Body Composition, Elemental Concentration and Morphometrics of Two Carnivorous Fishes in Rivers of Southern Punjab, Pakistan

Body Composition, Elemental Concentration and Morphometrics of two Carnivorous fishes in Rivers of Southern Punjab, Pakistan.

A thesis submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy in ZOOLOGY

Muhammad Yousaf (M. Sc. Zoology)

Institute of Pure & Applied Biology (Zoology Division) Bahauddin Zakariya University, Multan

“It Is He Who Has Made The Sea Subject, That Ye May Eat Thereof Flesh That Is Fresh And Tender. And That Ye May Extract There From Ornaments To Wear.”

(26: 14) – THE HOLY QURAN

STATEMENT AND DECLARATION

The work submitted in this thesis under the title, “Body Composition, Elemental Concentration and Morphometrics of two Carnivorous fishes in River of Southern Punjab, Pakistan” is in fulfillment of the requirements for the degree of Doctor of Philosophy.

I declare that this work is the result of my own investigations and has not already been accepted in substance for any degree, nor is it currently being submitted for any other degree.

All authors works referred to in this thesis have been fully acknowledged.

MUHAMMAD YOUSAF

Dated …………………....

I certify that above statement is correct. Supervisor…………………...... Prof. (R) Dr. Abdus Salam

DEDICATED TO

My Worthy Parents

All those who bring joy to my life

ACKNOWLEDGEMENTS I bow my head before ALMIGHTY ALLAH, the most merciful and the most beneficent who bestowed me with the ability to complete this work and the Holy Prophet Hazrat Muhammad (PBUH) who inspired me for the truth. I deem it an utmost pleasure to be able to express the heartiest gratitude and deep sense of devotion to my worthy supervisor Prof. (R) Dr. Abdus Salam, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, who has always inspired and guided me in the real sense and spirit of a teacher. The road towards my goal of becoming a research scientist has certainly been blessed by this person. By dint of his constant help, keen interest, healthy criticism and kind advice the completion of this thesis became possible. I also wish to express my gratitude to Dr. Muhammad Naeem, Asst. Professor, Institute of Pure and Applied Biology. His diligent guidance and caring nature created a very productive, positive, and exciting atmosphere in which to pursue this training. I feel great pleasure in expressing heart felt to Prof. Dr. Altaf Ahmad Dasti, Director, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, for his encouragement, co-operation and providing all research facilities. I am also thankful to Higher Education Commission of Pakistan for supporting this research through the Indigenous 5000 Scholarship scheme. I am also highly thankful to all the faculty of Institute of Pure and Applied Biology and Dr. Amin-u-din, Dr. Allah Baksh Gulshan and Sajad Hussain for their kind guidance & encouraging behavior at every step of my work. I also wish to record my sincere thanks to my research fellows and friends Imran Khaliq, Mushtaq Hussain, Kashif Umar, Aeysha Imtiaz, Qurat-ul-Ain, Shahbaz Ahmad, Shahida Rafiq and Imran Ali for their support and co-operation. In the end from the deepest core of my heart I offer my special acknowledge to my parents, brothers, sisters, my wife, my cute son Muhammad Shayan Yousaf, Muhammad Azaan Yousaf and other family members for their love, prays, whole hearted support and encouragement. Nothing can replace their positions. May they live long to see all my dreams come true. Muhammad Yousaf II

TABLE OF CONTENTS

Chapter No. Description Page ACKNOWLEDGEMENTS I TABLE OF CONTENTS II LIST OF TABLES V LIST OF FIGURES X ABBREVIATION XVI ABSTRACT 1 Chapter-1 GENERAL INTRODUCTION 3 5 1.1. Wallago attu 6 1.2.Sperata sarwari

Chapter-2 BODY COMPOSITION 10 2.1. INTRODUCTION 14 2.1.1. Aims and objectives 2.2. MATERIALS AND METHODS 15 2.2.1. Measurement of weight and length 15 2.2.2. Determination of water contents 15 2.2.3. Determination of ash contents 16 2.2.4. Determination of fat contents 16 2.2.5. Determination of protein contents 17 2.2.6. Determination of carbohydrates 17 2.2.7. Determination of condition factor (K) 18 2.2.8. Data analysis 18 2.3. RESULTS 19 2.3.1. Effect of body size on body constituents 19 2.3.2. Influence of water content on other body 20 constituents 2.3.3. Effect of condition factor (K) on body 21 constituents 2.3.4. Comparison of body constituents between two III

Species 21 2.3.5. Effect of sex on proximate composition 21 2.3.6. Effect of seasonal variations on the body 22 composition

2.3.6.1. Water content 22

2.3.6.2. Ash content 22

2.3.6.3. Fat content 22

2.3.6.4. Protein content 22

2.4. DISCUSSION 56

2.4.1. Water content 56

2.4.2. Ash content 57

2.4.3. Fat content 57

2.4.4. Protein content 59

2.4.5. Effect of condition factor on body composition 60

2.4.6. Effect of season on body composition 61

2.4.7. Effect of sex on body composition 62

2.4.8. Conclusion 62

Chapter-3 ELEMENTAL CONCENTRATION

3.1. INTRODUCTION 67

3.1.1. Aims and objectives 71

3.2. MATERIALS AND METHODS 72

3.2.1. Reagents and standards 72

3.2.2. Glassware 72

3.2.3. Instrumentation 72

3.2.4. Analytical procedure 73

3.2.5. Computation of results 73

3.3. RESULTS 74

3.3.1. Effect of body weight on elemental concentration 74

3.3.2. Effect of total length on elemental concentration 74

3.3.3. Comparison of elemental concentration between 93

two species IV

3.3.4. Effect of sex on elemental concentration 93 3.3.4. Effect of season on elemental concentration 93 3.4. DISCUSSION 104 3.4.1. Relationship between elemental concentration and size of fish 106 3.4.2. Influence of sex on elemental concentration 108 3.4.3. Comparison of elemental concentration 108 3.4.2. Influence of season on elemental concentration 108 Chapter-4 MORPHOMETRY 111 4.1. INTRODUCTION 111 4.1.1. Length-weight relationship 112 4.1.2. Length-length relationship 114 4.1.3. Condition factor (K) 114 4.1.4. Aims and objectives 116 4.2. MATERIALS AND METHODS 117 4.2.1. External morphometry 117 4.2.2. Internal morphometry 119 4.2.3. Statistical analysis 119 4.3. RESULTS 121 4.3.1. Total length-wet body weight 121 4.3.2. Condition factor-total length and wet body 121 weight 4.3.3. Wet body weight-length of external body 121 parameters 4.3.4. Total length-length of external body parameters 122 4.3.5. Wet body weight-weight of external body parts 122 4.3.6. Total length-weight of external body parts 123 4.3.7. Wet body weight-weight of internal body organs 123 4.3.8. Total length-weight of internal body organs 123 4.4. DISCUSSION 153 REFERENCES 158 V

LIST OF TABLES DESCRIPTION PAGE Table 2.1 Mean values and ranges of various body constituents of Wallago 23 attu Table 2.2 Mean values and ranges of various body constituents of Sperata 23 sarwari Table 2.3 Wet body weight (g) versus body constituents of Wallago attu 28 Table 2.4 Wet body weight (g) versus body constituents of Sperata 28 sarwari Table 2.5 Wet body weight (g) versus body constituents of Wallago attu 29 Table 2.6 Wet body weight (g) versus body constituents of Sperata 29 sarwari Table 2.7 Log wet body weight (g) versus body constituents of Wallago 30 attu Table 2.8 Log wet body weight (g) versus body constituents of Sperata 30 sarwari Table 2.9 Total length (cm) versus body constituents of Wallago attu 31 Table 2.10 Total length (cm) versus body constituents of Sperata sarwari 31 Table 2.11 Total length (cm) versus body constituents of Wallago attu 32 Table 2.12 Total length (cm) versus body constituents of Sperata sarwari 32 Table 2.13 Log total length (cm) versus body constituents of Wallago attu 33 Table 2.14 Log total length (cm) versus body constituents of Sperata 33 sarwari Table 2.15 %Water contents versus body constituents of Wallago attu 34 Table 2.16 %Water contents versus body constituents of Sperata sarwari 34 Table 2.17 Condition factor (K) versus body constituents of Wallago attu 35 Table 2.18 Condition factor (K) versus body constituents of Sperata 35 sarwari Table 2.19 ANOVA showing comparison of body composition of two 36 different species of freshwater catfishes of southern Punjab. VI

Table 2.20 Mean values and ranges of various body constituents of ♂ and ♀ 37 Wallago attu. Table 2.21 Mean values and ranges of various body constituents of ♂ and ♀ 38 Sperata sarwari Table 2.22 Seasonal variations in the percentage of the proximate 39 composition of Wallago attu. Table 2.23 Seasonal variations in the percentage of the proximate 39 composition of Sperata sarwari Table 2.24 Water content values of various fish species 63 Table 2.25 Ash content values of various fish species 64 Table 2.26 Fat content values of various fish species 65 Table 2.27 Protein content values of various fish species 66 Table 3.1 Mean and standard deviation values of elemental concentration 76 in carcasses of Wallago attu (whole fish) Table 3.2 Mean and standard deviation values of elemental concentration 76 in carcasses of Sperata sarwari (whole fish) Table 3.3 Log wet body weight (g) versus log elemental constituents (μg) 77 of Wallago attu Table 3.4 Log wet body weight (g) versus log elemental constituents (μg) 77 of Sperata sarwari. Table 3.5 Log total length (cm) versus log elemental constituents (μg) of 78 Wallago attu. Table 3.6 Log total length (cm) versus log elemental constituents (μg) of 78 Sperata sarwari. Table 3.7 ANOVA showing comparison of elemental concentrations (μg/g 94 dry weight) of two different species of freshwater catfishes of Southern Punjab Table 3.8 ANOVA showing comparison of elemental concentrations (μg/g 94 wet weight) of two different species of freshwater catfishes of southern Punjab. VII

Table 3.9 95 Mean values and ranges of various elemental constituents (μg/g wet weight) of ♂ and ♀ Wallago attu.

Table 3.10 95 Mean values and ranges of various elemental constituents (μg/g dry weight) of ♂ and ♀ Wallago attu.

Table 3.11 96 Mean values and ranges of various elemental constituents (μg/g wet weight) of ♂ and ♀ Sperata sarwari.

Table 3.12 96 Mean values and ranges of various elemental constituents (μg/g dry weight) of ♂ and ♀ Sperata sarwari.

Table 3.13 97 Seasonal variations in the mean values of different metals (μg/g dry weight) in Wallago attu.

Table 3.14 97 Seasonal variations in the mean values of different metals (μg/g wet weight) in Wallago attu.

Table 3.15 98 ANOVA table showing effect of season on metal concentrations (μg/g dry weight) in Wallago attu.

Table 3.16 98 ANOVA table showing effect of season on metal concentrations (μg/g wet weight) in Wallago attu.

Table 3.17 99 Seasonal variations in the mean values of different metals (μg/g dry weight) in Sperata sarwari.

Table 3.18 99 Seasonal variations in the mean values of different metals (μg/g wet weight) in Sperata sarwari.

Table 3.19 100 ANOVA table showing effect of season on metal concentrations (μg/g dry weight) in Sperata sarwari. VIII

Table 3.20 100 ANOVA table showing effect of season on metal concentrations (μg/g wet weight) in Sperata sarwari.

Table 3.21 110 The comparison of metal concentrations in different fish species.

Table 4.1 124 Mean values, ranges and standard deviations of various external morphometric parameters of Wallago attu and Sperata sarwari.

Table 4.2 125 Mean values, ranges and standard deviations of various internal morphometric parameters of Wallago attu and Sperata sarwari.

Table 4.3 126 Total length-Wet body weight relationship in Wallago attu and Sperata sarwari

Table 4.4 126 Total length-Condition factor and Wet body weight-Condition factor relationships in Wallago attu and Sperata sarwari.

Table 4.5 127 Regression equation, standard errors, correlation coefficient and t-test between wet body weight and other morphometric parameters of Wallago attu. Table 4.6 129 Regression equation, standard errors, correlation coefficient and t-test between wet body weight and other morphometric parameters of Sperata sarwari. Table 4.7 131 Regression equation, standard errors, correlation coefficient and t-test between total length and other morphometric parameters of Wallago attu. Table 4.8 133 Regression equation, standard errors, correlation coefficient and t-test between total length and other morphometric parameters of Sperata sarwari. Table 4.9 135 The regression parameters of various body fins weight in relation to wet body weight (W) of Wallago attu. IX

Table 4.10 135 The regression parameters of various body fins weight in relation to wet body weight (W) of Sperata sarwari.

Table 4.11 136 The regression parameters of various body fins weight with relation to total length (TL) of Wallago attu.

Table 4.12 136 The regression parameters of various body fins weight with relation to total length (TL) of Sperata sarwari.

Table 4.13 137 Regression Analysis of Various log internal body organs against log wet body weight (g) in Wallago attu.

Table 4.14 138 Regression Analysis of Various log internal body organs against log wet body weight (g) in Sperata sarwari.

Table 4.15 139 Regression Analysis of Various log internal body organs against log total length (cm) in Wallago attu.

Table 4.16 140 Regression Analysis of Various log internal body organs against log total length (cm) in Sperata sarwari.

Table 4.17 157 Length-Weight relationships for different fish species from different localities.

LIST OF FIGURES

DESCRIPTION PAGE Figure 2.1 Pi graph showing various body constituents in wet mass of 24 Wallago attu Figure 2.2 Pi graph showing various body constituents in dry mass of 24 Wallago attu Figure 2.3 Pi graph showing various body constituents in wet mass of 25 Wallago attu Figure 2.4 Pi graph showing various body constituents in dry mass of 25 Wallago attu Figure 2.5 Pi graph showing various body constituents in wet mass of 26 Sperata sarwari Figure 2.6 Pi graph showing various body constituents in dry mass of 26 Sperata sarwari Figure 2.7 Pi graph showing various body constituents in wet mass of 27 Sperata sarwari Figure 2.8 Pi graph showing various body constituents in dry mass of 27 Sperata sarwari Figure 2.9 The relationship between wet body weight and (a) Total water 40 contents (b) Total ash contents (c) Total fat contents (d) Total protein contents in wild Wallago attu Figure 2.10 The relationship between wet body weight and (a) Total ash 41 free matter (b) Total fat free matter (c) Total protein free matter, (d) Log wet body weight and log water content in wild Wallago attu Figure 2.11 The relationship between log wet body weight and (a) log ash 42 content (b) log fat content (c) log protein content (d) log ash free matter in wild Wallago attu Figure 2.12 The relationships between log wet body weight and (a) log fat 43 free matter (b) log protein free matter in wild Wallago attu XI

Figure 2.13 The relationships between total length and (a) total water 43 content (b) total ash content in wild Wallago attu Figure 2.14 The relationships between total length and (a) total fat content 44 (b) total protein content (c) total ash free matter (d) total fat free matter in wild Wallago attu Figure 2.15 (a) The relationship between total length and total protein free 45 matter, and log total length and (b) log water content (c) log ash content (d) log fat content in wild Wallago attu Figure 2.16 The relationships between log total length and (a) log protein 46 content (b) log ash free matter (c) log fat free matter (d) log protein free matter in wild Wallago attu Figure 2.17 The relationships between wet body weight and (a) total water 47 content (b) total ash content (c) total fat content (d) total protein content in wild Sperata sarwari. Figure 2.18 The relationships between wet body weight and (a) total ash 48 free matter (b) total fat free matter (c) total protein free matter (d) log wet body weight and log water content in wild Sperata sarwari. Figure 2.19 The relationships between log wet body weight and (a) log ash 49 content (b) log fat content (c) log protein content (d) log ash free matter in wild Sperata sarwari. Figure 2.20 The relationships between log wet body weight and (a) log fat 50 free matter (b) log protein free matter in wild Sperata sarwari. Figure 2.21 The relationships between total length and (a) total water 50 content (b) total ash content in wild Sperata sarwari. Figure 2.22 The relationships between total length and (a) total fat content 51 (b) total protein content (c) total ash free matter (d) total fat free matter in wild Sperata sarwari. Figure 2.23 The relationships between (a) total length and total protein 52 free matter, (b) log total length and log water content (c) log total length and log ash content (d) log total length and log fat content in wild Sperata sarwari. XII

Figure 2.24 The relationships between log total length and (a) log protein 53 content (b) log ash free matter (c) log fat free matter (d) log protein free matter in wild Sperata sarwari. Figure 2.25 Effect of season on the percentages of the body constituents in 54 Wallago attu. Figure 2.26 Effect of season on the percentages of the body constituents in 55 Sperata sarwari. Figure 3.1 (a) Wet body weight (g) versus Cu (μgg-1) (b) dry body weight 79 versus Cu (μgg-1) (c) total length (cm) versus Cu (μgg-1 dry weight) (d) total length (cm) versus Cu (μgg-1 wet weight) in Wallago attu. Figure 3.2 (a) Wet body weight (g) versus Cu (μgg-1) (b) dry body weight 80 versus Cu (μgg-1) (c) total length (cm) versus Cu (μgg-1 dry weight) (d) total length (cm) versus Cu (μgg-1 wet weight) in Sperata sarwari. Figure 3.3 (a) Wet body weight (g) versus Zn (μgg-1) (b) dry body weight 81 versus Zn (μgg-1) (c) total length (cm) versus Zn (μgg-1 dry weight) (d) total length (cm) versus Zn (μgg-1 wet weight) in Wallago attu. Figure 3.4 (a) Wet body weight (g) versus Zn (μgg-1) (b) dry body weight 82 versus Zn (μgg-1) (c) total length (cm) versus Zn (μgg-1 dry weight) (d) total length (cm) versus Zn (μgg-1 wet weight) in Sperata sarwari. Figure 3.5 (a) Wet body weight (g) versus Ni (μgg-1) (b) dry body weight 83 versus Ni (μgg-1) (c) total length (cm) versus Ni (μgg-1 dry weight) (d) total length (cm) versus Ni (μgg-1 wet weight) in Wallago attu. Figure 3.6 (a) Wet body weight (g) versus Ni (μgg-1) (b) dry body weight 84 versus Ni (μgg-1) (c) total length (cm) versus Ni (μgg-1 dry weight) (d) total length (cm) versus Ni (μgg-1 wet weight) in Sperata sarwari. XIII

Figure 3.7 (a) Wet body weight (g) versus Fe (μgg-1) (b) dry body weight 85 versus Fe (μgg-1) (c) total length (cm) versus Fe (μgg-1 dry weight) (d) total length (cm) versus Fe (μgg-1 wet weight) in Wallago attu. Figure 3.8 (a) Wet body weight (g) versus Fe (μgg-1) (b) dry body weight 86 versus Fe (μgg-1) (c) total length (cm) versus Fe (μgg-1 dry weight) (d) total length (cm) versus Fe (μgg-1 wet weight) in Sperata sarwari. Figure 3.9 (a) Wet body weight (g) versus Co (μgg-1) (b) dry body weight 87 versus Co (μgg-1) (c) total length (cm) versus Co (μgg-1 dry weight) (d) total length (cm) versus Co (μgg-1 wet weight) in Wallago attu. Figure 3.10 88 (a) Wet body weight (g) versus Co (μgg-1) (b) dry body weight versus Co (μgg-1) (c) total length (cm) versus Co (μgg-1 dry weight) (d) total length (cm) versus Co (μgg-1 wet weight) in Sperata sarwari.

Figure 3.11 89 (a) Wet body weight (g) versus Pb (μgg-1) (b) dry body weight versus Pb (μgg-1) (c) total length (cm) versus Pb (μgg-1 dry weight) (d) total length (cm) versus Pb (μgg-1 wet weight) in Wallago attu.

Figure 3.12 90 (a) Wet body weight (g) versus Pb (μgg-1) (b) dry body weight versus Pb (μgg-1) (c) total length (cm) versus Pb (μgg-1 dry weight) (d) total length (cm) versus Pb (μgg-1 wet weight) in Sperata sarwari.

Figure 3.13 91 (a) Wet body weight (g) versus Cd (μgg-1) (b) dry body weight versus Cd (μgg-1) (c) total length (cm) versus Cd (μgg-1 dry weight) (d) total length (cm) versus Cd (μgg-1 wet weight) in Wallago attu XIV

Figure 3.14 92 (a) Wet body weight (g) versus Cd (μgg-1) (b) dry body weight versus Cd (μgg-1) (c) total length (cm) versus Cd (μgg-1 dry weight) (d) total length (cm) versus Cd (μgg-1 wet weight) in Sperata sarwari.

Figure 3.15 101 Comparison of elemental concentrations between two catfishes of southern Punjab.

Figure 3.16 102 Comparison of elemental concentrations in male and female Wallago attu.

Figure 3.17 Comparison of elemental concentrations in male and female 103 Sperata sarwari. Figure 4.1 141 (a) The relationship between total body length (cm) and wet body weight (g) (b) The relationship between log total body length (cm) and log wet body weight (g) in Wallago attu.

Figure 4.2 141 (a) The relationship between total body length (cm) and wet body weight (g) (b) The relationship between log total body length (cm) and log wet body weight (g) in Sperata sarwari.

Figure 4.3 142 (a) The relationship between total body length (cm) and condition factor (k) (b) The relationship between wet body weight (g) and condition factor (k) in Wallago attu.

Figure 4.4 142 (a) The relationship between total body length (cm) and condition factor (k) (b) The relationship between wet body weight (g) and condition factor (k) in Sperata sarwari.

Figure 4.5 143 The relationship between total length (cm) and length of other body variables (cm) in Wallago attu.

Figure 4.6 144 The relationship between wet body weight (g) and length of XV

other body variables (cm) in Wallago attu.

Figure 4.7 145 The relationship between total length (cm) and length of other body variables (cm) in Sperata sarwari.

Figure 4.8 146 The relationship between wet body weight (g) and length of other body variables (cm) in Sperata sarwari.

Figure 4.9 147 The relationships between wet body weight (g) and fins weight (g) in (a) Wallago attu and (b) Sperata sarwari.

Figure 4.10 148 The relationships between total length (cm) and fins weight (g) in (a) Wallago attu and (b) Sperata sarwari.

Figure 4.11 The relationships between total length (cm) and fins weight 149 (g) in Wallago attu Figure 4.12 The relationships between total length (cm) and fins weight 150 (g) in Sperata sarwari. Figure 4.13 The relationships between total length (cm) and fins weight 151 (g) in Wallago attu. Figure 4.14 152 The relationships between total length (cm) and fins weight (g) in Sperata sarwari.

XVI

ABBREVIATIONS a Intercept AFB Anal fin base AFL Anal fin length b Regression coefficient BG Body girth cm Centimeter CFB Caudal fin base CFL Caudal fin length Cd Cadmium Co Cobalt Cu Copper DFB Dorsal fin base DFL Dorsal fin length df Degree of freedom ED Eye diameter Fe Iron FL Fork length g Gram HL Head length HW Head width IOL Inter orbital length K Condition factor L Length L3 Cube of length ManBL Mandibular barbells length MaxBL Maxillary barbells length MS Mean square N.S. Non significant Ni Nickel XVII

P Probability Pb Lead PFB Pectoral fin base PFL Pectoral fin length POL Post orbital length PDL Post dorsal length PPL Pre pelvic length PelFB Pelvic fin base PelFL Pelvic fin length PreOL Pre orbital length PreDL Pre dorsal length r2 Coefficient of determination S.D. Standard deviation S.E. Standard error SL Standard length SS Sum of square TL Total length W Weight Zn Zinc

ABSTRACT Seventy eight wild Wallago attu and eighty Sperata sarwari of different body sizes were collected for analysis of body composition, morphometric parameters and elemental concentration. Each sampled was measured, weighed, dried and powdered for the analysis of water content, ash content, fat content and protein content. It was observed that highly significant inverse correlations exist between percent water content and percent ash content (wet weight), percent fat content (wet weight) and percent protein content (wet weight) in both species. In Wallago attu, there was no effect of wet body weight and total body length on percent water contents but positive influence on percent ash contents (wet weight), percent fat contents (wet weight), percent protein contents (wet weight), percent ash free matter (wet weight and dry weight), percent fat free matter (wet weight) and percent protein free matter (wet weight and dry weight). In case of Sperata sarwari, wet body weight and total body length have positive influence on percent water contents, percent fat contents (wet weight), percent protein free matter (wet weight and dry weight) and negative influence on percent ash contents (wet weight), percent protein contents (wet weight), percent ash free matter (wet weight and dry weight) and percent fat free matter (wet weight). Condition factor has a highly significant positive correlation with percent fat content (wet weight) in both species. When comparative study was done, it was found that there were highly significant differences between these two species in ash contents (wet and dry weight), protein contents (dry weight), ash free matter contents (dry weight), fat free matter (wet weight) and protein free matter (wet and dry weight). There was no significant effect of sex on body constituents in both species. The results also indicated that the proximate composition of the Wallago attu and Sperata sarwari depend on season. It was found that body constituents varied in different months of the year. The predictive equations can be used to estimate values of body composition with a fair amount of accuracy for both species. Flame Atomic Spectrometry was used as an analytical tool for analysis of trace metal concentration in relation to body size. In Wallago attu, it was observed that the metals i.e. Cd, Co, Fe and Cu were found to increase isometrically while Zn, Ni and Pb showed negative allometry with increasing body weight and total length. In Sperata 2

sarwari, Cd, Co, Fe and Zn were found to increase isometrically while Ni, Cu and Pb showed negative allometric growth with body weight and total length. In both species, there were not significant differences in elemental concentration with relation to sex. The effect of season on elemental concentration was analyzed by using the ANOVA. Significant differences were observed in case of copper, zinc and lead concentrations in Wallago attu while zinc and nickel concentrations in Sperata sarwari. Wet body weight of both the species was not consistent with the cube law and showed positive allometry. The regression slope was W = 0.001698 L3.27 for W. attu and W = 0.001698 L3.28 for S. sarwari. The values of the slope b are significantly higher than b = 3.0, which shows that the weight grows more rapidly as compared to the cube of the length. Regression analysis showed that all the morphometric parameters except for eye diameter, mandible barbells length in W. attu and eye diameter, caudal fin length, nasal barbells length, maxillary barbells length and mandible barbells length in S. sarwari showed isometric growth with relation to wet body weight and total length of the fish. While the regression coefficient of all the fins weight except for dorsal fin in W. attu and caudal fin in S. sarwari showed positive allometric growth with body size. In internal morphometric studies, except for air bladder weight and gonads weight all the parameters showed negative allometric growth with relation to wet body weight and total length.

TABLE OF CONTENTS

Species 21 2.3.5. Effect of sex on proximate composition 21 2.3.6. Effect of seasonal variations on the body 22 composition

2.3.6.1. Water content 22

2.3.6.2. Ash content 22

2.3.6.3. Fat content 22

2.3.6.4. Protein content 22

2.4. DISCUSSION 56

2.4.1. Water content 56

2.4.2. Ash content 57

2.4.3. Fat content 57

2.4.4. Protein content 59

2.4.5. Effect of condition factor on body composition 60

2.4.6. Effect of season on body composition 61

2.4.7. Effect of sex on body composition 62

2.4.8. Conclusion 62

Chapter-3 ELEMENTAL CONCENTRATION

3.1. INTRODUCTION 67

3.1.1. Aims and objectives 71

3.2. MATERIALS AND METHODS 72

3.2.1. Reagents and standards 72

3.2.2. Glassware 72

3.2.3. Instrumentation 72

3.2.4. Analytical procedure 73

3.2.5. Computation of results 73

3.3. RESULTS 74

3.3.1. Effect of body weight on elemental concentration 74

3.3.2. Effect of total length on elemental concentration 74

3.3.3. Comparison of elemental concentration between 93

two species IV

GENERAL INTRODUCTION

Food is the most important basic requirement for the survival of the living beings

in this universe. “Whenever it is not available in sufficient quantities, there arise the problems of competition. It is a well-known fact that the population of the world is increasing in geometrical proportion whereas the food production in arithmetic proportion. This leads to the shortage of the food materials, which could be overcome either by controlling the population explosion or by the increasing the food production. The first one could not be done effectively and hence to adopt the alternative, there was a lot of struggle to find out the ways and means to increase the food production (Islam, 2004). The aquaculture is one of the major sources to overcome the shortage of food. It is the farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic

plants, in freshwater, brackish-water and seawater environments” (El-Sayed, 2006). Developing potential new-species in freshwater fish aquaculture is needed in order to diversify and develop sustainable fish aquaculture (Nyina-wamwiza et al., 2005). “Water is precious and a basic natural resource whereby conservation and management are

gaining importance for enhancing fisheries output through aquaculture expansion” (Mohanty, 2004). The dietary habits are among the major concerns of human and are increasing in importance all over the world. “Nutrients, both in amount and quality, are necessary for maintaining good health. Fish has been broadly accepted as a good source of protein and other elements for the maintenance of healthy body” (Andrew, 2001). They have significant role in nutrition, income, employment and foreign exchange earning of the

country (Mazumder et al., 2008). “Consumption of fish provides an important nutrient to a large number of people world-wide and thus makes a very significant contribution to nutrition. However, the space between the demand and supply of fish is widening due to increase in population, poor post-harvest handling, lack of processing, storage facilities and utilization of unconventional fish species” (Azam, et al., 2004; Carvalho et al., 2005;

Chukwu and Shaba, 2009). “The high production costs, shrinking profit margins, along with increasing pressures to produce high-quality products in an environmentally sustainable fashion are significant challenges for fish culture operations. Access to CHAPTER 1 4 GENERAL INTRODUCTION

models enabling reliable prediction of growth (biomass gain), feed requirement (or efficiency of feed utilization), composition of growth, and waste outputs could help fish culture operations improve feeding and waste management and, in turn, meet current

challenges in a sustainable manner (Dumas et al., 2007).” The relationship between man and fish can be found back to pre-historic times. In those days, man has used fish as a source of food because fish constitute an important

component of human diet. “Fish flesh can be converted into human body tissues more efficiently than the best meats of farm animals such as sheep, goat, cow, etc. Flesh of fish is generally white, soft and has pleasant taste and flavor. In terms of food value it is the most superior meat having less fat and more protein as compared to other fleshes” (Sinha

and Ramachandran, 1985).

“Economically, fish occupy a significant position in the socio-economic fabric of the South Asian countries by providing the population not only the nutritious food but

also income and employment opportunities (Talwar and Jhingran, 1991).” It is world wide accepted that the first vertebrate was fish. The term "fish" is most precisely used to describe any non-tetrapod chordate with a backbone, living a purely aquatic life, propelling and boyancing it by fins and breathing by gills. The various fish groups taken together account for more than half of the known vertebrates (Verma and

Pande, 2004; Nelson, 2006). “The fishes occupied wide range of habitat. Their range of distribution is from Antarctic water of about –2 °C to hot springs of California where temperature is as high as 52 °C. Antarctic water i.e. –2 °C does not freeze due to its high concentration of salt. The distribution in altitude ranges from 5000 meters above the sea level to some 11000 meters beneath it” (Ali, 1999). There are descriptions of an estimated 24,618 valid species of fishes. Some groups are expanding with newly described species, while others are decreasing. However, a net increase in species of the fish is shown every year (Nelson, 1994). The number may eventually increase to around

28500 (Jobling, 1995). Pakistan is gifted with fishery resources that have a massive potential for development. But the fishery sector plays a relatively small role in Pakistan’s economy as compared to other Asian countries. In 1985 the total out put of fish and fish products was approximately 0.8% of the country’s total GDP. The native fresh water fish fauna of CHAPTER 1 5 GENERAL INTRODUCTION

Pakistan comprises 3 Cohort, 5 Super Orders, 11 Orders, 26 Families, 83 Genera and 183 Species (Mirza, 2003; Naseem, 1995). But the total number of fishes used by human in the field of fisheries, aquaculture, sport fishing and the ornamental trade is 7000 (Forese and Pauly, 1998). The siluriformes is one of the biggest orders of fishes including more than 2,405

species in 412 genera and 34 families (Nelson, 1994). “Because of a great morphological diversity and wide distribution, catfishes are obviously an attractive group for experimental and evolutionary biologists. In many areas of the world, catfishes are popular sport fish and a valued food item. Many catfishes are also of great importance in inland fisheries and aquarium trade, as their quantity and biological adaptability are

outstanding” (Jhingran, 1991; Ferraris, 1991). In Pakistan, the main source of protein is cattle which are in direct competition with human beings for the production of fodder. Hence, due to limitation of land resources, the only choice left is to fully utilize available aquatic resources of the country

(Bhatti, 1991). “In Pakistan, catfishes are most abundant group of fish. They are part of the inland capture fishery and their only source is natural waters because they are not cultured in Pakistan” (Sandhu, 2000). Rearing fish under strictly controlled conditions can alter their slaughter yield, proximate composition, and other parameters of the flesh (Jankowska et al., 2007). Wild fish tend to be leaner than farmed fish (Haard, 1992) however, large variation due to size, nutritional status and season do occur (Lie, 2001). Catfishes belonging to Bagaridae, Clariidae, Pangasiidae and Siluridae families are widely distributed in different parts of the world and their culture had been a traditional practice in some parts of Southeast and South Asia (Salam, et al., 1994).

1.1 Wallago attu

“Wallago attu is one of the large freshwater catfish fished across the rivers, reservoirs and in connected watersheds of the Indian subcontinents. It is a bony fish, belonging to the family Siluridae” (Talwar and Jhingran, 1991). “The rapid growth (Goswami and Devraj, 1992), majestically elongated and silvery body look (Talwar and Jhingran, 1991), and high nutritional quality of flesh (Lilabati and Viswanath, 1996) encourage investigation into the aquaculture potential of this excellent food fish. The CHAPTER 1 6 GENERAL INTRODUCTION

present decline in yield from the wild fisheries enlists Wallago attu as an endangered species (Kurup, 1992).” Diagnostic features: Head broad, snout depressed. Body elongated and strongly

compressed. “Mouth very deeply cleft, its corner reaching far behind eyes. Teeth in jaws set in wide bands; vomerine teeth in two small patches. Barbels two pairs; maxillary barbels extending to anterior margin posterior of anal fin, mandibulary barbels to angle of mouth. Eyes small, with a free orbital margin. Dorsal fin small, anal fin very long (Taki, 1974). Mandibular barbel longer than pelvic fin; 24-30 gill rakers on the first arch (Rainboth, 1996). Eye in front of vertical through corner of mouth (Kottelat, 2001).” Distribution: It is found in Pakistan, India, Sri Lanka, Nepal, Bangladesh, Burma, Thailand, Vietnam, Kampuchea, Malay Peninsula, Afghanistan, Sumatra and Java

(Talwar and Jhingran, 1991; Giri et al., 2002). “Previously, abundant in the rivers, reservoirs, and in connected watersheds” (Silva and Davies, 1986; Bhat, 2004; Patra et al., 2005; Islam et al., 2006). In Pakistan it is reported from Indus plains and adjoining hilly areas (Mirza, 1975).

Size: “It grows to about 2 m, weighing more than 45 kg (Talwar and Jhingran, 1991) with

a calculated life span of about 10 years” (Goswami and Devraj, 1992).

Feeding: “Juveniles feed mainly on insects (Sokheng et al., 1999) and adults are strongly

piscivorous, feeding on small fishes, crustaceans, shrimps and mollusks” (Islam et al., 2006).

Reproduction: “Spawning occurs from May to October in Cambodia, June to July in

Bangladesh and Thailand, and July to August in Pakistan and Nepal” (Froese and Pauly, 2007).

1.2 Sperata sarwari

“Sperata sarwari is an Indus catfish (family: Bagridae) found in Pakistan and Indus drainage system in India (Mirza, et al., 1992). The status of Sperata sarwari in Pakistan is more or less endangered due to the poor knowledge of its biology, but also

due to the declining stocks of this fish in natural waters” (Shakir et al., 2008). The present study is being studied from this point of view in Pakistan CHAPTER 1 7 GENERAL INTRODUCTION

Diagnostic features: Body elongated, compressed posteriorly, abdomen rounded. Head large and depressed. “Snout broad and rounded. Eyes large with free orbital margin, in middle of head, not visible from below ventral surface. Diameter of eye about 20% of the head length. Mouth sub-terminal, transverse, moderately wide. Cleft of mouth not extending half way up to the orbit. Jaws sub-equal, upper being longer than the lower. Width of head 3/5 of its length. Occipital process not reaching half way to basal bone of the dorsal fin. A distinct inter-neural shield in between basal bone of dorsal fin and occipital process present. Teeth uniformly villiform on jaws and palate in bands. Barbells four pairs, the maxillary barbells (one pair) reach nearly the middle of the orbit. The outer mandibular barbells reach the base of the pectoral fin, while the inner one is short. Dorsal fin with one weak spine and seven soft rays while pectoral fin with one strong serrated spine and 9-10 soft rays. Ventral fins originate below last dorsal rays, not reaching the anal fin. Ventral fin rays 11-13. Caudal fin deeply forked with pointed lobes, the three outer rays in the upper lobe being much elongated. Caudal fin rays usually 17. Lateral

line present” (Sandhu, 2000). Distrubution: It is found in Afghanistan, Pakistan and India (Mirza, 2003).

Size: “Maximum size of 42 cm has been noted for Sperata sarwari so far (Mirza et al., 1992).” Feeding: It is a carnivorous fish, feeds mainly on animal food (Nawaz, et al., 1994, Sandhu and Lone, 2003).

Colour: “Bluish brown above becoming white beneath: fins yellowish: a black spot on

adipose dorsal” (Sandhu, 2000). Fishery information: This is a common giant catfish in the Punjab and of considerable fishery value. It is liked very much in the Punjab as its flesh contains only a few bones (Sandhu, 2000).

CHAPTER 1 8 GENERAL INTRODUCTION

Wallago attu (Malle)

CHAPTER 1 9 GENERAL INTRODUCTION

Sperata sarwari CHAPTER NO.2 10 BODY COMPOSITION

BODY COMPOSITION

2.1 INTRODUCTION Man has become more nutrition conscious, so there has been a demand for more information on nutritious values of fish. But there is little information available on

nutritional value of freshwater fish (Clement and Lovell, 1994). “Nutritional quality of food is related to its content of nutrients and their bioavailability. The fact that there is a link between diet and human health has increased consumer’ interests in healthy food and thereby the nutritional quality of food. Fish is an excellent source of protein and fish lipid has attracted much attention for its content of n-3 fatty acids” (Lie, 2001). “However, the gap between the demand and supply of fish is widening due to increase in population, poor post-harvest handling, lack of processing, storage facilities and utilization of unconventional fish species (Chukwu and Shaba, 2009).”

“Proximate composition illustrates the nutritional quality of food because analysis of biochemical composition including protein, fat and ash is very important to assess food value” (Kamal, et al., 2007). Biochemical evaluation is necessary to ensure the nutrition value as well as eating quality of the fresh fish (Azam, et al., 2004).

“Therefore, taking into consideration the various health risk and the nutritional benefits related with fish consumption; it has become important that, fish’s mineral and proximate composition and their health status be assessed in order to establish the safety level of the table sized species prior their consumption” (Fawole, et al., 2007). In Pakistan, little attention has been given on analysis of body composition of catfishes. The proximate body composition of some important commercial fishes of Pakistan has already been studied i.e. Oreochromis nilotica by Javaid et al., 1992; Labeo rohita by Salam and Janjua, 1992; Rita rita by Rafique, 1992; Catla catla by Mahmood, 1992; Ctenopharyngodon idella by Javed, 1996.

“Flesh quality can be characterized by the results of laboratory analyses of the basic chemical composition of flesh. The main assessed descriptors are the content of dry

matter, crude protein, lipids and ash” (Buchtova et al., 2005). “As with many animal products, fish and fishery products contain water, proteins and other nitrogenous compounds, lipids, carbohydrates, minerals and vitamins. However, the values of these CHAPTER NO.2 11 BODY COMPOSITION

body contents vary significantly from one species and one individual fish to another depending on age, sexual condition, feeding season, sampling time, activity and environmental condition. So, the evaluation of fish composition is usually directed to

lipid, protein and water as these compounds are predominant in fish metabolism” (Weatherley and Gill, 1987; Jobling, 1994; Huss, 1995; Clucas and Ward, 1996; Kalay et al., 2008; Tang et al., 2009). The measurement of proximate composition is often necessary to ensure that they meet the requirements of food regulations and commercial specifications (Watermann, 2000). “Moreover, fish body composition is a good indicator of condition, which is usually assessed from a measure of the deviation of the mass of an individual fish from average mass for length of the population (Le Cren, 1951). Although there is large volume of literature concerning to the body composition of fishes, but majority of it fails to fully define the ontogenetic, the spatial and the temporal changes that occur in body components. The key reason is that the measurement of proximate composition is a time-consuming and costly process (Hartman and Margraf, 2008). Protein is the essential component of animal tissue and is a crucial nutrient for

maintenance and growth (Ugwu et al., 2007). “Fish has long been accepted as an important source of high-quality protein in the human diet. It is known to be nutritious, tasty, easily digested and the cheapest sources of animal protein and other vital nutrients

required in human diets” (Webster and Carl, 2002; Osibona et al., 2009). Foran et al. (2005) also stressed that, fish is a highly proteinous food consumed by a larger

percentage of population because of its availability and deliciousness. “The nature and quality of nutrients in most animals is dependent upon their food type. Feeding habit of an individual fish species has also great effect on its body composition and there is

increased interest in the control of chemical composition and quality of farmed fish” (Lagler, et al., 1977; Shearer, 1994; Koskela et al., 1998; Yamamoto et al., 2000). There are also significant differences in the biochemical composition of wild and cultured fish. But these differences could be attributed to the type of diet (Alasalvar et al., 2002; Mnari et al., 2007). Fish protein takes an important place in human nutrition. It has high digestibility, biological and growth promoting value (Nargis, 2006). “The protein comprises structural proteins (actin, myosin, tropormyosin and actomyosin), sarcoplasmic proteins CHAPTER NO.2 12 BODY COMPOSITION

(myoalbumin, globulin and enzymes) and connective tissue proteins (collagen). Fish proteins contain all the essential amino acids and, like milk, eggs and mammalian meat proteins, have a very high biological value. In addition, fish proteins are a brilliant source of lysine, methionine and cysteine, and can considerably raise the value of cereal-based diets, which are poor in these essential amino acids” (Huss, 1995; Clucas and Ward,

1996). “The protein composition in muscles varies by muscle type, whether it is striated, smooth or cardiac muscle. The striated muscles are the predominant form in fish, and the flesh can be seen as “white” or “dark” meat. The white meat contains fewer fats than the dark meat and is usually composed of about 18% to 23% of protein, depending on the species and time of harvesting” (Suzuki, 1981). High protein content and a good water- holding capacity of proteins in fish muscle are also important as it often improves the texture of the fish flesh (Okland et al., 2005). However, significant variations in protein content are observed between fish species, and a relation seems to exist between chemical composition and depth of occurrence (Childress and Nygaard, 1973; Yancey et al., 1992). The percentage of water is good indicator of its relative contents of energy, proteins and fats. “Lower the percentage of water, greater the fats and protein contents and higher the energy density of the fish (Dempson et al., 2004). It means determining the relative amount of water in the fish one can acquire relative estimates of the energy, fat and lipid contents (Jonsson and Jonsson, 1998; Salam and Davies, 1994).” In recent years, fish fats have assumed great nutritional significance, because they have high polyunsaturated fatty acid levels (Puwastien et al., 1999) and important role as energy providers (Morata et al., 1982; Miglavs and Jobling, 1989; Collins and Anderson,

1995). “Fish fats contrast greatly from mammalian fatss in that they include up to 40 percent of long-chain fatty acids that are highly unsaturated and contain five or six double bonds. This difference entails both health (anti-thrombotic activity of polyunsaturated fatty acids) and technological (rapid development of rancidity) implications” (Huss, 1995; Clucas and Ward, 1996; Lombardo and Chicco, 2006). Proximate composition of different catfishes has been determined previously in different areas of the world but no data is available on the proximate composition of Wallago attu and Sperata sarwari in Pakistan. Basic knowledge of nutrients composition is required to facilitate the processing utilization and marketing of these valuable CHAPTER NO.2 13 BODY COMPOSITION

catfishes for human consumption. Present report highlights the body composition of Wallago attu and Sperata sarwari in relation to body size, sex, season and condition factor.

CHAPTER NO.2 14 BODY COMPOSITION

2.1.1 Aims and objectives of the study:

 To investigate the proximate composition of Wallago attu and Sperata sarwari.  The results of this study can be used by the fishing industry, nutritionists, investigators involved in processing and marketing.  To measure fat-water or protein-water relationships for predictive purpose.  To observe the effect of body size and condition factor on body composition parameters.  To evaluate the effect of sex and season on body composition of these catfishes.  To prepare tables of compositions of food.

CHAPTER NO.2 15 BODY COMPOSITION

2.2 MATERIALS AND METHODS Seventy eight specimens of wild Wallago attu and eighty specimens of wild Sperata sarwari of variable body sizes were sampled during 2005-2006 from different localities of Indus River of Southern Punjab with the help of a drag net. These were transported in plastic containers to the Fish Research Laboratory, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, where they were removed from plastic containers and were anaesthetized. After that, they were blotted dry with a paper towel and then different morphometric parameters of each fish were measured. 2.2.1 Measurement of weight and length: All weighed measurements were done by an electronic digital balance (MP-3000 Chyo, Japan) to the nearest 0.01 gram. Different body lengths parameters were measured by a wooden measuring tray to the nearest of 0.1 cm. 2.2.2 Determination of water contents: To estimate the water contents in each individual fish, the dead, pre weighed and pre measured fish were placed as a whole in pre weighed aluminum foil tray for drying till constant weight in an electric oven (Memmert, W. Germany) at 60 - 70oC. After the constant weight had achieved, the dry weight was finally recorded. %Dry weight was calculated by using following Formula. :

Dry weight of fish %Dry weight = x 100 Wet weight of fish

The total water mass in the fish body was calculated by using the following formula; Total water contents of fish = Wet body weight – Dry body weight %Water contents of the fish were calculated by the following formula.

Total water contents %Water contents of fish = x 100 Wet body weight

Or it can be calculated by suing the following formula; %Water contents of fish = 100 - % Dry weight of fish. CHAPTER NO.2 16 BODY COMPOSITION

For further analysis, each dry carcass was crushed in a pestle and mortar and powdered and homogenized in a Moulinex Electric Blender. 2.2.3 Determination of ash contents: To calculate ash contents in each individual fish 1 g of sample was taken in a pre - weighed heat resistant China clay crucible and ashed in a Muffle furnace for 12 hours at 450-500 0C and reweighed after cooling at 50 0C in an oven (Gallen Kamp, England) to calculate ash contents in dry mass of fish taken for ashing. Quantity of ash and %Ash in the sample was calculated by using the following Formula. Ash contents = initial mass of the sample – mass of the sample loss during heating Total amount of ash in dry mass of fish can be calculated as;

Total ash in dry mass of fish %Ash (dry mass of fish) = x 100 Dry mass of fish

While %ash (wet body weight) can be calculated by using the formula; Total ash content of fish % Ash (wet mass of fish) = x 100 Wet mass of fish

2.2.4 Determination of fat contents: The Fat contents were estimated using dry tissue by dry extraction method in which a mixture of Chloroform and Methanol in a ratio of 1:2 was taken, following the method of Bligh and Dyer (1959); Cui and Wootton (1988) and Salam and Davies (1994) one gram sample of powdered dry tissue was mixed into 10 ml of this mixture and stirred with a glass rod. The resultant mixture was left over night and then centrifuged. After centrifugation, the clear supernatant was removed carefully into washed, dried and pre weighed small bottles. These bottles were then placed in an incubator (Memmert ® 8540) at 40 to 50 0C to evaporate the solvent to dryness leaving the lipid fraction. Lipids were then weighed on an electronic balance (MP-3000 Chyo, Japan) to nearest (0.01) grams. To calculate the fat content in dry and wet body weight of fish and its percentage in all samples were calculated by using following formula; Fat contents = weight of the bottle with fat – wt of empty bottle CHAPTER NO.2 17 BODY COMPOSITION

Total fat content in dry mass of fish =

Mass of fat in the sample x dry mass of fish Mass of sample

Total fat in dry mass of fish %fat (dry mass of fish) = x 100 Dry mass of fish

While %fat (wet body weight) was calculated by using the formula;

Total fat content of fish % Fat (wet body weight) = x 100 Wet body weight of fish

2.2.5 Determination of protein contents: Total protein present in dry mass can be calculated by the difference method from the mass of other main constituents i.e. Ash, Fat and Water (Pandian and Raghurman, 1972; Caulton and Bursell, 1977; Salam and Janjua, 1992) i.e. either by subtracting ash contents + fat contents from dry weight of fish i.e. Total protein content of fish = Dry weight-(Total ash content + Total fat content) Total protein content of fish %Protein (dry weight) = x 100 Dry weight of fish

It was then converted to % protein (Wet body weight) by using the following formula;

Total protein content of fish % Protein (Wet body weight) = x 100 Wet weight of fish

2.2.6 Determination of carbohydrates: Carbohydrates do not form a major component of fish and thus are generally neglected due to their negligible amounts (Elliott, 1976; Caulton and Bursell, 1977; Salam and Davies, 1994). In the present study, no attempt has been made to calculate the carbohydrate contents of these catfishes. CHAPTER NO.2 18 BODY COMPOSITION

2.2.7 Determination of condition factor: A very widely used index in fish ecology studies is the Fulton’s Condition Factor (K) and is calculated by the formula; Condition factor = Weight /Length3 x 100 OR K = W /L3 x 100 (Weatherley, 1972; Ricker, 1975; Wootton, 1990 and Salam and Mahmood, 1993).

2.2.8 Data analysis: Statistical analysis including regression analysis, calculation of correlation coefficients, standard error of the estimates, student’s t-test, ANOVA and comparison of two means and plotting of data were carried out using EXCEL, LOTUS 1-2-3, MINITAB program on computer following Zar (1996).

CHAPTER NO.2 19 BODY COMPOSITION

2.3 RESULTS

The mean proximate composition values for Wallago attu were 76.08% for Water, 3.33% for ash (wet weight), 14.50% for ash (dry weight), 4.16% for fat (wet weight), 17.86% for fat (dry weight), 15.69% for protein (wet weight) and 67.64% for protein (dry weight). While in case of Sperata sarwari, these values were 76.05% for water, 4.17% for ash (wet weight), 17.53% for ash (dry weight), 4.11% for fat (wet weight), 17.06% for fat (dry weight), 15.67% for protein (wet weight) and 65.41% for protein (dry weight) (Table 2.1 and 2.2).

2.3.1 Effect of body size on body constituents:

In Wallago attu, wet body weight and total body length have no influence on percent water but negative influence on %fat free matter (dry weight) and positive influence on all other body constituents including %ash contents (wet weight), %fat contents (wet weight), %protein contents (wet weight), %ash free matter (wet weight and dry weight), %fat free matter (wet weight) and %protein free matter (wet weight and dry weight). The regression analysis was applied to assess the size dependence of percent water percent ash, percent fat and percent protein both in wet and dry body weight. The regression parameters of these relationships are given in (Table 2.5 & 2.11). When total values of each parameter of proximate composition (water, ash, fat and protein) was transformed into logarithm and plotted against log wet body weight and log total length showed very strongly correlation. The regression parameters of these relationships are given in the (Table 2.7 & 2.13).

In Sperata sarwari, wet body weight and total body length have positive influence on %water contents, %fat contents (wet weight), %protein free matter (wet weight and dry weight) and negative influence on %ash contents (wet weight), %protein contents (wet weight), %ash free matter (wet weight and dry weight) and %fat free matter (wet weight). While these have no effect on %fat free matter (dry weight). The regression parameters of these relationships are given in (Table 2.6 & 2.12). Total values of each parameter of proximate composition (water, ash, fat and protein) was when transformed into logarithm and plotted against log of wet body weight and log of total length, showed CHAPTER NO.2 20 BODY COMPOSITION

very strong correlation. The regression parameters of these relationships are given in (Table 2.8 & 2.14).

2.3.2 Influence of water content on other body constituents:

In Wallago attu %ash contents (wet weight and dry weight), %fat contents (dry weight) and %protein free matter (dry weight) have increasing trend in relation to %water. Percent fat contents (wet weight), %protein contents (wet weigh and dry weight), %ash free matter (wet weight and dry weight), %fat free matter (wet weight and dry weight) and %protein free matter (wet weight) have decreasing trend in relation to %water contents. The statistical parameters of these relationships are given in (Table 2.15).

In Sperata sarwari, %ash contents (dry weight) and %fat free matter (dry weight) increase with increasing %water. Percent water has no influence on %protein free matter (dry weight). While %ash contents (wet weight), %fat contents (wet weight and dry weight), %protein contents (wet weight and dry weight), %ash free matter (wet weight and dry weight), %fat free matter (wet weight) and %protein free matter (wet weight and dry weight) are inversely related to percent water. Each figure includes regression line for relationship between percent water and the body constituents in Wallago attu and Sperata sarwari mostly of these relationships are statistically significant. The statistical parameters of their relationships for Sperata sarwari are given in the Table 2.16.

2.3.3 Effect of condition factor (K) on body constituents: The index of fish condition used in this study for both species is “K”. Values of K for Wallago attu ranges between 0.312-0.720. It was observed that condition factor has no influence on percent water but negative influence on percent ash (dry weight), %protein (dry weight) and %fat free matter (dry weight) and positive influence on %ash (wet weight), %fat (wet weight and dry weight), %protein (wet weight), %ash free matter (wet weight and dry weight), %fat free matter (wet weight) and %protein free matter (wet weight). The statistical parameters of these relationships are given in (Table 2.17).

In Sperata sarwari K values ranges between 0.354-0.641. It was found that condition factor has negative effect on percent water, %ash contents, %protein contents CHAPTER NO.2 21 BODY COMPOSITION and %fat free matter while positive effect on %fat contents (wet weight), %ash free matter (wet weight and dry weight), %protein free matter (wet weight and dry weight). The statistical parameters of these relationships are given in (Table 2.18).

2.3.4 Comparison of body constituents between two Catfishes:

When data was analyzed statistically using analysis of variance (ANOVA) procedures, it was found that there was non-significant (P>0.05) differences between these two species of catfishes in relation to water contents, fat contents (wet and dry weight), protein contents (wet weight), ash free matter (wet weight), fat free matter (dry weight) and condition factor. There were highly significant differences between these two species in ash contents (wet and dry weight), protein contents (dry weight), ash free matter contents (dry weight), fat free matter (wet weight) and protein free matter (wet and dry weight) (Table 2.19).

2.3.5 Effect of Sex on body constituents: The percentages of various body constituents varied with the variation of sexes in the present study of catfishes. In case of Wallagu attu, mean values of %water contents, %ash contents (wet and dry weight) and %fat free matter (wet and dry weight) were slightly greater in male as compared to female, while that of %fat (wet and dry weight), %ash free matter (wet and dry weight) and %protein free matter (wet and dry weight) were some what greater in female as compared to male. %Protein contents (wet and dry weight) were not influenced by sexes (Table 2.20). While in case of Sperata sarwari, mean values of %water contents, %protein contents (wet and dry weight), %ash free matter (dry weight) and %fat free matter (dry weight) were greater in male while %ash contents (wet and dry weight), %fat contents (wet and dry weight) were greater in female (Table 2.21).

CHAPTER NO.2 22 BODY COMPOSITION

2.3.6 Effect of Seasonal Variations on the Body Composition:

The results indicated that the proximate composition of the Wallago attu and Sperata sarwari depend on season, that is described in the sections below.

2.3.6.1 Water content: The major constituent of the fish body was water. It was found that the water contents in different months varied from 75.28% (December) to 78.28% (May) in Wallago attu and 73.76% (December) to 77.09% (May) in Sperata sarwari (Table 2.22 & 2.23, Fig. 2.17 & 2.18). It has been shown that the water contents of these catfishes increased during summer, showing the breeding season of the fishes.

2.3.6.2 Ash content: The ash content ranged from 3.20% (January) to 3.71% (March) in Wallago attu and 3.92% (April) to 4.51% (October) in Sperata sarwari (Table 2.22 & 2.23, Fig. 2.17 & 2.18).

2.3.6.3 Fat content: The percentage composition of fat of catfishes has been determined and similar patterns of fluctuation to that of protein in both fishes were observed. It was found that the fat content ranged from 3.18% (May) to 4.81% (January) in Wallago attu and 2.53% (September) to 5.06% (November) in Sperata sarwari (Table 2.22 & 2.23, Fig. 2.17 & 2.18).

2.3.6.4 Protein content: It was found that the protein content varied from 14.19% (March) to 16.81% (August) in Wallago attu and in Sperata sarwari 14.76% (May) to 17.11% (December) (Table 2.22 & 2.23, Fig. 2.17 & 2.18).

CHAPTER NO.2 23 BODY COMPOSITION

Table 2.1: Mean values and ranges of various body constituents of Wallago attu, n = 78 in each case Body constituents (%) Mean ± S.D. Range Water contents 76.08 ± 2.15 69.57-82.43 Ash contents (wet weight) 3.33 ± 0.42 2.17-3.99 Ash contents (dry weight) 14.50 ± 2.23 9.0-18.02 Fat contents (wet weight) 4.16 ± 1.03 2.53-6.69 Fat contents (dry weight) 17.86 ± 3.51 11.0-25.0 Protein contents (wet weight) 15.69 ± 1.93 11.89-21.56 Protein contents (dry weight) 67.64 ± 3.82 57.0-75.99 Ash free matter (wet weight) 19.85 ± 2.41 16.50-26.77 Ash free matter (dry weight) 85.50 ± 2.23 81.98-91.0 Fat free matter (wet weight) 19.02 ± 1.91 15.42-24.40 Fat free matter (dry weight) 82.14 ± 3.51 75.0-89.0 Protein free matter (wet weight) 7.49 ± 1.11 5.84-10.37 Protein free matter (dry weight) 32.36 ± 3.82 24.01-43.0 S.D = Standard Deviation

Table 2.2: Mean values and ranges of various body constituents of Sperata sarwari, n = 80 in each case Body constituents (%) Mean ± S.D. Range Water contents 76.05 ± 3.20 69.57-82.43 Ash contents (wet weight) 4.17 ± 1.58 2.68-6.29 Ash contents (dry weight) 17.53 ± 4.24 10.99-25.00 Fat contents (wet weight) 4.11 ± 1.19 1.16-8.22 Fat contents (dry weight) 17.06 ± 2.12 5.00-28.99 Protein contents (wet weight) 15.67 ± 0.44 10.19-19.93 Protein contents (dry weight) 65.41 ± 6.37 54.00-75.00 Ash free matter (wet weight) 19.78 ± 1.63 13.53-25.56 Ash free matter (dry weight) 82.48 ± 4.24 75.00-89.00 Fat free matter (wet weight) 19.84 ± 2.01 14.24-24.26 Fat free matter (dry weight) 82.94 ± 2.12 71.00-95.00 Protein free matter (wet weight) 8.28 ± 2.77 5.78-13.08 Protein free matter (dry weight) 34.59 ± 6.37 25.00-46.00 S.D = Standard Deviation

CHAPTER NO.2 24 BODY COMPOSITION

%Fat , %As h, 4.16 3.33

%Pr ote in , 15.69

%Wate r , 76.08

Figure 2.1: Various body constituents in wet mass of Wallago attu

%As h, 14.5

%Fat, 17.86

%Protein, 67.64

Figure 2.2: Various body constituents in dry mass of Wallago attu

CHAPTER NO.2 25 BODY COMPOSITION

AFM, 19.85

FFM, 19.02

Water, 76.08 PFM, 7.49

Figure 2.3: Various body constituents in wet mass of Wallago attu

PFM, 32.36

AFM, 85.5

FFM, 82.14

Figure 2.4: Various body constituents in dry mass of Wallago attu

CHAPTER NO.2 26 BODY COMPOSITION

Ash Fat 4.17% 4.11%

Protein 15.67%

Water 76.05%

Figure 2.5: Various body constituents in wet mass of Sperata sarwari

Ash 17.52%

Fat 17.06%

Protein 65.42%

Figure 2.6: Various body constituents in dry mass of Sperata sarwari

CHAPTER NO.2 27 BODY COMPOSITION

AFM, 19.78

FFM , 19.84

Water 76.05 PFM, 8.28

Figure 2.7: Various body constituents in wet mass of Sperata sarwari.

PFM, 34.59

AFM, 82.48

FFM , 82.94

Figure 2.8: Various body constituents in dry mass of Sperata sarwari

CHAPTER NO.2 28 BODY COMPOSITION

Table 2.3: Wet body weight (g) versus body constituents of Wallago attu Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case. Body constituents r a b S.E. (b) t value when b = 0 Total water contents (g) 0.999*** 0.628 0.757 0.004 180.24 Total ash contents (g) 0.986*** -0.174 0.035 0.001 50.00 Total fat contents (g) 0.956*** -0.389 0.047 0.002 29.375 Total protein contents (g) 0.980*** -0.066 0.161 0.004 42.395 Total ash free matter (g) 0.984*** -0.455 0.208 0.004 48.395 Total fat free matter (g) 0.986*** -0.240 0.196 0.004 51.553 Total protein free matter (g) 0.985*** -0.563 0.082 0.002 48.118 Significance level: ***P<0.001

Table 2.4: Wet body weight (g) versus body constituents of Sperata sarwari Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case. Body constituents r a b S.E. (b) t value when b = 0 Total water contents (g) 0.996*** 0.570 0.758 0.008 94.75 Total ash contents (g) 0.954*** -0.019 0.042 0.001 42.00 Total fat contents (g) 0.815*** -1.997 0.054 0.004 13.50 Total protein contents (g) 0.948*** 1.446 0.146 0.006 24.33 Total ash free matter (g) 0.947*** -0.551 0.199 0.008 24.87 Total fat free matter (g) 0.963*** 1.427 0.188 0.006 31.33 Total protein free matter (g) 0.910*** -2.016 0.096 0.005 19.20 Significance level: ***P<0.001

CHAPTER NO.2 29 BODY COMPOSITION

Table 2.5: Wet body weight (g) versus body constituents of Wallago attu Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case. Body constituents (%) r a b S.E. (b) t value when b = 0 Water contents 0.010 76.112 -0.0001 0.002 -0.05 Ash contents (wet weight) 0.120 3.224 0.001 0.0003 1.667 Ash contents (dry weight) 0.123 14.850 -0.002 0.002 -1.063 Fat contents (wet weight) 0.448*** 3.570 0.003 0.001 4.143 Fat contents (dry weight) 0.346*** 16.301 0.008 0.002 3.167 Protein contents (wet weight) 0.265** 15.035 0.003 0.001 2.462 Protein contents (dry weight) 0.245* 68.844 -0.006 0.003 -2.148 Ash free matter (wet weight) 0.402*** 18.606 0.006 0.002 3.75 Ash free matter (dry weight) 0.124 85.146 0.002 0.002 1.063 Fat free matter (wet weight) 0.311** 18.259 0.004 0.001 2.846 Fat free matter (dry weight) 0.346*** 83.699 -0.008 0.002 -3.167 Protein free matter (wet weight) 0.491*** 6.794 0.003 0.001 4.857 Protein free matter (dry weight) 0.245* 31.156 0.006 0.003 2.148 Significance level: *P<0.05, **P<0.01, ***P <0.001

Table 2.6: Wet body weight (g) versus body constituents of Sperata sarwari Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case. Body constituents (%) r a b S.E. (b) t value when b = 0 Water contents 0.130 75.337 0.004 0.004 1.00 Ash contents (wet weight) 0.101 4.301 -0.001 0.001 -1.00 Ash contents (dry weight) 0.011 17.465 0.0003 0.004 0.075 Fat contents (wet weight) 0.267** 3.277 0.005 0.002 2.500 Fat contents (dry weight) 0.336** 13.280 0.022 0.007 3.143 Protein contents (wet weight) 0.319** 17.083 -0.008 0.003 -2.667 Protein contents (dry weight) 0.338** 69.255 -0.022 0.007 -3.143 Ash free matter (wet weight) 0.110 20.360 -0.003 0.003 -1.00 Ash free matter (dry weight) 0.011 82.535 -0.0004 0.004 -0.100 Fat free matter (wet weight) 0.330** 21.384 -0.009 0.003 -3.00 Fat free matter (dry weight) 0.336** 86.719 -0.022 0.007 -3.143 Protein free matter (wet weight) 0.209 7.579 0.004 0.002 2.00 Protein free matter (dry weight) 0.338** 30.745 0.022 0.007 3.143 Significance level: **P<0.01

CHAPTER NO.2 30 BODY COMPOSITION

Table 2.7: Log wet body weight (g) versus body constituents of Wallago attu Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case. Body constituents r a b S.E. (b) t value when b = 1 Log water contents (g) 0.999*** -0.077 0.982 0.003 -5.625 Log ash contents (g) 0.991*** -1.543 1.029 0.016 1.835 Log fat contents (g) 0.982*** -1.697 1.141 0.024 5.802 Log protein contents (g) 0.994*** -0.894 1.040 0.014 2.920 Log ash free matter (g) 0.995*** -0.839 1.062 0.012 5.202 Log fat free matter (g) 0.996*** -0.806 1.039 0.011 3.550 Log protein free matter (g) 0.994*** -1.325 1.091 0.014 6.565 Significance level: ***P<0.001

Table 2.8: Log wet body weight (g) versus body constituents of Sperata sarwari Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case. Body constituents r a b S.E. (b) t value when b = 1 Log water contents (g) 0.998*** -0.145 1.012 0.008 1.500 Log ash contents (g) 0.960*** -1.305 0.965 0.032 -1.094 Log fat contents (g) 0.841*** -1.791 1.174 0.086 2.023 Log protein contents (g) 0.961*** -0.588 0.900 0.029 -3.448 Log ash free matter (g) 0.969*** -0.610 0.956 0.028 -1.571 Log fat free matter (g) 0.974*** -0.515 0.914 0.024 -3.583 Log protein free matter (g) 0.948*** -1.224 1.062 0.041 1.512 Significance level: ***P<0.001

CHAPTER NO.2 31 BODY COMPOSITION

Table 2.9: Total length (cm) versus body constituents of Wallago attu Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case. Body constituents r a b S.E. (b) t value when b = 0 Total water contents (g) 0.941*** -265.32 12.774 0.525 24.336 Total ash contents (g) 0.928*** -12.383 0.587 0.027 21.822 Total fat contents (g) 0.909*** -17.132 0.800 0.042 19.002 Total protein contents (g) 0.939*** -58.219 2.766 0.116 23.883 Total ash free matter (g) 0.942*** -75.352 3.566 0.146 24.458 Total fat free matter (g) 0.943*** -70.602 3.352 0.136 24.614 Total protein free matter (g) 0.933*** -29.515 1.387 0.062 22.573 Significance level: ***P<0.001

Table 2.10: Total length (cm) versus body constituents of Sperata sarwari Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case. Body constituents r a b S.E. (b) t value when b = 0 Total water contents (g) 0.942*** -273.767 12.259 0.494 24.816 Total ash contents (g) 0.874*** -14.365 0.651 0.041 15.878 Total fat contents (g) 0.661*** -17.358 0.746 0.096 7.771 Total protein contents (g) 0.876*** -49.493 2.304 0.144 16.00 Total ash free matter (g) 0.846*** -66.851 3.050 0.218 13.991 Total fat free matter (g) 0.888*** -63.858 2.955 0.174 16.983 Total protein free matter (g) 0.780*** -31.723 1.398 0.127 11.008 Significance level: ***P<0.001

CHAPTER NO.2 32 BODY COMPOSITION

Table 2.11: Total length (cm) versus body constituents of Wallago attu Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case. Body constituents (%) r a b S.E. (b) t value when b = 0 Water contents 0.026 75.877 0.006 0.028 0.214 Ash contents (wet weight) 0.215* 2.999 0.010 0.005 2.00 Ash contents (dry weight) 0.162 15.832 -0.040 0.028 -1.433 Fat contents (wet weight) 0.506*** 2.248 0.058 0.011 5.124 Fat contents (dry weight) 0.370*** 13.067 0.145 0.042 3.474 Protein contents (wet weight) 0.339** 13.280 0.073 0.023 3.147 Protein contents (dry weight) 0.245* 71.089 -0.104 0.048 -2.198 Ash free matter (wet weight) 0.486*** 15.528 0.131 0.027 4.850 Ash free matter (dry weight) 0.164 84.156 0.041 0.028 1.448 Fat free matter (wet weight) 0.390*** 16.279 0.083 0.023 3.689 Fat free matter (dry weight) 0.370*** 86.933 -0.145 0.042 -3.474 Protein free matter (wet weight) 0.550*** 5.247 0.068 0.012 5.754 Protein free matter (dry weight) 0.245* 28.911 0.105 0.048 2.20 Significance level: *P<0.05, **P<0.01, ***P<0.001

Table 2.12: Total length (cm) versus body constituents of Sperata sarwari Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case. Body constituents (%) r a b S.E. (b) t value when b = 0 Water contents 0.230* 71.929 0.124 0.060 2.067 Ash contents (wet weight) 0.122 4.676 -0.015 0.014 -1.071 Ash contents (dry weight) 0.057 16.466 0.032 0.064 0.500 Fat contents (wet weight) 0.115 2.942 0.035 0.034 1.029 Fat contents (dry weight) 0.208 9.430 0.231 0.123 1.878 Protein contents (wet weight) 0.331** 20.449 -0.144 0.047 -3.064 Protein contents (dry weight) 0.234* 74.105 -0.263 0.123 -2.138 Ash free matter (wet weight) 0.209 23.392 -0.109 0.058 -1.879 Ash free matter (dry weight) 0.057 83.534 -0.032 0.064 -0.500 Fat free matter (wet weight) 0.347*** 25.126 -0.159 0.049 -3.245 Fat free matter (dry weight) 0.208 90.570 -0.231 0.123 -1.878 Protein free matter (wet weight) 0.060 7.618 0.020 0.037 0.541 Protein free matter (dry weight) 0.234* 25.895 0.263 0.123 2.138 Significance level: *P<0.05, **P<0.01, ***P<0.001

CHAPTER NO.2 33 BODY COMPOSITION

Table 2.13: Log total length (cm) versus body constituents of Wallago attu Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case. Body constituents r a b S.E. (b) t value when b = 3 Log water contents (g) 0.992*** -2.793 3.216 0.047 4.596 Log ash contents (g) 0.985*** -4.395 3.373 0.068 5.510 Log fat contents (g) 0.972*** -4.829 3.720 0.104 6.923 Log protein contents (g) 0.988*** -3.782 3.413 0.061 6.759 Log ash free matter (g) 0.988*** -3.779 3.479 0.061 7.805 Log fat free matter (g) 0.990*** -3.688 3.407 0.055 7.385 Log protein free matter (g) 0.985*** -4.332 3.565 0.072 7.843 Significance level: ***P<0.001

Table 2.14: Log total length (cm) versus body constituents of Sperata sarwari Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case. Body constituents r a b S.E. (b) t value when b = 3 Log water contents (g) 0.966*** -2.966 3.329 0.101 3.257 Log ash contents (g) 0.925*** -3.971 3.159 0.147 1.082 Log fat contents (g) 0.744*** -4.564 3.532 0.359 1.482 Log protein contents (g) 0.931*** -3.101 2.964 0.132 -0.273 Log ash free matter (g) 0.919*** -3.182 3.084 0.150 0.560 Log fat free matter (g) 0.943*** -3.063 3.007 0.120 0.058 Log protein free matter (g) 0.876*** -3.947 3.338 0.208 1.625 Significance level: ***P<0.001

CHAPTER NO.2 34 BODY COMPOSITION

Table 2.15: %Water contents versus body constituents of Wallago attu Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case. Body constituents (%) r a b S.E. (b) t value when b = 0 Ash contents (wet weight) 0.019 3.045 0.004 0.022 0.182 Ash contents (dry weight) 0.144 3.108 0.149 0.118 1.263 Fat contents (wet weight) 0.066 6.548 -0.031 0.055 -0.564 Fat contents (dry weight) 0.067 9.554 0.109 0.187 0.583 Protein contents (wet weight) 0.283** 35.022 -0.254 0.099 -2.566 Protein contents (dry weight) 0.144 87.182 -0.257 0.202 -1.272 Ash free matter (wet weight) 0.254 41.549 -0.285 0.124 -2.298 Ash free matter (dry weight) 0.144 96.852 -0.149 0.118 -1.263 Fat free matter (wet weight) 0.282** 38.047 -0.250 0.098 -2.551 Fat free matter (dry weight) 0.066 90.332 -0.108 0.187 -0.578 Protein free matter (wet weight) 0.054 9.595 -0.028 0.059 -0.475 Protein free matter (dry weight) 0.144 12.825 0.257 0.202 1.272 Significance level: **P<0.01

Table 2.16: %Water contents versus body constituents of Sperata sarwari Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case. Body constituents (%) r a b S.E. (b) t value when b = 0 Ash contents (wet weight) 0.274** 8.961 -0.063 0.025 -2.520 Ash contents (dry weight) 0.455*** -18.417 0.473 0.105 4.505 Fat contents (wet weight) 0.529*** 26.830 -0.299 0.054 -5.537 Fat contents (dry weight) 0.196 47.674 -0.403 0.227 -1.775 Protein contents (wet weight) 0.792*** 64.224 -0.638 0.056 -11.393 Protein contents (dry weight) 0.034 70.744 -0.070 0.234 -0.299 Ash free matter (wet weight) 0.973*** 91.056 -0.937 0.025 -37.48 Ash free matter (dry weight) 0.455*** 118.417 -0.473 0.105 -4.505 Fat free matter (wet weight) 0.826*** 73.186 -0.701 0.054 -12.981 Fat free matter (dry weight) 0.196 52.326 0.403 0.227 1.775 Protein free matter (wet weight) 0.592*** 35.793 -0.362 0.056 -6.464 Protein free matter (dry weight) 0.034 29.256 0.070 0.234 -0.299 Significance level: **P<0.01, ***P<0.001,

CHAPTER NO.2 35 BODY COMPOSITION

Table 2.17: Condition factor (K) versus body constituents of Wallago attu Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case. Body constituents (%) r a b S.E. (b) t value when b = 0 Water contents 0.009 74.601 1.189 15.424 0.077 Ash contents (wet weight) 0.108 3.027 0.679 0.720 0.943 Ash contents (dry weight) 0.101 16.025 -3.416 3.850 -0.887 Fat contents (wet weight) 0.434*** 1.146 6.743 1.605 4.203 Fat contents (dry weight) 0.412*** 8.082 21.880 5.558 3.937 Protein contents (wet weight) 0.117 14.166 3.410 3.324 1.026 Protein contents (dry weight) 0.318** 75.878 -18.430 6.292 -2.929 Ash free matter (wet weight) 0.278** 15.312 10.152 4.022 2.524 Ash free matter (dry weight) 0.103 83.955 3.456 3.847 0.898 Fat free matter (wet weight) 0.142 17.193 4.089 3.277 1.248 Fat free matter (dry weight) 0.412*** 91.922 -21.886 5.560 -3.936 Protein free matter (wet weight) 0.443*** 4.174 7.422 1.721 4.312 Protein free matter (dry weight) 0.319** 24.122 18.430 6.292 2.929 Significance level: **P<0.01, ***P<0.001

Table 2.18: Condition factor (K) versus body constituents of Sperata sarwari Statistical parameters of various relationships, correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case. Body constituents (%) r a b S.E. (b) t value when b = 0 Water contents 0.089 77.652 -3.544 4.489 -0.789 Ash contents (wet weight) 0.065 4.444 -0.598 1.034 -0.578 Ash contents (dry weight) 0.112 19.621 -4.637 4.655 -0.996 Fat contents (wet weight) 0.516*** -1.143 11.614 2.181 5.325 Fat contents (dry weight) 0.546*** -3.060 44.519 7.735 5.756 Protein contents (wet weight) 0.233* 19.046 -7.469 3.534 -2.113 Protein contents (dry weight) 0.484*** 83.439 -39.883 8.163 -4.886 Ash free matter (wet weight) 0.108 17.902 4.144 4.315 0.960 Ash free matter (dry weight) 0.112 80.379 4.637 4.655 0.996 Fat free matter (wet weight) 0.239* 23.490 -8.069 3.718 -2.170 Fat free matter (dry weight) 0.546*** 103.060 -44.519 7.735 -5.756 Protein free matter (wet weight) 0.453*** 3.301 11.015 2.456 4.485 Protein free matter (dry weight) 0.484*** 16.561 39.883 8.163 4.886 Significance level: **P<0.05, ***P<0.001,

CHAPTER NO.2 36 BODY COMPOSITION

Table 2.19: ANOVA showing comparison of body composition of two different species of freshwater catfishes of southern Punjab.

Body constituents MS F P Water (%) 0.04 0.01 0.923N.S. Ash (%wet wt.) 28.088 128.07 0.000*** Ash (%dry wt.) 361.76 69.85 0.000*** Lipid (%wet wt.) 0.12 0.09 0.768N.S. Lipid (%dry wt.) 25.2 1.51 0.221N.S. Protein (%wet wt.) 0.02 0.00 0.946N.S. Protein (%dry wt.) 196.1 10.88 0.001*** Ash free matter (%wet wt.) 0.22 0.04 0.839N.S. Ash free matter (%dry wt.) 361.40 69.82 0.000*** Fat free matter (%wet wt.) 26.77 7.40 0.007** Fat free matter (%dry wt.) 25.1 1.50 0.222N.S. Protein free matter (%wet wt.) 24.61 15.91 0.000*** Protein free matter (%dry wt.) 196.1 10.88 0.001*** Condition factor 0.001 0.27 0.603N.S. Significance level: **P<0.007, ***P<0.001, N.S. = non-significant

CHAPTER NO.2 37 BODY COMPOSITION

Table 2.20: Mean values and ranges of various body constituents of ♂ and ♀ Wallago attu.

Body constituents (%) Male Female Mean ±S.D Ranges Mean ±S.D Ranges Water contents 76.19 ± 1.95 71.58-82.43 76.00 ± 2.33 69.57-80.17 Ash contents (wet weight) 3.36 ± 0.38 2.56-3.99 3.31 ± 0.45 2.17-3.99 Ash contents (dry weight) 14.66 ± 1.91 11.00-18.02 14.36 ± 2.48 9.00-18.01 Fat contents (wet weight) 4.03 ± 0.91 2.80-6.69 4.27 ± 1.12 2.53-6.38 Fat contents (dry weight) 17.39 ± 2.86 12.00-23.01 18.26 ± 3.98 11.00-25.00 Protein contents (wet weight) 15.69 ± 1.91 12.22-20.80 15.69 ± 1.97 11.89-21.56 Protein contents (dry weight) 67.95 ± 2.90 61.01-72.97 67.38 ± 4.49 57.00-75.99 Ash free matter (wet weight) 19.72 ± 2.47 16.50-26.77 19.96 ± 2.38 16.61-25.98 Ash free matter (dry weight) 85.34 ± 1.91 81.98-89.00 85.64 ± 2.48 81.99-91.00 Fat free matter (wet weight) 19.05 ± 2.00 15.42-23.73 19.00 ± 1.85 15.64-24.40 Fat free matter (dry weight) 82.61 ± 2.86 76.99-88.00 81.74 ± 3.98 75.00-89.00 Protein free matter (wet 7.39 ± 0.98 5.99-10.34 7.58 ± 1.20 5.84-10.37 weight) Protein free matter (dry 32.05 ± 2.90 27.03-38.99 32.62 ± 4.49 24.01-43.00 weight) S.D = Standard deviation

CHAPTER NO.2 38 BODY COMPOSITION

Table 2.21: Mean values and ranges of various body constituents of ♂ and ♀ Sperata sarwari.

Body constituents (%) Male Female Mean ±S.D Ranges Mean ±S.D Ranges Water contents 76.19 ± 2.21 69.57-82.43 75.82 ± 2.30 70.88-80.17 Ash contents (wet weight) 4.10 ± 0.48 2.68-4.94 4.30 ± 0.54 3.38-6.29 Ash contents (dry weight) 17.32 ± 2.30 11.00-23.00 17.87 ± 2.36 13.00-25.00 Fat contents (wet weight) 3.98 ± 1.21 1.16-8.22 4.32 ± 1.34 1.60-8.14 Fat contents (dry weight) 16.60 ± 4.25 5.00-27.00 17.83 ± 5.05 7.00-29.00 Protein contents (wet weight) 15.73 ± 1.71 10.19-19.93 15.56 ± 1.97 11.10-19.21 Protein contents (dry weight) 66.08 ± 4.24 57.00-75.00 64.30 ± 5.09 54.00-74.00 Ash free matter (wet weight) 19.71 ± 2.13 13.53-25.56 19.89 ± 2.21 16.06-24.46 Ash free matter (dry weight) 82.68 ± 2.30 77.00-89.00 82.13 ± 2.36 75.00-87.00 Fat free matter (wet weight) 19.83 ± 1.79 14.23-24.26 19.86 ± 2.09 14.87-23.59 Fat free matter (dry weight) 83.40 ± 4.25 73.00-95.00 82.17 ± 5.05 71.00-93.00 Protein free matter (wet 8.08 ± 1.30 5.78-13.08 8.62 ± 1.42 5.96-12.90 weight) Protein free matter (dry 33.92 ± 4.24 25.00-43.00 35.70 ± 5.09 26.00-46.00 weight) S.D = Standard deviation

CHAPTER NO.2 39 BODY COMPOSITION

Table 2.22: Seasonal variations in the percentage of the proximate composition of Wallago attu.

Months Water (%) Protein (%) Fat (%) Ash (%) January 76.05 15.85 4.81 3.20 February 76.15 15.61 4.75 3.44 March 76.54 14.19 3.96 3.71 April 78.12 14.37 3.69 3.69 May 78.28 14.58 3.18 3.63 August 75.85 16.81 3.53 3.69 November 75.95 16.42 3.84 3.50 December 75.28 16.29 4.1 3.21

Table 2.23: Seasonal variations in the percentage of the proximate composition of Sperata sarwari.

Months Water (%) Protein (%) Fat (%) Ash (%) February 75.44 15.41 5.05 4.10 March 76.69 15.70 3.47 4.14 April 76.95 15.73 3.40 3.92 May 77.09 14.76 4.14 4.02 August 76.89 16.16 2.68 4.27 September 76.65 16.45 2.53 4.38 October 75.48 15.85 4.16 4.51 November 73.80 16.87 5.06 4.28 December 73.76 17.11 4.73 4.40

CHAPTER NO.2 40 BODY COMPOSITION

520 22.0

390 16.5

260 11.0

130 5.5 Total ash content(g) Total water content (g) content water Total

0 0.0 0 165 330 495 660 0 165 330 495 660 Wet body weight (g) Wet body weight (g)

(a) (b)

100 30.0

22.5 75

15.0 50

Total fat content (g) content fat Total 7.5

(g) content protein Total

0.0 0 0 165 330 495 660 0 165 330 495 660

Wet body weight (g) Wet body weight (g)

Figure 2.9: The relationships between wet body weight and (a) Total water contents (b) Total ash contents (c) Total fat contents (d) Total protein contents in wild Wallago attu.

CHAPTER NO.2 41 BODY COMPOSITION

140 128

105 96

70 64

35 32 Total fat free matter (g) matter free fat Total (g) matter free ash Total

0 0 0 165 330 495 660 0 165 330 495 660 Wet body weight (g) Wet body weight (g)

(a) (b)

2.80 52

2.35 39

1.90 26

1.45 13

Log content (g) water

(g) matter free protein Total 1.00 0 1.10 1.55 2.00 2.45 2.90 0 165 330 495 660 Wet body weight (g) Log wet body weight (g)

Figure 2.10: The relationships between wet body weight and (a) Total ash free matter (b) Total fat free matter (c) Total protein free matter (d) log wet body weight and log water content in wild Wallago attu.

CHAPTER NO.2 42 BODY COMPOSITION

1.40 1.5

0.95 1.0

0.50 0.5

0.05 (g) content fat Log 0.0 Log ashcontent (g)

-0.40 -0.5 1.1 1.6 2.0 2.5 2.9 1.1 1.6 2.0 2.5 2.9 Log wet body weight (g) Log wet body weight (g)

(a) (b)

2.10 2.10

1.65 1.65

1.20 1.20

0.75 0.75

Log protein content (g) content Logprotein

Logmatter (g) ashtotal free 0.30 0.30 1.10 1.55 2.00 2.45 2.90 1.1 1.6 2.0 2.5 2.9 Log wet body weight (g) Log wet body weight (g)

Figure 2.11: The relationships between log wet body weight and (a) log ash content (b) log fat content (c) log protein content (d) log ash free matter in wild Wallago attu.

CHAPTER NO.2 43 BODY COMPOSITION

2.10 1.70

1.65 1.25

1.20 0.80

0.75 0.35

Log protein free matter (g) matter free Log protein Log total fat free matter (g) matter Log free fat total 0.30 -0.10 1.10 1.55 2.00 2.45 2.90 1.10 1.55 2.00 2.45 2.90

Log wet body weight (g) Log wet body weight (g)

(a) (b)

Figure 2.12: The relationships between log wet body weight and (a) log fat free matter (b) log protein free matter in wild Wallago attu.

500 22.0

16.5 375

250 11.0

125 5.5 Total ash content (g)

(g) content water Total

0 0.0 15.00 23.75 32.50 41.25 50.00 15.00 23.75 32.50 41.25 50.00 Total length (cm) Total length (cm)

Figure 2.13: The relationships between total length and (a) Total water contents (b) Total ash contents in wild Wallago attu.

CHAPTER NO.2 44 BODY COMPOSITION

100 28 75 21

50 14

7 25 Total fat content (g) content fat Total

(g) content protein Total

0 0 15.00 23.75 32.50 41.25 50.00 15.00 23.75 32.50 41.25 50.00

Total length (cm) Total length (cm)

(a) (b)

128 128

96 96

64 64

32 32

Total fat free matter (g) matter free fat Total (g) matter free ash Total 0 0 15 24 33 42 51 15 24 33 42 51 Total length (cm) Total length (cm)

Figure 2.14: The relationships between total length and (a) Total fat content (b) Total protein content (c) Total ash free matter (d) total fat free matter in wild Wallago attu.

CHAPTER NO.2 45 BODY COMPOSITION

2.80 52

2.35 39

1.90 26

13 1.45

(g) content Log water (g) matte free protein Total 0 1.00 15 24 33 42 51 1.20 1.33 1.46 1.59 1.72 Total length (cm) Log total length (cm)

(a) (b)

1.40 1.5

0.95 1.0

0.50 0.5

0.05

Log fat content (g) content Log fat 0.0 Log ash content (g) content ash Log

-0.40 -0.5 1.20 1.33 1.46 1.59 1.72 1.20 1.33 1.46 1.59 1.72 Log total length (cm) Log total length (cm)

Figure 2.15: (a) The relationships between total length and Total protein free matter, and log total length and (b) log water content (c) log ash content (d) log fat content in wild Wallago attu.

CHAPTER NO.2 46 BODY COMPOSITION

2.1 2.10

1.7 1.65

1.2 1.20

0.8 0.75

(g) content Log protein

(g) matter free ash Log total 0.3 0.30 1.2 1.3 1.5 1.6 1.7 1.20 1.33 1.46 1.59 1.72 Log total length (cm) Log total length (cm)

(a) (b)

2.10 1.70

1.25 1.65

1.20 0.80

0.75 0.35

Log total fat free matter (g) matter free fat Log total 0.30 (g) matter free protein Log total -0.10 1.20 1.33 1.46 1.59 1.72 1.20 1.33 1.46 1.59 1.72 Log total length (cm) Log total length (cm)

Figure 2.16: The relationships between log total length and (a) log protein content (b) log ash free matter (c) log fat free matter (d) log protein free matter in wild Wallago attu.

CHAPTER NO.2 47 BODY COMPOSITION

310 21.1

240 16.3

170 11.5

100 6.7

Total ash content (g) (g) content water Total 30 1.9 40 140 240 340 440 40 140 240 340 440 Wet body weight (g) Wet body weight (g)

(a) (b)

77 36

27 59

18 41

(g) content fat Total 9 23 (g) content protein Total 0 5 40 140 240 340 440 40 140 240 340 440 Wet body w eight (g) Wet body weight (g)

Figure 2.17: The relationships between wet body weight and (a) Total water contents (b) Total ash contents (c) Total fat contents (d) Total protein contents in wild Sperata sarwari.

CHAPTER NO.2 48 BODY COMPOSITION

113 97

86 74

59 51

32 28 Total fat free matter (g) matter free fat Total Total ash free matter (g)

5 5 40 140 240 340 440 40 240 440

Wet body weight (g) Wet body weight (g)

(a) (b)

60 2.50

2.25 45

30 2.00

Log water content Log water 1.75 15

(g) matter free protein Total 1.50 0 1.65 1.90 2.15 2.40 2.65 40 240 440 Log wet body weight Wet body weight (g)

Figure 2.18: The relationships between wet body weight and (a) Total ash free matter (b) Total fat free matter (c) Total protein free matter (d) log wet body weight and log water content in wild Sperata sarwari.

CHAPTER NO.2 49 BODY COMPOSITION

1.50 1.30

1.05 1.10

0.80 0.70

(g) content fat Log 0.30

Log ash content (g) 0.55

0.30 -0.10 1.65 1.90 2.15 2.40 2.65 1.65 1.90 2.15 2.40 2.65

Log wet body weight (g) Log wet body weight (g)

(a) (b)

1.90 2.10

1.65 1.80

1.40 1.50

1.15 1.20 (g) content Log protien (g) matter free ash Log

0.90 0.90 1.65 1.90 2.15 2.40 2.65 1.65 1.90 2.15 2.40 2.65

Log wet body weight (g) Log wet body weight (g)

Figure 2.19: The relationships between log wet body weight and (a) log ash content (b) log fat content (c) log protein content (d) log ash free matter in wild Sperata sarwari.

CHAPTER NO.2 50 BODY COMPOSITION

1.95 1.75

1.50 1.70 1.25 1.45 1.00

1.20

(g) matter free fat Log 0.75

(g) matter free protein Log

0.95 0.50 1.65 1.90 2.15 2.40 2.65 1.65 1.85 2.05 2.25 2.45 2.65

Log wet body weight (g) Log wet body weight (g)

(a) (b)

Figure 2.20: The relationships between log wet body weight and (a) log fat free matter (b) log protein free matter in wild Sperata sarwari.

310 21.10

240 16.30

170 11.50

100 6.70 Total ash content (g) (g) content water Total

30 1.90 23 28 33 38 43 23 28 33 38 43 Total length (cm) Total length (cm)

Figure 2.21: The relationships between total length and (a) Total water contents (b) Total ash contents in wild Sperata sarwari.

CHAPTER NO.2 51 BODY COMPOSITION

77 36

27 59

41 18

(g) content fat Total 9 23

(g) content protein Total

0 5 23 28 33 38 43 23 28 33 38 43 Total length (cm) Total length (cm)

(b) (b)

113 97

86 74

59 51

32 28

(g) matter free fat Total (g) matter free ash Total 5 5 23 28 33 38 43 23 28 33 38 43 Total length (cm) Total length (cm)

Figure 2.22: The relationships between total length and (a) Total fat content (b) Total protein content (c) Total ash free matter (d) total fat free matter in wild Sperata sarwari.

CHAPTER NO.2 52 BODY COMPOSITION

60 2.50

45 2.25

30 2.00

15 1.75

(g) content water Log

(g) matter free Protein Total 0 1.50 23 28 33 38 43 1.36 1.43 1.50 1.57 1.64 Total length (cm) Log total length (cm)

(a) (b)

1.50 1.30

1.05 1.10

0.70 0.80

Log fat content (g) content fat Log Log ash content (g) content Log ash 0.55 0.30

0.30 -0.10 1.36 1.43 1.50 1.57 1.64 1.36 1.43 1.50 1.57 1.64

Log total length (cm) Log total length (cm)

Figure 2.23: (a) The relationships between total length and Total protein free matter, and log total length and (b) log water content (c) log ash content (d) log fat content in wild Sperata sarwari.

CHAPTER NO.2 53 BODY COMPOSITION

1.90 2.10

1.65 1.80

1.40 1.50

1.15 1.20

Log ash free matter (g) Log protein content (g) content Log protein

0.90 0.90 1.36 1.43 1.50 1.57 1.64 1.36 1.43 1.50 1.57 1.64 Log total length (cm) Log total length (cm)

(a) (b)

1.95 1.75

1.50 1.70

1.25 1.45 1.00

1.20 (g) matter free fat Log 0.75 (g) matter free protein Log 0.50 0.95 1.36 1.43 1.50 1.57 1.64 1.36 1.43 1.50 1.57 1.64 Log total length (cm) Log total length (cm)

Figure 2.24: The relationships between log total length and (a) log protein content (b) log ash free matter (c) log fat free matter (d) log protein free matter in wild Sperata sarwari.

CHAPTER NO.2 54 BODY COMPOSITION

Figure 2.25: Effect of season on the percentages of the body constituents in Wallago attu.

CHAPTER NO.2 55 BODY COMPOSITION

Figure 2.26: Effect of season on the percentages of the body constituents in Sperata sarwari.

CHAPTER NO.2 56 BODY COMPOSITION

2.4 DISCUSSION

Data on water, ash, fat and protein content, expressed in grams (g), have approximately similar values to those reported by other investigator for other fish species (Table.1.24 - 1.27).

2.4.1 Water content: The major component of fish body was water. The water content was recorded as 76.19% in male and 76.00% in female Wallago attu, while in case of Sperata sarwari 76.19% in male and 75.82% in female (Table 1). This result coincided with the findings of Mazumder et al. (2008) in A. mola 76.38%, Kamal et al. (2007) in Nandas nandas 75.75%, Clarias batrachus 76.06%, Osibona et al. (2009) in Clarias gariepinus (74.3%). This finding also agreed with observation of Marais and Erasmus (1977) in several freshwater fish species. But this result deviated from the findings of Scherer et al. (2006) in Ctenopharyngodon idella (77.34%), Orban et al. (2007) in Perca fluviatilis (80.28%) and Osibona et al. (2009) in Tilapia zillii (80.4%). The percent water and its relationships with other body components (fat, protein, and ash) is used as predictors of fish body composition. It can be determined in most laboratories and biological stations without the time, expense and expertise needed for traditional proximate analysis (Hartman and Margraf, 2008). “Crossin and Hinch (2005) presented microwave approaches to estimate water content in fishes. The negative correlation between water and fat content in fish may provide a quick and cost-effective index to relative energy content by measuring water content (Hislop et al., 1991). In the present study, there was inverse correlation between percent water content and percent protein and percent fat contents (table 2.15 & 2.16). Similar inverse relationship between percent fat and percent protein with percent water have been observed in whole fish by various investigators (Stirling, 1976; Elliott, 1976; Marais and Erasmus, 1977; Marais and Kissil, 1979; Salam and Janjua, 1991; Shearer, 1994; Osibona et al., 2009). As many researchers have developed predictive equations, it was concluded from the present study that the body composition of fish could be analyzed from water contents using regression

equations.” CHAPTER NO.2 57 BODY COMPOSITION

In Wallago attu and Sperata sarwari, there was no significant correlation between body size and percent water content. Although a little bit positive trend line is seen between body size and percent water content in Sperata sarwari. Many scientists have developed predictive equations and it was concluded that the body composition of fish could be analyzed with high degree of accuracy from water contents using regression equations.

2.4.2 Ash content: Ash represents a small proportion of fish composition. In Wallago attu the value of ash was observed 3.36%, 3.31% in male and female respectively with pooled value of 3.33%. In case of Sperata sarwari it was 4.10%, 4.30% in male and female respectively with pooled value of 4.17% (Table). The values of ash in above mentioned species deviated from the findings of Scherer et al. (2006) in Ctenopharyngodon idella (1.22%), Orban et al. (2007) in Perca fluviatilis (1.21%), Osibona et al. (2009) in Clarias gariepinus (1.2%), Tilapia zillii (1.2%). But this result coincided with the observations of Ali et al. (2001) in Channa punctata (4.26%), Kamal et al. (2007) in Clarias batrachus (3.74%), Heteropneustes fossilis (3.15%) and Anabas testudineus (3.31%).

In the present study, it was found that body size (wet body weight and total length) had positive influence on percent ash content in Wallago attu. While in case of Sperata sarwari, there was found negative trend line between body size (wet body weight and total length) and percent ash content. This result is in general agreement with the findings of O’ Connor et al., (1981) who found both increasing and decreasing trends in ash content as body weight increased (Gunther et al., 2005). 2.4.3 Fat Content: Tables 2.1 and 2.2 show the fat contents in two different species of catfishes. The fat content (wet weight) was estimated as 4.03% in male and 4.27% in female Wallago attu, while in case of Sperata sarwari 3.98% in male and 4.32% in female was found. The highest value of fat content was recorded in female Sperata sarwari (4.32%) and the lowest was in male Sperata sarwari (3.98%). Hossain et al. (1999) reported the fat contents of some selected fishes ranged from 1.87 to 9.55%. Gunther et al. (2005) also reported 4% ash in freshwater Salvelinus namaycush, the findings of the present study CHAPTER NO.2 58 BODY COMPOSITION

were with in the range. The fat contents recorded in these catfishes were higher from the result of Salam (2002) who estimated the highest fat content as 3.25 % in H. fossilis and Mazumder et al. (2008) in Puntius chola (3.05%), Ailia coila (3.53%), Pseudeutropius atherinoides (2.24%) and Chanda nama (1.53%). The proximate composition can be influenced by various factors like nutrition, age and gender but the major factor that affects the fat level is the reproduction period (Ergene, 2000; Samsun et al., 2005). Fishes with lipid content below 5% are considered lean (Stansby, 1982 and Ackman, 1989). Wallago attu and Sperata sarwari are thus, a good source of high protein and low lipid contents fishes. Lot of previous studies has identified relationships between water and fat compositions in vertebrates (Sinclair and Duncan, 1972; Love et al., 1974; Caulton and Bursell, 1977; Salam and Davies, 1994; Ali et al., 2005; Pangle and Sutton, 2005; Trudel et al., 2005). Iles & Wood (1965) reported a general ‘fat–water line’ relationship in herring Clupea harengus L. that they attributed to compensation by fish to maintain volume. Fishes are believed to gain water when in an energy deficit, and to replace water with fat. The present study found significant relationship between water content and per cent fat content. Here percent fat content had inverse relationship with percent water content (Figure). All these observations support that variations in the relative proportion of fats and water are the major changes in the body composition of Wallago attu and Sperata sarwari brought about by changes in the nutrient status of the fish. It was confirmed that the fat and water content was inversely dependent (Shearer, 1994; Salam et al., 2001). So it can be concluded water content measurement permits the estimation of flesh fat content for fat families of fishes. In both species of catfishes percent fat content had positive correlation with the wet body weight and total body length of fish. Because the fat content of whole body increases regularly with size and is associated with a decrease in water content as a general law for living organisms. Each species has a characteristic of maximum and minimum range of fatness and within a species the old fish generally accumulated relatively larger store (Peter, 1979). It is a direct consequence of the increasing potentialities for fat deposition with aging. Generally, if growth rate is stimulated at a given stage either in juvenile or in large commercial size fish, there is a simultaneous CHAPTER NO.2 59 BODY COMPOSITION

increase in the fat content of whole fish. “However, every stimulation of growth rate in response to different factors is generally associated with an increase in food uptake. Thus, the main factor that controls fat content is the diet (Fauconncau et al., 1995). This result is in general agreement with those found in some studies on rainbow trout and African freshwater food fishes (Reinitz, 1983; Degani, 1988 and Fagbenro et al., 2005). Kalay et al. (2008) also found that fat content increase with the growth rate of the fish. Variation in fat is largely due to proportion of lean and fat tissues with older animals having greater proportion than young ones (Degani, 1988).”

2.4.4 Protein content:

The protein content (wet weight) was estimated as 15.69 percent in both sex of Wallago attu, while in case of Sperata sarwari 15.73 percent in male and 15.56 percent in female with a pooled value 15.67 percent was found. The highest value was observed in male and lowest value recorded in female Sperata sarwari. It means that the studied fish are proteinous as Stansby (1976) classified protein content as high when it was greater than 15%. It indicates that the variation of protein contents among the studied fish is not so high. This result agrees coincides with the findings of Kamal et al. (2007) in

Mystus vittatus (15.62%) and of Mazumder et al. (2008) in Pseudeutropius atherinoides (15.84%). This result indicates that the protein contents in present species are lower than that of Clarias gariepinus (18.8%), Tilapia zillii (19.0%) by Osibona et al. (2009), Amblypharyngodon mola (18.46%), Chanda nama (18.26%) by Mazumder et al. (2008), Labeo rohita (18.49%), Catla catla (19.00%) by Ali et al. (2005). The protein contents of species found in the present study was also more or less similar to the result of Hossain et al. (1999). The variation found may be due to habitat, season, sex, and species specific.

Hartman and Margraf (2008) reported that there is significant relationship between water contents and protein contents in fishes. In Wallago attu and Sperata sarwari, there was highly negative correlation between percent water contents and percent protein contents (wet and dry weight). These results are in general agreement with that reported by other investigators (Love, 1970; Jobling, 1980; Salam and Davies, 1994 and Salam et al., 2001). Fishes gain water when in an energy deficit, and to replace water with fat when energy budgets exceed that needed for protein. It was found that CHAPTER NO.2 60 BODY COMPOSITION

whole water (%) decreased linearly and whole body protein and lipid (%) increased with ration size (Elliott, 1976). It is concluded that measuring water content permits the determination of flesh protein content for lean families of fishes. Many scientists have published the analysis of body composition of fish (Love,

1970, 1980; Weatherley and Gill, 1987). “But few have calculated the changes in body composition in relation to body size (Elloitt, 1976; Caulton and Bursell, 1977). In the present study, it was observed that total length and wet body weight of fish has positive influence on percent protein contents (wet weight) in case of Wallago attu but negative influence in Sperata sarwari. Fajmonova et al. (2003) and Kalay et al. (2008) also found that flesh of fish with a growth rate had a lower content of protein. Weatherley and Gill (1987) reported that the correlations of the protein contents with body weight were always very high, so that it was certainly reasonable to assume that estimates of body constituents against body weight would be reliable. They found that in Pimephales notatus, percent protein content tends to increase versus body weight but in trout beyond fingerling size percent protein tended to decrease with body weight. So McComish et al. (1974), Elliott (1976) and Weatherley and Gill (1983, 1984) found that length and wet

weight were so well correlated with body components similar to the present work.” 2.4.5 Effect of condition factor on body composition: “The selection of commonly consumed fish species is a first step toward identifying species of potential nutritional importance (Roos et al., 2007). Condition factor is considered to be one of the important factors influencing body composition in fish (Love, 1970; Groves, 1970; Caulton and Bursell, 1977; Salam and Davies, 1994).” This is also true for present study. In Wallago attu and Sperata sarwari highly significant correlation was found between condition factor and percent fat (wet and dry body weight), percent protein (dry body weight), percent fat free matter (dry body weight) and percent protein free matter (wet and dry body weight) but there is no significant relationship between condition factor and percent water content, percent ash content (wet and dry body weight) as in Table 2.17 & 2.18. The positive correlation between condition factor and percent protein content (dry weight) may be due to the fact that fast growing fishes put in new tissues in the form of muscles, which are largely proteins. While the CHAPTER NO.2 61 BODY COMPOSITION positive correlation between condition factor and percent fat content indicate that fat increases with increasing size of fish (Salam et al., 2001). Correlation between condition factor and percent body constituents may be significant or non-significant for different species. “The smallest fish had the quickest reconstruction of their energy store in spring, which can be expected on the basis of their smaller body size (Jobling, 1995), while larger fish increased their fat content continuously. In the present study percent fat content also showed highly positive correlation with condition factor. Caulton and Bursell (1977) reported that there is a linear decrease in water content, and exponential increase in fat content and a curvilinear increase in protein content in relation to increase of condition factor, while ash remains constant. They argue that care is needed when interpreting relationships between body constituents and condition factor.” 2.4.6 Effect of season on body composition: The present exploration also deals with proximate composition and seasonal variation of water, protein, fat and ash. It was also to understand the nutritive value and the fluctuation of the same in different season. Seasonal variation of water, protein, fat, and ash contents are indicated in Table 2.22 & 2.23 for Wallago attu and Sperata sarwari respectively. It was observed that the proportions of the components of body varied with the change of season. In both species the highest values of water were obtained in May that is the spawning time because at that time the fillets contained more water than any other time of the year. Such variation in composition might also be due to age and size differences. The finding is more or less similar to other fishes as well as vertebrates due to maturation of gonads (Dembergs, 1964; Suppes et al., 1967; Marais and Erasmus, 1977; Islam and Joadder, 2005; Nargis, 2006; Celik, 2008). In both species of catfishes (Wallago attu and Sperata sarwari) the over all fat and protein content decreased from March to June and increased from August to January. From these results it can be imagine that fat and protein content decreased in summer that may be due to spawning period because in this period water content increased. The fish also uses fats as energy sources in spring and that is why the fat content during spring was lower than that in the other seasons of the year (Kucukgulmez et al., 2008). Similar results were obtained on Anabas testudineus by Nargis (2006). However, in the case of CHAPTER NO.2 62 BODY COMPOSITION

protein and fat content, the variations were not significant but less variation of protein might be influenced by their feeding and breeding capabilities (Borgstrom, 1961 and Chakraborty et al., 1985). Stansby (1954) also investigated similar results in the trout that the highest value of muscle protein was observed immediately after spawning. Because after spawning the food that is consumed by the fish might have been used in the building up of the muscle instead of the germ cells in gonads. In the present study, there was no remarkable variation of ash as reported by Islam and Joadder (2005). The differences in season, depending on the availability of food at different time of the year, have a considerable effect on the tissue components particularly the fat (Ahmed et al., 1984). Medford and Mackay (1978) observed that percentage of fat and water of wet weight in muscle move to and fro considerably during the year. 2.4.7 Effect of sex on body composition: In the present study, effect of sex on proximate body composition is determined. There was no significant difference between male and female body components except for fat content. This result is in general agreement with the observation of Memid et al., (2006). However, the concentration of fat content is somewhat more in female than male in the present study (Table 2.20 & 2.21). 2.4.8 Conclusion: Although, the body composition of fish are closely related to nutrition, living area, fish size, catching season, seasonal, sexual variations and other environmental conditions but it is concluded that the body composition of Wallago attu and Sperata sarwari can be estimated directly from the weight or length of the fish using predictive regression model developed in this work with a high degree of accuracy.

CHAPTER NO.2 63 BODY COMPOSITION

Table 2.24

Water content values of various fish species

Species Water contents Sources

(% wet body

weight)

Oreochromis nilotica (male) 73.36 Javaid et al., 1992

Carassius auratus L. 78.49 Salam and Davies, 1997

Labeo rohita 72.81 Ali et al., 2005

Clarias gariepinus 76.71 Osibona et al., 2006

Ctenopharyngodon idella 77.34 Scherer et al., 2006

Clarias batrachus 76.06 Kamal et al., 2007

Nandas nandas 75.75 Kamal et al., 2007

Perca fluviatilis 80.28 Orban et al., 2007

Clarias anguillaris 80.95 Effiong and Mohammed, 2008

A. mola 76.38 Mazumder et al., 2008

Clarias gariepinus 74.3 Osibona et al., 2009

Tilapia zillii 80.4 Osibona et al., 2009

Wallago attu 76.08 Present study

Sperata sarwari 76.05 Present study CHAPTER NO.2 64 BODY COMPOSITION

Table 2.25

Ash content values of various fish species

Species Ash contents (% Sources

wet body weight)

Oreochromis nilotica (male) 4.83 Javaid et al., 1992

Labeo rohita 3.99 Ali et al., 2005

Clarias gariepinus 1.23 Osibona et al., 2006

Ctenopharyngodon idella 1.22 Scherer et al., 2006

Anabas testudineus 3.31 Kamal et al., 2007

Clarias batrachus 3.74 Kamal et al., 2007

Perca fluviatilis 1.21 Orban et al., 2007

Chanda nama 3.92 Mazumder et al., 2008

Clarias anguillaris 0.50 Effiong and Mohammed, 2008

Clarias gariepinus 1.2 Osibona et al., 2009

Tilapia zillii 1.2 Osibona et al., 2009

Wallago attu 3.33 Present study

Sperata sarwari 4.17 Present study

CHAPTER NO.2 65 BODY COMPOSITION

Table 2.26

Fat content values of various fish species

Species Fat contents (% wet Sources

body weight)

Oreochromis nilotica (male) 5.04 Javaid et al., 1992

Heteropneustes fossilis 3.25 Salam, 2002

Labeo rohita 4.71 Ali et al., 2005

Salvelinus namaycush 4.00 Gunther et al., 2005

Clarias gariepinus 1.15 Osibona et al., 2006

Mystus vittatus 7.53 Kamal et al., 2007

Clarias anguillaris 2.65 Effiong and Mohammed, 2008

Puntius chola 3.05 Mazumder et al., 2008

Pseudeutropius atherinoides 2.24 Mazumder et al., 2008

Clarias gariepinus 9.3 Osibona et al., 2009

Tilapia zillii 1.1 Osibona et al., 2009

Wallago attu 4.16 Present study

Sperata sarwari 4.11 Present study

CHAPTER NO.2 66 BODY COMPOSITION

Table 2.27

Protein content values of various fish species

Species Protein contents (% Sources

wet body weight)

Labeo rohita 15.68 Salam and Janjua, 1991

Oreochromis nilotica (male) 16.73 Javaid et al., 1992

Heteropneustes fossilis 18.25 Salam, 2002

Labeo rohita 18.49 Ali et al., 2005

Clarias gariepinus 19.64 Osibona et al., 2006

Mystus vittatus 15.62 Kamal et al., 2007

Clarias anguillaris 18.52 Effiong and Mohammed, 2008

Chanda nama 18.26 Mazumder et al., 2008

Pseudeutropius atherinoides 15.84 Mazumder et al., 2008

Clarias gariepinus 18.8 Osibona et al., 2009

Tilapia zillii 19.00 Osibona et al., 2009

Wallago attu 15.69 Present study

Sperata sarwari 15.67 Present study 8CHAPTER 2 BODY COMPOSITION

CHAPTER 3 67 ELEMENTAL CONCENTRATION

ELEMENTAL CONCENTRATION

3.1 INTRODUCTION Basically, Pakistan is an agricultural country with a population of 150 millions. Its aquatic ecosystem is rich in resources and can be divided into inland waters, estuarine waters and marine waters. The inland water bodies include rivers, streams, ponds and lakes as well as underground waters which supply water for irrigation and other human uses. The Indus River is the biggest river in Pakistan which irrigates southern Punjab and

flows toward Sindh. “The rich fauna from the aquatic ecosystem provides food for both the local consumption and export. Due to rapidly increasing human population and advancement of industries in the urban areas of the Punjab province of Pakistan, most of our rivers have become noxious. The industrial and sewage wastes, containing heavy metals and their compounds have become absolute death traps for aquatic life including fish which is highly nutritious, easily digestible and much hunted for food. The distribution and plenty of fish in both marine and freshwaters are influenced not only by

hydrographic conditions but also by the geography and climate of the land masses” (Moses, 1992; Javed, 2005). Water pollution significantly damages the aquatic and terrestrial organisms and ecosystems are greatly damaged and threatened. “The natural resources of fresh water like rivers, ponds, and lakes are polluted with different types of solid and liquid wastes. Researchers have estimated that during recent decades between 20-35% of the world’s

freshwater fish species have become endangered, threatened, or extinct (Nicole, 2005).” Because fish population is usually considered very susceptible to all kinds of environmental changes to which it is exposed as they are entirely aquatic with external mode of fertilization. Certain stages in the life cycle of fresh water fish are more susceptible to environmental and pollution stresses (Von Westernhagan, 1988). The trace elements play important functions in living cells and are essential for fish (Lall and Bishop, 1977). “They are integral parts of a large number of enzymes or serve as cofactors from their functions, and they may participate in the energy

metabolism of cells through red-ox reactions of the electron transport chain” (Lorentzen and Maage, 1999). For instance, Zinc is known to be involved in most metabolic CHAPTER 3 68 ELEMENTAL CONCENTRATION

pathways in plants, animals and humans. Its deficiency can lead to loss of appetite, growth retardation, skin changes and immunological abnormalities (Hambidge, 2000;

National Research Council, 1989). “Similarly iron serves as a carrier of oxygen to the tissues from the lungs by red blood cell haemoglobin, as a transport medium for electrons within cells, and as an integrated part of important enzyme systems in various tissues. Adequate iron in the diet is very important for decreasing the incidence of anemia, which is considered a major health problem, especially in young children. Low intake of iron causes retarded growth and mental development in children, as well as high morbidity rates and increased risk of early death in other vulnerable population groups, such as women at the reproductive age. Iron deficiency occurs when the demand for iron is high, e.g., in growth, high menstrual loss, and pregnancy, and the intake is quantitatively

inadequate or contains elements that render the iron unavailable for absorption” (Belitz and Grosch, 2001; SCN, 2004; Camara et al., 2005).

All living organisms require these mineral elements. “Some of these elements exist naturally in the environment including chromium, cobalt, copper, iron, manganese, molybdenum, vanadium, strontium, zinc etc. and are essential for living organisms. These essential metals can also produce toxic effects at high concentrations. However, some trace metals, which may be introduced into the aquatic environment from anthropogenic activities are not required for metabolic activity and are toxic at quite low concentrations

(Tyrrell et al., 2005).” Industrial wastes, sewage disposal, soil leaching and rainfall are considered critical factors for disturbing the natural environment. Composite effluents tainted with different heavy metals are major environmental pollutants of varied wetland ecosystems

(Neil et al., 1995; Wong, 2003; Prasath and Arivoli, 2008). “The increased use of metal- based fertilizer in agricultural revolution could also result in continued rise in concentration of metal pollutants in fresh water due to the water run-off” (Adefemi et al., 2008). On the other hand, body size, which is closely related to fish growth and metabolism, has also been shown to characteristic most of the variations of trace metal contents in fish (Moriarty et al., 1984). “All these metals get their way into aquatic systems, rivers, lakes or oceans through dumping wastes, atmospheric fallout, runoff of

terrestrial systems, accidental leaks and geological weathering” (Eisler, 1981). CHAPTER 3 69 ELEMENTAL CONCENTRATION

Fish population is generally considered very sensitive to all kinds of environmental changes to which it is exposed as they are entirely aquatic with external mode of fertilization. Fish absorbs elements from the surrounding water, but the diet is the main source of essential elements (Lall and Bishop, 1977; Prasath and Arivoli, 2008). When they exceed metabolic demand or requirement, they tend to become accumulated in tissues of organisms such as fish which can only metabolize it to lesser extents because most of these heavy metals are non-biodegradable (Lenntech, 2006). So, heavy metal contamination may have devastating effects on the ecological balance of the recipient environment and a diversity of aquatic organisms (Farombi et al., 2007; Vosyliene and Jankaite, 2006; Ashraj, 2005). The biomonitoring of pollutants using accumulator species is based on the capacity which has some plant and animal taxa to accumulate relatively large amounts of certain pollutants even from much diluted solutions. “Organisms used in environmental monitoring, instead of sediment and water sampling, have many advantages. Metals may accumulate in animals to levels much higher than are found in environment. It is also easy to measure pollutant level in physical environment; even they can be measured when their amounts in natural environment are lower than detection limits of the methods commonly used. The pollutant concentration in organism’s body tissue are the result of past as well as recent pollution level of environment in which organism lives, while pollution concentration in the water only indicates the situation at the present, at the time of sampling” (Agbozu et al., 2007). There is another advantage that biomonitors have wide geographical distribution, and contamination levels can be compared internationally (Rainbow, 1995).

“Many aquatic organisms have been used as bioindicators including aquatic insects (Rayms-Keller et al., 1998), fish (Widianarko et al., 2000), protozoa (Fernandez- Leborans and Herrero, 2000), plants and crustaceans (Mohan and Hosetti, 1999), barnacles (White and Walker, 1981; Powell and White, 1990). Fish species being at the top of food web accumulate more elements and are widely used as indicative factors to monitor variation of some pollutant levels in the environment (Phillips, 1980; Hellawel, 1986). There is an increasing interest in carrying out studies on metal levels of wild and

cultured food fishes (Jaffer et al., 1988; Salam et al., 1993).” CHAPTER 3 70 ELEMENTAL CONCENTRATION

“Catfishes are broadly used as indicative factors in freshwater systems for the estimation of heavy metal pollution because they are identified to concentrate these elements, providing a time integrated indication of environmental contamination. Elemental concentrations in the tissues of catfishes more precisely reveal the degree of environmental contamination (Opuene, 2005). The factors responsible for disturbing the level of metal concentrations and accumulation in catfishes are metal bioavailability, season of sampling, sex, size and changes in tissue composition and reproductive cycle”

(Risch, 1986).” Fish are located at the end of the aquatic food chain and may accumulate metals and pass them to human beings through food causing chronic or acute diseases (Fowler et al., 1991; Khan and Weis, 1993; Adeyeye et al., 1996). Dougherty et al. (2000) also reported that fish consumption is a major way of chemical exposure to man. Heavy metal pollutants are potentially dangerous to man when fish and water contaminated with metals are consumed (Jobling, 1994). Though, fish is healthy and nutritious but it is also a source of contamination, because of the amounts of elements it can contain, some of

which are toxic and some become toxic when absorbed over threshold level. “Nutrients composition data for common food fish is widely available as compared to the knowledge about elements present in fish, it is confined to some selected minerals and elements in few freshwater and seafood species” (Carvalho et al., 2005). It has been shown that whole-body element concentrations are reduced due to insufficient dietary intake (Maage and Julshamn, 1993). However, Shearer (1984) suggested that changes in whole-body and tissue element levels also depend on growth and stage of the life cycle. The result of heavy metal pollution can be dangerous to man and it often becomes compulsory to check chemical contaminants in foods from the aquatic environment to understand their hazard levels.

CHAPTER 3 71 ELEMENTAL CONCENTRATION

3.1.1 Aims and Objectives of the Study: The aim of the present study was;  To determine whether whole-body contents of Fe, Co, Cd, Cu, Ni, Pb and Zn vary with growth in two wild freshwater catfishes in river of southern Punjab.  To monitor metal pollution in Indus river, and to determine the potential human risk of consumption of fish.  To study the quality of Indus water because this is source of drinking water supply for huge population in different areas of the Southern Punjab.

CHAPTER 3 72 ELEMENTAL CONCENTRATION

3.2 MATERIALS AND METHODS

“Seventy eight wild Wallago attu of different body sizes, 16.7 to 50.2 cm total length and 14.54 to 648.82 g body weight and eighty Sperata sarwari of different body sizes 23.8 to 42.0 cm total length and 52.12 to 439.60 g body weight were sampled from Indus River D. G. Khan during 2005-2006 using a cast net and were transported live to the laboratory. Fresh fish were washed with tap water several times to remove adhering blood and slime, they were killed, blotted dry on a paper towel, weighed on an electronic digital balance (MP-3000 Chyo, Japan) and their length measured to nearest 0.1 cm on wooden measuring tray. Each dead fish was placed in a pre – weighed aluminium foil tray and dried whole to a constant weight in a drying oven (Memmert, W. Germany) at 60 – 70 C The dry carcasses were crushed in a pestle and mortar and powdered in an

electric blender.” 3.2.1 Reagents and standards:

“Analytical reagent grade chemicals supplied by Merck were used without further purification for the purpose of elemental analysis. Deionized water was used to prepare standard and sample solution. Stock standard solutions (1000 ppm) of each element were prepared by dissolving required amounts of the respective salts in water. Dilution of the stock solutions was made to prepare working acidic standards (0.1 M HNO3 final molar

concentration) in the measuring range.” 3.2.2 Glassware: All Pyrex glassware used for processing of the samples or for the preparation of standards were thoroughly washed once with detergent solution, tap water and then thrice with distilled water. It was then soaked in 10% nitric acid, rinsed with distilled water and kept for 6 hours in an electric oven at 150 C prior to use. 3.2.3 Instrumentation: Electrical balance H-80 (Mettler), Muffle furnance (SHEFFISLD CSF 1200), and Heating oven (Memmert, W. Germany). Atomic Absorption Spectrophotometer A-1800 (Hitachi, Japan) is a high speed, dual frequency, simultaneous photometric system with a facility of automatic background correction. Other salient features of the equipment include automatic selection of optimum operational conditions, automatic recording of CHAPTER 3 73 ELEMENTAL CONCENTRATION

the data, including the calibration curve and top level data accuracy. Detector gain and beam balance are all adjusted automatically. 3.2.4 Analytical procedure:

“Sample solutions were prepared as one gram of dried fish powder sample was ashed in a muffle furnace at 500 C for 12 hours. The ash contents were digested in

conical flask with 10 ml (70%) HNO3 on a hot plate at 82-100C, heated to dryness and diluted up to 25 ml with deionized water. These solutions were aspirated into Atomic Absorption Spectrophotometer and absorbance measurements were made for each element using specific instrumental conditions for flame atomization mode. Analysis of

each sample was carried out for three times.” 3.2.5 Computation of results: Elemental concentrations, Regression analysis and calculation of correlation coefficients were carried out with the help of different computer packages (MS. Excel/Lotus 1-2-3) on IBM computer following Zar (1999).

CHAPTER 3 74 ELEMENTAL CONCENTRATION

3.3 RESULTS The mean values, ranges and standard deviation of various elemental concentrations found in the carcasses of wild catfishes, Wallago attu and Sperata sarwari (whole fish on dry and wet weight basis) are summarized in Table-3.1 and 3.2 respectively. According to these results, the elemental concentrations for Wallago attu were zinc > iron > copper >lead > cobalt > nickel > cadmium and for Sperata sarwari, iron > copper > zinc > lead > cadmium > cobalt > nickel respectively. This result showed that zinc concentration was higher than any other metal in the whole body of Wallago attu, whereas in the Sperata sarwari the iron concentration was more than any other metal. 3.3.1 Effect of body weight on elemental concentration: In wallago attu, metals such as cadmium, cobalt, iron and copper were found to increase in direct proportion to an increase in body weight indicating isometric relationship (when the value of slope b is either equal to 1.0 or not significantly different from 1.0). Nickel, zinc and lead showed negative allometry with increasing body weight. With relation to dry body weight, copper, cobalt, nickel, zinc and lead were found to be decreased, cadmium increased while iron concentration remained constant. The regression parameters of the relationships between elemental concentrations and body weight are given in Table 3.3. In Sperata sarwari, metals such as cadmium, cobalt, iron and zinc were observed to increase in direct proportion to an increase in body weight showing isometric growth. However, copper, nickel and lead were found to decrease with the increasing of body weight (wet and dry) showing allormetric relationship between body weight and metal concentration. Regression parameters of the relationships are given in Table 3.4. 3.3.2 Effect of total length on elemental concentration: As variations were observed to be related to total length of the body, regression analysis was performed to assess the total length dependence of these metals. In Wallago attu, it was observed that cadmium, cobalt, iron and copper (wet weight) increased while nickel, zinc and lead (wet weight) decreased with the increasing of total length of fish. But the concentration of cadmium, cobalt, copper, iron, nickel, zinc and lead (dry weight) had decreasing trend with the increase of total length of fish. When the allometric CHAPTER 3 75 ELEMENTAL CONCENTRATION

approach was applied, it was found that the slope b of log-log regression of the relationship between total length and total metal body burden was more than 3 except Zn. The value of b showed that there were positive allometric relationships between total length and elemental concentrations. The regression parameters of the relationships between elemental concentrations and total length are given in Table 3.5. In Sperata sarwari, it was found that cadmium, cobalt and iron (wet and dry weight) had increasing trend while copper, nickel, zinc and lead (wet and dry weight) decreased with the increasing of body weight. Here, b values for nickel, iron, cobalt and cadmium were more than 3 while copper and lead had b values less than 3. This result showed allometric relationships between elemental concentrations and total length of the fish. Regression parameters of the relationships are given in Table 3.6.

CHAPTER 3 76 ELEMENTAL CONCENTRATION

Table 3.1: Mean and standard deviation values of elemental concentration in carcasses of Wallago attu (whole fish), n = 78

Concentration Elements µgg-1 of dry weight µgg-1of wet weight Mean ± S.D Mean ± S.D Cu 23.663 ± 2.012 5.440 ± 0.250 Zn 96.327 ± 13.231 22.274 ± 2.028 Ni 0.549 ± 0.003 0.126 ± 0.025 Fe 94.017 ± 42.688 21.672 ± 7.133 Co 1.048 ± 0.026 0.241 ± 0.015 Pb 2.069 ± 0.425 0.475 ± 0.188 Cd 0.311 ± 0.135 0.072 ± 0.019 S.D = Standard Deviation

Table 3.2: Mean and standard deviation values of elemental concentration in carcasses of Sperata sarwari (whole fish), n = 80

Concentration Elements µgg-1 of dry weight µgg-1 of wet weight Mean ± S.D Mean ± S.D Cu 56.346 ± 11.914 13.360 ± 1.734 Zn 14.908 ± 1.924 3.582 ± 0.170 Ni 0.870 ± 0.745 0.207 ± 0.219 Fe 320.661 ± 64.478 76.574 ± 25.943 Co 0.949 ± 0.189 0.226 ± 0.077 Pb 1.998 ± 1.175 0.476 ± 0.365 Cd 1.794 ± 0.030 0.426 ± 0.034 S.D = Standard Deviation

CHAPTER 3 77 ELEMENTAL CONCENTRATION

Table 3.3: Log wet body weight (g) versus log elemental constituents (μg) of Wallago attu. Statistical parameters of various relationships; correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case.

Wet body Elements a b S.E (b) r weight (g) 14.54 Cu 0.598 1.032 0.079 0.832*** Zn 1.508 0.904 0.057 0.877*** To Ni -0.799 0.940 0.045 0.923*** Fe 1.212 1.033 0.061 0.889*** 648.82 Co -0.654 0.997 0.055 0.900*** Pb -0.267 0.961 0.044 0.928*** Cd -1.321 1.063 0.056 0.909*** Significance level: ***P<0.001

Table 3.4: Log wet body weight (g) versus log elemental constituents (μg) of Sperata sarwari. Statistical parameters of various relationships; correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case.

Wet body Elements a b S.E (b) r weight (g) 52.12 Cu 1.228 0.937 0.109 0.698*** Zn 0.575 0.941 0.186 0.497*** To Ni -0.647 0.964 0.124 0.661*** Fe 1.846 1.011 0.066 0.866*** 439.60 Co -0.681 1.004 0.092 0.779*** Pb -0.132 0.907 0.066 0.841*** Cd -0.473 1.040 0.071 0.856*** Significance level: ***P<0.001

CHAPTER 3 78 ELEMENTAL CONCENTRATION

Table 3.5: Log total length (cm) versus log elemental constituents (μg) of Wallago attu. Statistical parameters of various relationships; correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 78 in each case.

Total Element a b S.E r length (cm) (b) 16.70 Cu -2.354 3.444 0.253 0.842*** Zn -1.032 2.986 0.186 0.878*** To Ni -3.400 3.079 0.154 0.916*** Fe -1.594 3.349 0.214 0.874*** 50.20 Co -3.392 3.252 0.191 0.890*** Pb -2.947 3.161 0.148 0.926*** Cd -4.224 3.455 0.196 0.896*** Significance level: ***P<0.001

Table 3.6: Log total length (cm) versus log elemental constituents (μg) of Sperata sarwari. Statistical parameters of various relationships; correlation coefficient (r), intercept (a), regression coefficient (b), standard error of b (S.E.) and n = 80 in each case.

Total Element a b S.E r length (cm) (b) 23.80 Cu -1.206 2.966 0.393 0.650*** Zn -2.017 3.075 0.640 0.479*** To Ni -3.264 3.125 0.436 0.631*** Fe -0.987 3.336 0.243 0.841*** 42.00 Co -3.436 3.274 0.329 0.748*** Pb -2.565 2.921 0.251 0.797*** Cd -3.260 3.347 0.273 0.811*** Significance level: ***P<0.001

CHAPTER 3 79 ELEMENTAL CONCENTRATION

12.0

48.0

9.0 36.0

6.0 24.0 Cu (µgg-1) Cu (µgg-1) Cu 3.0 12.0

0.0 0.0 0 150 300 450 600 0 50 100 150 Wet body weight (g) Dry body weight (g)

(a) (b)

12.0 48.0 9.0 36.0

6.0 24.0

wt) dry (µgg-1 Cu Cu (µgg-1 wet wt) wet (µgg-1 Cu 3.0 12.0

0.0 0.0 15 23 31 39 47 55 15 23 31 39 47 55 Total length (cm) Total length (cm)

Figure 3.1: (a) wet body weight (g) versus Cu (μgg-1) (b) dry body weight versus Cu (μgg-1) (c) total length (cm) versus Cu (μgg-1 dry weight) (d) total length (cm) versus Cu (μgg-1 wet weight) in Wallago attu.

CHAPTER 3 80 ELEMENTAL CONCENTRATION

24 107

19 84

14 61 Cu (µgg-1) Cu (µgg-1) Cu 9 38

4 15 40 140 240 340 440 0 50 100 150

Dry body weight (g) Wet body weight (g)

(a) (b)

107 24

84 20

16 61 12

wt) dry (µgg-1 Cu 38 wt) wet (µgg-1 Cu 8

15 4 22 27 32 37 42 22 27 32 37 42 Total length (cm) Total length (cm)

Figure 3.2: (a) wet body weight (g) versus Cu (μgg-1) (b) dry body weight versus Cu (μgg-1) (c) total length (cm) versus Cu (μgg-1 dry weight) (d) total length (cm) versus Cu (μgg-1 wet weight) in Sperata sarwari.

CHAPTER 3 81 ELEMENTAL CONCENTRATION

250 48 200

36 150

Zn (µgg-1) 100 (µgg-1) Zn 12 50

0 0 0 125 250 375 500 625 0 50 100 150 Wet body weight (g) Dry body weight (g)

(a) (b)

250 48.0 200 36.0 150 24.0 100 Zn (µgg-1 wet wt) wet (µgg-1 Zn wt) dry Zn (µgg-1 12.0 50

0.0 0 15 25 35 45 55 15 25 35 45 55 Total length (cm) Total length (cm)

Figure 3.3: (a) wet body weight (g) versus Zn (μgg-1) (b) dry body weight versus Zn (μgg-1) (c) total length (cm) versus Zn (μgg-1 dry weight) (d) total length (cm) versus Zn (μgg-1 wet weight) in Wallago attu.

CHAPTER 3 82 ELEMENTAL CONCENTRATION

12 55

9 44

33 6

Zn (µgg-1) Zn 22 Zn (µgg-1) 3 11

0 0 40 140 240 340 440 0 40 80 120

Wet body weight (g) Dry body weight (g)

(a) (b)

12 55

44 9

33 6 22

Zn (µgg-1 dry wt) dry (µgg-1 Zn Zn (µgg-1 wet wt) wet Zn (µgg-1 3 11

0 0 22 27 32 37 42 22 27 32 37 42 Total length (cm) Total length (cm)

Figure 3.4: (a) wet body weight (g) versus Zn (μgg-1) (b) dry body weight versus Zn (μgg-1) (c) total length (cm) versus Zn (μgg-1 dry weight) (d) total length (cm) versus Zn (μgg-1 wet weight) in Sperata sarwari.

CHAPTER 3 83 ELEMENTAL CONCENTRATION

0.25 1.25

0.20 1.00

0.15 0.75

0.10 0.50 Ni (µgg-1) Ni (µgg-1) Ni

0.05 0.25

0.00 0.00 0 150 300 450 600 0 50 100 150 Dry body weight (g) Wet body weight (g)

(a) (b)

0.23 1.25

1.00 0.17

0.75 0.11

0.50

Ni (µgg-1 wet wt) wet (µgg-1 Ni 0.06 wt) dry (µgg-1 Ni 0.25

0.00 0.00 15 23 31 39 47 55 15 23 31 39 47 55

Total length (cm) Total length (cm)

Figure 3.5: (a) wet body weight (g) versus Ni (μgg-1) (b) dry body weight versus Ni (μgg-1) (c) total length (cm) versus Ni (μgg-1 dry weight) (d) total length (cm) versus Ni (μgg-1 wet weight) in Wallago attu.

CHAPTER 3 84 ELEMENTAL CONCENTRATION

0.40 1.60

0.30 1.20

0.20 0.80 Ni (µgg-1) Ni (µgg-1) Ni 0.10 0.40

0.00 0.00 40 140 240 340 440 0 50 100 150 Wet body weight (g) Dry body weight (g)

(a) (b)

0.40 1.60

0.30 1.20

0.20 0.80

wt) wet (µgg-1 Ni 0.10 wt) dry (µgg-1 Ni 0.40

0.00 0.00 22 27 32 37 42 22 27 32 37 42 Total length (cm) Total length (cm)

Figure 3.6: (a) wet body weight (g) versus Ni (μgg-1) (b) dry body weight versus Ni (μgg-1) (c) total length (cm) versus Ni (μgg-1 dry weight) (d) total length (cm) versus Ni (μgg-1 wet weight) in Sperata sarwari.

CHAPTER 3 85 ELEMENTAL CONCENTRATION

45 200 36 150 27

100 18 Fe (µgg-1) Fe (µgg-1) Fe 50 9

0 0 0 150 300 450 600 0 50 100 150 Wet body weight (g) Dry body weight (g)

(a) (b)

45 200 36 150 27

100 18

Fe (µgg-1 dry wt) dry (µgg-1 Fe Fe (µgg-1 wet wt) wet (µgg-1 Fe 9 50

0 0 15 23 31 39 47 55 15 24 33 42 51 Total length (cm) Total length (cm)

Figure 3.7: (a) wet body weight (g) versus Fe (μgg-1) (b) dry body weight versus Fe (μgg-1) (c) total length (cm) versus Fe (μgg-1 dry weight) (d) total length (cm) versus Fe (μgg-1 wet weight) in Wallago attu.

CHAPTER 3 86 ELEMENTAL CONCENTRATION

525 130

425 105

325 80

(µgg-1) Fe (µgg-1) Fe

55 225

30 125 40 140 240 340 440 0 40 80 120 Wet body weight (g) Dry body weight (g)

(a) (b)

525 130

425 105

325 80

Fe (µgg-1 wet wt) wet (µgg-1 Fe wt) dry (µgg-1 Fe 225 55

30 125 22 27 32 37 42 22 27 32 37 42 Total length (cm) Total length (cm)

Figure 3.8: (a) wet body weight (g) versus Fe (μgg-1) (b) dry body weight versus Fe (μgg-1) (c) total length (cm) versus Fe (μgg-1 dry weight) (d) total length (cm) versus Fe (μgg-1 wet weight) in Sperata sarwari.

CHAPTER 3 87 ELEMENTAL CONCENTRATION

0.55 2.00

0.44 1.50

0.33

1.00

0.22 Co (µgg-1) (µgg-1) Co 0.50 0.11

0.00 0.00 0 165 330 495 660 0 50 100 150

Wet body weight (g) Dry body weight (g)

(a) (b)

0.60 2.00

0.45 1.50

0.30 1.00

wt) dry (µgg-1 Co Co (µgg-1 wet wt) wet (µgg-1 Co 0.15 0.50

0.00 0.00 15 23 31 39 47 55 15 23 31 39 47 55 Total length (cm) Total length (cm)

Figure 3.9: (a) wet body weight (g) versus Co (μgg-1) (b) dry body weight versus Co (μgg-1) (c) total length (cm) versus Co (μgg-1 dry weight) (d) total length (cm) versus Co (μgg-1 wet weight) in Wallago attu.

CHAPTER 3 88 ELEMENTAL CONCENTRATION

0.50 1.70

0.40 1.35 0.30

1.00 0.20 Co (µgg-1) Co (µgg-1) Co 0.65 0.10

0.30 0.00 40 140 240 340 440 0 50 100 150

Dry body weight (g) Wet body weight (g)

(a) (b)

1.70 0.50

0.40 1.35

0.30

1.00 0.20 Co (µgg-1 dry wt) dry (µgg-1 Co 0.65 wt) wet (µgg-1 Co 0.10

0.30 0.00 22 27 32 37 42 22 27 32 37 42 Total length (cm) Total length (cm)

Figure 3.10: (a) wet body weight (g) versus Co (μgg-1) (b) dry body weight versus Co (μgg-1) (c) total length (cm) versus Co (μgg-1 dry weight) (d) total length (cm) versus Co (μgg-1 wet weight) in Sperata sarwari.

CHAPTER 3 89 ELEMENTAL CONCENTRATION

1.00 4.30

0.80 3.30 0.60 2.30 0.40 Pb (µgg-1) Pb ((µgg-1) Pb 1.30 0.20

0.00 0.30 -50 100 250 400 550 700 0 200 400 600 800

wet body wt (g) Dry body weight (g)

(a) (b)

1.00 5.00

4.00 0.75

3.00 0.50 2.00

Pb ((µgg-1 dry wt) dry ((µgg-1 Pb Pb ((µgg-1 wet wt) wet ((µgg-1 Pb 0.25 1.00

0.00 0.00 15 23 31 39 47 55 15 23 31 39 47 55 Total length (cm) Total length (cm)

Figure 3.11: (a) wet body weight (g) versus Pb (μgg-1) (b) dry body weight versus Pb (μgg-1) (c) total length (cm) versus Pb (μgg-1 dry weight) (d) total length (cm) versus Pb (μgg-1 wet weight) in Wallago attu.

CHAPTER 3 90 ELEMENTAL CONCENTRATION

0.75 3.20

0.63 2.70

0.51 2.20

1.70

0.39 (µgg-1) Pb (µgg-1) Pb

1.20 0.27

0.70 0.15 0 50 100 150 40 140 240 340 440 Dry body weight (g) Wet body weight (g)

(a) (b)

3.20 0.75

2.70 0.63

2.20 0.51

1.70 0.39

Pb (µgg-1 dry wt) dry (µgg-1 Pb wt) wet (µgg-1 Pb 1.20 0.27

0.70 0.15 22 27 32 37 42 22 27 32 37 42

Total length (cm) Total length (cm)

Figure 3.12: (a) wet body weight (g) versus Pb (μgg-1) (b) dry body weight versus Pb (μgg-1) (c) total length (cm) versus Pb (μgg-1 dry weight) (d) total length (cm) versus Pb (μgg-1 wet weight) in Sperata sarwari.

CHAPTER 3 91 ELEMENTAL CONCENTRATION

0.16 0.75

0.60 0.12 0.45 0.08 0.30 Cd (µgg-1) Cd ((µgg-1) Cd 0.04 0.15

0.00 0.00 0 175 350 525 700 0 175 350 525 700

wet body wt (g) Dry body weight (g)

(a) (b)

0.15 0.64 0.12 0.48 0.09

0.32 0.06

Cd ((µgg-1 dry wt) dry ((µgg-1 Cd wt) wet ((µgg-1 Cd 0.16 0.03

0.00 0.00 15 23 31 39 47 55 15 23 31 39 47 55 Total length (cm) Total length (cm)

Figure 3.13: (a) wet body weight (g) versus Cd (μgg-1) (b) dry body weight versus Cd (μgg-1) (c) total length (cm) versus Cd (μgg-1 dry weight) (d) total length (cm) versus Cd (μgg-1 wet weight) in Wallago attu.

CHAPTER 3 92 ELEMENTAL CONCENTRATION

0.70 3.00

2.50 0.55

2.00 0.40 1.50 (µgg-1) Cd (µgg-1) Cd 0.25 1.00

0.10 0.50 40 140 240 340 440 0 50 100 150

Wet body weight (g) Dry body weight (g)

(a) (b)

3.00 0.70

2.50 0.58

2.00 0.46

1.50 0.34

Cd (µgg-1 dry wt) dry (µgg-1 Cd Cd (µgg-1 wet wt) wet (µgg-1 Cd 1.00 0.22

0.50 0.10 22 27 32 37 42 22 27 32 37 42

Total length (cm) Total length (cm)

Figure 3.14: (a) wet body weight (g) versus Cd (μgg-1) (b) dry body weight versus Cd (μgg-1) (c) total length (cm) versus Cd (μgg-1 dry weight) (d) total length (cm) versus Cd (μgg-1 wet weight) in Sperata sarwari.

CHAPTER 3 93 ELEMENTAL CONCENTRATION

3.3.3 Comparison of elemental concentrations between two species:

Data was analyzed statistically using analysis of variance (ANOVA) procedures to study the comparison of elemental concentrations between Wallago attu and Sperata sarwari. It was found that there were highly significant (P<0.000) differences between these two species of catfishes in relation to iron, cadmium, zinc and nickel concentrations (dry and wet weight). However, there were no significant differences (P>0.05) in cobalt and lead concentrations in these two species (Table 2.7 & 2.8).

3.3.4 Effect of sex on elemental concentration: The mean percentages of various elemental constituents bit varied with the variation of sexes in the present study of catfishes of southern Punjab of Pakistan. In case of Wallagu attu, mean values of %zinc contents, %copper contents and %lead contents (μg/g dry weight) were slightly greater in female as compared to female, while that of %iron contents, %cobalt contents and %nickel contents (μg/g dry weight) were some what greater in male as compared to female. Mean value of %cadmium contents (μg/g dry weight) was not influenced by sexes (Table 3.10). While in case of Sperata sarwari, mean values of %zinc contents, %cadmium contents and %lead contents (μg/g dry weight) were slightly more in female than male, while mean values of %iron contents, %copper contents, %cobalt contents and %nickel contents (μg/g dry weight) were greater in male than female (Table 3.12). But these variations in elemental concentrations were not significant (P>0.05) between male and female in these two species of catfishes. 3.3.5 Effect of season on elemental concentration: The mean values of various metals in (dry and wet body mass) in different months of the year are given in table 3.13 & 3.14 for Wallago attu and 3.17 & 3.18 for Sperata sarwari. In the present study, the effect of season on metal concentration was analyzed by using the ANOVA. Significant differences were observed in case of copper, zinc and lead concentrations in Wallago attu (table 3.15 & 3.16) and zinc, nickel concentrations in Sperata sarwari (table 3.19 & 3.20). But there were no significant differences in other metals with relation to season.

CHAPTER 3 94 ELEMENTAL CONCENTRATION

Table 3.7: ANOVA showing comparison of elemental concentrations (μg/g dry weight) of two different species of freshwater catfishes of Southern Punjab.

Metals MS F P Fe 2029 516.46 0.000*** Zn 2618 270.19 0.000*** Cu 4219 132.04 0.000*** Cd 86.785 711.59 0.000*** Co 0.385 2.69 0.103N.S. Ni 4.052 50.75 0.000*** Pb 0.199 0.48 0.489N.S. Significance level: ***P<0.001, N.S. = non-significant

Table 3.8: ANOVA showing comparison of elemental concentrations (μg/g wet weight) of two different species of freshwater catfishes of southern Punjab.

Metals MS F P Fe 1190 521.66 0.000*** Zn 13798 259.40 0.000*** Cu 2477 150.26 0.000*** Cd 4.957 802.69 0.000*** Co 0.0093 1.16 0.283N.S. Ni 0.2541 60.53 0.000*** Pb 0.000 0.00 0.976N.S. Significance level: ***P<0.000, N.S. = non-significant

CHAPTER 3 95 ELEMENTAL CONCENTRATION

Table 3.9: Mean values and ranges of various elemental constituents (μg/g wet weight) of ♂ and ♀ Wallago attu.

Body metals (%) Male Female Mean ±S.D Ranges Mean ±S.D Ranges Fe 22.03 ± 10.33 5.29-43.95 21.37 ± 10.55 7.62-46.74 Zn 21.58 ± 10.38 7.59-49.10 22.87 ± 9.77 6.90-49.58 Cu 5.15 ± 2.52 0.67-10.87 5.69 ± 2.33 0.58-9.57 Cd 0.07 ± 0.03 0.02-0.12 0.07 ± 0.03 0.02-0.12 Co 0.26 ± 0.10 0.08-0.46 0.22 ± 0.10 0.07-0.51 Ni 0.13 ± 0.04 0.05-0.22 0.12 ± 0.05 0.05-0.22 Pb 0.46 ± 0.18 0.14-0.85 0.49 ± 0.15 0.23-0.81

Table 3.10: Mean values and ranges of various elemental constituents (μg/g dry weight) of ♂ and ♀ Wallago attu.

Body metals (%) Male Female Mean ±S.D Ranges Mean ±S.D Ranges Fe 95.95± 45.20 24.68-209.70 92.36 ± 46.13 33.58-207.03 Zn 93.87 ± 44.82 34.28-195.53 98.43 ± 41.47 28.13-217.90 Cu 22.42 ± 11.35 3.07-49.96 24.73 ± 10.33 2.26-44.26 Cd 0.31 ± 0.12 0.07-0.55 0.32 ± 0.12 0.09-0.64 Co 1.14 ± 0.43 0.27-1.95 0.97 ± 0.41 0.32-1.96 Ni 0.58 ± 0.20 0.20-1.01 0.53 ± 0.20 0.21-1.06 Pb 1.99 ± 0.81 0.70-3.92 2.13 ± 0.73 0.89-3.98

CHAPTER 3 96 ELEMENTAL CONCENTRATION

Table 3.11: Mean values and ranges of various elemental constituents (μg/g wet weight) of ♂ and ♀ Sperata sarwari.

Body metals (%) Male Female Mean ±S.D Ranges Mean ±S.D Ranges Fe 76.35 ± 17.63 36.68-124.10 76.95 ± 20.39 37.05-109.28 Zn 3.30 ± 2.48 0.69-10.99 4.05 ± 3.05 0.68-12.40 Cu 13.50 ± 5.36 4.86-23.06 13.12 ± 4.96 5.32-22.68 Cd 0.41 ± 0.11 0.20-0.63 0.45 ± 0.09 0.23-0.60 Co 0.23 ± 0.09 0.10-0.47 0.22 ± 0.06 0.12-0.39 Ni 0.21 ± 0.09 0.03-0.34 0.20 ± 0.07 0.08-0.35 Pb 0.47 ± 0.12 0.20-0.72 0.49 ± 0.11 0.23-0.70

Table 3.12: Mean values and ranges of various elemental constituents (μg/g dry weight) of ♂ and ♀ Sperata sarwari.

Body metals (%) Male Female Mean ±S.D Ranges Mean ±S.D Ranges Fe 321.65 ± 72.88 193.84-518.35 319.02 ± 81.67 134.97-439.77 Zn 13.83 ± 10.25 2.73-48.86 16.71 ± 12.67 2.99-51.92 Cu 57.26 ± 23.46 20.45-106.48 54.83 ± 21.80 21.25-94.60 Cd 1.75 ± 0.49 0.81-2.66 1.87 ± 0.45 0.92-2.90 Co 0.96 ± 0.37 0.39-1.59 0.93 ± 0.26 0.51-1.62 Ni 0.89 ± 0.36 0.12-1.50 0.84 ± 0.31 0.31-1.51 Pb 1.97 ± 0.49 0.81-3.08 2.05 ± 0.52 0.94-3.17

CHAPTER 3 97 ELEMENTAL CONCENTRATION

Table 3.13: Seasonal variations in the mean values of different metals (μg/g dry weight) in Wallago attu.

Months Cu Zn Ni Fe Co Pb Cd January 19.49 65.084 0.517 89.800 1.086 2.116 0.334 February 22.906 93.232 0.499 109.773 1.132 1.850 0.307 March 4.364 43.642 0.524 74.191 0.698 1.506 0.196 April 32.614 130.311 0.453 56.133 1.536 2.457 0.289 May 22.965 53.928 0.518 98.43 1.113 1.416 0.347 August 30.006 183.371 0.400 40.008 1.534 1.100 0.233 November 26.488 99.778 0.587 87.553 1.078 2.599 0.328 December 23.988 99.735 0.587 93.889 0.924 1.985 0.304

Table 3.14: Seasonal variations in the mean values of different metals (μg/g wet weight) in Wallago attu.

Months Cu Zn Ni Fe Co Pb Cd January 4.457 19.592 0.120 20.876 0.255 0.483 0.077 February 5.490 22.430 0.121 26.039 0.272 0.443 0.074 March 0.911 9.109 0.109 15.485 0.146 0.314 0.041 April 7.152 28.345 0.099 12.253 0.331 0.527 0.061 May 5.324 12.552 0.120 22.884 0.257 0.327 0.080 August 6.909 42.222 0.092 9.212 0.353 0.253 0.054 November 5.72 21.599 0.128 19.260 0.235 0.559 0.071 December 5.600 23.469 0.135 21.694 0.213 0.469 0.071

CHAPTER 3 98 ELEMENTAL CONCENTRATION

Table 3.15: ANOVA table showing effect of season on metal concentrations (μg/g dry weight) in Wallago attu.

Metals df SS MS F P Cu 7 1698 243 2.21 0.042* Zn 7 38857 5551 3.34 0.004** Ni 7 0.2053 0.029 0.74 0.641NS Fe 7 17847 2550 1.28 0.273NS Co 7 2.166 0.309 1.85 0.091NS Pb 7 10.106 1.444 2.87 0.010** Cd 7 0.071 0.010 0.60 0.757NS Significant level; *P<0.05, **P<0.01, NS = non significant

Table 3.16: ANOVA table showing effect of season on metal concentrations (μg/g wet weight) in Wallago attu.

Metals df SS MS F P Cu 7 85.07 12.15 2.20 0.044* Zn 7 2094.8 299.3 3.28 0.004** Ni 7 0.009 0.001 0.69 0.682NS Fe 7 1181 169 1.67 0.131NS Co 7 0.124 0.018 1.88 0.084NS Pb 7 0.394 0.056 2.26 0.038* Cd 7 0.004 0.0006 0.74 0.637NS Significant level; *P<0.05, **P<0.01, NS = non significant

CHAPTER 3 99 ELEMENTAL CONCENTRATION

Table 3.17: Seasonal variations in the mean values of different metals (μg/g dry weight) in Sperata sarwari. Months Cu Zn Ni Fe Co Pb Cd February 50.016 17.538 0.557 327.441 0.938 2.109 1.805 March 68.277 10.849 0.752 298.359 0.878 2.189 1.672 April 53.437 26.091 0.859 319.597 0.966 2.039 2.039 May 57.967 13.104 0.899 322.493 0.953 1.978 1.939 August 39.441 15.539 1.207 334.448 1.012 2.139 1.703 September 35.145 14.839 1.170 360.757 0.900 2.105 1.688 October 65.336 36.559 0.815 285.554 0.879 2.036 1.343 November 65.091 6.803 1.152 282.955 0.721 1.727 1.390 December 55.533 12.236 0.734 328.092 1.029 1.912 1.739

Table 3.18: Seasonal variations in the mean values of different metals (μg/g wet weight) in Sperata sarwari. Months Cu Zn Ni Fe Co Pb Cd February 12.233 4.560 0.135 81.986 0.242 0.509 0.448 March 15.560 2.574 0.170 68.917 0.203 0.497 0.382 April 12.369 5.956 0.198 73.699 0.221 0.466 0.466 May 13.146 3.023 0.205 73.829 0.215 0.452 0.443 August 9.123 3.567 0.280 77.313 0.233 0.492 0.395 September 8.246 3.428 0.273 84.067 0.210 0.494 0.393 October 16.086 8.969 0.199 69.764 0.216 0.501 0.329 November 17.172 1.776 0.301 74.413 0.191 0.455 0.364 December 14.244 3.192 0.192 85.110 0.267 0.501 0.451

CHAPTER 3 100 ELEMENTAL CONCENTRATION

Table 3.19: ANOVA table showing effect of season on metal concentrations (μg/g dry weight) in Sperata sarwari.

Metals df SS MS F P Cu 8 4717 590 1.16 0.336NS Zn 8 3272 409 4.34 0.000*** Ni 8 1.869 0.234 2.22 0.036* Fe 8 21792 2724 0.45 0.888NS Co 8 0.340 0.043 0.37 0.932NS Pb 8 0.757 0.095 0.36 0.940NS Cd 8 2.635 0.329 1.55 0.156NS Significant level; *P<0.05, ***P<0.001, NS = non significant

Table 3.20: ANOVA table showing effect of season on metal concentrations (μg/g wet weight) in Sperata sarwari. Metals df SS MS F P Cu 8 308.3 38.5 1.51 0.170NS Zn 8 195.19 24.40 4.47 0.000*** Ni 8 0.099 0.012 2.16 0.041* Fe 8 2396 299 0.85 0.559NS Co 8 0.040 0.005 0.82 0.586NS Pb 8 0.045 0.006 0.39 0.924NS Cd 8 0.105 0.013 1.17 0.329NS Significant level; *P<0.05, ***P<0.001, NS = non significant

CHAPTER 3 101 ELEMENTAL CONCENTRATION

300 W. attu S. sarwari

225

150

concentrationsElemental 75

0 Fe Zn Cu

2.00 W. attu S. sarwari 1.50

1.00

0.50 concentrations Elemental

0.00 Ni Co Pb Cd

Figure 3.15: Comparison of elemental concentrations between Wallago attu and Sperata sarwari.

CHAPTER 3 102 ELEMENTAL CONCENTRATION

120 male female 100

concentrations metal Mean 20

0 Fe Cu Zn

2.50

male

2.00 female

1.50

1.00

concentrations metal Mean 0.50

0.00 Cd Co Ni Pb

Figure 3.16: Comparison of elemental concentrations in male and female Wallago attu.

CHAPTER 3 103 ELEMENTAL CONCENTRATION

350

300

250

male 200 female

150

100

Mean metal concentrations 50

0 Fe Cu Zn

2.50 male female 2.00

1.50

1.00

0.50

Mean metal concentrations

0.00 Cd Co Ni Pb

Figure 3.17: Comparison of elemental concentrations in male and female Sperata sarwari.

CHAPTER 3 104 ELEMENTAL CONCENTRATION

3.4 DISCUSSION Fishes are at the top of the food chain in the river and have tendency to concentrate metals from water. Therefore, accumulation of metals in fish can be considered as an index of metal pollution in the aquatic bodies (Mansour and Sidky, 2002; Tawari-Fufeyin and Ekaye, 2007; Karadede-Akin and Unlu, 2007). Awareness of elemental concentrations in fishes is essential for nature of management and human consumption of fish point of view. In the present study, the average concentrations of copper (Cu), zinc (Zn), nickel (Ni), iron (Fe), cobalt (Co), lead (Pb) and cadmium (Cd) in both species of catfish are summarized in tables 3.1 & 3.2. According to these results, Zinc has the highest concentration in Wallago attu while in case of Sperata sarwari iron was more concentrated. On the other hand, cadmium, nickel and cobalt were generally the lowest in both species. These results coincides with the finding of Al-Bader (2008) who studied that zinc was more concentrated in most available fish species followed by nickel and lead. Similar situations were reported by many researchers (Farkas et al., 2003; Silva and Shimizu, 2004; Dural et al., 2007; Uluozlu et al., 2007; Turkmen et al., 2008). The higher concentration of Zn found in the present study might be due to its essentiality in the metabolism of fish. It is an important for nucleic acid synthesis and also occurs in many enzymes. It has been reported that more than 180 μgl-1 of Zn concentrations are extremely dangerous in the environment. However, human tolerance of the metal is fine and toxicity is only expressed at very high level (Buffle, 1988). While high concentration of Fe may be its direct involvement with haemoglobin formation in fish blood. The minimum value for iron earlier reported is 2.805 μg/g for Heteropneustes fossilis (Jaffer et al., 1988) and maximum 669.0 μg/g for Catla catla (Salam et al., 1998). The present investigation is 94.02 μg/g (dry weight) and 21.67 μg/g (wet weight) for Wallago attu and 320.66 μg/g (dry weight) and 76.57 μg/g (wet weight) for Sperata sarwari that falls within this range. However, when in excessively high concentrations, these bioactive metals may pose serious threats to normal metabolic processes (Chatterjee et al., 2006). Cadmium (Cd) is one of the most toxic elements that causes carcinogenic effects in humans (Goering et al., 1994). Actually, here low level of cadmium is due to its non CHAPTER 3 105 ELEMENTAL CONCENTRATION

essentiality to the living organism, it is an immobile component which is hardly released. Therefore, the organism will minimize the uptake of this metal through some detoxification processes. However, cadmium levels measured in the present studies were nearly similar to cyprinid fish inhabiting metal-impacted streams in other studies (0.1–2.8 μg/g dry wt) (Andres et al., 2000; Has-Schon et al., 2006). The lowest and highest Pb concentration was found to be 0.141-0.847 μg/g wet weight, 0.701-3.976 μg/g dry weight in Wallago attu and 0.197-0.717 μg/g wet weight, 0.808-3.0170 μg/g dry weight in Sperata sarwari, respectively. Mean Pb concentration in this study was relatively lower than those reported from previous studies in Catla catla (12.29 μg/g), Labeo rohita (10.72 μg/g) (Javed, 2005), in Poecilia reticulate (34.9 μg/g) (Yap et al., 2008), but higher than those reported by Goldstein and Weese (1999) in Cyprinus carpio (0.14 μg/g). But the result of the present study coincides with the findings of Begum et al. (2005) in Tilapia nilotica (2.10 μg/g), Clarius batrachus (1.58 μg/g). Pb is mainly of atmospheric origin as a result of emissions from automobile exhaust fumes. Such sources of Pb could be more available to fishes caught from waters, at the banks of which, there are vast trunks of roads (Ghana, 2008) The ranges of international standards for fish are: zinc approximately 192– 480, copper 48–480, lead 2.4–48 μg/g dry weight (Yamazaki et al., 1996), provided that the conversion factor (wet/dry weight) is 4.8. The elemental concentration levels in present studies seem to be close to the international standards. Because in the present findings the concentrations were 96.33 and 14.91 μg/g for Zn; 23.66 and 56.35 μg/g for Cu; 2.07 and 1.99 μg/g for Pb (dry weight) in Wallago attu and Sperata sarwari respectively. This result coincided with the findings of Salam et al. (2002); Begum et al. (2005); Javed (2005); Ansari et al. (2006); Yap et al. (2008). When we compared our present values with the values of Canadian food standards (Cu: 100 μg/g; Zn: 100 μg/g), Hungarian standards (Cu: 60 μg/g; Zn: 150 μg/g) and the international standards (Cu: 10-100 μg/g; Zn: 40-100 μg/g) (Papagiannis et al., 2004; TFC, 2002), we find that our values are lower than their observations. From these results, we can conclude that these metals have no threat for consumption of these fishes. In the present studies, elemental composition showed variations in their concentrations both within and between the selected catfish species sampled. This CHAPTER 3 106 ELEMENTAL CONCENTRATION observation was supported by the findings of Windom et al. (1987); Javed and Hayat (1998); Chattopadhyay et al. (2002); Papagiannis et al. (2004) and Fawole et al. (2007) which showed that such variations in concentrations of these mineral elements from one species of fish to another might be due to the chemical forms of the elements, their concentrations in the local environment, metabolism and feeding patterns of fish and also the season in which studies were carried out. 3.4.1 Relationship between metal concentrations and size of fish: The comparison of simple correlations between metal concentrations and body length and weight showed a stronger dependency occurred between metal concentrations in the fish and body size of fish. Regression analysis was performed to evaluate the dependence of these metals with size. The allometric approach was used in which slope b of log-log regression of the relationship between total metal body load and total body length or weight, when compared with b=3 or b=1 is a good predictor for isometric or allometric increase of these metals with increasing body length or weight (Weatherley and Gill, 1987 and Salam and Davies, 1994). The effect of animal size on metal concentrations has been broadly accepted, mainly in monitoring studies. It is observed in most studies that the concentrations of different metals in the flesh, liver, gonads and bones of fish mostly decreased with increasing fish length. The negative relationships between elemental concentrations in the tissues and fish sizes were generally supported in the literature (Phillips, 1977; Bryan et al., 1980). In the present study, it was observed that all metals showed significant correlation (p<0.001) with total body weight and total body length in both species. In Wallago attu, the metals such as Nickel, zinc and lead were found to decrease with the increase of body weight showing negative allometry. While cadmium, cobalt, copper and iron were found to increase in direct proportion to an increase in body weight showing isometric growth (when the value of slope b is either equal to 1.0 or not significantly different from 1.0). In Sperata sarwari, cadmium, cobalt, iron and zinc showed direct proportion while copper, nickel and lead decreased with the increase of body weight showing isometric growth (Table 3.4).

CHAPTER 3 107 ELEMENTAL CONCENTRATION

The accumulation behavior of Zn, Cu, Fe, Co, Ni, Pb and Cd in whole body of Wallago attu and Sperata sarwari with the total length of fish was examined in terms of correlation coefficient (r). In Wallago attu, there were found good correlation coefficients for copper (0.84), zinc (0.88), iron (0.87), nickel (0.92), cobalt (0.89), cadmium (0.90) and lead (0.93) as in Table 3.5. While in case of Sperata sarwari, good correlation coefficients for iron (0.83), cobalt (0.75), cadmium (0.81) and lead (0.80) were found but copper (0.65), zinc (0.48) and nickel (0.63) showed poor correlation with total length of fish as in Table 3.6. These data are in good agreement with that reported by Evans et al. (1993) and Al-Yousuf et al. (2000). According to Farkas et al. (2000), there was negative correlation between metals (cadmium, copper, lead and zinc) and fish age but there was positive correlation for mercury. Nussey et al. (2000) reported that elemental concentrations (Cr, Mn, Ni, and Pb) decreased with an increase in the length of fish. In Wallago attu, it was observed that Zn, Ni, Fe, Cu, Cd, Pb and Co μg/g (dry weight) decreased with the increasing of total length which suggests that these metals are probably accumulated at lesser rate compared to its rate of excretion as the fish grow. While in case of Sperata sarwari Cu, Zn, Ni and Pb concentrations showed decline with the increase of total length of the fish. This result is in general agreement with the findings of Evans et al. (1993), Olszewska et al. (1994), Canli and Atli (2003) and Ansari et al. (2006). They found that Zn, Fe, Cu and some other essential metals do not increase in concentration with age and body length of the fish because they are thought to be under homeostatic control. Widianarko et al. (2000) investigated that there was a negative relationship between elemental concentrations and fish size. According to Al- Yousuf et al. (2000), copper and zinc levels increased with increasing fish size while manganese and cadmium levels decreased in skin of fish. Liang et al. (1999) investigated metal concentrations in different polycultured fish species and reported that metals in fish viscera were negatively correlated. Thus, elemental concentration was found to be higher in younger individuals than the older ones. It clearly indicates that with increasing fish length and weight the metal concentration decreases. Same results were observed in the present study. The negative correlation between fish age (length and weight) and the elemental concentration do not mean that there is a specific metal concentration at the start of the growth and there is no further addition of metals. But it is determined by the CHAPTER 3 108 ELEMENTAL CONCENTRATION

variation of feeding rate with age and the food speciation of certain age classes (Elder and Collins, 1991; Farkas et al., 2000; Nussey et al., 2000; Widianarko et al., 2000). 3.4.2 Influence of sex on elemental concentration in fish: In the present study, the average concentrations of zinc, cadmium and lead in S. sarwari and W. attu were found to be high in female as compared to male fishes but the differences are not so significant. Similar result for zinc was reported by Khan and Weis (1993). Al-Yousaf et al. (2000) reported that metal (Zn, Cu and Mn) concentrations in tissues of fishes collected from the Arabian Gulf were affected by the sex. They observed that the average metal concentrations in tissues of female fish were higher than those in male fish, indicating the difference in metabolic activities of the two sexes. 3.4.3 Comparison of elemental concentration in two species: In the present study, statistical comparisons revealed that metal concentrations were significantly different in Wallago attu and Sperata sarwari. Using analysis of variance (ANOVA) procedures, it was found that there were highly significant (P<0.000) differences between these two species of catfishes in relation to Fe, Cd, Cu, Zn and Ni concentrations (dry and wet weight). But there were no significance differences between Co and Pb concentrations in both species of catfishes. Previous findings also showed that different fish species contained strikingly different metal levels in their tissues (Kalay et al., 1999). In the previous studies of Salam et al. (2002), Javed (2005), Ansari et al. (2006) and Yap et al. (2008), we found that different species have different elemental concentrations (Tabel 3.13). These differences in elemental concentrations may be associated to the differences in environmental needs, swimming behaviors and the metabolic activities among different fish species. The differences in metal concentration in fish may also be due to their capability to induce metal-binding proteins such as metallothioneins (Kalay et al., 1999). 3.4.4 Influence of season on elemental concentration in fish: Previously, it has been observed that seasons have great effect on elemental concentrations in fishes (Farkas et al., 2000). In the present study, when analyzed the effect of season on metal concentration by using ANOVA, significant differences were observed in case of copper, zinc and lead in Wallago attu and zinc, lead concentrations in Sperata sarwari. These differences in metal concentration in different months of the year CHAPTER 3 109 ELEMENTAL CONCENTRATION in Wallago attu and Sperata sarwari may refer to seasonal changes in feeding habits. This fluctuation in elemental concentration may also be due to gain or loss of fish weight, sex, length, weight, or synthesis of metal binding protein in fish.

CHAPTER 3 110 ELEMENTAL CONCENTRATION

Table 3.21: The comparison of metal concentrations in different fish species.

Species Cu Zn Ni Fe Co Pb Cd Source Cirrhinus mrigala 24.1 65.7 - 538 - - - Salam et al., 2002 Labeo rohita - 94.28 10.72 253.52 - 4.65 - Javed, 2005 Cirrhinus mrigala - 88.17 8.34 239.99 - 4.62 - Javed, 2005 Catla catla 98.90 12.29 260.86 - 4.67 - Javed, 2005 Clarius batrachus 5.07 60.1 1.91 131 - 2.08 - Begum et al., 2005 Puntius chola 21.2 170.8 - 538 - - - Ansari et al., 2006 Poecilia reticulata 4.02 78.16 9.71 - - 36.36 2.57 Yap et al., 2008 Wallago attu 23.66 96.33 0.55 94.02 1.05 2.07 0.31 Present study Sperata sarwari 56.35 14.91 0.87 320.6 0.95 1.99 1.79 Present study

CHAPTER 4 111 MORPHOMETRICS

MORPHOMETRY 4.1 INTRODUCTION

“Morphometric study of fish describes the shape of fish in the simplest possible fashion, removing irrelevant information and thereby facilitating comparison between different fish species. So, morphometric is the study of shape variation and its co- variation with other variables of interests (Bookstein 1991; Dryden and Mardia 1998). Morphometricians use morphological information to understand the pattern of shape variation within and among sample (life stages, populations, species etc.) as well as in framing and testing hypothesis regarding the origin of those variations in the growth pattern. While taxonomists and systematists use morphological information to describe and diagnose species. Taxonomic classification of organisms, and understanding the diversity of biological life, were historically based on descriptions of morphological forms (Shearer, 1994; Dean et al., 2004). In fish, morphometric characters represent one of the major keys for determining their systematics, growth variability, ontogenetic trajectories (Kovac and Copp 1999).” Usually, a variety of morphological, physiological, meristical and behavioral characteristics are used to identify and classify fishes (Casselman et al., 1981; Ihssen et

al., 1981; Cadrin, 2000). “In practice, it is more common to use morphometric measurements (i.e., body length, body depth, head length, eye diameter, and jaw length). These morphometric measurements are usually presented as a proportion of standard, fork and total length (Howe, 2002). However, these methods often create problems (Jerry and Cairns 1998; Swain and Foote, 1999; Murta, 2002). As many scientists have been using these different length measurements of fish species, a lack of standardized methods has hindered attempts to produce the data. So, recently, genetic methods have been used for identification but they are costly and not readily available in the field (Hutchinson et al., 2001; Mariani et al., 2005). It is very important especially in comparative studies which little information seems to be available for fish species (Forese and Pauly, 2005).”

“Morphometrics can be affected by flowing water, trophic environment and different types of foraging associated with flow or trophic environments. While heritable genetic variation can account for some of the variation in body shape among these ecomorphs (Wainwright et al., 1991; Robinson and Wilson, 1996; Mittelbach et al., CHAPTER 4 112 MORPHOMETRICS

1999; Robinson et al., 2000; Hendry et al., 2006). It has also been observed that changes in length –weight parameter occur during metamorphosis. Metamorphosis from larva to juvenile reflects complex sequence of changes in external and internal morphology

(Deegan, 1985).”

“Geographical isolation can result in the development of different morphological features between fish populations because the interactive effects of environment, selection, and genetics on individual ontogenies produce morphometric differences with

in a species” (Cardin and Friedland, 1999; Poulet et al., 2005). Information on morphometric characters as well as length-weight patterns is necessary for assessment of the fishery to ensure sustainability and also form the basis for their inclusion in a regional food security programme.

4.1.1 Length-weight relationship The term growth means the signify change in magnitude. The changing variables may be length, volume, weight, mass, either of an organism’s whole body or of its various tissues. “The growth may also relate to the content of protein, lipid, other chemical constituents of the body or the caloric content of the whole body or of its components. However, the growth is considered in terms of increase in volume in most cases. The volume is represented by weight, which is related to the cube of linear dimension. It is fact that fish growth rates can respond sensitively to difference in food supply, population density and temperature under both natural and artificial conditions. It

is therefore, true that a relationship exists between length and weight in animals” (Weatherley and Gill, 1987; Shakir et al., 2008). Length-weight relationship is a mathematical formulation, which enables one variable to be predicted from the other (Brown and Murphy, 1991). “The relationship between weight and length for fish of a given population can be analyzed either by measuring weight and length of the same fish throughout their life or of a sample of fish taken at a particular time” (Wootton, 1990). The relationship between weight (W) and length (L) typically takes the allometric form as used by Weatherley and Gill (1987); Salam and Janjua (1991); and Naeem and Salam (2005): W = aLb CHAPTER 4 113 MORPHOMETRICS

In the linear form, this equation becomes: Log W = log a + b Log L Where a and b are constants estimated by regression analysis. If fish retains the same shape it grows isometrically and the length exponent b has the value b = 3.0, a value significantly larger or smaller than b = 3.0 shows allometric growth (Ricker, 1975; Bagenal and Tesch, 1978). Length and weight data are useful and standard results of fish sampling programs. Such data are essential for a wide number of studies, for example estimating growth rates, age structure, and other aspects of fish population dynamics (Kolher et al., 1995). In fish, size is generally more biologically relevant than age, mainly because several ecological and physiological factors are more size-dependent than age-dependent. Consequently, variability in size has important implications for diverse aspects of fisheries science and population dynamics (Erzini, 1994). Length-weight relationships are originally used to provide information on the condition of fish and may help to determine whether somatic growth is isometric or

allometric (Ricker, 1975). “Length–weight relationships (LWRs) are important in fishery management to calculate production and biomass of a fish population. The length-weight relationship also helps in predicting the condition, reproductive history, and life history of fish species and in morphological comparison of species and populations (Nikolsky, 1963; Wootton, 1990; Pauly, 1993; King, 1996; Gonçalves et al., 1997).”

“Length-weight regressions have been used frequently to estimate weight from length because direct weight measurements can be time consuming in the field (Sinovcic et al., 2004). Length-weight relationships are also widely used for: (i) conversion of growth-in-length equation to growth-in-weight for use in stock assessment models, (ii) estimation of biomass from length observations, (iii) estimation of the condition of fish, and (iv) between-region comparisons of life histories of certain species (Ricker, 1975; Weatherley and Gill, 1987; Wootton, 1990, 1998; Moutopoulos and Stergiou, 2002). Some recent examples of LWR studies include Salam and Mahmood, 1993; Craig et al., 2005; Britton and Harper, 2006; Hossain et al., 2006; Kalaycı et al., 2007; Ozcan, 2008 and Vaslet et al., 2008.” CHAPTER 4 114 MORPHOMETRICS

Although length-weight relationships are readily available for most European and North American freshwater and marine fishes (e.g. Bagenal and Tesch, 1978; Petrakis and Stergiou, 1995; Koutrakis and Tsikliras, 2003; Sinovcic et al., 2004; Oscoz et al., 2005; Leunda et al., 2006; Miranda et al., 2006), however adequate local information is still scarce for most carnivorous fish species. However, estimated growth parameters (length and weight) can deviate substantially from true estimates of the population parameters due to inadequacies in the sampling design (Safran, 1992). “For example, because nearly all fishery surveys are focused on commercial or recreational species, the resulting parameters are based on adults and the juvenile phase is often missing from the data sets. Present work will provide important information for the growth of catfish from Indus River and it can be helpful in future for the management of catfishes in Pakistan.”

4.1.2 Length-length relationship Total (TL), fork (FL) lengths and standard length (SL) are usually applied in

studies of fish growth and in systematic studies. “When making comparisons between populations, it is essential to use standard measures for all populations so that the results will be more reliable. That is why the length-length relationship of species under various environmental conditions should be known. So length-length relationship is important for comparative growth studies (Moutopoulos and Stergiou, 2002).”

4.1.3 Condition factor (K) The term ‘‘condition’’ is extensively used in ecological studies for the state of an

animal’s general health or its nutrient reserves (Schulte-Hostedde et al. 2005). “Condition factor studies take into consideration the health and general well-being of a fish that will determine present and future population success by its influence on growth, reproduction and survival. It is a quantitative parameter of the state of well-being of the fish as related to its environment; hence it represents how fairly deep bodied or robust fishes are. Thus animals of higher condition are expected to have greater probabilities of survival and future reproductive success (Kaufman and Johnston, 2007).” The condition of a fish reflects recent physical and biological circumstances, and fluctuates by interaction among CHAPTER 4 115 MORPHOMETRICS

feeding conditions, parasitic infections and physiological factors (Le Cren, 1951; Reynold, 1968). It is often assumed that body condition indices are good indicators of the energetic status of fish. Though several researchers have studied the relationships between condition indices and fish proximate composition (Salam and Janjua, 1991; Salam and Davies, 1994; Sutton et al., 2000; Salam et al., 2001; Simpkins et al., 2003; Brown and Murphy, 2004; Copeland and Carline, 2004; Pangle and Sutton, 2005), but few have examined this relationship in freshwater catfishes of this area. Further research is required to assess both the strength and the generality of relationships between condition indices and body composition in fish.

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4.1.4 Aims and Objectives of the Study: The aim of the present study is;  To develop a mathematical model between weight and length so as to derive one from the other.  To provide basic data on external as well as internal morphology (selected morphometric characters) of Wallago attu and Sperata sarwari from river of southern Punjab, Pakistan.  To determine whether there are significant morphometric differences in these two species.  To analyze growth variability of the characters studied.  This study can help in future for the comparison of fish measurements with other fishes in Pakistan.  The data on body measurement will be used to determine the geographical effect on nutritional value of the fish.  Age of fish can be determined by relatively mass versus length or size of other organs versus body length.  This study allows the estimation of biomass from length observation.

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4.2 MATERIALS AND METHODS Seventy eight specimens of wild Wallago attu and eighty specimens of wild Sperata sarwari of variable body sizes were sampled during 2005-2006 from different localities of Indus River of Southern Punjab with the help of a drag net. These fish were brought to the laboratory of Institute of Pure and Applied Biology, Bahauddin Zakariya University Multan. They were blotted dry and then all the morphometric parameters were measured individually as follows; 4.2.1 External morphometry: Nearly thirty external morphometric variables were measured on the head and body of each fish specimen using electronic digital balance, wooden measuring tray and other measuring scales to the nearest 0.1cm Wet Body Weight: In the laboratory, the fish were weighted on an electronic digital balance (MP-3000 Chyo, Japan) to the nearest 0.01g. Total length (TL): In fresh water rules measurement of total length is taken, flat not along the curve of the fish with mouth shut and tail fin pinched closed. Thus, total length was taken as the length from tip of the snout to the tip of the tail. Standard length (SL): Standard length was taken as the length from tip of the snout to the hidden base of the caudal fin. Fork length (FL): Fork length was taken as the length from the tip of the snout to the tip of the shortest median fin ray of the tail. Head length (HL): Head length was taken as the distance from the tip of the snout to the most distant point on the opercular membrane. Head width (HW): Head width was taken as a straight distance along the broadest part of the head in ventral position. Body girth (BG): Body girth was determined by drawing a string around the fish at its widest point marking where the string overlaps and then measuring the distance between the overlapping points on a conventional ruler. This measurement was taken perpendicular to the length of the fish. Inter-orbital width (IOW): Inter-orbital width was taken as the least distance between the bony rims between inner margins of eyes. CHAPTER 4 118 MORPHOMETRICS

Pre-orbital Length (PreOL): It was measured from the tip of the snout to the start of eye cup with the help of measuring scale. Post Orbital Length (POL): Post-orbital length was measured from the posterior edge of the eye cup to the posterior tip of the fleshy operculum with the help of measuring scale. Eye diameter (ED): Eye diameter was taken as the distance between the margins of the cartilaginous eyeball across the cornea. Pre dorsal Length: It is a length measured from anterior part of the mouth to the start of dorsal fin. It was measured with the help of wooden measuring tray. Post dorsal length: It is a length measured from dorsal fin of fish to the tip of the tail. It was measured with the help of wooden measuring tray. Pre Pelvic distance: It is a distance measured from the anterior part of the mouth to prior of pelvic fin. It was measured with the help of wooden measuring tray. Dorsal fin length: It was measured from anterior point of junction with body to the anterior tip of the fin.. It was measured with the help of measuring scale. Dorsal fin base: Dorsal fin base was taken as the greatest distance in straight line between the anterior most and posterior most point of junction with the body. Pectoral fin length: It was measured from anterior point of junction with body to the anterior tip of the fin. It was measured with the help of measuring scale. Pectoral fin base: Pectoral fin base was measured as the greatest distance in straight line between the anterior most and posterior most point of junction with the body with the help of measuring scale. Anal fin length: Anal fin was measured from anterior point of junction with body to the anterior tip of the fin. It was measured with the help of measuring scale. Anal fin base: It was measured as distance between 1st ray of anal fin and last fin ray. It was measured with the help of measuring scale. Caudal fin length: Caudal fin was measured from anterior point of junction with body to the anterior tip of the fin with the help of measuring scale. Caudal fin base: Caudal fin base was measured as the greatest distance in straight line between the anterior most and posterior most point of junction with the body with the help of measuring scale. CHAPTER 4 119 MORPHOMETRICS

Barbells length: All the barbells including nasal barbells, maxillary barbells and mandibular barbells were measured from base to tip of it with the help of measuring scale. Inter neural sheath: In case of Sperata sarwari, inter neural sheath is present which was measured by using the measuring scale. Dorsal fin Weight: It was excised with the help of sharp scissors, washed in distilled waster, blotted dry and weighed to a fraction of 0.01g. Pectoral fin weight: Pectoral fin was cut with the help of sharp scissors, washed in distilled water , blotted dry and weighed to the fraction of 0.01g. Anal fin weight: It was excised with the help of sharp scissors, washed in distilled waster, blotted dry and weighed to a fraction of 0.01g. Caudal fin weight: Caudal fin was cut with the help of sharp scissors, washed in distilled water, blotted dry and weighed to a fraction of 0.01 g. 4.2.2 Internal morphometry: In both species, all the specimens were dissected and visceral organs (heart, liver, gall bladder, intestine, spleen, stomach, gonads, kidney, air bladder and eye ball) were excised and removed carefully, then weighed individually on an electronic digital balance (Chyo, MP-3000, Japan) to the nearest 0.01 g.

4.2.3 Statistical Analysis: The statistical analysis and graphics were performed by using computer packages of Microsoft Excel, Lotus 1-2-3, Minitab etc, following (Fisher and Yates, 1963; Zar, 1996).

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Fig.: Different Morphometric measurements of Wallago attu.

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4.3 RESULTS The mean values, ranges and standard deviation (± S.D.) of various external and internal morphometric parameters for Wallago attu and Sperata sarwari are given in Table 4.1 and 4.2. The correlations of various morphometric parameters in relation to total body length and wet body weight are analyzed and described in the sections below. 4.3.1 Total length-Wet body weight: A highly significant position correlation (P<0.001) was found between total length and wet body weight in untransformed and log transformed data in both species of catfishes. On calculation of regression coefficient ‘b’ between the total body length and wet body weight, it was observed that it was b=3.27 for Wallago attu and b=3.28 for Sperata sarwari. It indicated that both the parameters increased at an accelerating rate, not consistent with the cube law, showing positive allometry (where b value is more than 3) (Table 4.3). 4.3.2 Condition factor-Total length and wet body weight: When condition factor k was plotted against total length and wet body weight, it was observed that it has increasing trend with increasing length or weight in both species of catfishes. The regression parameters of condition factor with wet body weight (W) and total length (TL) in both species are presented below; In Wallago attu, K = 0.32+0.004 TL (r=0.522) K = 0.40+0.0003 W (r=0.613) In Sperata sarwari, K = 0.33+0.004 TL (r=0.270) K = 0.38+0.0004 W (r=0.528)

4.3.3 Wet body weight-Length of external body parameters: In Wallago attu, when wet body weight was plotted against lengths of other body parameters, highly significant correlations (P<0.001) were observed between them. The regression coefficient ‘b’ values of all the parameters except head width, inter orbital length, post orbital length, dorsal fin base, pectoral fin base, pelvic fin base and maxillary barbells length were little bit lower than b=0.33 showing negative allometry (Table 4.5). CHAPTER 4 122 MORPHOMETRICS

In Sperata sarwari, highly significant correlation (P<0.001) was found between wet body weight and lengths of other body parameters. Here the regression coefficient ‘b’ has values little bit lower than b=0.33 indicating negative allometry growth except for inter orbital length, post orbital length, pelvic fin base and inter neural sheath which have b values either equal to b=0.33 or more than it (Table 4.6). 4.3.4 Total length-Length of external body parameters: Highly significant correlations (P<0.001) were found between total length and lengths of other body parts in both species i.e. Wallago attu and Sperata sarwari. However, the correlation coefficient for nasal barbells length (0.435), interior mandible barbells length (0.441), eye diameter (0.705), maxillary barbells length (0.725), exterior mandible barbells length (0.757) and caudal fin length (0.791) were found poor with total body length of Sperata sarwari. On calculation of regression coefficient, it was observed that in Wallago attu all the morphometric parameters showed isometric growth with total length of the fish (where b=1 or near to 1) except eye diameter (b=0.685), anal fin length (0.857), caudal fin length (0.892) and mandible barbells length (b=0.769). While in Sperata sarwari, except for head width (0.889), eye diameter (0.403), maxillary barbells length (0.535), nasal barbells length (0.623) and exterior mandible barbells length (0.701), all the morphometric parameters showed isometric growth with total length. The statistical relationship between total length and lengths of other body parameters for Wallago attu and Sperata sarwari are shown in tables 4.7 & 4.8 respectively. 4.3.5 Wet body weight-Weight of external body parts: Highly significant positive correlations were found between log transformed data of dorsal fin weight, pectoral fin weight, pelvic fin weight, anal fin weight and caudal fin weight versus log wet body weight in both Wallago attu and Sperata sarwari. When regression coefficient was calculated, it was found that ‘b’ value except for dorsal fin weight (b=0.865), was near to one showing isometric growth with relation to wet body weight of Wallago attu. In case of Sperata sarwari, except for caudal fin weight (0.843), b values for all the parameters were near about equal to one indicating isometric growth. The statistical results for Wallago attu and Sperata sarwari are given in tables 4.9 and 4.10 respectively. CHAPTER 4 123 MORPHOMETRICS

4.3.6 Total length-Weight of external body parts: Highly significant positive correlations were found between log transformed data of dorsal fin weight, pectoral fin weight, pelvic fin weight, anal fin weight, caudal fin weight with log wet body weight in both species of catfishes in the present study. When regression coefficient was calculated, it was found that ‘b’ values were more than 3 in all cases except for dorsal fin weight (2.85) showing positive allometric growth with relation to total length for the Wallago attu (table 4.11). In Sperata sarwari, except for caudal fin weight (2.80), b value was more than 3 indicating positive allometry (Table 4.12). 4.3.7 Wet body weight-Weight of internal body organs: Highly significant positive correlations were found between log transformed data of all the parameters versus log wet body weight in both species of catfishes. In Wallago attu, the regression coefficient ‘b’ for heart weight, liver weight, gall bladder weight, intestine weight, spleen weight, stomach total weight, stomach empty weight, kidney weight and eye ball weight against log wet body weight was found to be negative allometric (b>1) while for gonads weight and air bladder weight was found isometric (where b value was near to 1). In Sperata sarwari, except for air bladder weight, all the parameters showed negative allometric growth (b>1) with relation to wet body weight. These results are shown in table 4.13 and 4.14 for Wallago attu and Sperata sarwari respectively. 4.3.8 Total length-Weight of internal body organs: Highly significant positive correlations were found between log transformed data of all the internal body organ weight against log total length. When regression coefficient was applied, it was found that ‘b’ values for all the parameters except for gonads weight and air bladder weight were observed lower than 3 showing negative allometric growth in Wallago attu. In Sperata sarwari, b values for all the parameters except for air bladder weight were found less than 3 showing negative allometic growth against total length. The results of all these relationships are given in table 4.15 and 4.16 for Wallago attu and Sperata sarwari respectively.

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Table 4.1: Mean values, ranges and standard deviations of various external morphometric parameters of Wallago attu and Sperata sarwari.

Morphometric Wallago attu Sperata sarwari parameters Mean ± S.D. Ranges Mean ± S.D. Ranges

Wet body weight, g 205.72±159.21 14.54-648.82 173.51±70.49 52.12-439.60 Total length, cm 33.09 ± 8.89 16.70-50.20 33.11 ± 4.13 23.80-42.00 Fork length, cm 30.92 ± 8.39 15.10-46.60 27.26 ± 3.49 19.00-36.00 Standard length, cm 29.04 ± 7.96 14.40-44.00 25.37 ± 3.27 18.00-33.30 Head length, cm 6.38 ± 1.66 3.20-9.30 7.16 ± 0.90 5.30-9.70 Head width, cm 3.10 ± 0.96 1.30-5.20 3.01 ± 0.41 2.00-4.30 Body girth, cm 13.66 ± 3.91 6.00-21.90 13.07 ± 1.80 8.90-18.30 Eye diameter, cm 0.76 ± 0.15 0.40-1.00 0.78 ± 0.06 0.70-1.00 Inter orbital length cm 3.29 ± 1.00 1.60-5.50 1.59 ± 0.24 1.00-2.40 Pre orbital length, cm 2.16 ± 0.57 1.20-3.40 1.99 ± 0.27 1.40-2.70 Post orbital length, cm 3.61 ± 1.03 1.70-5.60 4.42 ± 0.62 3.10-6.00 Pre dorsal length, cm 8.16 ± 2.27 4.20-12.10 10.37 ± 1.34 7.50-13.50 Post dorsal length, cm 20.31 ± 5.65 10.00-31.00 11.46 ± 1.50 8.10-15.30 Pre pelvic length, cm 10.16 ± 2.80 4.90-15.80 14.55 ± 1.89 10.20-19.10 Dorsal fin length, cm 4.04 ± 1.10 2.00-6.40 5.69 ± 0.73 4.10-7.00 Dorsal fin base, cm 0.36 ± 0.12 0.10-0.60 3.38 ± 0.46 2.30-4.50 Dorsal fin weight, g 0.07 ± 0.05 0.01-0.19 0.51 ± 0.21 0.14-1.23 Pectoral fin length cm 4.17 ± 1.15 1.90-6.30 3.73 ± 0.49 2.50-4.80 Pectoral fin base, cm 1.15 ± 0.35 0.50-1.80 0.89 ± 0.13 0.60-1.20 Pectoral fin weight, g 0.34 ± 0.27 0.02-0.98 0.26 ± 0.10 0.07-0.48 Pelvic fin length, cm 1.94 ± 0.53 0.90-3.00 3.14 ± 0.40 2.30-4.10 Pelvic fin base, cm 0.98 ± 0.32 0.40-1.70 0.78 ± 0.12 0.50-1.10 Pelvic fin weight, g 0.07 ± 0.05 0.01-0.24 0.21 ± 0.09 0.06-0.54 Anal fin length, cm 1.48 ± 0.38 0.80-2.30 3.20 ± 0.41 2.30-4.10 Anal fin base, cm 16.92 ± 4.38 8.60-24.60 2.27 ± 0.31 1.60-3.00 Anal fin weight, g 0.71 ± 0.57 0.04-2.66 0.19 ± 0.08 0.06-0.59 Caudal fin length, cm 4.07 ± 1.04 1.80-6.30 7.69 ± 1.13 4.70-10.20 Caudal fin base, cm 1.12 ± 0.33 0.50-1.80 - - Caudal fin weight, g 0.19 ± 0.16 0.02-0.69 0.75 ± 0.30 0.25-1.99 Maxillary barbell L 12.76 ± 3.99 4.70-21.00 15.61 ± 1.43 11.50-18.40 Mandible barbell L 2.10 ± 0.49 0.90-3.20 - - Outer mandible BL - - 4.69 ± 0.55 3.50-5.90 Inner mandible BL - - 3.05 ± 0.97 1.50-8.30 Nasal barbell length - - 1.42 ± 0.25 0.80-2.00 Inter nural sheath, cm - - 2.28 ± 0.37 1.50-3.30 S.D. = Standard Deviation

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Table 4.2: Mean values, ranges and standard deviations of various internal morphometric parameters of Wallago attu and Sperata sarwari.

Morphometric Wallago attu Sperata sarwari parameters Mean ± Ranges Mean ± S.D. Ranges S.D. Heart weight (g) 0.19 ± 0.17 0.03-0.78 0.14 ± 0.06 0.05-0.38 Liver weight (g) 1.31 ± 1.02 0.16-4.03 0.79 ± 0.41 0.21-2.85 Gall bladder weight (g) 0.06 ± 0.04 0.01-0.17 0.04 ± 0.02 0.02-0.09 Intestine weight (g) 1.80 ± 1.17 0.30-4.83 1.34 ± 0.60 0.47-3.88 Intestine length (cm) 19.64 ± 6.00 7.50-32.60 22.94 ± 3.54 15.50-32.50 Spleen weight (g) 0.11 ± 0.06 0.01-0.31 0.10 ± 0.05 0.02-0.26 Stomach full weight (g) 4.18 ± 7.07 0.34-55.76 1.75 ± 1.07 0.54-8.54 Stomach empty weight (g) 2.46 ± 2.47 0.26-16.45 1.10 ± 0.44 0.40-2.93 Gonads weight (g) 0.28 ± 0.30 0.01-1.24 0.12 ± 0.10 0.03-0.35 Kidney weight (g) 0.95 ± 0.62 0.16-2.57 0.58 ± 0.30 0.13-1.79 Air bladder weight (g) 1.87 ± 1.58 0.10-5.80 2.41 ± 1.08 0.77-7.85 Eye ball weight (g) 0.14 ± 0.07 0.04-0.32 0.17 ± 0.10 0.06-0.25 S.D. = Standard Deviation

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Table 4.3: Total Length-Wet body weight relationship in Wallago attu and Sperata sarwari

Species Relationship n r a b S.E (b) Wallago Total length (cm) 78 0.945*** -353.96 16.92 0.67 attu Wet body weight (g) Lot total length (cm) 78 0.993*** -2.77 3.27 0.046 Log wet body weight (g) Sperata Total length (cm) 80 0.934*** -354.98 15.96 0.69 sarwari Wet body weight (g) Lot total length (cm) 80 0.964*** -2.77 3.28 0.102 Log wet body weight (g) Significant level = ***P < 0.001

Table 4.4: Total length-Condition factor and Wet body weight-Condition factor relationships in Wallago attu and Sperata sarwari.

Species Relationship n r a b S.E (b) Wallago Total length (cm) 78 0.522*** 0.32 0.004 0.001 attu Condition factor Wet body weight (g) 78 0.613*** 0.40 0.0003 0.00004 Condition factor Sperata Total length (cm) 80 0.270* 0.33 0.004 0.0001 sarwari Condition factor Wet body weight (g) 80 0.528*** 0.38 0.0004 0.0001 Condition factor Significant level = ***P < 0.001, *P < 0.05

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Table 4.5: Regression equation, standard errors, correlation coefficient and t-test between wet body weight and other morphometric parameters of Wallago attu.

Regression equation n r a b S.E (b) t-value when b=0.33

Log wet body wt (g) 78 0.994*** 0.816 0.305 0.004 - 6.25 Log FL Log wet body wt (g) 78 0.994*** 0.784 0.308 0.004 - 5.50 Log SL Log wet body wt (g) 78 0.993*** 0.167 0.289 0.004 - 10.25 Log HL Log wet body wt (g) 78 0.989*** -0.268 0.343 0.006 2.17 Log HW Log wet body wt (g) 78 0.985*** 0.443 0.313 0.006 - 2.83 Log BG Log wet body wt (g) 78 0.945*** -0.580 0.209 0.009 - 13.44 Log ED Log wet body wt (g) 78 0.991*** -0.215 0.331 0.005 0.20 Log IOL Log wet body wt (g) 78 0.974*** -0.275 0.277 0.007 - 7.57 Log PreOL Log wet body wt (g) 78 0.993*** -0.153 0.321 0.005 - 1.80 Log POL Log wet body wt (g) 78 0.995*** 0.227 0.310 0.006 - 3.33 Log PreDL Log wet body wt (g) 78 0.993*** 0.614 0.314 0.004 - 4.00 Log PDL Log wet body wt (g) 78 0.992*** 0.329 0.307 0.005 - 4.60 Log PPL Log wet body wt (g) 78 0.957*** -0.029 0.287 0.009 - 4.78 Log DFL Log wet body wt (g) 78 0.919*** -1.265 0.367 0.018 2.06 Log DFB Log wet body wt (g) 78 0.988*** -0.065 0.310 0.006 - 3.33 Log PFL Log wet body wt (g) 78 0.973*** -0.705 0.346 0.009 1.78 Log PFB Log wet body wt (g) 78 0.981*** -0.393 0.308 0.007 - 3.14 Log PelFL Log wet body wt (g) 78 0.965*** -0.805 0.358 0.011 2.55 Log PelFB Log wet body wt (g) 78 0.906*** -0.399 0.257 0.014 - 5.21 Log AFL CHAPTER 4 128 MORPHOMETRICS

Log wet body wt (g) 78 0.986*** 0.589 0.290 0.006 - 6.67 Log AFB Log wet body wt (g) 78 0.927*** 0.018 0.268 0.012 - 5.17 Log CFL Log wet body wt (g) 78 0.941*** -0.645 0.313 0.013 - 1.31 Log CFB Log wet body wt (g) 78 0.955*** 0.334 0.348 0.012 1.50 Log MaxBL Log wet body wt (g) 78 0.882*** -0.200 0.236 0.015 - 6.27 Log ManBL Significant level = ***P < 0.001 W = wet body weight, FL = fork length, SL = standard length, HL = head length, HW = head width, BG = body girth, ED = eye diameter, IOL = inter orbital length, PreOL = pre orbital length, POL = post orbital length, PreDL = pre dorsal length, PDL = post dorsal length, PPL = pre pelvic length, DFL = dorsal fin length, DFB = dorsal fin base, PFL = fectoral fin length, PFB = pectoral fin base, PelFL = pelvic fin length, PelFB = pelvic fin base, AFL = anal fin length, AFB = anal fin base, CFL = caudal fin length, CFB = caudal fin base, MaxBL = maxillary barbells length, ManBL = mandibular barbells length.

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Table 4.6: Regression equation, standard errors, correlation coefficient and t-test between wet body weight and other morphometric parameters of Sperata sarwari.

Regression equation n r a b S.E (b) t-value when b=0.33

Log wet body wt (g) 80 0.982*** 0.778 0.297 0.006 -5.5 Log FL Log wet body wt (g) 80 0.988*** 0.738 0.301 0.005 -5.3 Log SL Log wet body wt (g) 80 0.982*** 0.213 0.290 0.006 -6.67 Log HL Log wet body wt (g) 80 0.873*** -0.134 0.277 0.018 -2.94 Log HW Log wet body wt (g) 80 0.977*** 0.418 0.315 0.008 -1.88 Log BG Log wet body wt (g) 80 0.738*** -0.384 0.124 0.013 -15.85 Log ED Log wet body wt (g) 80 0.951*** -0.532 0.332 0.012 0.17 Log IOL Log wet body wt (g) 80 0.946*** -0.372 0.303 0.012 -2.25 Log PreOL Log wet body wt (g) 80 0.983*** -0.078 0.327 0.007 -0.43 Log POL Log wet body wt (g) 80 0.981*** 0.353 0.299 0.007 -4.43 Log PreDL Log wet body wt (g) 80 0.979*** 0.396 0.299 0.007 -4.43 Log PDL Log wet body wt (g) 80 0.989*** 0.490 0.304 0.005 -5.3 Log PPL Log wet body wt (g) 80 0.926*** 0.130 0.282 0.013 -3.69 Log DFL Log wet body wt (g) 80 0.973*** -0.169 0.315 0.009 -1.67 Log DFB Log wet body wt (g) 80 0.942*** -0.088 0.298 0.012 -2.67 Log PFL Log wet body wt (g) 80 0.850*** -0.696 0.290 0.020 -3.0 Log PFB Log wet body wt (g) 80 0.966*** -0.139 0.287 0.009 -4.78 Log PelFL Log wet body wt (g) 80 0.907*** -0.826 0.323 0.017 -0.41 Log PelFB Log wet body wt (g) 80 0.914*** -0.110 0.277 0.014 -3.79 Log AFL Log wet body wt (g) 80 0.930*** -0.308 0.300 0.013 -2.31 Log AFB CHAPTER 4 130 MORPHOMETRICS

Log wet body wt (g) 80 0.642*** 0.391 0.223 0.030 -3.57 Log CFL Log wet body wt (g) 80 0.384*** -0.211 0.162 0.044 -3.82 Log NBL Log wet body wt (g) 80 0.700*** 0.857 0.152 0.017 -10.47 Log MaxBL Log wet body wt (g) 80 0.743*** 0.223 0.202 0.021 -6.10 Log outer ManBL Log wet body wt (g) 80 0.443*** -0.086 0.252 0.058 -1.34 Log inner ManBL Log wet body wt (g) 80 0.950*** -0.438 0.358 0.013 2.15 Log Int. NS Significant level = ***P < 0.001 W = wet body weight, FL = fork length, SL = standard length, HL = head length, HW = head width, BG = body girth, ED = eye diameter, IOL = inter orbital length, PreOL = pre orbital length, POL = post orbital length, PreDL = pre dorsal length, PDL = post dorsal length, PPL = pre pelvic length, DFL = dorsal fin length, DFB = dorsal fin base, PFL = fectoral fin length, PFB = pectoral fin base, PelFL = pelvic fin length, PelFB = pelvic fin base, AFL = anal fin length, AFB = anal fin base, CFL = caudal fin length, CFB = caudal fin base, NBL = nasal barbell length, MaxBL = maxillary barbells length, ManBL = mandibular barbells length and Int.NS = internual sheeth.

CHAPTER 4 131 MORPHOMETRICS

Table 4.7: Regression equation, standard errors, correlation coefficient and t-test between total length and other morphometric parameters of Wallago attu.

Regression equation n r a b S.E t-value (b) when b = 1 Log total length (cm) 78 0.999*** -0.048 1.012 0.004 3.00 Log FL Log total length (cm) 78 0.999*** -0.085 1.018 0.005 3.60 Log SL Log total length (cm) 78 0.994*** -0.644 0.954 0.012 - 3.83 Log HL Log total length (cm) 78 0.984*** -1.219 1.123 0.023 5.35 Log HW Log total length (cm) 78 0.969*** -0.409 1.015 0.030 0.50 Log BG Log total length (cm) 78 0.940*** -1.160 0.685 0.029 - 10.86 Log ED Log total length (cm) 78 0.989*** -1.138 1.088 0.019 4.63 Log IOL Log total length (cm) 78 0.980*** -1.058 0.917 0.021 - 3.95 Log PreOL Log total length (cm) 78 0.992*** -1.052 1.059 0.015 3.93 Log POL Log total length (cm) 78 0.991*** -0.648 1.026 0.016 1.63 Log PreDL Log total length (cm) 78 0.999*** -0.275 1.041 0.006 6.83 Log PDL Log total length (cm) 78 0.992*** -0.532 1.012 0.014 0.86 Log PPL Log total length (cm) 78 0.962*** -0.841 0.952 0.031 - 1.55 Log DFL Log total length (cm) 78 0.916*** -2.287 1.205 0.061 3.36 Log DFB Log total length (cm) 78 0.990*** -0.938 1.025 0.017 1.47 Log PFL Log total length (cm) 78 0.978*** -1.681 1.144 0.028 5.14 Log PFB Log total length (cm) 78 0.984*** -1.260 1.017 0.021 0.81 Log PelFL Log total length (cm) 78 0.969*** -1.814 1.183 0.035 5.23 Log PelFB Log total length (cm) 78 0.915*** -1.133 0.857 0.043 - 3.33 Log AFL Log total length (cm) 78 0.995*** -0.236 0.964 0.011 - 3.27 Log AFB CHAPTER 4 132 MORPHOMETRICS

Log total length (cm) 78 0.938*** -0.747 0.892 0.038 - 2.84 Log CFL Log total length (cm) 78 0.945*** -1.525 1.033 0.041 0.80 Log CFB Log total length (cm) 78 0.963*** -0.651 1.153 0.037 4.14 Log MaxBL Log total length (cm) 78 0.872*** -0.847 0.769 0.050 - 4.62 Log ManBL Significant level = ***P < 0.001 TL = total length, FL = fork length, SL = standard length, HL = head length, HW = head width, BG = body girth, ED = eye diameter, IOL = inter orbital length, PreOL = pre orbital length, POL = post orbital length, PreDL = pre dorsal length, PDL = post dorsal length, PPL = pre pelvic length, DFL = dorsal fin length, DFB = dorsal fin base, PFL = fectoral fin length, PFB = pectoral fin base, PelFL = pelvic fin length, PelFB = pelvic fin base, AFL = anal fin length, AFB = anal fin base, CFL = caudal fin length, CFB = caudal fin base, MaxBL = maxillary barbells length, ManBL = mandibular barbells length.

CHAPTER 4 133 MORPHOMETRICS

Table 4.8: Regression equation, standard errors, correlation coefficient and t-test between total length and other morphometric parameters of Sperata sarwari.

Regression equation n r a b S.E t-value (b) when b = 1 Log total length (cm) 80 0.976*** -0.090 1.004 0.025 0.15 Log FL Log total length (cm) 80 0.979*** -0.136 1.013 0.024 0.54 Log SL Log total length (cm) 80 0.968*** -0.620 0.970 0.028 -1.07 Log HL Log total length (cm) 80 0.825*** -0.873 0.889 0.069 -1.61 Log HW Log total length (cm) 80 0.945*** -0.461 1.037 0.041 0.90 Log BG Log total length (cm) 80 0.705*** -0.721 0.403 0.046 -12.98 Log ED Log total length (cm) 80 0.924*** -1.464 1.096 0.051 1.88 Log IOL Log total length (cm) 80 0.937*** -1.253 1.021 0.043 0.49 Log PreOL Log total length (cm) 80 0.964*** -1.009 1.088 0.034 2.59 Log POL Log total length (cm) 80 0.974*** -0.518 1.009 0.027 0.33 Log PreDL Log total length (cm) 80 0.972*** -0.477 1.011 0.028 0.39 Log PDL Log total length (cm) 80 0.975*** -0.386 1.019 0.026 0.73 Log PPL Log total length (cm) 80 0.933*** -0.713 0.966 0.042 -0.81 Log DFL Log total length (cm) 80 0.955*** -1.069 1.051 0.037 1.38 Log DFB Log total length (cm) 80 0.937*** -0.960 1.007 0.043 0.16 Log PFL Log total length (cm) 80 0.826*** -1.511 0.959 0.074 -0.55 Log PFB Log total length (cm) 80 0.952*** -0.965 0.961 0.035 -1.11 Log PelFL Log total length (cm) 80 0.902*** -1.770 1.091 0.059 1.54 Log PelFB Log total length (cm) 80 0.881*** -0.878 0.909 0.055 -1.65 Log AFL Log total length (cm) 80 0.914*** -1.166 1.001 0.050 0.03 Log AFB CHAPTER 4 134 MORPHOMETRICS

Log total length (cm) 80 0.791*** -0.533 0.933 0.082 -0.82 Log CFL Log total length (cm) 80 0.435*** -0.800 0.623 0.146 -2.58 Log NBL Log total length (cm) 80 0.725*** 0.380 0.535 0.058 -8.02 Log MaxBL Log total length (cm) 80 0.757*** -0.395 0.701 0.068 -4.40 Log outer ManBL Log total length (cm) 80 0.441*** -0.824 0.852 0.196 -0.76 Log inner ManBL Log total length (cm) 80 0.943*** -1.482 1.209 0.048 4.35 Log Int. NS Significant level = ***P < 0.001 TL = total length, FL = fork length, SL = standard length, HL = head length, HW = head width, BG = body girth, ED = eye diameter, IOL = inter orbital length, PreOL = pre orbital length, POL = post orbital length, PreDL = pre dorsal length, PDL = post dorsal length, PPL = pre pelvic length, DFL = dorsal fin length, DFB = dorsal fin base, PFL = fectoral fin length, PFB = pectoral fin base, PelFL = pelvic fin length, PelFB = pelvic fin base, AFL = anal fin length, AFB = anal fin base, CFL = caudal fin length, CFB = caudal fin base, NBL = nasal barbell length, MaxBL = maxillary barbells length, ManBL = mandibular barbells length, Int.NS = inter nural sheeth.

CHAPTER 4 135 MORPHOMETRICS

Table 4.9: The regression parameters of various body fins weight in relation to wet body weight (W) of Wallago attu. Regression equation n r a b S.E (b) t-value when b=1 Log wet body weight 78 0.974*** -3.180 0.865 0.023 - 5.87 Log DFW Log wet body weight 78 0.989*** -2.930 1.059 0.018 3.28 Log PFW Log wet body weight 78 0.966*** -3.380 0.949 0.029 - 1.76 Log PelFW Log wet body weight 78 0.939*** -2.376 0.958 0.040 - 1.05 Log AFW Log wet body weight 78 0.965*** -2.905 0.940 0.029 - 2.07 Log CFW ***P < 0.001, DFW = dorsal fin weight, PFW = pectoral fin weight, PelFW = pelvic fin weight, AFW = anal fin weight, CFW = caudal fin weight

Table 4.10: The regression parameters of various body fins weight in relation to wet body weight (W) of Sperata sarwari.

Regression equation n r a b S.E (b) t-value when b=1 Log wet body weight 80 0.920*** -2.344 0.913 0.044 -1.98 Log DFW Log wet body weight 80 0.908*** -2.673 0.933 0.049 -1.37 Log PFW Log wet body weight 80 0.945*** -2.917 0.999 0.039 -0.03 Log PelFW Log wet body weight 80 0.933*** -2.932 0.984 0.043 -0.37 Log AFW Log wet body weight 80 0.910*** -2.012 0.843 0.043 -3.65 Log CFW ***P < 0.001, DFW = dorsal fin weight, PFW = pectoral fin weight, PelFW = pelvic fin weight, AFW = anal fin weight, CFW = caudal fin weight

CHAPTER 4 136 MORPHOMETRICS

Table 4.11: The regression parameters of various body fins weight with relation to total length (TL) of Wallago attu. Regression equation n r a b S.E (b) t-value when b=3 Log total length 78 0.973*** -5.603 2.850 0.077 - 1.95 Log DFW Log total length 78 0.991*** -5.905 3.497 0.053 9.38 Log PFW Log total length 78 0.971*** -6.056 3.140 0.089 1.57 Log PelFW Log total length 78 0.952*** -5.123 3.200 0.118 1.69 Log AFW Log total length 78 0.967*** -5.544 3.102 0.094 1.09 Log CFW ***P < 0.001, DFW = dorsal fin weight, PFW = pectoral fin weight, PelFW = pelvic fin weight, AFW = anal fin weight, CFW = caudal fin weight.

Table 4.12: The regression parameters of various body fins weight with relation to total length (TL) of Sperata sarwari. Regression equation n r a b S.E (b) t-value when b=3 Log total length 80 0.913*** -5.005 3.081 0.156 0.52 Log DFW Log total length 80 0.908*** -5.425 3.170 0.166 1.02 Log PFW Log total length 80 0.930*** -5.782 3.340 0.150 2.27 Log PelFW Log total length 80 0.923*** -5.784 3.310 0.156 1.99 Log AFW Log total length 80 0.890*** -4.405 2.802 0.162 -1.22 Log CFW ***P < 0.001, DFW = dorsal fin weight, PFW = pectoral fin weight, PelFW = pelvic fin weight, AFW = anal fin weight, CFW = caudal fin weight.

CHAPTER 4 137 MORPHOMETRICS

Table 4.13: Regression Analysis of Various log internal body organs against log wet body weight (g) in Wallago attu.

Relationships n r a b S.E.(b) Log wet body weight, g Log heart weight, g 78 0.904*** -2.453 0.742 0.040 Log wet body weight, g Log liver weight, g 78 0.890*** -1.608 0.743 0.044 Log wet body weight, g Log gall bladder weight, g 78 0.927*** -2.814 0.691 0.032 Log wet body weight, g Log intestine weight, g 78 0.951*** -1.367 0.709 0.026 Log wet body weight, g Log spleen weight, g 78 0.897*** -2.437 0.647 0.037 Log wet body weight, g Log stomach total weight, g 78 0.802*** -1.112 0.713 0.061 Log wet body weight, g Log stomach empty weight, g 78 0.946*** -.576 0.843 0.033 Log wet body weight, g Log gonads weight, g 78 0.803*** -3.109 1.061 0.090 Log wet body weight, g Log kidney weight, g 78 0.857*** -1.433 0.613 0.042 Log wet body weight, g Log air bladder weight, g 78 0.987*** -2.313 1.109 0.020 Log wet body weight, g Log eye ball weight, g 78 0.953*** -2.033 0.528 0.019 Significant level = ***P < 0.001

CHAPTER 4 138 MORPHOMETRICS

Table 4.14: Regression Analysis of Various log internal body organs against log wet body weight (g) in Sperata sarwari.

Relationships n r a b S.E.(b) Log wet body weight, g 80 0.869*** -2.693 0.821 0.053 Log heart weight, g Log wet body weight, g 80 0.828*** -2.217 0.939 0.072 Log liver weight, g Log wet body weight, g 80 0.762*** -2.931 0.690 0.066 Log gall bladder weight, g Log wet body weight, g 80 0.851*** -1.84 0.878 0.061 Log intestine weight, g Log wet body weight, g 80 0.899*** 0.639 0.325 0.018 Log intestine length, g Log wet body weight, g 80 0.658*** -2.950 0.853 0.111 Log spleen weight, g Log wet body weight, g 80 0.775*** -1.636 0.830 0.077 Log stomach total weight, g Log wet body weight, g 80 0.911*** -1.853 0.844 0.043 Log stomach empty weigt, g Log wet body weight, g 80 0.474*** -2.634 0.733 0.154 Log gonads weight, g Log wet body weight, g 80 0.752*** -2.252 0.890 0.088 Log kidney weight, g Log wet body weight, g 80 0.971*** -1.865 1.001 0.028 Log air bladder weight, g Log wet body weight, g 80 0.580*** -1.912 0.507 0.081 Log eye ball weight, g Significant level = ***P < 0.001

CHAPTER 4 139 MORPHOMETRICS

Table 4.15: Regression Analysis of Various log internal body organs against log total length (cm) in Wallago attu.

Relationships n r a b S.E.(b) Log total length, cm Log heart weight, g 78 0.891*** -4.479 2.411 0.141 Log total length, cm Log liver weight, g 78 0.873*** -3.619 2.401 0.154 Log total length, cm Log gall bladder weight, g 78 0.917*** -4.710 2.251 0.113 Log total length, cm Log intestine weight, g 78 0.943*** -3.321 2.314 0.094 Log total length, cm Log spleen weight, g 78 0.887*** -4.214 2.109 0.126 Log total length, cm Log stomach total weight, g 78 0.758*** -2.914 2.220 0.219 Log total length, cm Log stomach empty weight, g 78 0.924*** -3.840 2.713 0.128 Log total length, cm Log gonads weight, g 78 0.812*** -6.134 3.532 0.292 Log total length, cm Log kidney weight, g 78 0.854*** -3.138 2.012 0.140 Log total length, cm Log air bladder weight, g 78 0.979*** -5.371 3.623 0.086 Log total length, cm Log eye ball weight, g 78 0.590*** -3.503 1.734 0.065 Significant level = ***P < 0.001

CHAPTER 4 140 MORPHOMETRICS

Table 4.16: Regression Analysis of Various log internal body organs against log total length (cm) in Sperata sarwari.

Relationships n r a b S.E.(b) Log total length, cm 80 0.826*** -4.907 2.651 0.205 Log heart weight, g Log total length, cm 80 0.754*** -4.555 2.904 0.287 Log liver weight, g Log total length, cm 80 0.732*** -4.828 2.252 0.237 Log gall bladder weight, g Log total length, cm 80 0.770*** -4.006 2.699 0.254 Log intestine weight, g Log total length, cm 80 0.630*** -5.287 2.779 0.387 Log spleen weight, g Log total length, cm 80 0.728*** -3.827 2.651 0.283 Log stomach total weight, g Log total length, cm 80 0.864*** -4.122 2.722 0.180 Log stomach empty weight, g Log total length, cm 80 0.443*** -4.553 2.330 0.534 Log gonads weight, g Log total length, cm 80 0.678*** -4.433 2.730 0.335 Log kidney weight, g Log total length, cm 80 0.934*** -4.625 3.274 0.142 Log air bladder weight, g Log total length, cm 80 0.572*** -3.374 1.700 0.276 Log eye ball weight, g Significant level = ***P < 0.001

CHAPTER 4 141 MORPHOMETRICS

700

2.7 600 500 2.3 400 300 1.9

200

(g) weight body Wet 1.5

100 (g) weight body Log wet

0 1.1 15 25 35 45 55 1.20 1.35 1.50 1.65

Total body length (cm) Log total body length (cm)

(a) ( b) Figure 4.1: (a) The relationship between total body length (cm) and wet body weight (g) (b) The relationship between log total body length (cm) and log wet body weight (g) in Wallago attu.

440 2.65

340 2.40

240 2.15

(g) weight body Wet 140 1.90 (g) weight body Log wet

40 1.65 22 27 32 37 42 1.35 1.42 1.49 1.56 1.63

Total body length (cm) Log total body length (cm)

(a) (b)

Figure 4.2: (a) The relationship between total body length (cm) and wet body weight (g) (b) The relationship between log total body length (cm) and log wet body weight (g) in Sperata sarwari.

CHAPTER 4 142 MORPHOMETRICS

0.70 0.70

0.60 0.60

0.50 0.50

0.40 Condition factor (k) factor Condition 0.40 (k) factor Condition

0.30 0.30 15 25 35 45 55 0 160 320 480 640 Total Body length (cm) Wet body weight (g)

(a) (b)

Figure 4.3: (a) The relationship between total body length (cm) and condition factor (k) (b) The relationship between wet body weight (g) and condition factor (k) in Wallago attu.

0.64 0.64

0.58 0.58

0.52 0.52 0.46 0.46 Condition factor (k) factor Condition 0.40 (k) factor Condition 0.40 0.34 0.34 40 140 240 340 440 22 27 32 37 42 Wet body weight (g) Total body length (cm)

(a) (b)

Figure 4.4: (a) The relationship between total body length (cm) and condition factor (k) (b) The relationship between wet body weight (g) and condition factor (k) in Sperata sarwari. CHAPTER 4 MORPHOMETRICS

CHAPTER 4 143 MORPHOMETRICS

SL 40 HL BG PreOL 30 PostOL

PreDL

PostOL 20 PPL

Lengths of other variable (cm) 10

0 15 23 31 39 47 55 Total length (cm)

DFL 4 PFL

3 PelFL

Fins length(cm) AFL 2 CFL

0 15 23 31 39 47 55 Total length (cm)

Figure 4.5: The relationship between total length (cm) and length of other body variables (cm) in Wallago attu.

CHAPTER 4 144 MORPHOMETRICS

40 SL HL

HW 30 BG

IOL 20 Pr eOL Pos tOL 10 Length of various parameters (cm) Pr eDL Pos tDL

0 PPL 0 125 250 375 500 625

Wet body weight (g)

6.5

DFL 5.0 PFL PelFL AFL 3.5 CFL

Fins length (cm)

2.0

0.5 0 125 250 375 500 625 Wet body weight (g)

Figure 4.6: The relationship between wet body weight (g) and length of other body variables (cm) in Wallago attu.

CHAPTER 4 145 MORPHOMETRICS

FL 34.0 SL HL HW 25.5 BG IOL Pr eOL 17.0 Pos tOL Pr eDL

Pos tDL 8.5 PPL Length of other variables (cm)

0.0 22 27 32 37 42 Total length (cm)

8 DFL

PFL

6 PelFL AFL CFL Fins length (cm) 4

2 22 27 32 37 42 Total length (cm)

Figure 4.7: The relationship between total length (cm) and length of other body variables (cm) in Sperata sarwari.

CHAPTER 4 146 MORPHOMETRICS

FL SL 27 HL HW BG 18 IOL Pr eOL Pos tOL Pr eDL 9 Pos tDL Length of other variables (cm) PPL

0 40 140 240 340 440 Wet body weight (g)

DFL

PFL

PelFL 6 AFL CFL Fins length (cm) 4

2 40 140 240 340 440 Wet body weight (g)

Figure 4.8: The relationship between wet body weight (g) and length of other body variables (cm) in Sperata sarwari.

CHAPTER 4 147 MORPHOMETRICS

2.50

2.00

DFW 1.50 PFW

PelFW 1.00 Fins weight (g) AFW CFW 0.50

0.00 0 140 280 420 560 700 Wet body weight (g)

(a)

2.0

1.5

DFW 1.0 PFW PelFW

Fins weight (g) AFW 0.5 CFW

0.0 40 140 240 340 440 Wet body weight (g)

(b)

Figure 4.9: The relationships between wet body weight (g) and fins weight (g) in (a) Wallago attu and (b) Sperata sarwari.

CHAPTER 4 148 MORPHOMETRICS

2.50 DFW 2.00 PFW PelFW 1.50 AFW CFW 1.00

Fins weight (g)

0.50

0.00 12 20 28 36 44 52 Total length (cm)

(a)

2.0

DFW PFW 1.5 PelFW

AFW

CFW 1.0

(g) weight Fins 0.5

0.0 22 27 32 37 42 Total length (cm)

(b)

Figure 4.10: The relationships between total length (cm) and fins weight (g) in (a) Wallago attu and (b) Sperata sarwari.

CHAPTER 4 149 MORPHOMETRICS

Heart w t 1.40 Gall bladder w t. Spleen w t. Gonads w t 1.05 Eye ball w t.

0.70

0.35 (g) weight organs Internal

0.00 0 140 280 420 560 700

Wet body weight (g)

6.40 Liver w t. Intestine w t. Kidney w t. Air bladder w t. 4.80

3.20

Internal organs weight (g) 1.60

0.00 0 140 280 420 560 700 Wet body weight (g)

Figure 4.11: The relationships between total length (cm) and fins weight (g) in Wallago attu

CHAPTER 4 150 MORPHOMETRICS

0.40

0.30 Heart w t

Gall bladder wt. Spleen w t. 0.20 Gonads w t

Eye ball w t.

0.10 (g) weight organs Internal

0.00 40 140 240 340 440 Wet body weight (g)

7.5

Liver w t. Intestine w t. 6.0 stomach empty w t Kidney w t.

4.5 Air bladder w t.

3.0

Internal organs weight (g) 1.5

0.0 40 140 240 340 440 Wet body weight (g)

Figure 4.12: The relationships between total length (cm) and fins weight (g) in Sperata sarwari.

CHAPTER 4 151 MORPHOMETRICS

1.25

1.00 Heart w t Gall bladder w t. Spleen w t. 0.75 Gonads w t Eye ball w t.

0.50

Internal organs weight (g) 0.25

0.00 12 20 28 36 44 52 Total length (cm)

6.00

4.50 Liver w t. Intestine w t. Kidney w t. Air bladder w t. 3.00

Internal organs weight (g) 1.50

0.00 12 20 28 36 44 52

Total length (cm)

Figure 4.13: The relationships between total length (cm) and fins weight (g) in Wallago attu.

CHAPTER 4 152 MORPHOMETRICS

0.40

Heart w t Gall bladder w t. 0.30 Spleen w t. Gonads w t Eye ball w t.

0.20

Internal organs weight (g) 0.10

0.00 22 27 32 37 42 Total length (cm)

7.5

Liver w t. 6.0 Intestine w t. stomach empty w t Kidney w t. Air bladder w t. 4.5

3.0

Internal organs weight (g) 1.5

0.0 22 27 32 37 42 Total length (cm)

Figure 4.14: The relationships between total length (cm) and fins weight (g) in Sperata sarwari.

CHAPTER 4 153 MORPHOMETRICS

4.4 DISCUSSION Research on different fish species collected from commercial as well as from natural water show that mostly fishes do not obey to the cube law because they change their shape with growth and the exponent ‘b’ may have values significantly lower or higher than 3.0 (Martin, 1949; Naeem et al., 1992; Salam et al., 1994; Naeem and Salam, 2005). But when the specific magnitude of a fish remains unchanged and retains the same shape during its lifetime, then it is growing isometrically and the value of regression coefficient b would be accurately 3.0 (Wootton, 1990). A value more or less than 3.0 indicates allometric growth (Ricker, 1975). In the present study, weight-length relationship in both species, Wallago attu and Sperata sarwari, do not obey the cube law like an ideal fish. The value of ‘b’ was found to be 3.27 for Wallago attu and 3.28 for Sperata sarwari that is more than 3.0 in both species. So, both species analysed here showed positive allometric growth. It indicates that in these fishes increase of weight was higher as compared to the cube of their length. Because, according to Froese (2006), an over-proportional increase in length relative to growth in weight is reflected in an exponent of b < 2.5 or to the contrary, an exponent of b > 3.5 shows an over-proportional increase in weight relative to growth in length. The length-weight relationships were highly significant (P < 0.001) for both species analysed, with ‘r’ values > 0.93. The length-weight relationships of both species are summarized in Table 4.3 and Fig. 4.1 & 4.2. These results are in general agreement with the findings of Sinha (1975) for Clarias batrachus (3.30), Naeem et al. (2000) for Oncorhynchus mykiss (3.12), Esmaeili and Ebrahimi (2006) for Barbus luteus (3.159), Hossain et al. (2006) for Amblypharyngodon mola (3.397) and Naeem and Salam (2005) for Aristichthys nobilis (3.32). But this result is higher than the observations of Salam et al. (1994) for Oncorhynchus mykiss (2.98), Ali et al. (2000) for Channa punctata (2.90), Zafar et al. (2003) for catla catla (3.02) (Table 4.17). According to Koutrakis and Tsikliras (2003), the parameter b on length-weight relationship varies between 2 and 4. But all regressions coefficients (b) estimated in the present studies were within the expected range 2.5-3.5. According to Pauly and Gayanilo (1997), b values may range from 2.5 to 3.5 suggesting that results of the present studies are valid. CHAPTER 4 154 MORPHOMETRICS

Condition factor and relative weight of fish provide external measures of overall health. The condition factor (K) may vary with length, when the average weight of the fish does not increase proportionately to the cube of length (Carlander et al., 1952). When weight increases less than the cube of length then condition factor would tend to decrease with the growth of fish and when weight increases more rapidly than the cube of length, K would increase with increase in length (Wootton, 1990). In the present study, condition factor (K) increases with increasing the total length and wet body weight of both species (Table 4.4 and Fig. 4.3-4.4). It means that the body form changes as the fish becomes larger. It is therefore, concluded that Wallago attu and Sperata sarwari are growing faster with increasing size and violate the cube law. It means that the wild conditions in these areas are much suitable for rearing and stocking of these catfishes. Similar results of condition factor have been reported for various fish species in Pakistan (Salam et al., 1993; Naeem et al., 2000; Naeem and Salam, 2005). The factors which affect the value of b in length-weight relationships also affect the condition factor but its interpretation is a complicated matter and should be done with due care to avoid confusions (LeCren, 1951). During growth changes in size bring about changes in shape and body proportions. Allometric exponents on log-log scale relating body weight to the length of body parts is b = 0.33 representing isometric growth relationship (Alexander and Mcneil, 1971). In the present study values of b of mostly morphometric parameters show that they are not significantly different from that of an ideal value (b = 0.33). So, these parameters show isometric growth with wet body weight in both Wallago attu and Sperata sarwari. But the regression coefficient values for eye diameter, caudal fin length, nasal barbells length, maxillary barbells length and manudibular barbells length in Sperata sarwari were significant low than b = 3.0. So, these morphometric parameters show negative allometric growth with wet body weight of fish. These results are in general agreement with the finding of Naeem and Salam (2005) for Aristichthys nobilis. According to Alexander and Mcneil (1971), the allometric exponents on log-log scale relating total length to the length of body parts is b = 1.0 representing isometric growth relationship. In the present study, when the allometric approach was applied, it was found that the slope b of log-log regression of the relationship between total length CHAPTER 4 155 MORPHOMETRICS

and lengths of most other body parts were equal to one or close to one showing isometric growth in both species. But the regression coefficients b for eye diameter, anal fin length, caudal fin length and mandibular barbells length in Wallago attu, head width, eye diameter, nasal barbells length, maxillary barbells length, mandibular barbells length in Sperata sarwari were significantly lower than b=1.0 showing negative allometric growth with total length. While head width, dorsal fin base, pectoral fin base, pelvic fin base, maxillary barbells length in Wallago attu and inter-neural sheath in Sperata sarwari showed positive allometric growth with total length. The change in b values may be because of various factors including season, gonadal maturity, habitat, sex, stomach fullness, health and preservation techniques which effect the growth of various morphometric parameters (Tesch 1971; Begenal and Tesch1978; Wootton 1998) which were not accounted for in the present study. The isometric growth is due to proportionate growth of these parameters maintaining symmetrical form (Naeem and Salam, 2005). All length-length relationships in the present study were highly significant (P < 0.001), with most of the coefficient of determination values being > 0.7; few exceptions were nasal barbells length (r=0.435), mandibular barbells length (r = 441) for Sperata sarwari. It is clear from the results that all the body morphometric parameters grow symmetrically. The regression parameters of the relationships between log total length and log lengths of other body parameters are given in Tables 4.7 & 4.8, Fig. 4.5 & 4.7. The observations of previous researches have proved that during growth, change in size brings about changes in shape and body proportions. Relative growth of body parts were classified as allometric where b value significantly different from 3, while isometric when b = 3 or close to 3. The allometric relationships analysis in animals has attracted huge attention among scientists since the early work (Huxely, 1932; Alexander, 1971; Lagler et al., 1977; Wootton, 1990; Salam and Davies, 1994; Naeem and Salam, 2005). In the present study, highly significant positive correlations were found between log transformed data of all the fins weight versus log total length. The regression coefficient b indicates that all the fins weight in both species showed positive allometric growth against total length except for dorsal fin weight in Wallago attu and caudal fin weight in Sperata sarwari which showed negative allometric growth with total length (fig. 4.9). CHAPTER 4 156 MORPHOMETRICS

This result coincides with the findings of Ammanullah (2000) for silver carp and grass carp. In numerous fish species relative growth has been studied for various organs including the brain (Bauchot et al., 1977); heart (Feller et al., 1983 Weatherley and Gill, 1983), liver (Weatherley and Gill, 1983) and gonads (Delahunty and de-Vlaming, 1980). In the present internal morphometric studies, all the parameters except for air bladder weight, gonads weight in Wallago attu and air bladder weight in Sperata sarwari showed negative allometric growth with wet body weight and total length of fish (where b>1 for weight and b>3 for length). These results coincide with the findings that the organs with high metabolic activity decrease in weight relative to the whole body with growth (Oikawa, et al., 1992; Ammanullah et al., 1999) (Tables 4.13-4.16, fig. 4.11-4.14). However, this study was projected as a starting point; further studies are required to arrive at definite conclusions.

CHAPTER 4 157 MORPHOMETRICS

Table 4.17: Length-Weight Relationships for Different Fish Species from Different Localities.

Species b values Sources Mystus pelusium 2.999 Heydarnejad, 2009 Salmo trutta 3.16 Oscoz et al., 2005 Gobio gobio 3.33 Oscoz et al., 2005 Oncorhynchus mykiss 3.12 Naeem et al., 2000 Labeo rohita (immature) 3.06 Salam and Janjua, 1991 Mystus vittatus 3.058 Hossain et al., 2006 Amblypharyngodon mola 3.397 Hossain et al., 2006 Aristichthys nobilis 3.32 Naeem and Salam, 2005 Wallago attu 3.27 Present study Sperata sarwari 3.28 Present study

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