ArticlePDF Available

An approach to optimizing dietary protein to growth and body composition in walking catfish, Clarias batrachus (Linneaeus, 1758)

PLOS
PLOS One
Authors:

Abstract and Figures

Clarias batrachus is a commercially important food fish. In the present study, effect of varying dietary protein levels was evaluated on the survival, growth parameters and proximate composition of C. batrachus. Diets comprising 25%, 30%, 35%, 40%, 45%, and 50% crude protein (CP) were supplied to fish in T1, T2, T3, T4, T5, and T6, respectively, at the rate of 5% of fish body weight for the entire 90 days, twice daily. Size of each stocked C. batrachus was recorded after 15 days. Results revealed 100% survival rate of C. batrachus in all treatments. Significantly highest (P<0.001) mean value of weight gain (g/fish), percent weight gain, daily growth rate, specific growth rate and protein efficiency ratio (PER) in C. batrachus were recorded, reared in T4 by feeding 40% CP in diet. The best FCR value (1.90±0.02) for C. batrachus was obtained in T4 by feeding 40%CP in diet. Mean value of water, ash, fat and protein contents (wet mass) were ranged 74.10–79.23%, 3.12–4.68%, 3.90–4.43% and 13.09–16.79% for C. batrachus in the studied treatment groups. Water content (%) was found significantly (P<0.05) higher in the body of C. batrachus for T1, T2, T3 and T6 than for T4 and T5. Ash was found significantly (P<0.05) higher in the fish reared in T4 and T5. Fat content in the wet body mass of C. batrachus was found significantly higher in T4 and T1. While, significant higher (P<0.05) values of mean protein content was noted in C. batrachus reared in T4 and T5. Body composition of C. batrachus was also categorically affected by body size, however, condition factor showed non-significant correlation in most of the relationships in the present study. Overall, results indicated that feeding appropriate diet (containing 40% CP) to the fish resulted good growth performance, lower FCR and higher protein content in the fish. Present study provides valuable knowledge of optimal dietary protein level in C. batrachus which will help in commercial success of aquaculture.
This content is subject to copyright.
RESEARCH ARTICLE
An approach to optimizing dietary protein to
growth and body composition in walking
catfish, Clarias batrachus (Linneaeus, 1758)
Zara Naeem
1
, Amina Zuberi
1
, Muhammad Ali
2
, Ammar Danyal Naeem
3
,
Muhammad NaeemID
3
*
1Fisheries and Aquaculture Program, Department of Zoology, Faculty of Biological Sciences, Quaid-i-Azam
University, Islamabad, Pakistan, 2Vice Chancellor, Quaid-i-Azam University, Islamabad, Pakistan,
3Institute of Zoology, Bahauddin Zakariya University, Multan, Pakistan
*dr_naeembzu@yahoo.com
Abstract
Clarias batrachus is a commercially important food fish. In the present study, effect of vary-
ing dietary protein levels was evaluated on the survival, growth parameters and proximate
composition of C.batrachus. Diets comprising 25%, 30%, 35%, 40%, 45%, and 50% crude
protein (CP) were supplied to fish in T1, T2, T3, T4, T5, and T6, respectively, at the rate of
5% of fish body weight for the entire 90 days, twice daily. Size of each stocked C.batrachus
was recorded after 15 days. Results revealed 100% survival rate of C.batrachus in all treat-
ments. Significantly highest (P<0.001) mean value of weight gain (g/fish), percent weight
gain, daily growth rate, specific growth rate and protein efficiency ratio (PER) in C.batrachus
were recorded, reared in T4 by feeding 40% CP in diet. The best FCR value (1.90±0.02) for
C.batrachus was obtained in T4 by feeding 40%CP in diet. Mean value of water, ash, fat
and protein contents (wet mass) were ranged 74.10–79.23%, 3.12–4.68%, 3.90–4.43% and
13.09–16.79% for C.batrachus in the studied treatment groups. Water content (%) was
found significantly (P<0.05) higher in the body of C.batrachus for T1, T2, T3 and T6 than for
T4 and T5. Ash was found significantly (P<0.05) higher in the fish reared in T4 and T5. Fat
content in the wet body mass of C.batrachus was found significantly higher in T4 and T1.
While, significant higher (P<0.05) values of mean protein content was noted in C.batrachus
reared in T4 and T5. Body composition of C.batrachus was also categorically affected by
body size, however, condition factor showed non-significant correlation in most of the rela-
tionships in the present study. Overall, results indicated that feeding appropriate diet (con-
taining 40% CP) to the fish resulted good growth performance, lower FCR and higher
protein content in the fish. Present study provides valuable knowledge of optimal dietary
protein level in C.batrachus which will help in commercial success of aquaculture.
1. Introduction
Walking catfish, Clarias batrachus, is one of the most well-known catfish species and a com-
mon food fish due to its lack of intramuscular bones, distinctive flavour and excellent
PLOS ONE
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 1 / 15
a1111111111
a1111111111
a1111111111
a1111111111
a1111111111
OPEN ACCESS
Citation: Naeem Z, Zuberi A, Ali M, Naeem AD,
Naeem M (2024) An approach to optimizing dietary
protein to growth and body composition in walking
catfish, Clarias batrachus (Linneaeus, 1758). PLoS
ONE 19(5): e0301712. https://doi.org/10.1371/
journal.pone.0301712
Editor: Amit Ranjan, Tamil Nadu Dr J Jayalalithaa
Fisheries University, INDIA
Received: January 10, 2024
Accepted: March 20, 2024
Published: May 3, 2024
Peer Review History: PLOS recognizes the
benefits of transparency in the peer review
process; therefore, we enable the publication of
all of the content of peer review and author
responses alongside final, published articles. The
editorial history of this article is available here:
https://doi.org/10.1371/journal.pone.0301712
Copyright: ©2024 Naeem et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: All relevant data are
within the paper.
Funding: The author(s) received no specific
funding for this work.
nutritional content. Moreover, this fish can be easily stored and transported alive to markets.
As a result, consumers are always eager to pay more for this fish [1]. This commercially impor-
tant fish species is widely used as an aquaculture and marketed as live, fresh, and frozen due to
its high economic value as food fish [2]. It can live in a variety of low-oxygen settings, includ-
ing swamps and marshes, and burrows within the mudflat throughout the summer [3]. Adap-
tations like terrestrial dispersal, aerial respiration, and high tolerance to hypoxia and ammonia
can therefore be studied using C.batrachus as the ideal model [4].
Fish is considered as a crucial constituent of supportable diets for the future [5]. Subse-
quently, fish production stagnates, upcoming demand will depend on aquacultural products
[6]. Growing aquaculture production will need an upsurge production of fish feed [7] and to
improve the capability of farmed fish to assimilate feed consumption into biomass which can
help to reduce feed use in the fisheries industry and thus will enhance its sustainability through
condensed expenditures and ecological effects [8].
An important issue in fisheries industry is feeding, particularly when it affects production
costs and the health and growth of fish [9]. Feed expenses mark up 40–50% of total production
costs of fish [10]. Furthermore, growth optimization in the fish farming system is imperative
to confirm success [11]. Fish growth at all stages in its life history is mainly controlled by dif-
ferent factors, including feeding rate, food intake, feeding frequency, food type, and the ability
for nutrient absorption [12]. The capability to alter ingested feed into body mass growth can
be observed by the feed conversion ratio (FCR). It can be enhanced by modification in feed
composition [13]. As, FCR is a commonly used measure of conversion which is commonly
used over the entire production life of a fish, and obviously, the amount of feed changes during
this period [14], however, assessing the FCR in different life stages, like juvenile and younger
stages, may be helpful for better management.
In fish feed, protein is the largest nutrient and considered the most costly source for quality
health and optimum growth of a fish [15], but it also influences growth performance and feeds
conversion ratio of fish [1618]. Fish usually ingest protein to attain non-essential and essen-
tial amino acids, essential for enzymatic function, muscle formation, and to supply energy
[19]. Though, both excessive and inadequate protein in the feed not only affects the quality
and growth of fish but also influence expenditure on aquaculture and as well as water quality.
Therefore, optimal dietary protein level is imperative for best growth and to support good
health in fish culture system [20].
Proximate body composition helps to rank different fish species based on their nutritional
and functional benefits and to assess the energy value of the fishes. Thus, allows consumers,
feed formulators and researchers to select the fish according to their requirements for their
nutritional values and/or processing [2124]. The significance of proximate composition has
been discovered in the study of fish bioenergetics and the effect of pollutants. It acts as a good
indicator of fish physiology [25]. Fish proximate body composition constituents (fat, protein,
water, organic content and ash) are influenced by diet, feed rate, sex, genetic strain, age, species
and also by changing body size and condition factor [2628].
The objective of the present study was to assess the survival rate, growth performance, feed
conversion ratio and proximate composition of Clarias batrachus fed on varying dietary pro-
tein levels.
2. Materials and methods
2.1. Ethics statement
2.1.1. Institutional review board statement. It has been confirmed that the experimental
data collection complied with appropriate permissions from Ethical Review Committee,
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 2 / 15
Competing interests: The authors have declared
that no competing interests exist.
Department of Zoology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad,
Pakistan. The study did not involve humans.
2.2. Experimental design
Fish fry of Clarias batrachus comprising 0.5–1.38 g wet body weight (W) and 3.90–7.40 cm
total length (TL) were procured from the Tawakkal Fish Hatchery & Farm, Muzaffargarh,
Pakistan, and acclimatized on rice polish in glass aquaria for two weeks. Feeding trial was con-
ducted in eighteen glass aquaria (volume 50 L), each having working dimensions of 60 x 40 x
44 cm
3
. After acclimatization, a total of 180 fish fry of C.batrachus were randomly stocked
comprising ten fish in each aquarium (30 per treatment) and three replicates were followed for
each treatment.
Six experimental diets (Table 1) comprising 25, 30, 35, 40, 45, and 50% crude protein (CP)
were supplied to the fish in treatment-1 (T1), treatment-2 (T2), treatment-3 (T3), treatment-4
(T4), treatment-5 (T5) and treatment-6 (T6), respectively. Proximate composition of experi-
mental feeds was calculated following the studies of NRC [29], Preston [30] and NDDB [31].
Feed was given to the fish at the rate of 5% of fish body weight for the entire 90 days of the
experimental period, twice (0900 and 1800) in two equal meals, with 16 hours light and 8
hours dark cycle daily. Dissolved oxygen and pH of water in each aquarium were monitored
daily. The temperature of each aquarium was maintained at 24–26˚C during the study period.
Size (W and TL) of each stocked C.batrachus were recorded after 15 days to adjust the feeding
rates and to calculate different growth parameters i.e. length gain, percent length gain, mean
final weight, weight gain, daily growth rate, percent weight gain, feed conversion ratio (FCR),
Table 1. Ingredients (%) used for feed formulation and proximate composition of various diets.
Ingredients T1
(CP-25)
T2
(CP-30)
T3
(CP-35)
T4
(CP-40)
T5
(CP-45)
T6
(CP-50)
Canola Meal 5 5 5 5 5 2
Corn Gluten Meal 30% 10 9 5 5 3 0
Corn Gluten Meal 60% 10 15 15 15 5 3
Fishmeal 10 10 15 21 30 37
Rice Polish 25 15 10 4 3 0
Sarson Meal 5 2 5 5 3 5
Soybean Meal 10 15 25 31 40 44
Sunflower Meal 5 5 5 5 3 2
Wheat Bran 15 19 10 4 3 2
Dicalcium Phosphate 1 1 1 1 1 1
Vitamin Premixes 1 1 1 1 1 1
Soybean Oil 2 2 2 2 2 2
Carboxymethyl Cellulose (CMC) 1 1 1 1 1 1
Proximate Composition of the Diets (%)
Moisture 8.96 9.28 8.95 8.25 8.86 8.9
Dry Matter (DM) 91.04 90.72 91.05 91.75 91.14 91.1
Crude Protein (CP) 25.15 29.95 30.00 34.80 40.10 45.03
Crude Fat (CF) 8.11 6.91 7.20 7.50 7.82 8.02
Ash 8.16 7.83 7.63 7.86 7.90 7.91
Fiber 8.38 8.05 8.10 8.03 8.22 8.07
Nitogen Free Extract (NFE) 41.24 37.98 38.12 33.56 27.10 22.07
NFE = DM-(%CP+ %CF + %Ash + %Fiber)
https://doi.org/10.1371/journal.pone.0301712.t001
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 3 / 15
specific growth rate (SGR%) and protein efficiency ratio (PER). At the end of the feeding trial,
the total number of fingerlings in each tank was counted to calculate survival rate.
Growth performance of C.batrachus fed varying levels of dietary protein was measured as a
function of the weight gain by calculating the following statistics:
Percent Length Gain (%LG) = (Avg. final lengthAvg. initial length /initial length) ×100
Percent weight gain (%WG) = (Avg. final weight Avg. initial weight/initial weight) ×100
Daily Growth Rate (DGR) = Avg. final body weight Avg. initial body weight/growth
period (in days)
Feed conversion ratio (FCR) = Dry feed intake (g)/biomass gain (g)
Specific growth rate (SGR%) = 100×(Ln final weight Ln initial weight) / growth period
Protein efficiency ratio (PER) = Weight gain (g)/protein intake (g)
At the end of the feeding trial, fish specimens were immersed and kept in solution of
MS222 (250mg/L) for 10 minutes to euthanize the fish. Proximate composition was analysed
by taking of whole body of the fish. In brief, specimens of C.batrachus were dried to a constant
weight at 80˚C in an oven (Incucell, MMM Medcenter Einrichtungen GmbH, MMM-Group)
to determine water content in the fish. Ash was determined by incineration using muffle fur-
nace (RJM-1.8-10A) at 550˚C for 12 hr. Fat was determined by extracting in a chloroform and
methanol solution (1:2). Protein contents in C.batrachus were assessed by difference from
mass of other constituents, following the approach adopted by Naeem and Salam [27].
2.3. Statistical analyses
The data were subjected to ANOVA followed by Duncan’s new multiple range test to study the
differences among treatments in SPSS version 23. Mean differences among treatment were
determined by Duncan’s multiple range test and considered significant at p<0.05. Correlation
and regression analyses (Y = a + bX) were also performed to study the effect of fish size on
proximate composition in C.batrachus. Correlation coefficients for regression analyses were
considered significant at p<0.05, p<0.01 and p<0.001.
3. Results
Growth performance of the walking catfish (Clarias batrachus) fed with different feed treat-
ments (25%, 30%, 35%, 40%, 45%, and 50% CP) is presented in Table 2. Survival rate (%) of C.
batrachus was found 100% in all the studied treatment groups. Fortnightly length gain (cm)
and fortnightly weight gain (g) of C.batrachus in different studied treatments is represented in
Figs 1and 2, respectively.
Length gain and percent length gain (%LG) of C.batrachus showed non-significant differ-
ences (P>0.05) among various studied treatment groups. However, dietary protein levels sig-
nificantly affected (P<0.05) mean final weight, weight gain, daily growth rate, percent weight
gain, FCR, SGR%, and PER of C.batrachus (Table 2).
Significantly highest (P<0.001) mean value (6.96±0.04) of weight gain (g/fish) in C.batra-
chus was recorded in the fishes that were reared in T4 by feeding 40%CP in the diet. Daily
growth rate of C.batrachus was significantly highest (P<0.05) in T4 (40%CP) with a mean
(±SE) value of 0.63±0.005. The highest (P<0.001) mean (±SE) value of percent weight gain
(80.84±0.28%) was also recorded in the fishes that were fed 40%CP in T4, while that was the
lowest (56.14±1.04%) in T1 (25%CP), as shown in Table 2.
The best FCR value of C.batrachus was obtained in T4 by feeding the fish 40% crude pro-
tein in diet, as it remained the significantly (P<0.001) lowest (1.90±0.02) among various stud-
ied treatments. While the highest FCR value was recorded as 5.24±0.11 in T1, in which C.
batrachus were supplied 25% dietary protein level. Specific growth rate (SGR%) of C.batrachus
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 4 / 15
was found significant highest (P<0.05) in T4(40%CP) with mean value being 0.80±0.01, while
the lowest (0.40±0.01) in T1 by providing fish 25% crude protein in diet. Highest (P<0.05)
mean value of protein efficiency ratio (PER) for C.batrachus was also recorded as 1.32±0.01in
feeding treatment which was supplied with a diet containing 40% protein level (T4). The low-
est mean PER value (0.60±0.02) for C.batrachus was found in T6 in which fish were supplied a
diet containing 50% protein.
Mean value of water, ash, fat and protein contents (% wet mass) were ranged from 74.10
±0.31% - 79.23±0.52%, 3.12±0.07% - 4.68±0.05%, 3.90±0.06% - 4.43±0.05% and 13.09±0.58% -
Table 2. Descriptive statistics (Mean±SE) for various growth parameters of Clarias batrachus fed upon various dietary crude protein levels in different treatments.
Parameters T1
(CP-25)
T2
(CP-30)
T3
(CP-35)
T4
(CP-40)
T5
(CP-45)
T6
(CP-50)
p-value
Survival rate of fish (%) 100 100 100 100 100 100
Mean Initial Length (cm) (iTL) 5.29±0.04
ns
5.25±0.02
ns
5.28±0.02
ns
5.31±0.05
ns
5.38±0.08
ns
5.27±0.09
ns
.692
Mean Final Length (cm) (fTL) 6.71±0.08
ns
6.59±0.03
ns
6.72±0.08
ns
6.67±0.09
ns
6.70±0.10
ns
6.60±0.10
ns
.793
Length gain (cm) (LG) 1.42±0.06
ns
1.32±0.04
ns
1.44±0.07
ns
1.36±0.04
ns
1.33±0.02
ns
1.33±0.07
ns
.439
Percent Length Gain (%LG) 21.15±0.63
ns
19.96±0.57
ns
21.42±0.78
ns
20.37±0.30
ns
19.79±0.03
ns
20.16±0.93
ns
.384
Mean Initial Weight (g) (iW) 1.37±0.01
ns
1.30±0.01
ns
1.37±0.02
ns
1.33±0.01
ns
1.33±0.02
ns
1.31±0.03
ns
.093
Mean Final Weight (g) (fW) 3.13±0.04
c
3.26±0.03
c
5.41±0.01
b
6.96±0.04
a
5.01±0.01
b
4.18±0.05
c
<.001
Weight Gain (g/fish) (WG) 1.76±0.06
c
1.96±0.02
c
4.04±0.01
b
5.63±0.05
a
3.68±0.04
b
2.87±0.04
c
<.001
Percent Weight Gain (%WG) 56.14±1.04
c
60.18±0.22
c
74.63±0.35
b
80.84±0.28
a
73.40±0.54
b
71.97±0.47
b
<.001
Daily Growth Rate (g/day) (DGR) 0.19±0.004
c
0.22±0.002
c
0.45±0.002
b
0.63±0.005
a
0.41±0.004
b
0.32±0.004
bc
<.001
Feed Conversion Ratio (FCR) 5.24±0.11
a
4.78±0.012
a
2.70±0.02
b
1.90±0.02
c
2.64±0.04
b
3.33±0.09
b
<.001
Specific Growth Rate (SGR%) 0.40±0.01
c
0.44±0.002
c
0.66±0.01
b
0.80±0.01
a
0.64±0.01
b
0.55±0.01
bc
<.001
Protein Efficiency Ratio (PER) 0.76±0.02
bc
0.70±0.002
c
1.06±0.01
b
1.32±0.01
a
0.84±0.01
b
0.60±0.02
c
<.001
Mean values sharing the same superscript in a row are not significantly different (p>0.05),
ns
= not significant
T1 = 25%CP, T2 = 30%CP, T3 = 35%CP, T4 = 40%CP, T5 = 45%CP, T6 = 50%C
https://doi.org/10.1371/journal.pone.0301712.t002
Fig 1. Fortnightly mean length (cm) of Clarias batrachus in different studied treatments.
https://doi.org/10.1371/journal.pone.0301712.g001
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 5 / 15
16.79±0.27% in the studied treatments (Table 3). Analysis of variance (ANOVA) revealed sig-
nificant difference in all body constituents (both in wet and dry masses) among the studied
treatments (T1-T6). Water content (%) was found significantly (p<0.05) higher in the body of
C.batrachus for T1, T2, T3 and T6 than for T4 and T5. Ash (wet mass) was found significantly
higher in the fish reared in T4 (4.68±0.05%) and T5 (4.53±0.06%), while the lowest in T6 (3.12
±0.07%). Fat content in the wet body mass of C.batrachus was found significantly higher in T4
and T1. Significant higher value of mean protein content in wet mass was noted in C.batra-
chus reared in T4 (CP-40) and T5 (CP-45).
Water content (%) in the body of C.batrachus showed highly significant negative correla-
tion (p<0.001) with ash content (% wet mass) reared in T1 by feeding 25% of crude protein,
and significant (p<0.01) in T2, T3 and T6; while non-significant correlation was observed in
T4 and T5. Fat content was found significantly correlated (p<0.001) with water (%) only in T1
and T2. However, protein content of (p<0.001) showed highly significant negative correlation
(p<0.001) in all the studied treatment (Table 4).
Fig 2. Fortnightly mean weight (g) of Clarias batrachus in different studied treatments.
https://doi.org/10.1371/journal.pone.0301712.g002
Table 3. Mean values (±SE) of various constituents in percentage (%) of wet and dry mass of Clarias batrachus reared in different treatments.
Constituents T1
(CP-25)
T2
(CP-30)
T3
(CP-35)
T4
(CP-40)
T5
(CP-45)
T6
(CP-50)
p-value
Water (%) 78.81±0.74
a
79.23±0.52
a
78.33±0.30
a
74.10±0.31
b
75.50±0.50
b
78.97±0.40
a
<.001
Ash Wet mass 3.68±0.14
b
3.72±0.10
b
3.41±0.09
c
4.68±0.05
a
4.53±0.06
a
3.12±0.07
d
<.001
Dry mass 17.50±0.43
b
18.03±0.45
ab
15.73±0.34
c
18.14±0.25
ab
18.69±0.43
a
14.90±0.31
c
<.001
Fat Wet mass 4.42±0.11
a
3.95±0.09
c
3.90±0.06
c
4.43±0.05
a
4.18±0.07
b
4.22±0.07
ab
.002
Dry mass 21.22±0.52
a
19.15±0.36
b
18.09±0.34
bc
17.13±0.21
c
17.28±0.51
c
20.28±0.53
ab
.001
Protein Wet mass 13.09±0.58
b
13.09±0.41
b
14.35±0.26
b
16.79±0.27
a
15.80±0.51
a
13.70±0.40
b
<.001
Dry mass 61.29±0.83
c
62.82±0.62
bc
66.18±0.55
a
64.73±0.38
ab
64.03±0.86
b
64.82±0.76
ab
<.001
Mean values sharing the same superscript in a row are not significantly different (p>0.05)
https://doi.org/10.1371/journal.pone.0301712.t003
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 6 / 15
Size (wet weight and total length) of the fish represented highly significant correlation
(p<0.001) with all the body constituents in all the studied treatment groups for the studied cat-
fish, C.batrachus (Tables 5and 6).Water showed negative allometric pattern for all the studied
treatments groups with an increase in body weight of C.batrachus. Ash contents showed posi-
tive allometry for all the studied treatments groups except for T3 (CP35) which represented
isometric pattern (b = 1.036). Slope (b value) represented positive allometry for fats in the
body of C.batrachus in T1, T2 and T4, negative allometry in T6, while isometry in T3 and T5.
Positive allometry was also found in all treatments except for T5 (CP45) which represented
isometry with an increase in body weight of the studied fish (Table 5). On the other hand, all
the body constituents showed negative allometry for all studied treatment groups with an
increase in total length of C.batrachus (Table 6).
Table 7 showed that condition factor remained significantly correlated with water only in
T2 (r = 0.427, p<0.01), T3 (r = 0.618, = p<0.001) and T4 (r = 0.540, p<0.01). Ash content
was found insignificantly correlated (p>0.05) in all treatments except for T2 which was found
negatively correlated (r = 0.608, p<0.001) with condition factor of C.batrachus. Fat was also
found significant (r = 0.367, p<0.05) with condition factor for only T4, in which the fish was
fed a diet containing 40% crude protein. Significant correlation was also found in T3
(r = 0.636, p<0.01) and T4 (r = 0.507, p<0.001).
4. Discussion
Evaluation of the optimum dietary protein level is one of the most critical factors for the suc-
cess of aquaculture operations. In the present work growth performance of Clarias batrachus
was compared between different feeding treatments with six varying levels of formulated diets
Table 4. Statistical regression parameters of percentage water (%W) content versus % body constituents in wet mass of C.batrachus reared in different treatments.
Equation Treatment r a b SE of b t-Stat
%Ash = a+b%Water T1 -0.754*** 14.631 -0.139 0.023 -5.965
T2 -0.563** 12.657 -0.113 0.032 -3.538
T3 -0.552** 15.843 -0.159 0.046 -3.439
T4 -0.324
ns
8.729 -0.055 0.031 -1.783
T5 -0.144
ns
5.839 -0.017 0.023 -0.758
T6 -0.416** 8.506 -0.068 0.029 -2.382
%Fat = a+b% Water T1 -0.703*** 12.654 -0.105 0.020 -5.143
T2 -0.702*** 13.442 -0.120 0.023 -5.123
T3 -0.266
ns
8.139 -0.054 0.038 -1.434
T4 -0.324
ns
8.729 -0.055 0.031 -1.783
T5 0.081
ns
3.293 0.012 0.028 0.424
T6 0.105
ns
2.702 0.019 0.035 0.549
% Protein = a+b% Water T1 -0.967*** 72.715 -0.757 0.039 -19.600
T2 -0.965*** 73.900 -0.767 0.040 -18.993
T3 -0.909*** 76.017 -0.787 0.069 -11.345
T4 -0.968*** 80.655 -0.862 0.043 -20.081
T5 -0.982*** 90.869 -0.994 0.037 -26.654
T6 -0.959*** 88.793 -0.951 0.054 -17.500
r = Correlation Coefficient; a = Intercept; b = Slope; S.E = Standard Error
*** =p<0.001
** =p<0.01;
ns
>0.05
https://doi.org/10.1371/journal.pone.0301712.t004
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 7 / 15
containing 25% (T1), 30% (T2), 35% (T3), 40% (T4), 45% (T5) and 50% crude protein (T6).
Results of the growth experiment showed that the survival rate was recorded as 100% in all of
the studied groups, indicating high tolerance of the fish in the confined system and also repre-
sents that rearing conditions were good (optimal). Results of the present study agreed well with
a previously conducted study by Farhat and Khan [32], which reported a survival rate of 100%
in C.gariepinus by feeding the fish with 30%, 35%, 40%, 45%, and 50% crude protein (CP).
Results of present study also revealed that highest daily growth rate (0.63±0.005 g/day) was
observed in fish that were supplied 40% CP (T4) followed by 35% CP (0.45±0.002 g/day) in
T3, and the lowest (0.19±0.004 g/day) was found in fish fed on 25% CP in T1 for C.batrachus.
The observed difference in daily growth rate among the treatments was found to be statistically
(p<0.05) significant. Treatment groups showed difference in growth rate indicating the
importance of supplementary feeds on the growth and production of fish. In general, the daily
growth rate of C.batrachus recorded in the present experiment was found similar to that previ-
ously described by Tadesse [33], who have reported a daily growth rate of 0.23 to 0.52 g/day in
African catfish, Clarias gariepinus, fingerlings which were reared in tanks; but lower than that
of documented (1.12 g/day to 1.64 g/day) by Yalew [34], for different stocking density in C.
gariepinus. This lower growth rate of the fish than the study of Yalew [34] might be due to the
difference in feed composition of the ingredients or difference in fish size.
Table 5. Statistical regression parameters of log transformed wet body weight (g) versus log transformed total body constituents in wet mass of C.batrachus reared
in different treatments.
Equation Treatment r a b S. E. (b) tvalue when b = 1
Water = a+bWet Weight T1 0.983*** 0.019 0.746 0.027 -36.23
T2 0.984*** -0.005 0.811 0.028 -34.54
T3 0.992*** -0.018 0.879 0.022 -45.01
T4 -0.968*** 80.655 -0.862 0.043 -20.081
T5 0.957*** 0.079 0.712 0.042 -23.28
T6 0.971*** -0.017 0.863 0.041 -23.65
Ash = a+bWet Weight T1 0.960*** -1.906 1.956 0.109 -7.18
T2 0.830*** -1.637 1.399 0.181 -4.13
T3 0.680*** -1.498 1.036 0.215 -3.62
T4 0.798*** -1.450 1.143 0.166 -4.87
T5 0.841*** -1.432 1.124 0.139 -6.05
T6 0.845*** -1.798 1.465 0.178 -4.14
Fat = a+bWet Weight T1 0.963*** -1.661 1.624 0.088 -9.80
T2 0.927*** -1.676 1.530 0.119 -6.87
T3 0.817*** -1.400 0.987 0.134 -6.47
T4 0.905*** -1.849 1.587 0.143 -5.38
T5 0.718*** -1.369 0.983 0.183 -4.48
T6 0.676*** -1.233 0.769 0.161 -5.43
Protein = a+bWet Weight T1 0.916*** -1.410 2.062 0.173 -3.70
T2 0.921*** -1.304 1.818 0.148 -4.93
T3 0.959*** -1.313 1.641 0.093 -9.09
T4 0.877*** -1.482 1.838 0.194 -3.33
T5 0.718*** -1.369 0.983 0.183 -4.48
T6 0.820*** -1.325 1.736 0.233 -2.56
r = Correlation Coefficient; a = Intercept; b = Slope; S.E = Standard Error
*** =p<0.001
https://doi.org/10.1371/journal.pone.0301712.t005
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 8 / 15
FCR (Feed conversion ratio) is a vital gauge of the fineness of fish diet. A lower FCR desig-
nates better consumption of feed by a fish [35]. In the present research, the FCR values ranged
from 1.90 to 5.24 and varied significantly (p<0.05) between feeding treatments. Ogunji et al.
[36] declared FCR values of 1.2–1.5 as good range for fish raised with balanced diet and also
suggested that inclusion of more animal ingredients in fish diet may provide higher growth
rate and lower FCR of fish in the future. Although FCR value between 1.2 and 1.5 represent a
good indicator, it could not be used as absolute standard in all fish species, as it can change
according to several culturing factors. As, Tadesse [33] reported the lowest feed conversion
ratio (FCR = 2.14) in fish fed with 40% CP, indicating its suitability for African catfish finger-
lings than the other test diets. Further, in the present investigation, the lowest FCR value (1.90
±0.02) was noted in fish provided with 40% CP, representing that the fish consumed the feed
better than the other test feeds (25%, 30%, 35%, 45%, 50% CP) of the experiment for C.batra-
chus. The best FCR for C.batrachus in T4 might be due to the high proportion of protein
derived from easily digestible animal ingredients. FCR of the present study in C.batrachus is
very similar to those reported by Tadesse [33]. On the other hand, Ogunji and Awoke [37],
have reported lower FCR values of 1.61 for C.gariepinus reared in tanks under greenhouse.
Unlike these results of FCR in catfishes, Iqbal and Naeem [18], and Ishtiaq and Naeem [16],
noted the lowest food conversion ratio (FCR) fed upon 25% CP in the carp hybrid fry (Labeo
Table 6. Statistical regression parameters of log transformed total length (cm) versus log transformed total body constituents (g) in wet mass of C.batrachus reared
in different treatments.
Equation Treatment r a b S. E. (b) tvalue when b = 1
Water = a+bTotal Length T1 0.664*** -0.412 0.961 0.208 -13.48
T2 0.801*** -0.450 1.048 0.151 -18.84
T3 0.802*** -0.029 0.792 0.113 -25.65
T4 0.794*** 0.320 0.476 0.070 -42.32
T5 0.854*** 0.054 0.633 0.074 -39.87
T6 0.836*** -0.146 0.814 0.103 -28.43
Ash = a+bTotal Length T1 0.662*** -3.078 2.568 0.559 -2.80
T2 0.864*** -2.817 2.313 0.259 -9.25
T3 0.675*** -1.687 1.147 0.241 -11.31
T4 0.686*** -1.096 0.739 0.151 -19.16
T5 0.749*** -1.469 0.997 0.170 -16.69
T6 0.782*** -2.101 1.486 0.228 -11.69
Fat = a+bTotal Length T1 0.660*** -2.623 2.119 0.464 -4.35
T2 0.780*** -2.571 2.046 0.316 -7.46
T3 0.704*** -1.462 0.949 0.184 -15.36
T4 0.686*** -1.096 0.739 0.151 -19.16
T5 0.631*** -1.391 0.859 0.203 -13.91
T6 0.586*** -1.352 0.730 0.194 -14.72
Protein = a+bTotal Length T1 0.588*** -2.492 2.521 0.666 -1.98
T2 0.767*** -2.347 2.406 0.387 -5.34
T3 0.845*** -1.444 1.611 0.196 -13.67
T4 0.748*** -0.905 1.179 0.201 -13.74
T5 0.606*** -1.415 1.583 0.399 -5.93
T6 0.697*** -1.566 1.615 0.320 -7.77
r = Correlation Coefficient; a = Intercept; b = Slope; S.E = Standard Error
*** =p<0.001
https://doi.org/10.1371/journal.pone.0301712.t006
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 9 / 15
rohita and Catla catla ) and carp (Catla catla), respectively. While Khalid and Naeem [38],
reported lowest FCR in grass carp (Ctenopharyngodon idella) by feeding only 20% protein in
diet. The variation might be due to differences in dietary habits of carps and catfishes.
In the present investigation, the SGR value was highest for C.batrachus fed with 40% pro-
tein and lowest for 25% dietary protein in fish. SGR increases with increasing dietary protein
levels up to 40% in C.batrachus and above optimum protein level, SGR decreased. These
results agree with the outcomes of Mohanta et al. [39] and Gandotra et al. [40] who also
reported that SGR increased with increasing dietary protein levels.
Present observation further reveals that fish-fed diet having 40% protein displayed signifi-
cantly (P<0.05) higher PER than those supplied with other dietary protein levels. Though a
propensity of growing PER values from 0.60 to 1.32 with the increase of each protein level in
diet up to 40% was noted, and afterward a significant drop in PER values were recorded in
diets containing higher protein level. Similar trend was also documented by Ahmed and
Ahmad [17], in Oncorhynchus mykiss fingerlings reared in the Himalayan region of India.
In the present study, whole body proximate composition of C.batrachus was categorically
affected by dietary treatment. Similar results were recorded for Pagrus pagrus, [41], Totoaba
Table 7. Statistical regression parameters of condition factor (K) versus percentages (%) of body constituents (wet mass, g) for C.batrachus reared in different
treatments.
Equation Treatment r a b S. E. (b) tvalue when b = 1
Water = a+bCondition Factor T1 0.019
ns
78.436 0.364 3.600 0.101
T2 0.427** 72.967 5.417 2.204 2.457
T3 0.618*** 74.220 2.211 0.541 4.085
T4 0.540** 70.019 1.685 0.505 3.338
T5 0.303
ns
72.029 2.010 1.218 1.651
T6 0.351
ns
75.625 2.203 1.131 1.948
Ash = a+bCondition Factor T1 -0.068
ns
3.923 -0.235 3.593 -0.065
T2 -0.608*** 5.509 -1.546 1.935 -0.799
T3 -0.203
ns
3.798 -0.209 0.674 -0.311
T4 -0.151
ns
4.876 -0.079 0.593 -0.133
T5 -0.235
ns
4.853 -0.188 1.242 -0.151
T6 -0.400*3.741 -0.411 1.107 -0.371
Fat = a+bCondition Factor T1 -0.122
ns
4.768 -0.338 3.574 -0.095
T2 -0.317
ns
4.743 -0.685 2.313 -0.296
T3 -0.041
ns
3.960 -0.030 0.688 -0.043
T4 -0.367*4.907 -0.199 0.558 -0.356
T5 -0.016
ns
4.202 -0.015 1.277 -0.012
T6 0.200
ns
3.868 0.230 1.183 0.194
Protein = a+bCondition Factor T1 0.014
ns
12.874 0.209 3.601 0.058
T2 -0.316
ns
16.781 -3.186 2.313 -1.377
T3 -0.636*** 18.023 -1.971 0.531 -3.713
T4 -0.507** 20.198 -1.407 0.517 -2.721
T5 -0.269
ns
18.916 -1.808 1.231 -1.469
T6 -0.324
ns
16.766 -2.022 1.143 -1.769
r = Correlation Coefficient; a = Intercept; b = Slope; S.E = Standard Error
*** =p<0.001
** =p<0.01
*=p<0.05;
ns
p>0.05
https://doi.org/10.1371/journal.pone.0301712.t007
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 10 / 15
macdonaldi [42], Culter alburnus Basilewsky [43], Catla catla [44], and Genetically Improved
Farmed Tilapia [45]. It is also documented that proximate composition depends on the fish
species, fish size, dietary protein sources and environmental conditions [46]. However, this
finding is in contrast to those reported in other studies for Seriola dumerili [47] and Solea sene-
galensis [48] and Siniperca scherzeri [49].
Present study revealed that mean value of water and protein contents were ranged 74.10–
79.23% and 13.09–16.79% in the studied treatment in which C.batrachus were fed with differ-
ent levels of dietary protein. These values fit within the range of those reported in previous
study for other strictly carnivorous fish species of the same genus, Clarias gariepinus [50]. Sig-
nificantly lower water content and higher whole-body protein contents were found in C.batra-
chus fed with a diet containing 40% CP and 45% CP than those of the fish fed with 25%, 30%,
35% and 50% CP in diets. However, Kim et al. [51] have reported no significant effect of die-
tary protein levels of 20%, 30% and 40% on crude protein of the Juvenile Catfish, Silurusasotus.
On the other hand, Ishtiaq and Naeem [44] have observed that dietary crude protein levels def-
initely affect the water and protein contents of Catla catla. Hence, the results indicated that
farmer can achieve not only higher growth and low FCR but can attain higher protein and
lipid contents in the C.batrachus by feeding the fish with 40% crude protein, rather higher
crude protein (45%CP) in diet.
Ash contents of C.batrachus fed with the experimental diets was also significantly affected
by dietary protein levels, which is in accordance with Hien et al. [52] for Clarias microcephalus.
The body lipid content generally increased as the dietary protein level increased in the present
investigation as previously reported by Bai et al. [53] for yellow puffer. On the contrary, Kim
et al. [51] documented that as the protein content of whole body increases, whole-body lipid
content decreases. However, in the present study, though, lipid contents were significantly
affected by dietary protein levels, but no increasing or decreasing effect was observed with an
increase in dietary protein. These discrepancies may be attributed to the difference in experi-
mental condition mainly dietary protein levels or due to fish species variation, as feed, inten-
sive feeding or starvation, maturity stage [54,55], sex [56], condition factor [57], age and
seasonal variations [58] and body size [59] have been found to have a pronounced impact on
the proximate composition of different fish species.
Literature shows that body weight of a fish influences the various body constituents [16], and
fat and protein increase while ash and water decrease with the increasing total length [59].
Hence, regression analyses were also performed to observe the effect of fish size on proximate
composition of C.batrachus. Highly significant correlation (p<0.001) between fish size (weight
and length) and body constituents (water, ash, fat and protein) were noted in the present work
and found in agreement to those reported by Naeem and Ishtiaq [60] for Mystus bleekeri, Bano
et al. [61] for Labeo calbasu and Ishtiaq and Naeem [16] for Catla catla. Negative allometric pat-
tern for water contents indicated an increase in this content with lesser proportion. While pro-
tein constituents were found increasing with greater proportion (positive allometrric pattern)
with an increase in fish size when compared with b = 1 for body weight and b = 3 for total
length. The negative allometry for water and positive allometry for protein is evident in many
studies [16,43,60,61] and hence the findings of present study indorse the same trend.
Furthermore, body composition of a fish species can be assessed from water content by per-
forming regression analyses. It allows to predict other constituents of body (protein, fat and
ash), with the consistent lessening of costs when performing one, in spite of diverse analyses.
These opinions have furnished by [16,62], and are in agreement with the results of the present
study, especially for protein contents in the body of C.batrachus which showed negative corre-
lation (p<0.001) in all the studied treatments, which is found in in conformity with the find-
ings of those reported by Bano et al. [61].
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 11 / 15
Some studies documented a noticeable impact of condition factor on the proximate compo-
sition, however, most of the studies have reported insignificant relationships between body
constituents and condition factor, as body weight of a fish is not always proportional to the
cube of its total length [63]. The findings of the present study are in general agreement with
those reported with Naeem and Ishtiaq [60] in wild Mystus bleekeri, Khalid and Naeem [64] in
farmed Ctenophyrngodon idella and Kousar et al. [45] in Genetically Improved Farmed
Tilapia.
As, higher cost of a fish feed containing higher crude protein is considered a limitations or
challenge in implementing the recommended 40% crude protein diet on a commercial scale,
but farming industry should not compromise as it influences positively on the growth perfor-
mance, FCR and quality of fish as food. Moreover, delving the further research is recom-
mended to explore the lasting effects of employing the optimal 40% crude protein diet on C.
batrachus, considering aspects related to reproduction and overall health.
5. Conclusion
This investigation specifies that dietary protein levels affect the growth, FCR and proximate
composition of Clarias batrachus. The best growth parameters and chemical composition
(containing highest level of protein, mineral and fat constituents) can be achieved by feeding
the catfish with a diet comprising 40% crude protein (CP) than other dietary protein levels
(25%, 30%, 35%, 45% or 50% CP), and consequently, it is suggested that addition of 40% pro-
tein in feed is ideal for growth and effective feed utilization of the walking catfish, C.batrachus.
It is also evident that despite the variations, the mean values of percentage protein in different
treatments of this study indicates that C.batrachus is a good source of protein to consumers.
Moreover, body size shows a pronounced impact on body composition of fish. Data produced
in the current research would be beneficial in evolving nutritionally balanced diets for the
semi-intensive and intensive culture of this catfish.
Author Contributions
Conceptualization: Amina Zuberi, Muhammad Ali.
Data curation: Zara Naeem, Amina Zuberi, Ammar Danyal Naeem, Muhammad Naeem.
Formal analysis: Zara Naeem, Muhammad Naeem.
Investigation: Zara Naeem.
Methodology: Zara Naeem, Ammar Danyal Naeem, Muhammad Naeem.
Project administration: Amina Zuberi.
Resources: Ammar Danyal Naeem.
Software: Zara Naeem.
Supervision: Amina Zuberi.
Validation: Zara Naeem.
Visualization: Zara Naeem, Muhammad Ali.
Writing original draft: Zara Naeem.
Writing review & editing: Zara Naeem, Amina Zuberi, Muhammad Ali, Muhammad
Naeem.
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 12 / 15
References
1. Rahman SM, Alsaquft AS, Alkhamis YA, Rahman MM, Ahsan MN, Mathew RT, et al. Short term stor-
age of Asian walking catfish (Clarias batrachus Linnaeus, 1758) gametes. Advances in Animal and Vet-
erinary Sciences. 2020; 8(12):1394–1401.
2. Srivastava S, Kushwaha B, Prakash J, Kumar R, Nagpure N, Agarwal S, et al. Development and char-
acterization of genic SSR markers from low depth genome sequence of Clarias batrachus (Magur).
Journal of Genetics. 2016; 95:603–9.
3. Li N, Bao L, Zhou T, Yuan Z, Liu S, Dunham R, et al. Genome sequence of walking catfish (Clarias
batrachus) provides insights into terrestrial adaptation. BMC genomics. 2018; 19(1):1–16.
4. Das B. The bionomics of certain air-breathing fishes of India, together with an account of the develop-
ment of their air-breathing organs. Philosophical Transactions of the Royal Society B. 2016; 216:183–
219.
5. Froehlich HE, Runge CA, Gentry RR, Gaines SD, Halpern BS. Comparative terrestrial feed and land
use of an aquaculture-dominant world. Proceedings of the National Academy of Sciences. 2018;
115:5295–5300. https://doi.org/10.1073/pnas.1801692115 PMID: 29712823
6. FAO I. The state of world fisheries and aquaculture 2016. Contributing to food security and nutrition for
all, Food and Agriculture Organization of the United Nations, Rome, Italy. 2016; pp.171–189.
7. Troell M, Naylor RL, Metian M, Beveridge M, Tyedmers PH, Folke CKJ, et al. Doesaquaculture add
resilience to the global food system? Proceedings of the National Academy of Sciences. 2014;
111:13257–13263.
8. De Verdal H, Komen H, Quillet E, Chatain B, Allal F, Benzie JA, et al. Improving feed efficiency in fish
using selective breeding: a review. Reviews in Aquaculture. 2018; 10:833–851.
9. Tian HY, Zhang DD, Li XF, Zhang CN, Qian Y, Liu WB. Optimum feeding frequency of juvenile blunt
snout bream Megalobrama amblycephala. Aquaculture. 2015; 437:60–66.
10. Anderson JS, Higgs DA, Beams RM, Rowshandeli M. Fish meal quality assessment for Atlantic salmon,
Salmosalar, reared in seawater. Aquaculture Nutrition. 1997; 3:25–38.
11. Wang N, Xu X, Kestemont. Effect of temperature and feeding frequency on growth performances, feed
efficiency and body composition of pikeperch juveniles Sander lucioperca. Aquaculture. 2009; 289:70–
73.
12. Akbulut B, Feledi T, Lengye S, Ronyai A. Effect of feeding rate on growth performance, food utilization
and meat yield of starlet, Acipense rruthenus (Linne, 1758). Journal of Fisher Scientific. 2013; 7:216–
224.
13. NRC N. Nutrient requirements of fish and shrimp. Washington, DC: National Academy Press.
2011; pp.235–242.
14. Alana
¨ra
¨A, Kadri S, Paspatis M. Chapter 14-Feeding management, in: Houlihan D., Boujard T., Jobling
M. (Eds.), Food Intake in Fish. Blackwell Science Ltd, Oxford, UK. 2001; pp.332–353.
15. Wang JT, Han T, Li XY, Yang YX, Yang M, Hu SX, et al. Effects of dietary protein and lipid levels with
different protein-to-energy ratios on growth performance, feed utilization and body composition of juve-
nile red-spotted grouper, Epinephelus akaara. Aquaculture Nutrition. 2017; 23:994–1002.
16. Ishtiaq A, Naeem M. Effect of dietary protein levels on body composition of Catlacatlafrom Pakistan.
Sindh University Research Journal (Science Series). 2019; 51(2):309–318.
17. Ahmed I, Ahmad I. Effect of dietary protein levels on growth performance, hematological profile and bio-
chemical composition of fingerlings rainbow trout, Oncorhynchus mykiss reared in Indian Himalayan
region. Aquaculture Reports. 2020; 16:100268–76.
18. Iqbal R, Naeem M. Impact of graded dietary protein on growth parameters of hybrid (Labeo rohita and
Catla catla ) from Southern Punjab, Pakistan. Sarhad Journal of Agriculture. 2021; 37:893–900.
19. Yang SD, Liou CH, Liu FG. Effects of dietary protein level on growth performance, carcass composition
and ammonia excretion in juvenile silver perch (Bidyanus bidyanus). Aquaculture. 2002; 213: 363–372.
20. Guo Z, Zhu X, Liu J, Han D, Yang Y, Lan Z, et al. Effects of dietary protein level on growth performance,
nitrogen and energy budget of juvenile hybrid sturgeon, Acipenser baerii×A.gueldenstaedtii. Aqua-
culture. 2012; 338:89–95.
21. Murray J, Burt JR. The Composition of Fish. Torry Advisory Note No. 38, Ministry of Technology. Tor.
Res. Station, U.K. 2001; pp. 14.
22. Azam K, Ali MY, Asad-Uz-Zaman M, Basher MZ, Hossain MM. Biochemical assessment of selected
fresh fish. Journal of Biological Sciences. 2004; 4:9–10.
23. Kamal D, Khan AN, Rahman MA, Ahmad F. Biochemical Composition of some small indigenous fresh
water fishes from the river Mouri, Khulna, Bangladesh. Pakistan Journal of Biological Sciences. 2007;
10: 1559–1561. https://doi.org/10.3923/pjbs.2007.1559.1561 PMID: 19069978
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 13 / 15
24. Ahmed I, Jan K, Fatma S, Dawood MAO. Muscle proximate composition of various food fish species
and their nutritional significance: A review. Journal of Animal Physiology and Animal Nutrition. 2022;
106:690–719. https://doi.org/10.1111/jpn.13711 PMID: 35395107
25. Ahmed I, Sheikh ZA. Study on the seasonal variation in the chemical composition, hematological profile,
gonado-somatic index and hepato-somatic index of snow trout, Schizothorax niger from the freshwater
Dal Lake, Kashmir. American Journal of Food Technology. 2017; 12(1):1–13.
26. Sankar TV, Anandan R, Mathew S, Asha KK, Lakshmanan PT, Varkey J, et al. Chemical composition
and nutritional value of anchovy (Stolephorus commersonii) caught from Kerala coast, India. European
Journal of Experimental Biology. 2013; 3(1):85–89.
27. Naeem M, Salam A. Proximate composition of fresh water bighead carp, Aristichthys nobilis, in relation
to body size and condition factor from Islamabad, Pakistan. African Journal of Biotechnology. 2010; 9
(50):8687–8692.
28. Azam SM, Naeem M. Proximate Body Composition of Talang Queenfish (Scomberoides commerson-
nianus Lace
´pède, 1801) from Pakistan. Sarhad Journal of Agriculture. 2022; 38(1): 204–209.
29. National Research Council (NRC). Nutrient requirements of fish. Washington, D.C., National Academy
Press. 1993.
30. Preston RL. Feed Composition Table. BEEF Magazine. 2016. Available online: https://www.
beefmagazine.com/sites/beefmagazine.com/files/2016-feedcomposition-tables-beef-magazine.pdf
31. NDDB. Nutritive value of commonly available feeds and fodders in India. Animal Nutrition Group,
National Dairy Development Board, Anand-388 001, India. 2012. https://www.nddb.coop/sites/default/
files/pdfs/Animal-Nutrition-booklet.pdf
32. Farhat KM, Khan MA. Growth, feed conversion and nutrient retention efficiency of African catfish, Clar-
ias gariepinus (Burchell) fingerling fed diets with varying levels of protein. Journal of Applied Aquacul-
ture. 2011; 23:304–316.
33. Tadesse Z. Effect of different levels of protein diets on growth performance of African catfish (Clarias
gariepinus Burchell, 1822) fingerlings in tanks. Ethiopian Journal of Biological Sciences. 2019; 18:109–
122.
34. Yalew A. Aspects of the Reproductive Biology, Growth Performance and Survival of the African Catfish,
Clarias gariepinus (Burchell, 1822) in captivity for Enhancing Aquaculture. Ph.D. thesis, Addis Ababa
University, Add is Ababa. 2018; pp.88-91.
35. Mugo-Bundietal JE, Oyuu-Okoth CC, Ngugi, Manguya-Lusega D, Rasowo J, Chepkurei BV. Utilization
of Caridina nilotica (Poux) meal as a protein ingredient in feeds for Nile tilapia (Oreochromis niloticus).
Aquaculture Research. 2013; 2:1–12.
36. Ogunji JO, Toor C, Schulz C, Kloas W. Growth performance and nutrient utilization of Nile tilapia, Oreo-
chromis niloticus fed housefly maggot meal (Magmeal) diets. Turkish Journal of Fisheries and Aquatic
Science. 2008; 8:141–147.
37. Ogunji JO, Awoke J. Effect of environmental regulated water temperature variations on survival, growth
performance and haematology of African catfish, Clarias gariepinus. Our Nature. 2017; 15:26–33.
38. Khalid M, Naeem M. Effect of graded protein levels on growth performance,survival and feed conver-
sion ratio of Ctenopharyngodon idella from Pakistan. Sindh University Research Journal (Science
Series). 2018; 50: 633–638.
39. Mohanta KN, Mohanty SN, Jena JK, Sahu NP. Protein requirement of silver barb, Puntius gonionotus
fingerlings. Aquaculture Nutrition. 2008; 14: 143–152.
40. Gandotra ROOPMA, Parihar DS, Koul MEENAKSHI, Gupta VAINI, Kumari RITU. Effect of varying die-
tary protein levels on growth, feed conversion efficiency (FCE) and feed conversion ratio (FCR) of Catla
catla (HAM.) fry. Journal of international academic research for multidisciplinary. 2014; 2:28–35.
41. Schuchardt D, Vergara JM, Fernandez-Palacios H, Kalinowski CT, Hernandez- Cruz CM, Izquierdo
MS, et al. Effects of different dietary protein and lipid levels on growth, feed utilization and body compo-
sition of red porgy (Pagrus pagrus) fingerlings. Aquaculture Nutrition. 2008; 14:1–9.
42. Rueda-Lo
´pez S, Lazo JP, Reyes GC, Viana MT. Effect of dietary protein and energy levels on growth,
survival and body composition of juvenile Totoaba macdonaldi. Aquaculture. 2011; 319:385–90.
43. Zhang YL, Song L, Liu RP, Zhao ZB, He H, Fan QX, et al. Effects of dietary protein and lipid levels on
growth, body composition and flesh quality of juvenile topmouth culter, Culter alburnus Basilewsky.
Aquac. Res. 2015; 47:2633–41.
44. Ishtiaq A, Naeem M. Effect of different dietary protein levels on growth performance of Catla catla (Ham-
ilton) reared under polyculture system. Sarhad Journal of Agriculture. 2019; 35: 976–984.
45. Kousar A, Naeem M, Masud S. Effect of different dietary levels of protein on the proximate composition
of genetically improved farmed tilapia (GIFT) from Pakistan. Sarhad Journal of Agriculture. 2020; 36
(2):517–525.
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 14 / 15
46. NRC. National Research Council, Nutrient requirements of fish. National Academy Press, Washington
DC. 1993.
47. Vidal AT, Garcia FDG, Gomez AG, Cerda MJ. Effect of the protein/energy ratio on the growth of Medi-
terranean yellowtail (Seriola dumerili). Aquaculture Research. 2008; 39:1141–8.
48. Valente LMP, Linares F, Villanueva JLR, Silva JMG, Espe M, Esco
´rcio C, et al. Dietary protein source
or energy levels have no major impact on growth performance, nutrient utilization or flesh fatty acids
composition of market sized Senegalese sole. Aquaculture. 2011; 318:128–37.
49. Sankian Z, Khosravi S, Kim YO, Lee SM. Effect of dietary protein and lipid level on growth, feed utiliza-
tion, and muscle composition in golden mandarin fish Siniperca scherzeri. Fisheries and Aquatic Sci-
ences. 2017; 20(1):1–6.
50. Ali MZ, Jauncey K. Effect of dietary protein to energy ratio on body composition, digestive enzymes and
blood plasma components in Clarias gariepinus (Burchell, 1822). Indian Journal of Fisheries. 2005; 52
(2):141–150.
51. Kim KD, Lim SG, Kang YJ, Kim KW, Son MH. Effects of dietary protein and lipid levels on growth and
body composition of juvenile far eastern catfish Silurus asotus. Asian-Australasian Journal of Animal
Science. 2012; 25(3):369–377.
52. Hien TTT, Tuan L, Tu TLC, Tam BM. Dietary protein requirement of bighead catfish (Clarias macroce-
phalus Gunther, 1864) fingerling. Inter. J. Sci. Res. Pub. 8(11): 4–10.
53. Bai S.C., Wang X.J. and Cho E.S. 1999. Optimum dietary protein level for maximum growth of juvenile
yellow puffer. Fisheries Science. 2018; 65:380–3.
54. Boran G, Karacam H. Seasonal changes in proximate composition of some fish species from the Black
sea. Turkish Journal of Fisheries Aquatic Science. 2011; 11(1)1–5.
55. Karki S, Chowdhury S, Nath S, Murmu P, Dora KC. Seasonal changes in proximate composition and
textural attributes of farm raised chocolate mahseer (Neolissochilus hexagonolepis). Journal of Ento-
mology and Zoological Studies. 2019; 7(4):696–701.
56. Yousaf M, Salam A, Naeem M. Body composition of freshwater Wallago attu in relation to body size,
condition factor and sex from southern Punjab, Pakistan. African Journal Biotechnology. 2011; 10
(20):4265–4268.
57. Naeem M, Rasul A, Salam A, Iqbal S, Ishtiaq A, Khalid M, et al. Proximate analysis of female population
of wild feather back fish (Notopterus notopterus) in relation to body size and condition factor. African
Journal of Biotechnology. 2011; 10(19):3867–3871.
58. Silva JJ, Chamul RS. Composition of marine and freshwater finfish and shellfish species and their prod-
ucts. In Martin R. E., Carter E. P., Flick E. J. and Davis L. M. (Eds.), Marine and freshwater products
handbook (pp. 31–46). Lancaster. 2000.
59. Naeem M, Ishtiaq A. Proximate composition of Mystus bleekeri in relation to body size and condition
factor from Nala Dhaik, Sialkot, Pakistan, African Journal of Biotechnology. 2011; 10(52):10765–
10773.
60. Barakat I, Saad A, Nisafi I. Effect of sex, season and size on the chemical composition of red sea goat-
fish Parupeneus forsskali (Fourmanoir and Gue
´ze
´, 1976) caught from the marine water of Lattakia Gov-
ernorate (Syria). Uttar Pradesh Journal of Zoology. 2022; 43(15): 43–50.
61. Bano S, Naeem M, Masud S. Effect of different dietary protein levels on proximate composition of
Labeo calbasu from Pakistan. International Journal of Biology,Pharmacy and Allied Sciences. 2019; 8
(11): 2095–2103.
62. Yeannes MI, Almandos ME. Estimation of fish proximate com position starting from water content. Jour-
nal of Food Composition and Analysis. 2003; 16:81–92.
63. Salam A, Davies PMC. Body composition of northern pike (Esox lucius L.) in relation to body size and
condition factor. Fisheries Research. 1994; 19(3–4): 193–204.
64. Khalid M, Naeem M. Proximate analysis of grass carp (Ctenopharyngodon idella) from Southern Pun-
jab, Pakistan. Sarhad Journal of Agriculture. 2018; 34(3):632–639.
PLOS ONE
Approach to optimizing dietary protein to growth in walking catfish, Clarias batrachus (Linneaeus, 1758)
PLOS ONE | https://doi.org/10.1371/journal.pone.0301712 May 3, 2024 15 / 15
... chanos) criado en estanques de agua salobre. En tanto que para la especie acuícola C. batrachus se obtuvo que alimentar a los peces con una dieta adecuada (que contenía 40% de proteína cruda) resultó en un buen rendimiento de crecimiento, un índice de conversión alimenticia más bajo y un mayor contenido de proteína en los peces (Naeem et al., 2024). Se han realizado investigaciones nutricionales en algunas especies de pimelódidos de interés comercial en América del Sur, como, Pseudoplatystoma corruscans (Teixeira et al., 2010) y Rhamdia quelen (Filho & Fracalossi, 2006). ...
Article
Full-text available
The objective of this study was to evaluate the effect of three protein levels (35%, 40%, and 45% Crude Protein) and a single energy level (4800 kcal/kg) on the development parameters and zootechnical indices of 45 juvenile mota (Calophy sus macropterus, Lichtenstein, 1819) with an average size and weight of 16.49±0.1 cm and 25.62±0.2 g under laboratory conditions, using a feeding frequency of three times per day (ad libitum). A completely randomized design (CRD) was applied with three treatments and three replications (9 plastic tanks of 100 liters), at a density of 1 fish/20 L, over a period of 75 days. The average limnological parameters were maintained stable through water exchange. The results reveal a significant difference betweenthe 40% Crude Protein level compared to 35% and 45% Crude Protein, both with the same energy level (4800 kcal/kg). The 40% Crude Protein level had a favorable effect on weight, length, absolute growth rate (AGR), specific growth rate (SGR), relative growth rate (RGR), feed conversion (FC) (p<0.05), and survival remained at 100% (p>0.05). It is concluded that protein levels of 35%, 40%, and 45% Crude Protein influence the growth of the fish, with notable growth in size and body weight gain.
Article
Full-text available
The effects of seasonal and sexual differences and Total Lenght on the chemical composition of the Red Sea goatfish Parupeneus forsskali caught from the marine waters of Lattakia Governorate were investigated. Moisture, crude protein, crude fat, and ash were determined as a percentage of the fish muscles. The results revealed that the autumn season was the highest in terms of nutritional components (protein 22.08%, fat 9.78%, ash 2.42% of fresh fish muscle), While the Summer season was the lowest (protein 19.32%, fat 5.46%, ash 1.20%). The results also showed the superiority of females in the values of the nutritional components over males, where the values were for females (protein 22.3%, fat 8.9%) and males (protein 20.7%, fat 6.8%), while The results also showed the superiority of males in the values of ash over females of ash (male 1.5%, female 1.3%). Regarding the body length factor, the results showed a significant positive relationship between an increase in Total length and an increase in protein and fat and a significant inverse relationship with both ash and moisture content.
Article
Full-text available
The growth performance of African catfish, Clarias gariepinus fed on three levels of protein diets (30% CP, 35% CP and 40% CP) formulated from plant, animal and agro-industrial by-products were experimentally evaluated in recirculating tanks. A total of nine tanks, each with 1 m 3 volume were used in the feeding experiment. The experiment was conducted in triplicate tanks at a stocking density of 12 fish fingerlings per tank. Before the commencement of the actual experiment, stocked fish were left to acclimatize in their tanks for a week. All fish were fed 5% of their body weight per day, and the ration was given twice a day in the morning (10:00 am) and afternoon (4:00 pm) for all treatment groups. The initial total length (TL) and total weight (TW) of each fish was measured to the nearest 0.1 cm and 0.1 g, respectively. Similarly, monthly TL and TW of all fish were measured to compute the growth rate and adjust the daily ration accordingly throughout the experiment period (January 2019 to July 2019). Some physico-chemical parameters of the tank water including dissolved oxygen, water temperature, pH, conductivity as well as level of ammonia were recorded. The results of the experiment showed very significant variations on the growth of fish between the treatment groups (p<0.05). Fish fed with 40% crude protein showed the highest daily growth rate (0.52 g/day) followed by fish fed with 35% CP and 30% CP. Similarly, the lowest feed conversion ratio (FCR=2.1) was recorded in fish fed with 40% CP, indicating its suitability for African catfish fingerlings than the other test diets. The overall survival rate varied from 85.2%-92% per treatment. The physico-chemical parameters of the rearing tanks were close to the lower limits of DO and water temperature required for the growth of African catfish. The low daily growth rate of C. gariepinus observed in this study might be attributed to the combined effects of low quality of the test feeds and poor water quality recorded in rearing tanks.
Article
Full-text available
The present study was carried out to investigate the viability of gametes from Asian walking catfish (Clarias batrachus) following short-time storage under hatchery condition at room temperature (26–28°C) and at chilled temperature (2–4ºC) using a household refrigerator. Eggs stored at refrigeration for 5 min resulted in a drastic reduction of fertilization success (36%) in comparison with those stored at room temperature (86%). Eggs without water have had significantly higher successes of fertilization than those stored with water in both storage conditions. On the other hand, prolonged potency was observed for sperm stored in refrigerator than those kept outside at room temperature. Sperm kept in refrigerator with both water and dextrose solutions were consistently viable for at least 48 hours. At room temperature, however, sperm diluted with dextrose showed comparatively higher fertilization (up to 50 min, 27–98%) than sperm diluted with water (up to 10 min, 25–87%). Similar results were obtained when the whole testis was stored. Sperm–egg contact time experiment showed a quick fusion and it required only a minute to achieve 100% fertilization. The results of this study provide evidence on the short-time storage of catfish sperm that might be of relevance to hatchery operators including, for example, production of quality seeds by sacrificing less numbers of male individuals.
Article
Full-text available
A 10-week feeding trial was undertaken to determine the optimum dietary protein requirement of fingerling rainbow trout, Oncorhynchus mykiss. Six casein-gelatin based isocaloric (20.90 kJ 100 g −1 , gross energy) diets containing graded levels of dietary protein (300-550 g kg −1 crude protein) were formulated. Twenty fingerlings (1.56 ± 0.22 g; 5.80 ± 0.50 cm) were randomly stocked in triplicate groups in 75 L circular trough fitted with continuous flow-through system (water volume 2-2.5 L −1) and fed experimental diets at 5% BWday −1 at 0800, 1200 and 1700 h. Significant (P < 0.05) differences in live weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER) and body protein deposition (BPD) were noted. Quadratic regression analysis of SGR, FCR, PER and BPD data indicated requirements for dietary protein at 464.5, 471.0, 444.0 and 449.6 g kg −1 of dry diet, respectively. Maximum protein, low moisture and intermediate body fat contents were recorded with fish fed at 450 kg −1 protein diet, while highest HSI value was observed at lowest protein level. Significant differences (P < 0.05) were also observed in Hb, Hct and RBC values of fish fed varying protein diets. Based on the above results, it is recommended that rainbow trout fingerlings require protein in the range of 450-471 g kg −1 for its optimum growth and efficient feed utilization.
Article
Today, there is a growing awareness about the importance of eating nutritious foods and fish is gaining momentum as a result of its unique nutritional benefits. Fish are considered as nutritionally valuable part of the human diet because of the presence of both macronutrients (proteins, lipids and ash) and micronutrients (vitamins and minerals). These nutrients are indispensable in human nutrition and have proven to be involved in several metabolic functions. The nutritional content can be used to rank different fish species based on their nutritional and functional benefits, allowing consumers to make better decisions according to their requirements. Proximate composition of fish includes determination of moisture, protein, fat and ash contents, which constitutes about 96%−98% of the total constituents of the fish body. The study of these components gives us a clear understanding in assessing the energy value of the fishes. In the present study, an attempt has been made to provide a concise review about the proximate composition of various fish species from different parts of the world in order to evaluate the high‐protein, low‐fat food with excellent nutritional values and to enlighten the different exogenous and endogenous factors that are actually responsible for their variation. The review also provides an insight into the characteristics of the chemical composition of various fish species, which are gaining importance for the sector involving fish and fishery products for domestic and foreign trade and for appreciating as animal feed all over the world.