Immune system and production of pacific white leg shrimp on the different stocking density and sediment redox potential
View/ Open
Date
2016Author
Wiyoto
Sukenda
Harris, Enang
Nirmala, Kukuh
Djokosetiyanto, Daniel
Metadata
Show full item recordAbstract
Pacific white leg shrimp is a desirable species for shrimp farmers, which has
eral advantages such as the availability of specific pathogen free post larvae, i relatively fast
growth, and high survival rate. Pacific white leg shrimp Li 'P,enaeus vannamei has become one of
the most important species in aquaculture sectors, including in Indonesia. Indonesian shrimp
production had en dramatically increased during the last decade, from 191 148 MT in 2003 to
593 280 MT in 2014 or about 213% increase. The increase of shrimp production is ostly due to new
openings of farming area and by intensification by increasing the stocking density. However,
despite the progressive increase in production, shrimp-farming industry still encounters some major
challenges among which is disease outbreak. Disease outbreak and environmental quality in shrimp
culture systems are closely related. It has been suggested that viral and bacterial diseases,
together with poor soil and water quality, were the main causes of the reported shrimp mass
mortality in several studies.
The aim of this study is to evaluate the effects of stocking density and sediment redox potential
on the shrimp production performance and non-specific immune response. This study consisted of
three main research stages with the following objectives: first, to observe the behavioural
activity of L. vannamei and its oxygen consumption, as well as sediment oxygen demand in relation
to sediment redox condition; second, to evaluate the effect of shrimp density on the animals immune
system and growth performance, as well as the water quality in the culture system; and third, to
evaluate the effects of sediment redox potential and shrimp stocking density on the sediment and
water quality parameters, shrimp production performance, and immune response and resistance upon
white spot syndiome virus (WSSV) challenge
The first experiment was conducted in semi outdoor laboratory using 18 units of aquarium with a
dimension of 30 cm x 30 cm x 100 cm. Each aquarium was filled with filtered seawater and 5 cm deep
soil substrate with different redox pote tial at the bottom of each tank. Shrimp were randomly
distributed into the tank at a stocking density of 130 shrimps m·²• One hour after being
transferred to the aguarium, the shrimp swimming behaviour was observed for 6 consecutive hours,
during which no feed was given to the shrimp. At the initial and end of expe ·ment, dissolved
oxygen was measured at different depth. The study showed that sediment redox potential did not
influence L. vannamei behavioural profile. Shrimp stayed on the tank bottom for most of the time in
all treatments and these demonstrate that these animals were unable to stay for a long time in the
water co , . Dissolved oxygen decreased with the increase of the water depth incHcating that
dissolved oxygen on the bottom was consumed by both shrimp and s i; ent with the more negative
sediment redox potential the higher sediment
en demand.
In the second experiment, a completely randomized experimental design
was applied with four different stocking densities, i.e. 50, 150, 300 and 600 shr· s m·2 with four
repetitions. Eighteen units of fibre tanks with a dimension
of 48 cm x 48 cm x I 00 cm were used as the experimental containers. The tanks were fil ed with
filtered seawater to a height of 90 cm. Healthy shrimp at intermolt stag ere selected and randomly
distributed to each tank at the density according to ill treatments. The dissolved oxygen
concentration, temperature, pH and sa· l}' of the culture water were measured daily. Water samples
were collected wee: y to measure the concentrations of total ammoniacal nitrogen, nitrite,
nitrate, and tal alkalinity. Shrimp growth performance comprising of average body wei t, specific
growth rate, survival, as well as immune parameters including total ... aemocyte count,
phenoloxydase, and respiratory burst were measured
. The results of the experiment demonstrated that maintaining shrimp de sr_ at 300 shrimp m·2 and
600 shrimps m·2 led to significant reductions in
pro-d
ction performance, water quality and shrimp immunity.
lie procedures for the third experiment were similar to those in the second
expe ent. In this experiment, however, sediment with different sediment redox potential (-65 mV,
-108 mV and -206 mV) was added onto the bottom of each
, stocking density (60 and 120 shrimps m"2), and a challenge test was
performed at the end of the experiment. Sediment sample was collected from each experi ental tank
at the initial and the final day of experimentation to measure the total or·anic C, total organic
N, total P, S, Fe, and Mn concentrations in the sediment. The same manner as in the second
experiment was carried out for the water samples, growth performance and shrimp immune parameter.
The redox potentia of the sediment clearly affected the total concentration of some major metal
elements, such as Mn, Fe, and S, which functioned as terminal electron accepto11s in subsequent
anaerobic respiration in the sediment. The shrimp density strong! affected all water quality
parameters measured in this study except H2S concentration. The redox potential of sediments also
demonstrated significant effects on all water quality parameters except total amoniacal
nitrogen concen ation. Furthermore, the results clearly showed that a redox potential of - 206 mVi
significantly reduced the dissolved oxygen concentration in the sediment water interface and
increased the generation of H2S in water column. Thereby, this red0x potential level is not
advisable for shrimp culture system. Maintaining shrimp in -206 mV sediment redox potential led to
significant reductions in
production performance and resistance against WSSV. Stocking density did not
affect e shrimp growth, but significantly reduced the production. When coupled with highly reduced
sediment redox potential, increasing stocking density up to
12_0 shrunps m·2 significantly reduced the shrimp immunity and resistance against
w'ssv.
In conclusion, the present study showed that L. vannamei tend to stay at the pond bottom. The
present study demonstrated that redox potential significantly affected the shrimp welfare including
its susceptibility to disease and ultimately the , uction. In this regard, maintaining the pond
sediment in an optimal
Collections
- DT - Fisheries [714]