mean standard deviation) and heritability parameters of cyst size selection experiments under field and laboratory culture conditions of P, F1 and F2
samples; number in parentheses is sample size
Artemia small-sized cyst selection N T H Van et al.
Aquaculture Research, 2014, 45, 1591–1599
and second field run, respectively, corresponding
with average h² values of 0.23 0.06 in F1 and
0.74 0.19 in F2).
Discussion
Artemia is a crustacean characterized by its short
generation time and high productivity; therefore,
mass selection could be suitable for selecting desirable traits in this genus, such as small cyst size.
The inbreeding rate is supposed to be low as the
selected population still contains a very high number of individuals. In this study, selection experiments targeted the production of small-sized
Artemia cysts by application of selection over two
consecutive generations.
The results indicated that the response to selection was similar in both F1 and F2, with a cyst size
reduction in approximately 3% per generation. In
the field trials, both estimated and realized
response were markedly higher in F2 than in F1,
with average values for both trials in the range of
3.7–4.1% and 0.02–1.7%, respectively, whereas
this was not the case in the laboratory test. The
variation in responses between laboratory and field
condition as well as between generations could be
attributed to different rearing conditions in the
three tests. Although the conditions in the laboratory test were maintained stable, they were less
controlled in the field tests. These conditions are
supposed to interact differently with the genetic
characteristics of the population and hence with
the success of the selection process. This is illustrated by the difference between the estimated and
realized response values over successive generations. The former is calculated based on populations (selected and control lines of the same
generation) raised under more or less the same
culture conditions, whereas this is not the case for
the latter (parental and offspring generations).
Another factor possibly accountable for the
difference in response in field and laboratory tests
is selection intensity, calculated as the selection
differential S divided by the phenotypic standard
deviation of the trait. According to Muir (2000),
mass selection applied with higher selection intensity leads to a higher response to selection, but
only over a limited number of successive generations. With the relatively big amount of cysts
harvested from the pond culture, the selection differential in the field tests could be smaller than in
the lab tests, where only tiny amounts of cysts
© 2012 John Wiley & Sons Ltd, Aquaculture Research, 45, 1591–1599
Artemia small-sized cyst selection N T H Van et al.
Aquaculture Research, 2014, 45, 1591–1599
were available for selection. The selection intensity
in the field material varied little, from 1.16 (F1) to
1.18 (F2), whereas for the lab tests, these values
were 1.39 at F1, but only 0.79 in F2.
Nevertheless, the phenotypic gain (percentage
decrease in cyst diameter) from both field and laboratory results were consistent in demonstrating
that selection pressure played a very important role
during selection. After short-term selection of two
generations, the total response in size reduction (as
compared with the P population) was very similar
in field and laboratory conditions (5.82 1.44%
and 6.07%, respectively, or 2.91–3.04% per generation) even though rearing conditions were different. This response was higher than what was
found by Shirdhankar and Thomas (2003) with bidirectional mass selection of small- and big-sized A.
franciscana nauplii from Great Salt Lake, USA; the
response in the selection line for small nauplii was
7.65–9.31% size reduction over six generations,
corresponding with 1.28–1.55% per generation,
which is lower than the 2.91–3.04% in our results.
However, our response values are rather low compared with body size values obtained for other
aquatic animals for which responses in the range
of 7–20% per generation have been documented
(Rezk et al. 2003, 2009; Zheng, Zhang, Liu, Zhang
& Guo 2004; Maluwa & Gjerde 2007; He, Guan,
Yuan & Zhang 2008).
In a selection program, realized heritability (h²)
is considered the criterion to evaluate the effective
transmission of a selected trait from parent to the
next generation (Lutz 2001; Beaumont, Boudry &
Hoare 2010). In our study, h² was of intermediate
magnitude in F1 (0.34 and 0.23 0.06 in laboratory and field tests respectively) and high in F2
(0.51 and 0.74 0.19). The heritability of quantitative Artemia traits, although poorly documented
compared with other aquatic animals, is highly
variable, ranging from low (0.02) to high (0.95)
depending on the observed traits (Browne, Sallee,
Grosch, Segreti & Purser 1984; Browne et al. 2002;
Shirdhankar et al. 2004; Briski, Van Stappen,
Bossier & Sorgeloos 2008). The heritability values
may be affected by the environmental conditions,
which were different in our respective experiments.
According to Browne et al. (2002), studying
Artemia reproductive and life span traits, the environmental component contributes more to total
phenotypic variation than the genetic one. This
has been demonstrated for Artemia cyst size as
well, which has been documented as negatively
correlated with salinity and temperature of salt
ponds during the reproduction phase (Guermazi,
Habib & Lotfi 2009).
Furthermore, the variation in heritability
between generations and between laboratory and
field conditions might also be related to parental
genetic drift (Beaumont et al. 2010) or to the
action of natural selection. If the targeted traits
coincide with improved fitness, natural selection
will work in synergy with the selection program;
in the opposite case, it will counteract it (Gjedrem
& Thodesen 2005). The action of natural selection,
combined with phenotypic plasticity, may be an
explanation of the increasing proportion of small
cysts with a size less than 200 lm, amounting up
to almost 30% of the population in the field tests
and 14% in the laboratory test at the end of our
selection (data not shown).
In summary, our results from both laboratory
and field trials demonstrated that there was a
response to selection of small-sized cysts in Artemia.
Realized heritability suggests that effective progress
could be made through selection. However, environmental conditions may have interfered with the
results, especially in the field trial. Therefore, the
environmental interactions including the maternal
effect should be further investigated. Long-term
selection experiments, both at laboratory and field
scale, are necessary to learn more about trait heritability before setting up a mass selection program
aiming to produce small Artemia cysts for specific
aquaculture purposes.
Acknowledgments
Christ Mahieu, Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium,
is acknowledged for help in cyst diameter analysis.
Automated cyst analysis equipment was kindly
made available by Geert Rombaut, INVE Technologies, Baasrode, Belgium.
References
Anh N.T.N., Hoa N.V., Van Stappen G. & Sorgeloos P.
(2009) Effect of different supplemental feeds on proximate composition and Artemia biomass production in
salt ponds. Aquaculture 286, 217–225.
Baylon J.C., Ma-Eugenie B.A. & Maningo N.C. (2004)
Ingestion of Brachionus plicatilis and Artemia salina
nauplii by mud crab Scylla serrata larvae. Aquaculture
Research 35, 62–70.
© 2012 John Wiley & Sons Ltd, Aquaculture Research, 45, 1591–1599
1597
Artemia small-sized cyst selection N T H Van et al.
Aquaculture Research, 2014, 45, 1591–1599
Beaumont A.R., Boudry P. & Hoare K. (2010) Genetic
variation of traits. In: Biotechnology and Genetics in
Fisheries and Aquaculture (2nd edn) (ed. by Andy R.
Beaumont, Pierre Boudry & Kathrin Hoare), pp 99–
126. Willey-Blackwell, Oxford, UK.
Briski E., Van Stappen G., Bossier P. & Sorgeloos P.
(2008) Laboratory production of early hatching
Artemia sp. cysts by selection. Aquaculture 282, 19–25.
Browne R.A., Sallee S.E., Grosch D.S., Segreti W.O. &
Purser S.M. (1984) Partitioning genetic and environmental components of reproduction and lifespan in
Artemia. Ecology 65, 949–960.
Browne R.A., Moller V., Forbes V.E. & Depledge M.H.
(2002) Estimating genetic and environmental components of variance using sexual and clonal Artemia.
Journal of Experimental Marine Biology and Ecology 267,
107–119.
Conceicßao L.E.C., Yufera M., Makridis P., Morais S. &
Dinis M.T. (2010) Live feeds for early stages of fish
rearing. Aquaculture Research 41, 613–640.
Eaton A.D., Clesceri L.S. & Greenberg A.E. (1995) Standard Methods for the Examination of Water and Wastewater (19th edn). American Public Health Association
Washington, USA.
Faleiro F. & Narciso L. (2009) Brachionus vs Artemia duel:
optimizing first feeding of Upogebia pusilla (Decapoda:
Thalassinidea) larvae. Aquaculture 295, 205–208.
Galley T.H., Green B.C., Watkins L. & Le Vay L. (2011)
Development of larval culture techniques for the shore
crab, Carcinus maenas (L). Aquaculture International 19,
381–394.
Gjedrem T. & Thodesen J. (2005) Selection. In: Selection
and Breeding Programs in Aquaculture (ed. by T. Gjedrem),
pp. 89–111. Springer, The Netherlands.
Guermazi W., Habib A. & Lotfi A. (2009) Correspondence
of the seasonal patterns of the Brine Shrimp, Artemia
salina (Leach, 1819) (Anostraca) with several environmental factors in an arid solar saltern (Sfax, Southern
Tunisia). Crustaceana 82, 327–348.
He M., Guan Y., Yuan T. & Zhang H. (2008) Realized
heritability and response to selection for shell height in
the pearl oyster Pinctada fucata (Gould). Aquaculture
Research 39, 801–805.
Hoa N.V. (2002) Seasonal Farming of the Brine Shrimp
Artemia Franciscana in Artisanal Salt Ponds in Vietnam:
Effects of Temperature and Salinity. PhD dissertation
Ghent University, Ghent, Belgium, 184pp.
Kenway M., Macbeth M., Salmon M., McPhee C., Benzie J.,
Wilson K. & Knibb W. (2006) Heritability and genetic
correlations of growth and survival in black tiger
prawn Penaeus monodon reared in tanks. Aquaculture
259, 138–145.
Lavens P. & Sorgeloos P.. (eds) (1996) Manual on the
Production and use of Live Food for Aquaculture. FAO
Fisheries Technical Paper No 361. Food and Agricul-
1598
ture Organization of the United Nations, Rome
295pp.
Lavens P. & Sorgeloos P. (2000) The history, present
status and prospects of the availability of Artemia cysts
for aquaculture. Aquaculture 181, 397–403.
Leger P., Bengtson D.A., Simpson K.L. & Sorgeloos P.
(1986) The use and nutritional value of Artemia as a
food source. Oceanography and Marine Biology: An
Annual Review 24, 521–623.
Li S.F., He X.J., Hu G.C., Cai W.Q., Deng X.W. & Zhou P.Y.
(2006) Improving growth performance and caudal fin
stripe pattern in selected F6–F8 generations of GIFT
Nile tilapia (Oreochromis niloticus L.) using mass selection.
Aquaculture Research 37, 1165–1171.
Lutz C.G. (2001) Selection and realized heritability. In:
Practical Genetics for Aquaculture (ed. by Greg Lutz), pp.
66–90. Fishing News Books, Blackwell Science, Oxford,
UK.
Maluwa A.O. & Gjerde B. (2007) Response to selection
for harvest body weight of Oreochromis shiranus. Aquaculture 273, 33–41.
Muir W.M. (2000) The interaction of selection intensity,
inbreeding depression, and random genetic drift on
short and long-term response to selection: results using
finite locus and finite population size models incorporating directional dominance. Journal of Animal Science
79, 1–11.
Nhu V.C., Dierckens K., Nguyen T.H., Tran M.T. &
Sorgeloos P. (2009) Can umbrella-stage Artemia franciscana substitute enriched rotifers for Cobia (Rachycentron canadum) fish larvae? Aquaculture 289, 64–69.
Rezk M.A., Smitherman R.O., Williams J.C., Nichols A.,
Kucuktas H. & Dunham R.A. (2003) Response to three
generations of selection for increased body weight in
channel catfish, Ictalurus punctatus, grown in earthen
ponds. Aquaculture 228, 69–79.
Rezk M.A., Ponzoni R.W., Khaw H.L., Kamel E., Dawood T. & John G. (2009) Selective breeding for
increased body weight in a synthetic breed of Egyptian Nile tilapia, Oreochromis niloticus: response to
selection and genetic parameters. Aquaculture 293/,
187–194.
Shirdhankar M.M. & Thomas P.C. (2003) Response to
bi-directional selection for naupliar length in Artemia
franciscana. Aquaculture Research 34, 535–542.
Shirdhankar M.M., Thomas P.C. & Barve S.K. (2004)
Phenotypic estimates and heritability values of Artemia
franciscana. Aquaculture Research 35, 35–39.
Vanhaecke P. & Sorgeloos P. (1980) International Study
on Artemia. IV. The biometrics of Artemia strains from
different geographical origin. In: The Brine Shrimp
Artemia, Vol. 3. Ecology, Culturing, use in Aquaculture
(ed. by G. Persoone, P. Sorgeloos, O. Roels & E. Jaspers), pp. 393–405. Universa Press, Wetteren, Belgium.
© 2012 John Wiley & Sons Ltd, Aquaculture Research, 45, 1591–1599
Artemia small-sized cyst selection N T H Van et al.
Aquaculture Research, 2014, 45, 1591–1599
Zheng H., Zhang G., Liu X., Zhang F. & Guo X. (2004)
Different responses to selection in two stocks of the bay
scallop, Argopecten irradians Lamarck (1819)”. Journal of
Experimental Marine Biology and Ecology 313, 213–223.
Zheng H., Zhang G., Liu X. & Guo X. (2006) Sustained
response to selection in an introduced population of
the hermaphroditic bay scallop Argopecten irradians
Lamarck (1819). Aquaculture 255, 579–585.
© 2012 John Wiley & Sons Ltd, Aquaculture Research, 45, 1591–1599
1599