EVALUATION MORPHOLOGY, GROWTH

PERFORMANCE AND SENSORY ATTRIBUTES OF

FOUR RED HYBRID TILAPIA (OREOCHROMIS SP.)

STRAINS.

MOHD ZHARIF BIN RAMLI

MASTER OF SCIENCE

2017

Evaluation of Morphology, Growth Performance and

Sensory Attributes of Four Red Hybrid Tilapia

(Oreochromis Sp.) Strains.

by

MOHD ZHARIF BIN RAMLI

A thesis submitted in fulfillment of the requirements for the degree of

Master of Science

Faculty of Agro Based Industry

UNIVERSITI MALAYSIA KELANTAN

2017

i

THESIS DECLARATION

I hereby certify that the work embodied in this thesis is the result of the original

research and has not been submitted for a higher degree to any other University or

Institution

OPEN ACCESS I agree that my thesis is to be made immediately

available as hardcopy or on-line access (full text)

EMBARGOES I agree that my thesis is to be made available as

hardcopy or on-line (full text) for a period

approved by the Post Graduate Committee

Dated from until

CONFIDENTIAL

(Contains confidential information under the

Official Secret Act)*

RESTRICTED

(Contains restricted information as specified by

the organization where the research was done)*

I acknowledge that Universiti Malaysia Kelantan reserves the right as follows.

1. The thesis is the property of Universiti Malaysia Kelantan. 2. The library of Universiti Malaysia Kelantan has the right to make copies for

the purpose of research only.

3. The library has the right to make copies of the thesis for academic exchange.

SIGNATURE SIGNATURE OF SUPERVISOR

IC/PASSPORT NUMBER NAME OF SUPERVISOR

Date: Date:

ii

ACKNOWLEDGEMENTS

In The Name of Allah, The Most Beneficent, The Most Merciful

I would like to extend my greatest gratitude to Allah in such His blessing for me to

explore new knowledge and broadening the perspective in the research. Firstly, my

sincere thanks goes to my main supervisor Assoc. Prof. Dr. Lee Seong Wei and co-

supervisor Prof. Dr. Wan Zahari Bin Mohamed. Not to forget, my former co-

supervisor Dr. Soon Jan Mei as well. My appreciation for precious support, guidance,

advice and immense knowledge throughout the study and thesis completion. I

certainly honored to know them since my first glance as researcher. Special thanks to

Universiti Malaysia Kelantan and the Ministry of Higher Education of Malaysia for

funding recent study through the Niche Research Grant Scheme (NRGS)

(R/NRGS/A07.00/00387A/006/2014/000152) and MyBrain. Furthermost, I would like

to convey appreciations to my parents, Ramli bin Mat and Morni bt Arshad for all-

inclusive and absolute support. To my sisters and brothers for supporting me

spiritually throughout this study and my life as well. Last but not least, I should say

thank you to my buddies Zack, Arep, Zaty, Zee and Martina for their dedication of

time, energy and expertise since day one. Not to forget to remark, to all my friends and

staffs for their assistance all over the research and dissertation completion. Thank You

(Zharif, R., 2017).

May Allah reward you for the good

iii

TABLE OF CONTENTS

PAGE

THESIS DECLARATION i

ACKNOWLEDGEMENT ii

TABLE OF CONTENTS iii

LIST OF TABLES vii

LIST OF FIGURES viii

LIST OF ABBREVIATIONS ix

LIST OF SYMBOLS x

LIST OF EQUATIONS xi

ABSTRAK xii

ABSTRACT xiii

CHAPTER 1 INTRODUCTION

1.1 General introduction of tilapia 1

1.1.1 Taxonomy and general morphology of tilapia 6

1.2 Problem statements 9

1.3 Significance of study 9

1.4 Objectives 10

1.5 Scope of study 10

iv

CHAPTER 2 LITERATURE REVIEW

2.1 Breeding techniques, nutrition and ecological parameters 11

2.1.1Broodstock management and fry production 13

2.2 Phenotype (morphometric characteristics) characterisation 16

2.3 Evaluation of Growth Performances, Feed Conversion Ratio (FCR),

Specific Growth Rate (SGR) and Survival Rate (SR).

24

2.4 Sensory analysis 29

CHAPTER 3 METHODOLOGY

3.1 Experimental design in producing four strains of red hybrid tilapia. 34

3.1.1 Broodstocks management 36

3.1.2 Broodstock nutrition 37

3.1.3 Collection of fries 38

3.2 Growth performance evaluation 38

3.2.1 Introduction of fry into hapas 39

3.2.2 Fry nutrition 39

3.2.3 Weight measurement 40

3.2.4 Growth performance analysis 40

3.2.5 Statistical analysis 42

3.3 Morphometric characteristics measurement 43

3.4 Sensory analysis 47

3.4.1 Sample preparation 47

3.4.2 Sensory test conditions 48

v

3.4.3 Characteristics of the evaluators 49

3.4.4 Analysis of sensory attributes 49

3.4.5 Statistical analysis 49

CHAPTER 4 RESULTS

4.1 Characterisation of red hybrid tilapia morphology 50

4.1.1 A summary of morphometric characteristics measured in a ratio to

total length (TL) and logarithm for two broodstocks of red hybrid

tilapia.

50

4.1.2 A summary of morphometric characteristics measured in a ratio to

total length (TL) for four strains of red hybrid tilapia

55

4.1.3 Morphology characteristics distance 59

4.2 Growth performance of four strains red hybrid tilapia. 63

4.2.1 Water parameters 63

4.2.2 Growth performances 64

4.3 Sensory analysis 66

4.3.1 Characterisation of surveyed participants 66

4.3.2 Sensory analysis attributes on four strains of redtilapia. 70

4.3.4 Ranking test 73

CHAPTER 5 DISCUSSION 74

CHAPTER 6 CONCLUSION 91

REFERENCES 94

APPENDIX A 105

APPENDIX B 107

vi

APPENDIX C 108

APPENDIX D 109

APPENDIX E 115

LIST OF PUBLICATIONS 116

vii

LIST OF TABLES

NO. PAGE

1.1 Taxonomy of Oreochromis niloticus and Oreochromis mossambicus 7

2.1 The summary of phenotypic measures in characterising tilapia stocks. 23

2.2 The summary of growth performance of tilapia 28

2.3 The summary of sensory analysis on fish attributes. 33

3.1 Broodstock ratio with different combination 36

3.2 Changes in weight and CP (%) according to life stages (fry to adult). 40

3.3 Quantitative phenotype traits based on morphometric characteristics

for differentiation analysis among the red hybrid tilapia

46

4.1 Mean ± S.D of quantitative phenotype traits based on morphometric

characteristics ratio for differentiation analysis, among different four

strains of red hybrid tilapia.

58

4.2 The morphological distance between different strains based on

morphological ratio.

62

4.3 Average values with S.D of water temperature, pH, and dissolved oxygen (O2D) and salinity during the experiment period.

63

4.4 Growth performance and survival rate of four strains of red hybrid

tilapia.

64

4.5 Sensory rating differences obtained from four strains red hybrid

tilapia.

70

4.6 Summary of correlation coefficients between sensory attributes for

four red hybrid tilapia strains.

72

viii

LIST OF FIGURES

NO. PAGE

1.1 General morphology of red hybrid tilapia (Oreochromis sp.) 8

3.1 Morphometric characteristics of red hybrid tilapia broodstocks. 35

3.2 Experimental hapas in the earthen pond 37

3.3 Four strains of red hybridtilapia 44

3.4 Morphometric characteristics indices 45

4.1 Red hybrid tilapia O.niloticus and O.mossambicus. 52

4.2 Mean ratio of morphometric characteristics of male broodstocks 53

4.3 Mean ratio of morphometric characteristics of female broodstocks 53

4.4 Mean log of morphometric characteristics of male broodstocks 54

4.5 Mean log of morphometric characteristics of femalebroodstocks 54

4.6 Morphometric distance relationship taxa inferred using the UPGMA

method.

59

4.7 Morphometric distance taxa relationship inferred using the average

linkage (between groups) in hierarchical cluster analysis method.

61

4.8 Percentage (%) of evaluators’ gender participated in sensoryanalysis. 67

4.9 Percentage (%) of evaluators’ age participated in sensory analysis. 68

4.10 Percentage (%) of evaluators’ races participate in sensoryanalysis 69

4.11 Preference ranking of four strains of red hybrid tilapia ranked by

evaluators in sensory analysis.

73

ix

LIST OF ABBREVIATIONS

RGR Relative Growth Rate

SGR Specific Growth Rate

FCR Feed Conversion Ratio

SR Survival Rates

FM Fish Meal

O2D Dissolved Oxygen

CP Crude Protein

GIFT Genetic Improved Farmed Tilapia

x

LIST OF SYMBOLS

% Percentage

± Plus Minus

oC Degree Celcius

mg/l Milligram per liter

g gram

kg kilogram

MT Metric Tones

ppt Part per thousand

mm millimeter

m2 Meter square

cm centimeter

m meter

♀ Female

♂ Male

xi

LIST OF EQUATIONS

PAGE

Relative Growth Rate (RGR) 41

Feed Conversion Ratio (FCR) 41

Specific Growth Rate (SGR) 41

Survival rate (SR) 41

xii

Penilaian Morfologi, Prestasi Pertumbuhan dan Ciri-ciri Sensori pada Empat

Jenis Tilapia Merah Hibrid (Oreochromis Sp.)

ABSTRAK

Penurunan hasil pengeluaran tilapia disebabkan oleh kemerosotan ciri-ciri baik

pada ikan tilapia tersebut. Kajian terkini menyelidik tilapia merah hibrid dengan

menekankan ciri-ciri fizikal, tumbesaran dan rasa yang berpotensi untuk

dipertingkatkan. Empat baka tilapia merah hibrid dihasilkan melalui empat kombinasi

yang berbeza; (i) ♂O.niloticus x ♀O.niloticus (A), (ii) ♂O.mossambicus x

♀O.mossambicus (B), (iii) ♂O.niloticus x ♀O.mossambicus (C) dan (iv)

♂O.mossambicus x ♀O. niloticus (D). Anak ikan dipelihara dalam 12 hapas (3.0 m x 2.0 m x 1.2 m) di dalam kolam tanah dengan diberi makan makanan komersial (35-

40% Protein Kasar) 5% daripada berat badan dengan kepadatan 10 individu/m3 selama

70 hari. Dua puluh tiga ciri-ciri morfometri dan 6 parameter prestasi tumbesaran dinilai secara serentak. Manakala, analisis sensori pula dijalankan selepas 4 bulan ikan

dibesarkan di dalam kolam tanah. Data morfometri dianalisis dalam nisbah allometri diikuti dengan analisis kluster hieraki. Ciri-ciri morfometri dan prestasi tumbesaran

dinilai melalui analisis varians (ANOVA). Keputusan kajian menunjukkan 9 ciri-ciri seperti lebar badan ( Bw1 ) , jarak antara duri akhir sirip dorsal dengan duri pertama

sirip anal ( D1da ), jarak sirip kaudal dengan sirip anal ( DcaL ), ketinggian badan ( BH) , panjang pra- pektoral (PCL ), panjang pra-pelvik (PPL ), panjang pra -anal (PAL

), panjang pra-orbit (POL) , panjang sirip pelvik ( PlvL ) menunjukkan perbezaan yang

signifikan (p<0.05) antara baka. Analisis kluster hieraki memperincikan baka ini

kepada 2 kumpulan dan 1 sub-kumpulan yang disimpulkan sebagai perbezaan pada

baka. Berat mula (Wi), Berat akhir (Wf), Perbezaan Kadar Pertumbuhan (RGR),

Kadar Pertukaran Makanan (FCR), Kadar Pertumbuhan Spesifik (SGR) and Kadar

Survival (SR) dinilai. Paraneter ini tidak berbeza secara statistik (p<0.05) di antara

baka. Walau bagaimanapun, baka A mempunyai skor yang paling tinggi iaitu Wf

(19.63±0.69), RGR (2357.06±66.78), FCR (1.33±0.02) dan SGR (4.57±0.03) secara

perangkaan. Min prestasi tumbesaran paling rendah direkodkan pada baka B iaitu Wf (17.772±0.98), RGR (2130.88±92.14), FCR (1.50±0.02) dan SGR (4.43±0.06).

Manakala, prestasi tumbesaran baka C dan D pula didapati pada nilai min purata. SR

direkodkan tinggi (>90%) pada semua baka dengan tiada perbezaan signifikan

(p<0.05). Data analisis sensori yang tidak parametrik dinilai menggunakan ujian

Kruskal-Wallis. Secara umumnya, tiada perbezaan signifikan (p>0.05) antara ciri-ciri

(rasa, bau dan jusnya) kecuali pada tekstur.Hasil kajian ini menunjukkan ciri-ciri unik

yang membezakan baka-baka dan kombinasi pembiakbakaan efektif dalam

menghasilkan baka dengan ciri-ciri yang baik. Penglibatan ♀ O.niloticus ialah elemen

utama dalam peningkatan ciri-ciri pada tilapia hibrid merah.

xiii

Evaluation of Morphology, Growth Performance and Sensory Attributes of Four

Red Hybrid Tilapia (Oreochromis Sp.) Strains.

ABSTRACT

Deterioration of good characteristics in tilapia stocks causes the decline in its

production yield. Current research investigated red hybrid tilapia strains by

emphasising on physical, growth and taste characteristics which have the potential to

be improved. Four red hybrid tilapia strains were produced by four different

combinations; (i) ♂O.niloticus x ♀O.niloticus (A), (ii) ♂O.mossambicus x

♀O.mossambicus (B), (iii) ♂O.niloticus x ♀O.mossambicus (C) and (iv)

♂O.mossambicus x ♀O. niloticus (D). Fries were reared in 12 hapas (3.0 m x 2.0 m x 1.2 m) in earthen pond, fed 5% of their body weight with commercial feed (35-

40%Crude Protein) at stocking density of 10 individuals/m3 for 70 days. Twenty-three

morphometric characteristics and 6 parameters of growth performance were evaluated

concurrently. Meanwhile, sensory analysis of the fish was carried out after 4 months of

being raised in the earthen pond. The morphometric data were analysed in allometric

ratio followed by hierarchical cluster analysis. Morphometric and growth performance

characteristics were analysed by analysis of variance (ANOVA).The results showed 9

characteristics which are body width (Bw1), distance from end of dorsal ray to 1st anal

fin (D1daL), distance from caudal to anal fin (DcaL), body height (BH), pre-pectoral

length (PCL), pre-pelvic length (PPL), pre-anal length (PAL), pre-orbital length

(POL), pelvic fin length (PlvL) were found to be significantly different (p<0.05)

between these strains. Hierarchical cluster analysis characterised these strains into 2

groups and 1 sub-group which inferred the variation between strains. Initial weight

(Wi), Final weight (Wf), Relative Growth Rate (RGR), Feed Conversion Ratio (FCR),

Specific Growth Rate (SGR) and Survival Rate (SR) were calculated. No statistical

difference (p<0.05) between evaluated strains were found in these parameters.

However, strain A had the highest score in Wf (19.63±0.69), RGR (2357.06±66.78),

FCR (1.33±0.02) and SGR (4.57±0.03) in numerical data. Lowest mean values of

growth performances were recorded on strain B which was Wf (17.77±0.98), RGR

(2130.88±92.14), FCR (1.50±0.02) and SGR (4.43±0.06). Meanwhile, the growth

performance of strains C and D were found to be at average mean value. SR was

highly scored (>90%) in all strains with no statistical difference (p<0.05). Non-

parametric data of sensory analysis were analysed by Kruskal-Wallis test. Generally,

there is no significant difference (p>0.05) between attributes (taste, odour and

juiciness) except for texture. These findings showed that unique characteristics

distinguished between strains and combination of breeding effectively produced

strains with good characteristics. Utilisation of ♀ O.niloticus is the key element for

characteristics improvements in red hybrid tilapia strains.

1

CHAPTER 1

INTRODUCTION

1.1 General introduction of tilapia.

In the aquaculture industry, several species of tilapia were introduced for

the purpose of human consumption. The Nile tilapia (Oreochromis niloticus L.)

from the Cichlidae family is presently the major species introduced into

aquaculture for commercialisation, consumption and research purposes. It is easy

to breed and managed in various types of aquaculture systems, fast growers,

effective feed converter, resistant to certain diseases and endures the changes in

water parameters (Salah, 2008) It was reported that, Malaysia produced

44,099.24 tons of tilapia in 2013; 80% of which were red tilapia (Mazuki, 2015).

In the mid-80’s, the farming of this high value aquaculture species started in

Malaysia, yielding the highest production of red hybrid tilapia in 2012 (52,295.30

MT) (Mazuki, 2015). This statistic was recorded due to the high demand of this

tilapia strain compared to Nile tilapia and Genetically Improved Farmed Tilapia

(GIFT) developed by World Fish, Malaysia (Olievera et al., 2014). In fact, the

wholesale value of aquaculture production of freshwater culture showed that red

tilapia and black tilapia were sold at RM 246,368.46 /MT and RM 33,122.54

/MT, respectively (DOF, 2014).

2

Red tilapia remains highly favoured in the market due to its hardy

characteristics that farmer finds rewarding. In addition, attractive attributes like its

red colour and ‘clean’ appearance made this strain highly valued (Popma &

Lovshin, 1995; Allaman et al., 2013). In 1960’s, Taiwanese red hybrid tilapia was

produced in Taiwan resulted by crossing between a normal male O. niloticus with

mutant reddish-orange female O. mossambicus (Popma & Masser, 1999).

Meanwhile in Florida in the 1970’s, red tilapia strain was produced resulted by

crossing a red-gold O. mossambicus with normal coloured female O. hornorum

(Popma & Masser, 1999). Crossing a wild Blue tilapia (O. aureus) with mutant

pink Nile tilapia produced a red tilapia strain in Israel (Popma & Masser, 1999).

These original red hybrid tilapia strains were crossed with other Oreochromis

species and distributed around the world. In fact, 70 domesticated species are

commercially important, thus cultured around the world (Peterman, 2011). Red

hybrid tilapia strains were widely farmed In South East Asia, O.mossambicus in

Thailand and O.niloticus and Oreochromis sp. in Malaysia (Pongthana et al.,

2010).

History has revealed how the red hybrid tilapia was established. Breeding

programme has led to a significant implication in red hybrid tilapia production and

improvement. Previously, several works were reported in improving the red

hybrid tilapia performance in an aquaculture system aimed to increase salinity

tolerance, growth rates, disease resistance and product quality (Hernández et al.,

2001; Pongthana et al., 2010; Thodesen et al., 2013). However, red hybrid tilapia

3

experienced introgressive hybridization due to inappropriate management and

some breeding programmes involved were not reported. As a result, red hybrid

tilapia was changed in terms of its genetics and appearances, which contributed to

the declining quality of economic traits (Karuppannan et al., 2013).

Breeding goal is significant in designing a breeding programme and its

management; particularly in tilapia production, and it is a dynamic activity.

Previous studies were carried out aimed for product quality improvement

(Hernández et al., 2001), production cost reduction (Workagegn & Gjoen, 2012),

external colour traits (Thodesen et al., 2013) and etc. In order to achieve these

goals, aquaculturist device a breeding programme involving several species and

improved strains of tilapia. Hybridization appears to be a promising option

breeding programme in tilapia; regardless interspecific or intraspecific, the finding

was remarkable. More often than not, breeding goals were emphasised on the

economical traits possessed by the targeted fish. For example, the economic traits

like growth rate, survival rate and the appearance of food fish. These traits changes

as time passes since the viability of the food fish is determined by the consumers

or market demand. For instance, GIFT is a successful strain that produced through

a breeding programme which have a higher growth rate and survival (Gjerdrem,

2012). In fact, the success of the breeding programme is dependent upon the basic

principles of hybridization; where species or strains chosen must contain variation

(Gjerdrem & Baranski, 2009).

4

Gjerdrem & Baranski (2009) highlighted that variation is an essential

condition before a breeding programme can be initiated. The selected traits must

vary between individuals since portion of the variation is contributed by genetic

differences. These traits were anticipated to be inherited by progeny. Variation in

the population can be characterised by their phenotypes, growth performances and

quality of sensory attributes (Gjerdrem & Baranski, 2009). Variability of traits

provide information about the species which can possibly be utilised in a breeding

programme.

Variations in phenotypes segregate the species and indicate the

economically desired morphology (Škrijelj et al., 2011). Morphometric

characteristics apparently was discovered as a method to identify fish population,

which is of great interest in tilapia aimed for population characterisation, their

growth performance and useful for taxonomic status (Amon et al., 2013; Melo et

al., 2013; Oliveira et al., 2014). This method is widely practiced in fisheries and

aquaculture studies since it can directly identify the species without killing the

animals (Kosai et al., 2014). However, the analysis of morphology indicates the

variation in physical appearance traits but not directly the species. Therefore,

species characterisation and genetic marker information are complementing one

another in making the analysis a reliable one. In spite of that, the recent

investigation emphasises on the biometric study, which also concerns the

verification of the speciesinvolved.

5

In addition, the variation in growth performance can also be influenced by

genetics besides food quality and environmental factors. Growth performance

variation between strains could be inferred as a result of genotype differences

(Workgagegn & Gjoen, 2012). This work is vital in selecting the best strains for

an effective breeding programme which possess traits that can be incorporated into

the breeding goals. In fact, these economic traits were reported to have reduced

production cost, efficiently utilised the feed, and improved the product quality

(Workgagegn & Gjoen, 2012).

Each aquaculture product has a distinct consumer preference. Market

demands quickly change due to the fluctuation of consumer preference and eating

behaviour which pave the industry striving to satisfy their demands (Silva et al.,

2015). In general, aquaculture products were designed to achieve desirable sensory

attributes of the species in terms of tenderness, flesh colour and flavour (Kilcast,

2000). Aquaculturist satisfied the consumer demand through breeding programme,

utilisation of optimal customised feeds, culture technologies and proper

management practices (Hernández et al., 2001; Hernández et al., 2007). Sensory

attributes can possibly be improved through these approaches, though it is

challenging to create a quality guideline due to the fluctuation in consumer

demands. For instance, the high performance GIFT had failed to compete with the

production of red hybrid tilapia in Malaysia as shown in the previous statistics.

This situation occurred due to consumers’ preference for the red hybrid tilapia,

hence promoting the farming of this strain. Consequently, sensory attributes are

6

susceptible to consumer preferences hence require modifications in the breeding

goal, trait assessment and other farming practices over time (Gjerdrem & Baranski,

2009).

1.1.1 Taxonomy and general morphology of tilapia

‘Tilapia’ is a common name in several countries around the world.

Taxonomically, they are divided into three groups, namely Sarotherodon sp.,

Oreochromis sp. and Tilapia sp. They were distinguished from one another based

on reproductive features. Sarotherodon sp. and Oreochromis sp. are mouth

brooders whereas Tilapia sp. guards their nest. These cichlids fish are endemic to

the freshwater habitat in Africa and domesticated for table purposes. The

taxonomy of the species Oreochromis niloticus and Oreochromis mossambicus

were shown in Table 1.1.

7

Table 1.1: Taxonomy of Oreochromis niloticus and Oreochromismossambicus

Kingdom Animalia

Phylum Chordata

Class Actinopterygii

Order Perciformes

Family Cichlidae

Genus Oreochromis

Species Oreochromis niloticus (Linnaeus, 1758)

Oreochromis mossambicus (Peters, 1852)

Source: Integrated Taxonomic Information System (ITIS), (2015)

8

morphology characteristics are similar which has a compressed body, cycloid

scales and short upper jaw length, showing no sexual dimorphism. Dorsal spines

and pelvic fin held by the bony spines. It also has soft ray parts at the continuous

dorsal fin. The caudal fin provided with soft rays and it is truncated. During the

spawning season, the pectoral, dorsal and caudal fins become reddish in colour.

The genital opening is located behind the anus which the morphology is different

between genders.

Dorsal Spines

Mouth

Figure 1.1: General morphology of red hybrid tilapia (Oreochromis sp.)

Pectoral Fin

Anal Fin

Pelvic Fin

Dorsal Fin

The morphology of tilapia can be described as shown in the guideline in

Figure 1.1 (Rakocy, 2005; Srijaya et al., 2011). In tilapia species, the main

9

1.2 Problem statements

Recently the production of tilapia in Malaysia was declined based on DOF

report (DOF, 2015). This declination may be due several factors such as

insufficient supply of seeds to local farmers and poor management of tilapia stocks

in farm (Karuppanan et al., 2013; Mazuki, 2015). These situations lead to

deterioration of physical appearance, growth performance and sensory quality

which affecting the yield. These problems caused the existence of variability traits

in tilapia stocks. Exploitation of the traits present in tilapia stocks through

combination in breeding programme will discover tilapia with the economic traits

for food fish.

1.3 Significance of study

Characterisation of tilapia morphometric is significant as a prerequisite for

breeding programmes where selection requires variation between species and

predicts the size of fish carcass. Evaluations of growth performance variation for

these strains provide the information for profitable tilapia farming.

Complementary to the breeding goals, sensory attributes variation between strains

may be exploited in the breeding programme. Generally, these works were carried

out comprising of these elements aimed to produce red hybrid tilapia with good

physical appearance, fast growth and acceptance by consumers.

10