Chabet Dis, Refes, Varó, Hontoria, Amat and Navarro
6
feeding appendages (Merchie 1996). Populations of nauplii
of varied sizes have advatages over uniformly sized nauplii
because fish larvae spend less energy taking up a smaller
number of bigger nauplii to satisfy their food necessities
and hence spend that energy on significantly faster growth
(Beck and Bengtson 1982).
Ghomari (2013) reported that chorion thickness was
higher for Artemia salina and varied between 10 μm
(Garaet El Taref) and 13.1 μm (Relizane), compared with
parthenogenetic populations in which it varied between
6.5 μm (Ezzamoul) and 9.5 μm (Melghir). However, in
the present study, the parthenogenetic population of
Bethioua exhibited a higher value in chorion thickness.
Sorgeloos and Kulasekarapandian (1984) noted that a
thick chorion offers better protection to the cysts against
mechanical shocks. In addition to the quality evaluation
studies of Artemia from Ezmoul, Amarouayache and Kara
(2015) found that the average diameter of the hydrated
cysts fluctuated between 247.18 µm and 247.86 µm;
whereas, the diameter of the decapsulated cysts varied
between 217.6 ± 13.3 µm and 225.1 ± 6.29 µm. These
values correspond to a chorion thickness ranging between
11.73 µm and 14.79 µm for Artemia salina from the Chott
Marouane for cysts and nauplii with a diameter of 236.5
µm and 428.7 µm, respectively (Kara et al. 2004). These
values were smaller than those of the cysts and nauplii of
the parthenogenetic strain from El-Bahira with diameters
of 277.26 µm and 549.12 µm, respectively (Derbal et al.
2010). The largest cysts and nauplii, as well as adults,
of Artemia were found in parthenogenetic strains (Amat
1980). In bisexual populations, cysts and nauplii of the New
World (the Americas) are in general smaller than those
from the Old World (Africa, Asia and Europe). The largest
sizes were registered in Artemia tibetiana from Tibet with
cysts of 323 µm and nauplii of 667 µm (Van Stappen et al.
2003), whereas the lowest values were those of Artemia
franciscana from Mexico (Baja California) (RodriguezAlmaraz et al. 2006).
Decapsulation improved hatching, as shown in Table 1.
Similarly, Kara et al. (2004) reported that the cysts of the
Chott Marouane had a hatching percentage of 24.7 ± 3.5%
in chorionated cysts, which improved to 35 ± 2% after
decapsulation. In addition, similar findings were observed
by Ghomari (2013), where the hatching percentage
increased from 153 540 nauplii g −1 to 220 667 nauplii g −1
in Bethioua, from 13 111 nauplii g −1 to 20 667 nauplii g −1 in
Rélizane and from 14 222 nauplii g −1 to 76 667 nauplii g −1
El Goléa. In comparison with other strains, the hatching
percentage obtained in the current study is in between the
lowest (20%) and the highest (90%) values reported by
Sorgeloos et al. 1986. Consequently, they can be used as
an acceptable food source in aquaculture hatcheries. The
differences in hatching results of the cysts from Bethioua,
El Melah, and Timimoune populations support the idea
of geographical location, although always associated
with environmental variables. The sebkhas of El Melah
and Timimoune located in the southern part of Algeria
are characterised by a desert-type climate, dry and hot in
summer and cold in winter; however, the Bethioua sebkha
located in the northwestern part of Algeria has a semi-arid
character with much more rainfall. In this sense, Brown
and Carpelan (1971) pointed at temperature and oxygen
levels as the most important variables in humid climates,
whereas osmotic pressure and oxygen can be considered
more relevant in arid regions. The hatching synchrony
could be considered short for Bethioua and El Melah
populations (7.5 h) and high for Timimoune population
(10.0 h), in comparison with 6.7 h for Bethioua, 10.6 h
for Relizane and 11.1 h for El Golea (Ghomari 2013), 6 h
for Ezmoul (Amarouayache and Kara 2015), 6.5 h for a
Namibian population, 11 h for a Madagascar population
(Triantaphyllidis et al. 1996), 9.5–13 h for a Colombian
Caribbean population (Camargo et al. 2005) and 13–49 h
for a Tunisian population (Ben Naceur et al. 2012). Lavens
et al. (1986) suggested that the development of instars I to
II and III beyond 12 h is accompanied by a 27% reduction
in the energy value by instar III. At this stage, metanauplii
are translucent and swim faster and, as a result, they
were more difficult to catch by the predator larvae. This is
of relevance for aquaculture, because their lower energy
content will reduce the energy uptake by the predator per
hunting effort and therefore growth will be reduced.
Hatching synchrony is an important criterion in the use
of nauplii as live prey, because it facilitates production of
the maximal number of instar I nauplii available within a
short time span (Van Stappen 1996a). In the case of poor
synchrony, much of energy reserves will be consumed
by nauplii that hatched before the last nauplii and before
harvesting was completed. To avoid this, harvesting
has to be done sequentially to avoid a mixed instar
I-II-III population when harvesting at T 90 . Poor hatching
synchrony also involves higher infrastructural costs for the
aquaculturist because of the impossibility of restocking
the same hatching containers for the next day’s harvest.
From this point of view, the Bethioua population has the
best hatching characteristics among the three populations.
It is important to note that no correlation has been found
between hatching performance and nutritional value
(Bengtson et al. 1991).
The total lipids from the decapsulated cysts of the
Artemia populations sampled were within those reported
in the literature for other strains and populations. For
example, the Great Salt Lake and the San Francisco Bay
cysts contained 14.7 and 15.7% of lipids (dry weight),
respectively (Dendrinos and Thorpe 1987; GarciaOrtega et al. 1998). In comparison with other Algerian
strains, the results obtained here can be regarded as
average. Ghomari (2013) found values ranging between
19.27% and 24.43% and interestingly the higher values
were found in samples from Bethioua and El Golea. The
differences observed in total lipid from different Artemia
strains can be due to their genetic structure and/or habitat
characteristics, especially concerning food availability and
quality; however, the composition of algae plays major roles
in this variation (Fujita et al. 1980; Schauer et al. 1980;
Leger et al. 1986; Mura et al. 1997). This also translates
to fatty acid composition and significant differences
have been found in the profiles of the different Algerian
populations studied here. Tizol-Correa et al. (2006) reported
significant difference in the fatty acid profiles of different
Artemia population from tropical salterns from southern
Mexico and Cuba, and emphasised that differences in the
6
feeding appendages (Merchie 1996). Populations of nauplii
of varied sizes have advatages over uniformly sized nauplii
because fish larvae spend less energy taking up a smaller
number of bigger nauplii to satisfy their food necessities
and hence spend that energy on significantly faster growth
(Beck and Bengtson 1982).
Ghomari (2013) reported that chorion thickness was
higher for Artemia salina and varied between 10 μm
(Garaet El Taref) and 13.1 μm (Relizane), compared with
parthenogenetic populations in which it varied between
6.5 μm (Ezzamoul) and 9.5 μm (Melghir). However, in
the present study, the parthenogenetic population of
Bethioua exhibited a higher value in chorion thickness.
Sorgeloos and Kulasekarapandian (1984) noted that a
thick chorion offers better protection to the cysts against
mechanical shocks. In addition to the quality evaluation
studies of Artemia from Ezmoul, Amarouayache and Kara
(2015) found that the average diameter of the hydrated
cysts fluctuated between 247.18 µm and 247.86 µm;
whereas, the diameter of the decapsulated cysts varied
between 217.6 ± 13.3 µm and 225.1 ± 6.29 µm. These
values correspond to a chorion thickness ranging between
11.73 µm and 14.79 µm for Artemia salina from the Chott
Marouane for cysts and nauplii with a diameter of 236.5
µm and 428.7 µm, respectively (Kara et al. 2004). These
values were smaller than those of the cysts and nauplii of
the parthenogenetic strain from El-Bahira with diameters
of 277.26 µm and 549.12 µm, respectively (Derbal et al.
2010). The largest cysts and nauplii, as well as adults,
of Artemia were found in parthenogenetic strains (Amat
1980). In bisexual populations, cysts and nauplii of the New
World (the Americas) are in general smaller than those
from the Old World (Africa, Asia and Europe). The largest
sizes were registered in Artemia tibetiana from Tibet with
cysts of 323 µm and nauplii of 667 µm (Van Stappen et al.
2003), whereas the lowest values were those of Artemia
franciscana from Mexico (Baja California) (RodriguezAlmaraz et al. 2006).
Decapsulation improved hatching, as shown in Table 1.
Similarly, Kara et al. (2004) reported that the cysts of the
Chott Marouane had a hatching percentage of 24.7 ± 3.5%
in chorionated cysts, which improved to 35 ± 2% after
decapsulation. In addition, similar findings were observed
by Ghomari (2013), where the hatching percentage
increased from 153 540 nauplii g −1 to 220 667 nauplii g −1
in Bethioua, from 13 111 nauplii g −1 to 20 667 nauplii g −1 in
Rélizane and from 14 222 nauplii g −1 to 76 667 nauplii g −1
El Goléa. In comparison with other strains, the hatching
percentage obtained in the current study is in between the
lowest (20%) and the highest (90%) values reported by
Sorgeloos et al. 1986. Consequently, they can be used as
an acceptable food source in aquaculture hatcheries. The
differences in hatching results of the cysts from Bethioua,
El Melah, and Timimoune populations support the idea
of geographical location, although always associated
with environmental variables. The sebkhas of El Melah
and Timimoune located in the southern part of Algeria
are characterised by a desert-type climate, dry and hot in
summer and cold in winter; however, the Bethioua sebkha
located in the northwestern part of Algeria has a semi-arid
character with much more rainfall. In this sense, Brown
and Carpelan (1971) pointed at temperature and oxygen
levels as the most important variables in humid climates,
whereas osmotic pressure and oxygen can be considered
more relevant in arid regions. The hatching synchrony
could be considered short for Bethioua and El Melah
populations (7.5 h) and high for Timimoune population
(10.0 h), in comparison with 6.7 h for Bethioua, 10.6 h
for Relizane and 11.1 h for El Golea (Ghomari 2013), 6 h
for Ezmoul (Amarouayache and Kara 2015), 6.5 h for a
Namibian population, 11 h for a Madagascar population
(Triantaphyllidis et al. 1996), 9.5–13 h for a Colombian
Caribbean population (Camargo et al. 2005) and 13–49 h
for a Tunisian population (Ben Naceur et al. 2012). Lavens
et al. (1986) suggested that the development of instars I to
II and III beyond 12 h is accompanied by a 27% reduction
in the energy value by instar III. At this stage, metanauplii
are translucent and swim faster and, as a result, they
were more difficult to catch by the predator larvae. This is
of relevance for aquaculture, because their lower energy
content will reduce the energy uptake by the predator per
hunting effort and therefore growth will be reduced.
Hatching synchrony is an important criterion in the use
of nauplii as live prey, because it facilitates production of
the maximal number of instar I nauplii available within a
short time span (Van Stappen 1996a). In the case of poor
synchrony, much of energy reserves will be consumed
by nauplii that hatched before the last nauplii and before
harvesting was completed. To avoid this, harvesting
has to be done sequentially to avoid a mixed instar
I-II-III population when harvesting at T 90 . Poor hatching
synchrony also involves higher infrastructural costs for the
aquaculturist because of the impossibility of restocking
the same hatching containers for the next day’s harvest.
From this point of view, the Bethioua population has the
best hatching characteristics among the three populations.
It is important to note that no correlation has been found
between hatching performance and nutritional value
(Bengtson et al. 1991).
The total lipids from the decapsulated cysts of the
Artemia populations sampled were within those reported
in the literature for other strains and populations. For
example, the Great Salt Lake and the San Francisco Bay
cysts contained 14.7 and 15.7% of lipids (dry weight),
respectively (Dendrinos and Thorpe 1987; GarciaOrtega et al. 1998). In comparison with other Algerian
strains, the results obtained here can be regarded as
average. Ghomari (2013) found values ranging between
19.27% and 24.43% and interestingly the higher values
were found in samples from Bethioua and El Golea. The
differences observed in total lipid from different Artemia
strains can be due to their genetic structure and/or habitat
characteristics, especially concerning food availability and
quality; however, the composition of algae plays major roles
in this variation (Fujita et al. 1980; Schauer et al. 1980;
Leger et al. 1986; Mura et al. 1997). This also translates
to fatty acid composition and significant differences
have been found in the profiles of the different Algerian
populations studied here. Tizol-Correa et al. (2006) reported
significant difference in the fatty acid profiles of different
Artemia population from tropical salterns from southern
Mexico and Cuba, and emphasised that differences in the