International Journal of Aquaculture, 2013, Vol.3, No.13, 63
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72
http://ija.sophiapublisher.com
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Kohno et al., 1990; Kohno et al., 1997). Difficulties in
rearing early stage larvae of groupers have become the
major bottleneck hindering the development of mass
fingerling production (Kohno et al., 1997). Marte (2003)
summarized the difficulty of rearing grouper into three
area: 1) spawned eggs and larvae are very small and
the small mouth gape in early larvae limits the choice
of initial live feed; 2) grouper are extremely sensitive
to mechanical disturbance; 3) long duration of larval
rearing (>60 days).
In this review, we will use the life cycle of grouper
larvae as a framework to review internal factors
regulating ontogenetic development in fish larvae and
environmental factors affecting the general develoment of
grouper larvae. To understand the cause of high larvae
mortality in early life history, we will review factors
related to the ontogenetic development, and then we
focus on issues of first feeding of grouper larvae in
intensive aquaculture. At the end, we will review
the management strategies of using live feeds in
grouper hatcheries.
1
Ontogenetic Development
1.1
Eggs and Embryo
The eggs size of groupers is generally less than one
millimeter (Table 1). Like most marine teleosts,
nutrition during the embryonic phase is derived from
yolk reserve (Ma et al., 2012). The embryonic period
starts from fertilization and ends at the commencement
of exogenous feeding. It is divided into three major
phase: cleavage egg, embryo, and free embryo (Moyle
and Cech, 2003). Figure 1 illustrates the embryonic
development of Malabar grouper
Epinephelus
malabaricus
.
Cleavage egg (A-F), and embryo (G-L)
are defined according to Moyle and Cech (2003).
Embryonic development is a complex process and egg
quality and hatching environments directly affect
embryonic development and the sizes of fish at
hatching and first feeding (Robin and Gatesoupe, 2001).
Table 1 Comparison of the eggs and larvae of
Epinephaline
Serranids
Species
Egg diameter
(
mm)
Incubation temperature (
℃
)
Hatching
time (h)
Length at hatching
(
mm)
Duration of Yolksac
absorbation (day)
Reference
Epinephelus
malabaricus
0.87
-
0.93
25
-
31
29
-
26
1.71
-
1.98
3
-
4
Leu et al., 2005;
Yoseda et al., 2006
E. tauvina
0.80
-
0.90
27
-
30
25
-
20
1.50
-
2.4
3
Lim 1993; Hussain
et al., 1980
E. fuscoguttatus
0.89
28
-
30
19
-
18
1.80
-
1.90
-
Lim 1993
E. suillus
28
-
30
20
-
18
1.62
-
Duray et al.,1996;
Duray et al.,1997
E. coioides
0.74
-
0.85
24.9
-
28
21
-
19
1.33
-
1.86
3
Doi et al.,1991;
Zou et al., 2003
E. costae
0.89
-
0.95
25
-
25.5
28
-
24
1.69
-
1.85
3
Glamuzina et al., 2000
E. akaara
0.70
-
0.77
25
-
27
25
-
23
1.45
-
1.56
4
Ukawa et al., 1966
E. polyphekadion
0.71
-
0.83
26
-
29
21
-
19
1.70
-
1.80
2
Rasem et al., 1997
E. marginatus
0.74
-
0.94
23
33
-
30
1.40
-
1.67
3
-
4
Glamuzina et al., 1998
E. merra
0.71
-
0.73
26.5
-
28.3
27
-
24
1.40
-
1.60
2
Jagadis et al., 2006
1.1.1
Egg quality
Egg quality is generally derived from broodstock
nutrition (Izquierdo et al., 2001; Mazorra et al., 2003;
Sawanboonchun et al., 2008; Ma et al., 2012). Since
protein, lipoprotein, glycogen, and enzymes contents
in yolk reserve directly affect embryonic development
(
Gunasekera et al., 1995; Harrell and Woods, 1995;
Sargent et al., 1999), proper controlled broodstocks
nutrition is essential in breeding marine fish. For
instance, Dhert et al. (1991) showed that
E. tauvina
broodstock given trash fish injected the emulsified
enrichment diet Marila diet significantly increased oil
globule diameter, total lipids, eicosapentaenoic acid,
docosahexaenoic acid, and larval survival at day 7.
Nutrients such as essential fatty acids (EFA)
(
Fernández-Palacios et al., 1995), vitamin E
(
Fernández-Palacios et al., 1998), carotenoids (Craik, 1985),
vitamin C (Blom and Dabrowski, 1995), dietary
protein, vitamin B
1
,
and vitamin B
6
(
Izquierdo et al., 2001)
in broodstock diets have been considered as essential