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Research Article
Effect of C/N Ratio Levels and Stocking Density of Catla Spawn
(Gibelion catla) on Water Quality, Growth Performance, and
Biofloc Nutritional Composition in an Indoor Biofloc System
Sonia Solanki , S. J. Meshram, H. B. Dhamagaye, S. D. Naik, P. E. Shingare, and B. M. Yadav
Department of Aquaculture, College of Fisheries (DBSKKV), Shirgaon, Ratnagiri 415629, Maharashtra, India
Correspondence should be addressed to Sonia Solanki; soniyasolanki22693@gmail.com
Received 16 November 2022; Revised 8 February 2023; Accepted 6 June 2023; Published 12 June 2023
Academic Editor: Hamed Ghafarifarsani
Copyright ©2023 Sonia Solanki et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
A 20-day 3 ∗3 factorial experiment was conducted in 100 L HDPE experimental tanks to investigate the eect of the C/N ratio (10,
15, and 20) and stocking density (3, 4, and 5 spawn L
−1
) on Gibelion catla spawn nursery rearing in the indoor biooc system. Rice
bran was used as the carbon source for manipulating C/N ratios. Each treatment was stocked with catla spawn of average length
(6.7 ±0.4 mm) and average weight (1.6 ±0.2 mg). Water parameters showed that increasing the C/N ratio from 10 to 20 sig-
nicantly (p<0.05) reduced total ammonia nitrogen (TAN) and nitrite nitrogen (NO
2
-N) and increased nitrate nitrogen (NO
3
-
N) in the water. e insignicant dierence (p>0.05) and lowest nal average length, average length gain, average weight gain,
and specic growth rate (SGR) were recorded in C/N ratios of 10 and 15 compared to a C/N ratio of 20. A signicant dierence
(p<0.05) in survival was observed with the increasing C/N ratio. Increasing the sh stocking density resulted in higher mortality.
However, a higher amount of fry produced was observed in the treatments with 3 and 4 spawn L
−1
. Crude protein content
increased signicantly (p<0.05) with the increasing C/N ratio with higher content in C/N 20. No signicant dierence (p>0.05)
in proximate composition of biooc was observed in dierent stocking density groups. In conclusion, the application of the biooc
technology with a C/N ratio of 20 at a stocking density of 4 spawn L
−1
could be recommended to increase the production of catla
fry in the indoor biooc system.
1. Introduction
e success of the aquaculture industry relies on a steady
supply of high-quality seed as one of its key inputs, ac-
counting for 5–10% of aquaculture production costs [1, 2].
In India, Indian major carps account for 87 percent of the
country’s total freshwater aquaculture production [3].
Hatchery-produced seed meets demand, but hatcheries
are more concerned with quantity than quality, and the
spawn-to-fry yield ratio of these species is 3 :1 in earthen
ponds, with catla fry performance always being lower in
terms of growth and survival [4–6]. Fish in the nursery
stage are also often subjected to intensication which
generally increases stress and subsequently susceptibility
to infectious disease, hence requiring proper management
to obtain optimum growth and survival [7, 8]. Biooc
systems (BFTs) are a potential alternative strategy for the
intensication of sh larviculture which enhances im-
munity of the cultures.
Biooc technology is studied for its application in
nurseries as an additional feed source for postlarvae, to
provide extra essential nutrients [9–11] and improve
water quality to support better larval survival and growth
[12, 13]. BFT has been applied successfully in the nursery
phase in dierent sh and shrimp species such as Oreo-
chromis niloticus [12], Rhamdia quelen [13], Clarias
gariepinus [14], Labeo rohita [15–17], Carassius auratus
[8], Farfantepenaeus brasiliensis [18], and Penaeus
vannamei [19].
Maintenance of appropriate carbon to nitrogen (C/N) is
of prime importance for optimal performance of culture
species in the biooc system [20]. e addition of the
Hindawi
Aquaculture Research
Volume 2023, Article ID 2501653, 11 pages
https://doi.org/10.1155/2023/2501653
external carbon source manipulates the carbon-to-nitrogen
ratio for uptake of nitrogen elements and subsequent
conversion to microbial proteins in the BFT system [21–23].
e carbon source and the C/N ratio inuence the nutri-
tional content and quality of biooc [24–26]. An increase in
the C/N ratio induces shifting of the biooc community to
a heterotrophic system that eectively maintains TAN and
NO
2
-N at lower concentrations even at higher stocking
densities in the culture water [27–30].
Freshwater sh production under the BFT system is still
new, and studies on sh larval development are even rarer
[8, 12, 13]. erefore, the objectives of this study were to
evaluate its use in nursery rearing of the Gibelion catla at
varying C/N ratios and stocking densities in the indoor
biooc system.
2. Materials and Methods
2.1. Experimental Design, Biooc Preparation, Fish Stocking,
and Management. Gibelion catla spawn (n= 25000) pro-
cured from CIFA, Bhubneshwar, Orissa, India, were
transported to Wet Laboratory, Department of Aqua-
culture, College of Fisheries, Ratnagiri, Maharashtra,
India, and the same were acclimatized for 3 days in two-
1000 L FRP (breglass reinforced plastic) tanks fed
with GNOC two times a day and 2 L of green water every
day in morning hours. A factorial design (3 ×3) was
performed with three C/N ratios (10, 15, and 20) [21] as
the rst factor and three-level stocking densities, viz., 3, 4,
and 5spawn L
−1
[15] as the second factor in a completely
randomized design with triplicates. An experiment was
conducted for 20 days in 100 L capacity HDPE (high-
density polyethylene) tanks lled with up to 80 L working
volume.
Biooc inoculum was prepared by mixing 5 g L
−1
pond
soil, 10 mg L
−1
ammonium sulphate, and 200 mg L
−1
carbon
source (rice bran) [27] in a 500 L FRP tank lled with ground
water up to 300 L. When biooc concentration reached
20 ml L
−1
, it was used for inoculation in the already prepared
experimental tanks at a rate of 5 L of inoculum to 75 L of
freshwater. e rice bran (33.33% carbon) was added once in
a day based on the calculation described by De Schryver et al.
[21] to maintain the desired C: N ratio in the BFT treatment
during the experiment. An air pump (HAILEA, Model:
HAP-60) having a capacity of about 60 W was used for
aeration to meet oxygen demand of the shes and keep the
ocs in continuous suspension.
For the experiment, 8640 spawn (Gibelion catla) were
used and stocked at a rate of 3, 4, and 5 spawn L
−1
, re-
spectively, after acclimatization. A subsample of spawn was
taken from the stock and weighed using an electronic digital
balance (Himedia; precision: 1 mg) to determine the initial
live body weight which was average (1.6 ±0.2 mg). Locally
available GNOC and rice bran powdered, sieved, and mixed
in a 1 :1 ratio were used as a feed source for spawn. e shes
were fed in the morning at 10:00 am and evening 4:00 pm at
a rate of 400% body weight per day for rst ve days and
800% body weight per day for next fteen days [15]. In
biooc tanks, no regular water exchange was carried out
except the addition of water to compensate the
evaporation loss.
2.2. Physicochemical Parameters of Water. Water quality
parameters such as temperature, pH, dissolved oxygen
(DO), alkalinity, total ammonia nitrogen (TAN), nitrite
nitrogen (NO
2
-N), and nitrate nitrogen (NO
3
-N) were
monitored every fth day during the experimental period.
pH and temperature of the water were estimated using
a universal indicator and a mercury thermometer, re-
spectively. Dissolved oxygen and alkalinity of water were
estimated as per the standard procedures [31]. Total
ammonia nitrogen (TAN), nitrite nitrogen (NO
2
-N),
and nitrate nitrogen (NO
3
-N) were determined with API®
commercial test kits (API®freshwater master test kit).
For total suspended solid (TSS) estimation, 100 ml of
the water sample was collected from each replicate
and ltered through a predried and weighed glass bre
(GF/C) lter paper using the micropore vacuum lter.
Floc volume was measured by allowing the oc to settle
down in the Imho cone for 20 minutes without
disturbance [32].
2.3. Growth Analysis. Initial weight and length of spawn
were taken. All surviving fry were counted at the end of the
experiment. e average weight gain, percent weight gain,
average length gain, percent length gain, specic growth rate
(SGR), and survival were calculated using the following
equations:
2Aquaculture Research
average weight gain (mg) � f inal weight (mg)– initial weight (mg),
weight gain (%) � (final weight −initial weight)
initial weight
×100,
average length gain (mm) � f inal length (mm)– initial length (mm),
length gain (%) � (final weight −Initial weight)
initial weight
×100,
SGR %
da y
�(ln f inalweight −ln initial weight)
number of da ys
×100,
survival (%) � total number of survived fish
total number of f ish stocked
×100,
apparent f eed conversion ratio (AFCR) � total feed intake
weight gain .
(1)
2.4. Proximate Composition of Biooc. At the end of the
experiment, concentrated oc samples were collected from
each tank using a 100 m mesh and dried in an oven at 60°C
and then preserved in a refrigerator till the proximate
analysis was performed [33]. e nutritional contents of
biooc such as crude protein (Kjeldahl method), crude lipids
[34], ash content [35], and moisture [35] were analysed.
2.5. Statistical Analysis. e experimental data such as
length gain, weight gain, SGR, and survival percentage were
analysed by two-way analysis of variance. Dierences were
considered signicant at p<0.05. If dierence was found
signicant, the means were compared by Tukey’s test. e
statistical analysis was performed by using SPSS 16.0.
3. Results
3.1. Water Quality Parameters. e mean values of water
quality parameters and outcomes of two-way ANOVA are
presented in Table 1. ere was a signicant (p<0.05) eect
of the C/N ratio and stocking density on the water quality in
biooc treatments. Furthermore, there was no signicant
(p>0.05) interaction eect of the C/N ratio and stocking
density on the water quality of dierent treatments. In-
creasing stocking densities signicantly (p<0.05) reduced
DO content in water. pH was signicantly dierent
(p<0.05) among dierent C/N ratios with reduced pH at
a higher C/N ratio, but no signicant dierence (p>0.05)
was observed in stocking densities. Total alkalinity reduced
signicantly (p<0.05) with an increase in the C/N ratio, but
no signicant dierence (p>0.05) was observed in C/N 15
and 20. A higher stocking density showed a signicantly
lower (p<0.05) value of total alkalinity. e increase in the
C/N ratio signicantly (p<0.05) reduced TAN and NO
2
-N.
However, the level of TAN did not vary signicantly
(p>0.05) in stocking densities. Levels of NO
2
-N increased
signicantly (p<0.05) with an increase in the stocking
density from SD3 to SD5. e NO
3
-N level was signicantly
(p<0.05) lower in C/N 10, but no signicant dierence
(p>0.05) was observed in C/N 15 and 20. A signicant
(p<0.05) increase in the level of NO
3
-N was observed with
increasing stocking densities of catla spawn. TSS was sig-
nicantly (p<0.05) lower in C/N 10, and no signicant
dierence (p>0.05) was observed in C/N 15 and 20.
However, TSS increased signicantly (p<0.05) with an
increase in the stocking density. Floc volume increased
signicantly (p<0.05) with an increase in both the C/N ratio
and stocking density.
3.2. Eect on Survival and Growth Parameters of Gibelion catla
Fry. Growth performance of catla spawn in the biooc
system after 20 days of the rearing period is presented in
Table 2. Based on two-way ANOVA, there was a signicant
(p<0.05) eect of the C/N ratio and stocking density on
growth performance and survival of spawn. But there was no
signicant (p>0.05) interaction between C/N ratios and
stocking densities on the growth performance and survival
of spawn in the biooc treatments. e nal average body
weight, weight gain, percent weight gain, nal length, length
gain, percent length gain, and specic growth rate (SGR)
were signicantly (p<0.05) higher, and AFCR was signif-
icantly the lowest (p<0.05) in C/N 20. No signicant dif-
ference (p>0.05) was observed in growth performance,
SGR, and AFCR of spawn at C/N 10 and C/N 15. An increase
in the C/N ratio signicantly (p<0.05) increased the sur-
vival rate. e stocking density inuenced the growth pa-
rameters dierently. e highest growth performance in
terms of average nal weight, weight gain, percent weight
gain, and specic growth rate (SGR) was obtained in the
lower stocking density of SD3 except for SD4 which did not
show a signicant dierence (p>0.05) with the spawn of the
former group. AFCR of sh was signicantly (p<0.05)
lower at a lower stocking density of SD3. Signicantly
(p<0.05) higher nal length, length gain, and percent length
Aquaculture Research 3
Table 1: Water quality parameters recorded from dierent experimental groups during the experimental period based on two-way ANOVA.
Water
parameters
C/N ratio Stocking density (no.’s L
−1
)Two-way
ANOVA Interaction
10 15 20 3 4 5 C/N SD C/N ×SD
Temperature (°C) 26.79 (25.1–28.2) 26.76 (25.0–28.1) 26.81 (25.0–28.1) 26.74 (25.0–28.0) 26.80 (25.1–28.2) 26.82 (25.1–28.1) NS NS NS
DO (mg L
−1
) 5.9
a
(5.4–6.2) 5.8
a
(4.6–6.2) 5.7
a
(4.6–6.2) 5.9
A
(4.6–6.2) 5.8
AB
(4.8–6.2) 5.7
B
(4.6–6.2) NS ∗∗ NS
pH 7.70
a
(7.0–8.5) 7.70
a
(7.0–8.5) 7.40
b
(6.5–8.5) 7.70
A
(7–8.5) 7.50
A
(6.5–8.5) 7.60
A
(6.5–8.5) ∗∗ NS NS
Total alkalinity (mg L
−1
) 42.67
a
(28–56) 39.06
b
(26–52) 37.17
b
(22–52) 41.22
A
(24–56) 40.67
A
(26–54) 37.00
B
(22–54) ∗∗ ∗∗ NS
TAN (mg L
−1
) 0.26
a
(0.091–0.560) 0.24
ab
(0.085–0.559) 0.22
b
(0.050–0.754) 0.24
A
(0.05–0.48) 0.25
A
(0.073–0.472) 0.26
A
(0.068–0.754) ∗∗ NS NS
Nitrite-N (mg L
−1
) 0.030
a
(0.012–0.065) 0.025
b
(0.010–0.057) 0.022
c
(0.01–0.042) 0.019
C
(0.01–0.031) 0.023
B
(0.01–0.038) 0.035
A
(0.011–0.065) ∗∗ ∗∗ NS
Nitrate-N (mg L
−1
) 12.27
b
(2.27-29.76) 13.76
a
(2.34-28.98) 14.45
a
(3.64-29.75) 11.27
C
(2.29-26.64) 13.40
B
(3.19-28.74) 15.81
A
(2.27-29.76) ∗∗ ∗∗ NS
TSS (mg L
−1
) 98.35
b
(28.2–204.49) 124.29
a
(28.4–240.19) 125.40
a
(39.1–250.98) 93.55
C
(28.2–198.23) 113.80
B
(43.92–235.89) 140.68
A
(52.89–250.98) ∗∗ ∗∗ NS
Floc volume (ml L
−1
) 3.09
c
(0.5–9.0) 4.31
b
(0.5–12) 5.49
a
(1–15) 2.33
C
(0.5–6) 4.56
B
(0.5–9) 6.01
A
(0.75–15) ∗∗ ∗∗ NS
e mean values followed by the dierent superscript letter in each factor indicate signicance at p<0.05. If the eects were signicant, ANOVA was followed by Tukey’s test. ∗∗Indicates a signicant dierence at
p<0.05. NS, not signicant.
a,b,c
Values of water parameters of C/N ratio groups in a row with dierent superscripts dier signicantly (p<0.05).
A,B,C
Values of water parameters of stocking density groups in a row
with dierent superscripts dier signicantly (p<0.05).
4Aquaculture Research
Table 2: Nursery production performance of Gibelion catla cultured in biooc systems with dierent C/N ratios (10, 15, and 20:1) and stocking density (3, 4, and 5 no.’s L
−1
) for 20 days
based on two-way ANOVA.
Growth
performance
C/N ratio Stocking density (no.’s L
−1
)Two-way
ANOVA Interaction
10 15 20 3 4 5 C/N SD C/N xSD
Average initial length (mm) 6.7 ±0.4
a
6.7 ±0.4
a
6.7 ±0.4
a
6.7 ±0.4
A
6.7 ±0.4
A
6.7 ±0.4
A
NS NS NS
Average nal length (mm) 18.34 ±0.83
b
18.77 ±1.21
b
19.76 ±0.89
a
19.86 ±0.93
A
18.91 ±0.94
B
18.10 ±0.80
B
∗∗ ∗∗ NS
Average length gain (mm) 11.68
b
12.09
b
13.08
a
13.19
A
12.23
B
11.42
B
∗∗ ∗∗ NS
Percent length gain (%) 174.73
b
181.19
b
195.99
a
197.47
A
183.3
B
171.14
B
∗∗ ∗∗ NS
Average initial weight (mg) 1.6 ±0.2
a
1.6 ±0.2
a
1.6 ±0.2
a
1.6 ±0.2
A
1.6 ±0.2
A
1.6 ±0.2
A
NS NS NS
Average nal weight (mg) 56.09 ±9.83
b
61.02 ±14.90
b
76.69 ±15.38
a
75.17 ±16.22
A
64.01 ±15.83
AB
54.62 ±7.98
B
∗∗ ∗∗ NS
Weight gain (mg) 54.49
b
59.42
b
75.09
a
73.57
A
62.41
AB
53.02
B
∗∗ ∗∗ NS
Percent weight gain (%) 3405.50
b
3713.60
b
4693.10
a
4598.10
A
3900.70
AB
3313.50
B
∗∗ ∗∗ NS
SGR (%/day) 7.33
b
7.48
b
7.96
a
7.92
A
7.58
AB
7.29
B
∗∗ ∗∗ NS
AFCR 4.21
a
3.94
a
3.10
b
3.18
B
3.78
AB
4.29
A
∗∗ ∗∗ NS
Survival (%) 66.85
c
70.12
b
74.68
a
73.43
A
71.01
A
67.22
B
∗∗ ∗∗ NS
e mean values followed by the dierent superscript letters in each factor indicate signicance at (p<0.05). If the eects were signicant, ANOVA was followed by Tukey’s test. ∗∗Indicates a signicant dierence
at p<0.05. NS, not signicant.
a,b,c
Values of nursery production performance of Gibelion catla cultured in biooc systems of C/N ratio groups in a row with dierent superscripts dier signicantly
(p<0.05).
A,B,C
Values of nursery production performance of Gibelion catla cultured in biooc systems in stocking density groups in a row with dierent superscripts dier signicantly (p<0.05).
Aquaculture Research 5
gain were observed in a lower stocking density of SD3. An
increase in the stocking density signicantly (p<0.05) re-
duced the survival percent of spawn. However, no signicant
dierence (p>0.05) in survival was observed for SD3 and
SD4 for catla fry production. e interaction of the C/N ratio
and stocking density was not signicant (p>0.05) for all the
growth parameters.
3.3. Proximate Composition of Biooc. e results of prox-
imate compositions of biooc are presented in Table 3. Based
on two-way ANOVA, there is a signicant eect of the C/N
ratio on the proximate composition of biooc with crude
protein content increased signicantly (p<0.05) with the
increasing C/N ratio, and the ash content was signicantly
(p<0.05) lower in the higher C/N ratio group. e C/N 15
group did not show any signicant dierence for crude
protein and ash content with C/N 10 and 20 groups. No
signicant dierence (p>0.05) in moisture and crude lipid
content was observed for various C/N groups. ere is no
signicant (p>0.05) eect of the stocking density, C/N
ratio, and stocking density interaction on the biooc
composition.
4. Discussion
4.1. Water Quality. Water quality is strongly inuenced by
the stocking density of the cultured animal, environmental
parameters, species combination, and quality and quantity
of nutritional input added to the system [25, 36]. In the
present study, temperature remained within the range
(23.0–28°C) required for culture of catla spawn [37, 38].
Fluctuations in pH, DO, and nitrogenous waste concen-
trations are usual features of biooc systems [33, 39]. In-
creasing weight of culture species and boosted bacterial
population often decreases DO of the BFT system, as ob-
served in the present study at a higher stocking density
[40, 41]. A higher DO level reduces larger and compact oc
sizes into smaller ones allowing sh to easily consume the
oc and hence enhances sh growth [42, 43]. e higher DO
content in biooc treatment with lower stocking (SD3)
might have resulted in the reduction of oc size and have
provided better opportunity for spawn to consume oc and
enhance growth. An increase in the nitrication process and
respiration rate of heterotrophic microorganisms reduces
pH and alkalinity of the culture system, which was reected
in this study with the increased C/N ratio [13, 25, 28, 44, 45].
pH below 7 negatively aects the nitrication rate and the
growth of the cultured species [46, 47]. e average pH was
in the suitable range (7.40–7.70) as reported in earlier studies
for nursery rearing of spawn in indoor systems [6] except for
reduced pH and alkalinity in a higher stocking density,
which might have aected the survival and growth of spawn
in the experimental units due to acid stress as the pH eect is
related to age and development, and larval stages are most
sensitive to pH changes [48, 49]. e increase in hetero-
trophic bacteria increases acid production through the ni-
trication process and consumes alkalinity in the intensive
biooc system which reduced total alkalinity with the
increased C/N ratio and stocking density [50]. e TAN and
NO
2
-N levels were within the safe range for catla spawn [51].
Furthermore, reduction of TAN with the increasing C/N
ratio shows that the TAN-N levels were inuenced by
varying C/N ratios as during microbial assimilation, certain
microbes present in the biooc has potential to assimilate
TAN into microbial biomass, and that higher carbon inputs
support faster production of heterotrophic bacteria, thus
converting dissolved nitrogen into bioocs [28, 52, 53].
Although there was no signicant dierence in TAN-N
concentration in dierent stocking densities, a higher
mean concentration of nitrogenous compounds in a higher
stocking density could be the result of higher biomass in the
system and retarded development of nitrifying bacteria
before biooc formation [50, 54, 55]. e presence of more
nitrifying bacteria converts ammonia to nitrite and then
nitrite to nitrate which might have resulted in increased
nitrate-N concentration at a higher stocking density in BFT
[28, 56]. Becerril–Cort´
es et al.[57] recorded similar nitrate-
N concentration for tilapia fry.
e C/N ratio and stocking density have a signicant
eect on the TSS and oc volume. In zero water exchange
tanks, TSS tends to increase over time primarily due to
decreased water exchange, a high amount of organic sub-
stances, and an increase in microbial biomass [58]. Excessive
TSS levels can become detrimental, particularly with some
sh; however, the ideal TSS concentration for sh in biooc
is not determined [56, 59]. e TSS concentration up to
300 mg/L showed no negative eect on growth performance
of goldsh larvae [8]. An increase in the TSS concentration
aects the growth performance of sh larvae; however, lower
TSS levels provide a more nutritious food source for the
larvae [13]. e increase in the C/N ratio and stocking
density increased TSS and oc volumes which might have
reduced the survival of spawn at a higher stocking density.
Hosain et al. [56] observed lower survival of Macro-
branchium rosenbergii postlarvae at a higher oc volume of
up to 10 ml/L when molasses and wheat bran were used as
a carbon source. Similarly, in the present study, oc volume
increased over time, which might have led to reduced
survival of catla spawn at higher stocking densities.
4.2. Eect on Survival and Growth Parameters of Gibelion catla
Fry. Gibelion catla is a surface feeder and can also explore
the middle and bottom layers of water [60, 61]. Alikunhi [62]
designated species as a surface and midwater feeder. Catla
spawn starts feeding on plankton (mainly zooplankton)
from the third day after hatching. Dening the biooc, it is
the heterotrophic conglomeric aggregation of microbial
communities, such as phytoplankton, bacteria, and living
and dead particulate organic matter, and the presence of
zooplankton species such as rotifers, moina, daphnia, co-
pepods, and freshwater infusoria makes the BFT system
prosper for rearing of spawn [17, 63].
e present study is the rst to analyse the nursery
rearing of catla spawn in the BFT system. Dierent C/N
ratios signicantly aect the growth of catla spawn, and the
performance was better in the C/N 20 treatment. As bacteria
6Aquaculture Research
need about 20 units of carbon per unit of nitrogen assim-
ilated [27], in this study, it is conrmed that a C/N ratio of
20 : 1 favored biooc promotion which acts as a supple-
mental food source available 24 hrs [33, 64–66]. e im-
provement in growth of catla spawn at C/N 20 could be
associated with the presence of adequate natural protein-
lipid source and other nutrients at any time as observed for
Carassius auratus larvae at C/N ratios of 20 and 25 : 1 and
Labeo rohita spawn at C/N 15 and 20 [17], whereas the
insignicant dierence in the C/N 10 and 15 groups might
indicate the limited number of prey production as reduction
in organic carbon addition can slow down the formation of
oc as observed with lower oc volume at a lower C/N ratio
in the present study [29, 67], or consumption of biooc does
not contribute to growth of the sh [12]. Biooc is known to
improve feed utilisation of sh by supplementing essential
amino acids, vitamins, lipids, and minerals and stimulates
digestive enzyme activity resulting in improved digestion of
nutrients in the sh gut [68]. Lower AFCR at a higher C/N
ratio of 20 in the present study conrms biooc contribution
as complementary natural feed and suggests for improved
feed utilisation in the sh reared in the biooc system [25].
e stocking density is one of the important factors de-
termining the survival, growth, and nal biomass of the
culture [69]. In the present study, a lower stocking density of
SD3 resulted in improved growth performance as compared
to other groups. e results agree with the ndings of Dey
et al. [17] who observed enhanced growth of Labeo rohita
spawn in terms of nal length, nal weight, and SGR at
a lower stocking density (1, 2, and 3 spawn L
−1
) than at
a higher stocking density (4 and 5 spawn L
−1
) in biooc
systems. Impaired growth of goldsh larvae with an increase
in the stocking density in the BFT system was recorded by
Besen et al. [8]. e average total length and weight of fry
after 20 days of rearing were in the range of 18.10–19.86 mm
and 54.62–76.69 mg, respectively (Table 2). e growth
performance was better with higher length and weight gain
obtained in short duration than fry rearing under normal
indoor conditions; hence, reducing the rearing period in
indoor can increase production. e higher performance of
the spawn in the BFT system indicates that bioocs were
consumed by the spawn and optimized growth. In this study,
AFCR is inuenced by the stocking density. AFCR signi-
cantly increased in a high stocking density of the SD5 group,
which might indicate a reduction or decrease in eciency of
the sh to graze microbial community at higher density
[70, 71]. No signicant dierence in AFCR and growth
performance of spawn in the SD4 group with SD3 might
indicate biooc consumption as supplemental feed, and
favorable eects of biooc such as better water quality,
“antistress” probiotic eect, and presence of exogenous
microbial enzymes and endogenous digestive enzymes may
promote digestion of food and improve the performance of
sh in the biooc system as reported in earlier studies
[68, 72].
Survival is considered the most important parameter for
culturing success during the larval and nursery phases.
Higher survival at C/N 20 compared to a lower C/N ratio
could be due to better water quality and greater availability
of prey in the BFT system [8, 56, 73]. e consumption of
microbial oc enhances larvae tolerance to environmental
stress, hence, improving survival [73, 74]. Fry survival
showed an inverse relationship with the stocking density. A
higher stocking density aects the growth performance of
spawn mainly due to physiological stress caused due to
overcrowding which leads to competition for food and space
and poor water quality [4, 37, 75]. A similar decreasing trend
in survival was also obtained with catla and rohu fry stocked
at a rate of 100, 125, and 150 larvae/15-L aquarium, re-
spectively, in the recirculating system [76]. In the present
study, SD4 showed an insignicant dierence with SD3;
similarly, survival was unaected by increasing stocking
densities of goldsh larvae from 10 larvae L
−1
to 30 larvae L
−1
in the BFT system, suggesting adoption of a higher stocking
density for larger quantity of larvae production [8]. Also,
indoor rearing allows for intensive seed rearing as it prevents
higher mortality due to predation and ecological
problems [4].
4.3. Proximate Composition of Biooc. e proximate
composition of microbial ocs varies according to the
carbon source, proximal feed composition, environmental
conditions, culture time, and other factors [77, 78]. In this
study, biooc collected from dierent treatments showed
nutritional values with 22.66 to 26.53% crude protein, 1.83 to
2.17% crude lipid, and 10.5 to 11.4% ash. e signicant
dierence in biooc nutritional composition in dierent
C/N ratio treatments of the present study indicates that the
amount of carbon source aects the nutritional composition
Table 3: Proximate composition of biooc (% dry weight) collected from Gibelion catla based on the biooc technology (BFT) system after
20 days of the experimental period.
Biooc
proximate
(%)
C/N ratio Stocking density (no.’s/L) Two-way
ANOVA Interaction
10 15 20 3 4 (A) 5 (A) C/N SD C/N ×SD
Moisture 86.7
a
87.1
a
87.4
a
87.3
A
86.1 87.8 NS NS NS
Crude protein 22.66
b
24.26
ab
26.53
a
24.60
A
24.32 24.52 ∗∗ NS NS
Crude lipid 1.8
a
2.1
a
2.2
a
2.0
A
2.0 2.1 NS NS NS
Ash 11.4
a
10.8
ab
10.5
b
10.9
A
11.1 10.7 ∗∗ NS NS
e mean values followed by the dierent superscript letters in each factor indicate signicance at p<0.05. If the eects were signicant, ANOVA was
followed by Tukey’s test. ∗∗Indicates a signicant dierence at p<0.05. NS, not signicant.
a,b,c
Values of the proximate composition of biooc of C/N ratio
groups in a row with dierent superscripts dier signicantly (p<0.05).
A,B,C
Values of the proximate composition of biooc of stocking density groups in
a row with dierent superscripts dier signicantly (p<0.05).
Aquaculture Research 7
of microbial oc. e stocking density in the biooc system
did not inuence the biooc nutritional composition. e
C/N 20 treatment protein and ash content were similar with
those of Romano et al.[79] when using raw rice bran as
a carbon source for the culture of African catsh, and C/N 10
and C/N 15 showed similar content with that of Megahed
and Mohamed [80] when shrimp feed with 25% protein feed
and C/N ratio of 12.1. Higher crude protein in the C/N20
treatment could be due to the richness of microorganism in
the treatment [56], but dierences in nutritional composi-
tions among dierent treatments might be due to dierence
in microbial community [81]. In the present study, the crude
lipid and ash content were in the range as observed by
Becerril–Cort´
es et al. [57] in rice bran-developed biooc
except for lower crude protein. Lipid is the important source
of metabolic energy for growth of sh. Lower lipid with
higher oc volume can cause decrease in survival as observed
in this study [56], though higher values of crude lipid in
a higher C/N ratio might have attributed to higher growth
and survival of spawn compared to other treatments.
5. Conclusion
e present study demonstrates that increasing the C/N
ratio to 20 : 1 can improve the nursery rearing of Gibelion
catla in the biooc system at a stocking density of 3 spawn
L
−1
. Biooc conditions support the microbial protein con-
tent which is known to be highly nutritious for the spawn
during their nursery rearing. It is likely that catla spawn were
able to obtain this nutrition for their growth. e best
growth results are obtained with a stocking density of 3
spawn L
−1
. However, an increase in a stocking density of 4
spawn L
−1
can be supported with the increased survival
percentage of fry.
Data Availability
e data supporting the ndings of the study are available
from the corresponding author upon request.
Conflicts of Interest
e authors declare that they have no conicts of interest in
the study.
Acknowledgments
e authors are thankful to the authorities of Dr. B.S.K.K.V.,
Dapoli for gratifying the permission to pursue this study and
providing all the necessary facilities at College of Fisheries,
Ratnagiri.
References
[1] A. Ghosh, B. C. Mohapatra, P. P. Chakrabarti, A. Hussan, and
A. Das, “Induced breeding of Catla catla carried out at low
temperature in FRP carp hatchery of Arunachal Pradesh,
India,” Journal of Environmental Biology, vol. 40, no. 3,
pp. 328–334, 2019.
[2] K. K. Marx, J. K. Sundaray, A. Rathipriya, and M. M. Abishag,
Broodstock Management and Fish Seed Production, CRC
Press, Boca Raton, FL, USA, 2020.
[3] B. Bais, “Fish scenario in India with emphasis on Indian major
carps,” International International Journal of Avian & Wildlife
Biology, vol. 3, no. 6, pp. 409–411, 2018.
[4] S. K. Swain, S. N. Mohanty, and S. D. Tripathi, “Growth and
survival in relation to various stocking densities of catla (Catla
catla Ham.) spawn fed on a dry articial diet,” Indian Journal
of Fisheries, vol. 46, no. 1, pp. 87–90, 1999.
[5] B. K. Biswas, S. Shah, K. Takii, and H. Kumai, “A comparison
of growth performance of Indian major carps, Catla catla
(Hamilton) and Cirrhinus cirrhosus (Bloch) from natural and
hatchery sources in Bangladesh,” Aquaculture Science, vol. 56,
no. 2, pp. 245–251, 2008.
[6] P. C. Das, S. P. Kamble, K. C. Parida, and K. N. Mohanta,
“Eect of dietary incorporation of sh/prawn meal on per-
formance of Catla catla (Hamilton) during nursery phase,”
Indian Journal Of Fisheries, vol. 64, no. 1, pp. 44–48, 2017.
[7] S. F. Snieszko, “e eects of environmental stress on out-
breaks of infectious diseases of shes,” Journal of Fish Biology,
vol. 6, no. 2, pp. 197–208, 1974.
[8] K. P. Besen, L. da Cunha, F. R. Delziovo et al., “Goldsh
(Carassius auratus) larviculture in biooc systems: level of
Artemia nauplii, stocking density and concentration of the
bioocs,” Aquaculture, vol. 540, Article ID 736738, 2021.
[9] J. Ekasari, R. Crab, and W. Verstraete, “Primary nutritional
content of bio-ocs cultured with dierent organic carbon
sources and salinity,” HAYATI Journal of Biosciences, vol. 17,
no. 3, pp. 125–130, 2010.
[10] Z. Y. Ju, I. Forster, L. Conquest, W. Dominy, W. C. Kuo, and
F. David Horgen, “Determination of microbial community
structures of shrimp oc cultures by biomarkers and analysis
of oc amino acid proles,” Aquaculture Research, vol. 39,
no. 2, pp. 118–133, 2008.
[11] W. J. Xu, L. Q. Pan, D. H. Zhao, and J. Huang, “Preliminary
investigation into the contribution of bioocs on protein
nutrition of Litopenaeus vannamei fed with dierent dietary
protein levels in zero-water exchange culture tanks,” Aqua-
culture, vol. 350-353, pp. 147–153, 2012.
[12] J. Ekasari, D. R. Rivandi, A. P. Firdausi et al., “Biooc
technology positively aects Nile tilapia (Oreochromis nilo-
ticus) larvae performance,” Aquaculture, vol. 441, pp. 72–77,
2015.
[13] M. A. Poli, R. Schveitzer, and A. P. de Oliveira Nuner, “e
use of biooc technology in a South American catsh
(Rhamdia quelen) hatchery: eect of suspended solids in the
performance of larvae,” Aquacultural Engineering, vol. 66,
pp. 17–21, 2015.
[14] H. Fauji, T. Budiardi, and J. Ekasari, “Growth performance
and robustness of African Catsh Clarias gariepinus
(Burchell) in biooc-based nursery production with dierent
stocking densities,” Aquaculture Research, vol. 49, no. 3,
pp. 1339–1346, 2018.
[15] H. V. Meshram, S. J. Meshram, H. B. Dhamagaye,
B. R. Chavan, and S. D. Naik, “Eect of dierent supple-
mentary feeds on rohu, Labeo rohita (Hamilton, 1822) spawn
reared in biooc system,” International Conference on
Challenges and Opportunities for Sustainable Fisheries and
Aquaculture Development Abstract, vol. 78, 2019.
[16] K. Sawant, S. Meshram, H. Dhamagaye, B. R. Chavan,
R. M. Tibile, and V. R. Vartak, “Growth and Survival of Labeo
rohita (Hamilton, 1822) fry in biooc system using various
8Aquaculture Research
dietary protein levels,” Journal of Experimental Zoology India,
vol. 23, pp. 765–769, 2020.
[17] S. S. Dey, R. M. Tibile, A. S. Pawase, S. J. Meshram,
D. I. Pathan, and A. Nayak, “Evaluation of dierent stocking
densities and carbon: nitrogen ratios on growth, body
composition and production performance of Labeo rohita
(Hamilton, 1822) spawn in biooc based-nursery system,”
Aquaculture Research, vol. 53, no. 14, pp. 4989–5005, 2022.
[18] M. Emerenciano, E. L. Ballester, R. O. Cavalli, and
W. Wasielesky, “Biooc technology application as a food
source in a limited water exchange nursery system for pink
shrimp Farfantepenaeus brasiliensis (Latreille, 1817),”
Aquaculture Research, vol. 43, no. 3, pp. 447–457, 2012.
[19] A. Panigrahi, C. Saranya, K. Ambiganandam, M. Sundaram,
M. R. Sivakumar, and K. Kumaraguru vasagam, “Evaluation
of biooc generation protocols to adopt high density nursery
rearing of Penaeus vannamei for better growth performances,
protective responses and immuno modulation in biooc
based technology,” Aquaculture, vol. 522, Article ID 735095,
2020.
[20] A. F. M. El-Sayed, “Use of biooc technology in shrimp
aquaculture: a comprehensive review, with emphasis on the
last decade,” Reviews in Aquaculture, vol. 13, no. 1, pp. 676–
705, 2021.
[21] P. De Schryver, R. Crab, T. Defoirdt, N. Boon, and
W. Verstraete, “e basics of bio-ocs technology: the added
value for aquaculture,” Aquaculture, vol. 277, no. 3-4,
pp. 125–137, 2008.
[22] A. Panigrahi, M. Sundaram, S. Chakrapani, S. Rajasekar,
J. Syama Dayal, and G. Chavali, “Eect of carbon and nitrogen
ratio (C: N) manipulation on the production performance and
immunity of Pacic white shrimp Litopenaeus vannamei
(Boone, 1931) in a biooc-based rearing system,” Aquaculture
Research, vol. 50, no. 1, pp. 29–41, 2019.
[23] R. Debbarma, P. Biswas, and S. K. Singh, “An integrated
biomarker approach to assess the welfare status of Ompok
bimaculatus (Pabda) in biooc system with altered C/N ratio
and subjected to acute ammonia stress,” Aquaculture, vol. 545,
Article ID 737184, 2021.
[24] J. A. P´
erez-Fuentes, M. P. Hern´
andez-Vergara, C. I. P´
erez-
Rostro, and I. Fogel, “C: N ratios aect nitrogen removal and
production of Nile tilapia Oreochromis niloticus raised in
a biooc system under high density cultivation,” Aquaculture,
vol. 452, pp. 247–251, 2016.
[25] A. Panigrahi, C. Saranya, M. Sundaram et al., “Carbon: ni-
trogen (C:N) ratio level variation inuences microbial com-
munity of the system and growth as well as immunity of
shrimp (Litopenaeus vannamei) in biooc based culture
system,” Fish & Shellsh Immunology, vol. 81, pp. 329–337,
2018.
[26] M. Mugwanya, M. A. Dawood, F. Kimera, and H. Sewilam,
“Biooc systems for sustainable production of economically
important aquatic species: a review,” Sustainability, vol. 13,
no. 13, p. 7255, 2021.
[27] Y. Avnimelech, “Carbon/nitrogen ratio as a control element
in aquaculture systems,” Aquaculture, vol. 176, no. 3-4,
pp. 227–235, 1999.
[28] J. M. Ebeling, M. B. Timmons, and J. J. Bisogni, “Engineering
analysis of the stoichiometry of photoautotrophic, autotro-
phic, and heterotrophic removal of ammonia–nitrogen in
aquaculture systems,” Aquaculture, vol. 257, no. 1-4,
pp. 346–358, 2006.
[29] W. J. Xu, T. C. Morris, and T. M. Samocha, “Eects of C/N
ratio on biooc development, water quality, and performance
of Litopenaeus vannamei juveniles in a biooc-based, high-
density, zero-exchange, outdoor tank system,” Aquaculture,
vol. 453, pp. 169–175, 2016.
[30] Y. Zhu, S. Wang, L. Huang et al., “Eects of sucrose addition
on water quality and bacterioplankton community in the
Pacic White Shrimp (Litopenaeus vannamei) culture sys-
tem,” Aquaculture Research, vol. 52, no. 9, pp. 4184–4197,
2021.
[31] Apha (American Public Health Association), Standard
Methods for the Examination of Water and Wastewater,
American Public Health Association, Washington, DC, USA,
21 edition, 2005.
[32] Y. Avnimelech, Biooc Technology: A Practical Guide Book,
World Aquaculture Society, Baton RougeSorrento, LA, USA,
2009.
[33] M. E. Azim and D. C. Little, “e biooc technology (BFT) in
indoor tanks: water quality, biooc composition, and growth
and welfare of Nile tilapia (Oreochromis niloticus),” Aqua-
culture, vol. 283, no. 1-4, pp. 29–35, 2008.
[34] J. Folch, M. Lees, and G. S. Stanley, “A simple method for the
isolation and purication of total lipids from animal tissues,”
Journal of Biological Chemistry, vol. 226, no. 1, pp. 497–509,
1957.
[35] A. Aoac, Ocial Methods of Analysis, Association of ocial
analytical chemists, Washington DC, USA, 16 edition, 1995.
[36] J. S. Diana, J. P. Szyper, T. R. Batterson, C. E. Boyd, and
R. H. Piedrahita, “Water quality in ponds,” in Dynamics of
Pond Aquaculture, H. S. Egna and C. E. Boyd, Eds., CRC Press
LLC, Boca Raton, FL, USA, 1997.
[37] J. K. Jena, P. K. Mukhopadhyay, and P. K. Aravindakshan,
“Dietary incorporation of meat meal as a substitute for sh
meal in carp fry rearing,” Indian Journal of Fisheries, vol. 45,
no. 1, pp. 43–49, 1998.
[38] A. M. Mondal, H. S. Murthy, and S. K. Satheesha, “Eect of
varying stocking density on growth and survival of Catla catla
fry in nursery cisterns,” Fishery Technology, vol. 37, no. 2,
pp. 95–97, 2000.
[39] G. Luo, Q. Gao, C. Wang et al., “Growth, digestive activity,
welfare, and partial cost-eectiveness of genetically improved
farmed tilapia (Oreochromis niloticus) cultured in a recircu-
lating aquaculture system and an indoor biooc system,”
Aquaculture, vol. 422-423, no. 23, pp. 1–7, 2014.
[40] M. A. Burford, P. J. ompson, R. P. McIntosh, R. H. Bauman,
and D. C. Pearson, “Nutrient and microbial dynamics in high-
intensity, zero-exchange shrimp ponds in Belize,” Aquacul-
ture, vol. 219, no. 1-4, pp. 393–411, 2003.
[41] D. Yuniasari, D. Yuniasari, Sukenda, and J. Ekasari, “Nursery
culture performance of Litopenaeus vannamei with probiotics
addition and dierent C/N Ratio under laboratory condition,”
Hayati Journal of biosciences, vol. 17, no. 3, pp. 115–119, 2010.
[42] B. M. Wilen and P. Balmer, “e eect of dissolved oxygen
concentration on the structure, size and size distribution of
activated sludge ocs,” Water Research, vol. 33, no. 2,
pp. 391–400, 1999.
[43] M. Shamsuddin, M. B. Hossain, M. Rahman et al., “Appli-
cation of Biooc Technology for the culture of Heteropneustes
fossilis (Bloch) in Bangladesh: stocking density, oc volume,
growth performance, and protability,” Aquaculture In-
ternational, vol. 30, no. 2, pp. 1047–1070, 2022.
[44] R. Schveitzer, R. Arantes, P. F. S. Cost´odio et al., “Eect of
dierent biooc levels on microbial activity, water quality and
performance of Litopenaeus vannamei in a tank system op-
erated with no water exchange,” Aquacultural Engineering,
vol. 56, pp. 59–70, 2013.
Aquaculture Research 9
[45] N. Mirzakhani, E. Ebrahimi, S. A. H. Jalali, and J. Ekasari,
“Growth performance, intestinal morphology and nonspecic
immunity response of Nile tilapia (Oreochromis niloticus) fry
cultured in biooc systems with dierent carbon sources and
input C: N ratios,” Aquaculture, vol. 512, Article ID 734235,
2019.
[46] W. Wasielesky Jr, H. Atwood, A. Stokes, and C. L. Browdy,
“Eect of natural production in a zero-exchange suspended
microbial oc based super-intensive culture system for white
shrimp Litopenaeus vannamei,” Aquaculture, vol. 258, no. 1-
4, pp. 396–403, 2006.
[47] P. S. Furtado, L. H. Poersch, and W. Wasielesky, “Eect of
calcium hydroxide, carbonate and sodium bicarbonate on
water quality and zootechnical performance of shrimp
Litopenaeus vannamei reared in bio-ocs technology (BFT)
systems,” Aquaculture, vol. 321, no. 1-2, pp. 130–135, 2011.
[48] R. Llyod and D. H. M. Jordan, “Some factors aecting the
resistance of rainbow trout (Salmo gairdneri R.) to acid
water,” International Journal of Air and Water Pollution,
vol. 8, Article ID 393403, 1964.
[49] P. H. Sapkale, R. K. Singh, and A. S. Desai, “Optimal water
temperature and pH for development of eggs and growth of
spawn of common carp (Cyprinus carpio),” Journal of Applied
Animal Research, vol. 39, no. 4, pp. 339–345, 2011.
[50] J. A. Hargreaves, “Biooc production systems for aquacul-
ture,” Stoneville MS Southern Regional Aquaculture Center,
vol. 4503, pp. 1–11, 2013.
[51] C. E. Boyd, “Pond water aeration systems,” Aquacultural
Engineering, vol. 18, no. 1, pp. 9–40, 1998.
[52] J. A. Hargreaves, “Photosynthetic suspended-growth systems
in aquaculture,” Aquacultural Engineering, vol. 34, no. 3,
pp. 344–363, 2006.
[53] A. B. Dauda, N. Romano, M. Ebrahimi et al., “Inuence of
carbon/nitrogen ratios on biooc production and biochemical
composition and subsequent eects on the growth, physio-
logical status and disease resistance of African catsh (Clarias
gariepinus) cultured in glycerol-based biooc systems,”
Aquaculture, vol. 483, pp. 120–130, 2018.
[54] E. W. Magondu, H. Charo-Karisa, and M. C. J. Verdegem,
“Eect of C/N ratio levels and stocking density of Labeo
victorianus on pond environmental quality using maize our
as a carbon source,” Aquaculture, vol. 410-411, pp. 157–163,
2013.
[55] H. Sarsangi Aliabad, A. Naji, S. R. S. Mortezaei, I. Sourinejad,
and A. Akbarzadeh, “Eects of restricted feeding levels and
stocking densities on water quality, growth performance,
body composition and mucosal innate immunity of Nile ti-
lapia (Oreochromis niloticus) fry in a biooc system,”
Aquaculture, vol. 546, Article ID 737320, 2022.
[56] M. E. Hosain, S. M. Nurul Amin, M. S. Kamarudin, A. Arshad,
and N. Romano, “Eects of C/N ratio on growth, survival and
proximate composition of Macrobrachium rosenbergii post
larvae reared under a corn starch based zero-exchange
brackish water biooc system,” Aquaculture Research,
vol. 52, no. 7, pp. 3015–3025, 2021.
[57] D. Becerril-Cort´es, M. D. C. Monroy-Dosta,
M. G. C. Emerenciano et al., “Eect on nutritional compo-
sition of produced bioocs with dierent carbon sources
(Molasses, coee waste and rice bran) in Biooc system,”
International Journal of Fisheries and Aquatic Studies, vol. 6,
no. 2, pp. 541–547, 2018.
[58] M. H. Khanjani, M. M. Sajjadi, M. Alizadeh, and I. Sourinejad,
“Study on nursery growth performance of Pacic white
shrimp (Litopenaeus vannamei Boone, 1931) under dierent
feeding levels in zero water exchange system,” Iranian Journal
of Fisheries Sciences, vol. 15, no. 4, pp. 1465–1484, 2016.
[59] Y. Avnimelech, Biooc Technology a Practical Guide Book,
Wiley, Hoboken, NJ, USA, 2012.
[60] K. S. Misra, “An aid to the identication of the shes of India,
Burma, and ceylon. II. Clupeiformes, bathyclupeiformes,
galaxiiformes, scopeliformes and ateleopiformes,” Records of
the Zoological Survey of India, vol. 50, no. 3-4, pp. 367–422,
1953.
[61] V. G. Jhingran, Synopsis of Biological Data on Catla, FAO,
Rome, Italy, 1968.
[62] K. H. Alikunhi, “Fish culture in India,” Farm Bulletin, vol. 20,
pp. 1–144, 1957.
[63] N. H. Nguyen, L. T. Trinh, D. T. Chau, K. Baruah, T. Lundh,
and A. Kiessling, “Spent brewer’s yeast as a replacement for
shmeal in diets for giant freshwater prawn (Macrobrachium
rosenbergii), reared in either clear water or a biooc envi-
ronment,” Aquaculture Nutrition, vol. 25, no. 4, pp. 970–979,
2019.
[64] O. Schneider, V. Sereti, E. H. Eding, and J. A. Verreth,
“Molasses as C source for heterotrophic bacteria production
on solid sh waste,” Aquaculture, vol. 261, no. 4, pp. 1239–
1248, 2006.
[65] G. Wang, E. Yu, J. Xie et al., “Eect of C/N ratio on water
quality in zero-water exchange tanks and the biooc sup-
plementation in feed on the growth performance of crucian
carp, Carassius auratus,” Aquaculture, vol. 443, pp. 98–104,
2015.
[66] K. Minabi, I. Sourinejad, M. Alizadeh, E. R. Ghatrami, and
M. H. Khanjani, “Eects of dierent carbon to nitrogen ratios
in the biooc system on water quality, growth, and body
composition of common carp (Cyprinus carpio L.) nger-
lings,” Aquaculture International, vol. 28, no. 5, pp. 1883–
1898, 2020.
[67] W. J. Xu, T. C. Morris, and T. M. Samocha, “Eects of two
commercial feeds for semi-intensive and hyper-intensive
culture and four C/N ratios on water quality and perfor-
mance of Litopenaeus vannamei juveniles at high density in
biooc-based, zero-exchange outdoor tanks,” Aquaculture,
vol. 490, pp. 194–202, 2018.
[68] H. Adineh, M. Naderi, M. Khademi Hamidi, and M. Harsij,
“Biooc technology improves growth, innate immune re-
sponses, oxidative status, and resistance to acute stress in
common carp (Cyprinus carpio) under high stocking den-
sity,” Fish & Shellsh Immunology, vol. 95, pp. 440–448, 2019.
[69] G. K. F´oes, C. Fr´oes, D. Krummenauer, L. Poersch, and
W. Wasielesky, “Nursery of pink shrimp Farfantepenaeus
paulensis in biooc technology culture system: survival and
growth at dierent stocking densities,” Journal of Shellsh
Research, vol. 30, no. 2, pp. 367–373, 2011.
[70] W. Wasielesky, C. Froes, G. F´
oes, D. Krummenauer, G. Lara,
and L. Poersch, “Nursery of Litopenaeus vannamei reared in
a biooc system: the eect of stocking densities and com-
pensatory growth,” Journal of Shellsh Research, vol. 32, no. 3,
pp. 799–806, 2013.
[71] H. Adineh, M. Naderi, H. Jafaryan, M. Khademi Hamidi,
M. Youse, and E. Ahmadifar, “Eect of stocking density and
dietary protein level in biooc system on the growth, digestive
and antioxidant enzyme activities, health, and resistance to
acute crowding stress in juvenile common carp (Cyprinus
carpio),” Aquaculture Nutrition, vol. 2022, Article ID
9344478, 12 pages, 2022.
[72] G. Liu, Z. Ye, D. Liu et al., “Inuence of stocking density on
growth, digestive enzyme activities, immune responses,
10 Aquaculture Research
antioxidant of Oreochromis niloticus ngerlings in biooc
systems,” Fish & Shellsh Immunology, vol. 81, pp. 416–422,
2018.
[73] J. Ekasari, M. A. Suprayudi, W. Wiyoto et al., “Biooc
technology application in African catsh ngerling pro-
duction: the eects on the reproductive performance of
broodstock and the quality of eggs and larvae,” Aquaculture,
vol. 464, pp. 349–356, 2016.
[74] K. F. Liu, C. H. Chiu, Y. L. Shiu, W. Cheng, and C. H. Liu,
“Eects of the probiotic, Bacillus subtilis E20, on the survival,
development, stress tolerance, and immune status of white
shrimp, Litopenaeus vannamei larvae,” Fish & Shellsh Im-
munology, vol. 28, no. 5-6, pp. 837–844, 2010.
[75] P. K. Sahu, J. Jena, and P. C. Das, “Nursery rearing of kalbasu,
Labeo calbasu (Hamilton), at dierent stocking densities in
outdoor concrete tanks,” Aquaculture Research, vol. 8, no. 7,
Article ID 70116074017192, 2007.
[76] J. Sharma and R. Chakrabarti, “Role of stocking density on
growth and survival of catla, Catla catla, and rohu, Labeo
rohita, larvae and water quality in a recirculating system,”
Journal of Applied Aquaculture, vol. 14, no. 1-2, pp. 171–178,
2003.
[77] M. Emerenciano, G. Gaxiola, and G. Cuzon, “Biooc tech-
nology (BFT): a review for aquaculture application and animal
food industry,” Biomass now-cultivation and utilization,
vol. 56, pp. 301–328, 2013.
[78] J. Ekasari, D. Angela, S. H. Waluyo et al., “e size of biooc
determines the nutritional composition and the nitrogen
recovery by aquaculture animals,” Aquaculture, vol. 426-427,
pp. 105–111, 2014.
[79] N. Romano, A. B. Dauda, N. Ikhsan, M. Karim, and
M. S. Kamarudin, “Fermenting rice bran as a carbon source
for biooc technology improved the water quality, growth,
feeding eciencies, and biochemical composition of African
catsh Clarias gariepinus juveniles,” Aquaculture Research,
vol. 49, no. 12, pp. 3691–3701, 2018.
[80] M. E. Megahed and K. Mohamed, “Sustainable growth of
shrimp aquaculture through biooc production as alternative
to shmeal in shrimp feeds,” Journal of Agricultural Science,
vol. 6, no. 6, p. 176, 2014.
[81] W. J. Xu and L. Q. Pan, “Enhancement of immune response
and antioxidant status of Litopenaeus vannamei juvenile in
biooc-based culture tanks manipulating high C/N ratio of
feed input,” Aquaculture, vol. 412-413, pp. 117–124, 2013.
Aquaculture Research 11
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