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UNIVERSITI PUTRA MALAYSIA
DISTRIBUTION AND ECOLOGY OF THE MALAYSIAN MAHSEER (GENUS: TOR)
IN KENYIR LAKE, MALAYSIA
LIENG SOPHA
ITMA 1999 1
DISTRIBUTION AND ECOLOGY OF THE
MALA YSIAN MAHSEER (GENUS: TOR)
IN KENYIR LAKE, MALAYSIA
By
LIENG SOPHA
Thesis Submitted in Fulfillment of the Requirements for the Degree of Master of Science in the
Faculty of Applied Science and Technology UNIVERSITI PUTRA MALAYSIA
October 1999
ACKNOWLEDGEMENTS
First and foremost, I would l ike to extend my sincere gratitude to Prof. Dr.
Hj. Mohd. Azmi Ambak, chairman of the supervisory committee, for his invaluable
contribution, advice, tutelage, careful supervision of my Master programme in the
Universiti Putra Malaysia and providing research assistantship from the IRPA
Project (No 50258-13) throughout the course of the study. Without his constant
encouragement this thesis would never have been written .
I am profoundly indebted to the committee members, Assoc . Prof. Dr.
Mohd. Zaki Mohd. Said, and Assoc. Prof. Dr. Sakri Ibrahim, Universiti Putra
Malaysia for their encouragement, invaluable guidance, constructive comments and
critical review of my work throughout the study period.
I wish to express my sincere thanks to the Government of Malaysia for
granting the sponsorship through the Malaysian Technical Co-operation Programme
(MTCP) for the study, particularly Mr. Zainal Abidin bin Abu Hassan and Mr.
Adnan bin Ibon, Training Division for Director General Public Service Department
Malaysia. This thanks is also due to the Malaysian Embassy to Cambodia for
assisting in handling the grant.
I gratefully acknowledge the assistance of the Royal Government of
Cambodia for al lowing me to pursue the study programme smoothly through
placing my service in deputation . I also thank the Ministry of Forestry,
11
Fisheries and Agriculture. I would l ike to extend my sincere gratitude for their
assistance in one way or another particularly to :
Mr. Ly Kim Han, Director, Department of Fisheries, Cambodia
Mr. Nao Thuok, Vice Director, Department of Fisheries, Cambodia and
National Project Director of the Freshwater Capture Fisheries
Management Project,
Mr. Touch Seang Tana, former Project Director,
Mr. Nicolaas van Zalinge, C.T.A./Senior Fishery Biologist for the
Freshwater Capture Fisheries Management Project.
Heartfelt acknowledgement and gratitude go to Assoc. Prof. Dr. Noor Azhar
Shazil i , Dean of Graduate School who helped me in every possible way. I 'd l ike to
express my sincere thanks and gratitude to Prof. Dr. Law Ah Theem for thoroughly
editing the manuscripts . The appreciation are also to Assoc. Prof. Dr. Lokman
Hussain, Dr. Khalid Bin Hj . Sarno, Dr. Abol-Munafi A.B . and Mr. Liew Hock
Chark, University Putra Malaysia who have helped and guided me in one way or
another. I 'd like to thank to Mr. Esa bin Mohd Daim, Mrs. Arbaiyah Mohd Isa and
Mr. Abdul Aziz Bahsir for their administration. I'd to thank to Mr. lalal K.C.A. for
consultation, Mr. Shahreza Md Sheriff for translating the abstract from English to
Malaysian language and Mr. Olubunmi Akins for editing the manuscripts.
I wish to extend my appreciation to all staffs of the UPM, Terengganu
Campus, including Mr. A. Manaf, Hj . Hosni lalauddin, Hj. Sukiman Sengat and Mr.
III
Sulaiman, Mrs. Marhaini , Mr. Muhammad Embong, Mr. Johari , Mr. Ismai l , Mr.
Sharol, Mr. Muhamad Ibrahim, Mr. Fazil, Mr. Wan Awang, Mr. Rashid, Mr. Rosli ,
and Mr. Kasim for their innumerable assistance and co-operation in the sample
field, laboratory and logistics. The acknowledgement goes also to Miss Rose, Zira,
and Lina for their co-operation and assistance.
My sincere thanks are also due to all my post-graduate friends and well
wishes including Mr. Zulkamal M.R., Mr. Seang Meng, Joni H., Subarjo, Rozihan
M. , M. Yusoff, Musse G.H. , Razarudin 1., Dinh T.D. , Liem P.T. Miss Aishah Y. ,
Miss Nazlin R.M.S . , Miss Suhaila who have assisted me in providing different
inputs directly or indirectly which contributed to the accomplishment of this work.
Finally, the heartfelt gratitude goes to my parents for their encouragement,
untiring guidance and support. The gratitude is also to my grandma who frequently
guided me when she was stil l alive. I 'd l ike to thank to my parents in laws for their
support and encouragement. Special thanks are for my wife, Mrs. Meng Phall ine for
their patience, encouragement, and understanding throughout the study period. My
daughter, Sopha Var Leak also deserves appreciation for motivation.
IV
TABLE OF CONTENTS
"ERPUST AWN !liLT AN ABDUL SAMAC UNiVERSlTl PUTRA MALAYSIA
Pages
ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 11
LIST OF FIGURES LIST OF TABLES LIST OF PLATES
. . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .
• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 0 • • • • • • • • • • • • • • • • • • • • • •
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .
x
xii xi i i
ABSTRACT ABSTRAK
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 0 ' • • • • • • • • •
xiv xvii
LIST OF ABBREVIATIONS . . .. . . . . . . . . . . . . " . , . . . . . . . . . . . . . . . . . . . . . . . . . xx
CHAPTER
I
II.
III.
INTRODUCTION
Background of the Study Statement of the Problems 7
Significance of the Study . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Objectives of the Study ... .... ..... ............. .... ..... ..... .... 14
DESCRIPTION OF THE STUDY AREA 1 5
General Features . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Flora and Fauna . . . . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Limnological Profi le Sampling Sites
LITERA TURE REVIEW
Taxonomy
Fish Distribution
Habitat Selection Microhabitat
v
23
26
27
27
32
36
37
IV.
Macrohabitat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Feeding Ecology
MAHSEER DISTRIBUTION AND HABITAT PROFILE
Introduction
39
40
43
43
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Materials and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Mahseer Distribution and Abundance . . . . . . . . . . . . . . . . . . . 48
Habitat Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Water Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1
Water Velocity
Transition Zone
Pool
R iffle
Run
Substrate
Aquatic Plants and Leaves of Tree . . . . . . . . . . . . . . . . . .
Shade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' " . . . . . . . . . . . . .
Effects of Man
Tree Trunk
Water Chemistry
Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mahseer Distribution and Abundance . . . . . . . . . . . .. . . . . .
Tor tambraides
Tor sora .................................................. .
Habitat Profile . . . ' " . . . . . . . . . . . . . . . ' " . . . . . . . . . . . . . . . . . . . . . .
Water Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Velocity
Transition Zone, Pools, Riffle and Run . . . . . . . . . .
Substrate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Aquatic Plants and Leaves of Trees
VI
51
51
52
53
53
55
55
55
55
56
56
58
58
58
64
65
65
65
66
66
67
V.
Shade
Effect of Man
Tree Trunk Water Chemistry
Water Temperature Water Transparency pH Conductivity Dissolved Oxygen Hardness of Water
67
67
68
68
68
69 69 70
70 70
Calcium and Magnesium . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1 Discussions
Mahseer distribution
Habitat Profi le Water chemistry
Water Temperature Water Transparency pH Conductivity Dissolved Oxygen Hardness of Water
Calcium and Magnesium . . . . . . . . . . . . . . . . . . . . . . . . . . .
HABITAT UTILIZATION OF TOR SORO (C &V)
Introduction Objectives Materials and Methods
Microhabitat ' " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Avai labil ity of Microhabitat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Microhabitat Analysis
Statistical Analysis
VII
72 72
76 8 1
8 1
8 1 8 1 82
82
83
83
85
85 88
89 89
93
94
95
VI.
Results
Macrohabitat Analysis 96
97
... "'crohabitat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Water Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " 97
Water Velocity
Substrate
102
105
Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' " 1 09 Fish Aggregation Species Association Distance from Fish Position to
1 14
1 1 7
the Edge of Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 8 Macrohabitat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 9
Discussions 1 23
FEEDING ECOLOGY OF THE MALAYSIAN MAHSEER 1 28
Introduction 1 28
1 3 1 Materials and Methods
Result
Food Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 1 Feeding Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . '" 1 32
Relative Length of Gut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 32
Foo d compo sit io n
Feeding Apparatus
Relative Length of Gut Discussions
1 33 133 1 35 1 38 1 39
V1ll
VII. SUMMARY AND CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 46
Summary
Conclusion
Further Study
BIBLIOGRAPHY
APPENDICES
1 46
1 53
1 55
1 57
1 74
VITAE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 97
IX
LIST OF FIGURES
Figure Page
1 . Map of the Peninsular Malaysia Showing the Location of Kenyir Lake 1 6
2. Map of Kenyir Lake
3 . Monthly Rainfall Fluctuation i n Kenyir Lake.
1 7
1 9
4. Map of Kenyir Lake Showing the Malaysian mahseer Distribution 59
5. Water Level Fluctuation in Kenyir Lake . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6. Water Depth Used by, Available to, and Preferred by Tor sora at Sg. Buluh Nipis IT and Sg. Mandak IT . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7. Depth Used by Tor sora of Different S ize Classes at S g. Buluh Nipis II and S g. Mandak IT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0 1
8 . Water Velocity Used by, Available to, and Preferred by Tor sora at Sg. Buluh Nipis II and Sg. Mandak II . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 03
9. Water Velocity Used by Tor sora of Different S ize Classes at Sg. Buluh Nipis IT and Sg. Mandak IT . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 05
1 0. Substrate Used by, Available to, and Preferred by Tor sora at S g. Buluh Nipis IT and Sg. Mandak IT . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 06
1 1 . Different Use of Substrate in Pre-monsoon and in Monsoon at Sg. Buluh Nipis IT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
. 1 2. Different Use of Substrate in Pre-monsoon and Monsoon at Sg. Mandak II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 08
1 3 . The Use of Cover by Tor sora Compared with Cover Available at Sg. Buluh Nipis IT and Sg. Mandak IT . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 09
1 4. Distance from Fish Focus Point to Nearby Cover at Sg . Buluh Nipis IT 110
1 5 . Distance from Fish Focus Point to nearby Cover at S g. Mandak II 1 1 0
1 6. Aggregation of Tor sora in Pre-monsoon and in Monsoon at Sg . Buluh Nipis II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 4
x
17. Aggregation of Tor sora by Fish Size Categories at Sg. Buluh Nipis IT 1 15
18. Aggregation of Tor sora in Pre-monsoon and in Monsoon at
Sg. Mandak IT 1 16
19. Aggregation of Tor sora by Fish Size Categories at Sg. Mandak IT 1 16
20. Association of Tor sora with other Fish Species at Sg. Buluh Nipis IT
and at Sg. Mandak IT 1 17
2 1. Distance from Fish Focus Point to the Edge of Stream at Sg . Buluh Nipis IT . . .. . . ...... ...... .............. ............. 1 18
22. Distance From Fish Focus Point to the Edge of Stream at Sg . Mandak IT . . . . . . . .. . . . . . .. .. . .. . . . . . ....... ............ ......... 1 19
23. Macrohabitat Use of Tor sora by Habitat Types at Sg. Buluh Nipis IT. 1 20
24. Macrohabitat Use of Tor sora by Habitat Types at Sg. Mandak II 1 21
25. Macrohabitat Use of Tor sora by Fish Size Categories at
Sg . Buluh Nipis IT 1 2 1
26. Macrohabitat Use of Tor sora by Size Categories at Sg. Mandak IT 1 22
27. Percentage of Food Items Encountered in Gut Contents of Tor sora 1 34
28. Number of Guts Contained Food and no Food 1 34
xi
LIST OF TABLES
Table
1 . Morphometric Index Data of the Lake Kenyir
2. Limnoiogical Prof i le of Lake Kenyir
3 . Fish Abundance Categories
Pages
1 8
24
50
4. Location of the Malaysian Mahseer were Distributed in Lake Kenyir 60
5. Mahseer Distribution and Characteristics of their Habitat 6 1
6 . Distribution and Abundance of Tor tambroides in Lake Kenyir 63
7 . Distribution of Microhabitat Used and Available (Depth, and Water Velocity), Between and within Sites, and Distribution of Fish Sizes at Sg. Buluh Nipis IT and Sg. Mandak IT. . . . . . . . . . . . . .. . . . . . . . . . . . .. 99
8. Range of Depth and Velocity that have a Suitability Index � 0.5 Based on Site-Specific Use and Preference Model that have been Normalised to 1.0. . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 99
9. Seasonal Use and Availability of Depth and Velocity Distribution at Sg. Buluh Nipis IT and Sg. Mandak IT. . . . . . . . . . . . . . . . . . .. 1 02
1 0. Relation between the Use of Cover and Fish of Different Size
Categories at Sg. Buluh Nipis II ............... ......... .... III
II. Relation between the Use of Cover and Fish of Different Size Categories at Sg. Mandak IT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
12 . Relation between Fish and the Use of Cover by Season at Sg . Buluh Nipis IT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 3
1 3. Relation between Fish and the Use of Cover by Season at Sg . Mandak IT .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 113
14. Relative Length of Gut (R .L.G.) of Tor soro (C & V) Caught from Sg. Buluh Nipis IT and Tor tambroides
(Bleeker) Caught from Sg. Berang. . . . . .. . . . .. . . . . . ... . . . .. . ... 1 38
xii
LIST OF PLATES
Plates
1 . Tor tambroides (Bleeker) (left) and Hampala macrolepidota van Hasselt (right) in Kenyir Lake . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1
2. Juvenile Tor tambraides in Kenyir Lake 44
3. Juven i le Tor sora in Lake Kenyir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4. Under Water Observation of Fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5 . Direct Visual Observation of Fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
6. Transition Zone
7. Pool Zone
8. Riffle Zone
9. Run Zone
1 0 . Activities of Data Collection at the Field
1 1 . Photo Showing that both the Juvenile Tor sora (above) and Tor tambroides (below) have no Teeth on the lower and upper
52
53
54
54
9 1
Jaw and both Fish Species have Thick Lips. 1 36
12 . Photo showing that both the Juvenile Tor sora (right) and Tor tambroides (left) have Pharyngeal Teeth on the lower and upper Pharyngeal Arch. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 36
1 3 . S ide view of the Mouth of Juvenile Tor sora (left) and Tor tambraides (right) showing that both Fish S pecies have the Same Protracted, and Sl ightly Inferior Mouth . 1 37
1 4 . Photo of the Alimentary Canals of Juvenile Tor sora (the photo above) and Tor tambroides (the photo below ) showing that the Stomachs of both Fish Species had a S lightly Extended Tube. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 37
xiii
Abstract of the thesis presented to the Senate of Utliversiti Putra Malaysia in Fulfilment of the requirements for the Degree of Master of Science.
DISTRIBUTION AND ECOLOGY OF THE MALAYSIAN MAHSEER IN LAKE KENYIR, MALAYSIA.
by
LIENG SOPHA October 1999
Chairman: Prof. Dr. Hj. Mohd. Azmi Bin Ambak Faculty: Faculty of Applied Science and Technology
A study on distribution and ecology of the Malaysian mahseer (Tor sora
Cuvier & Valenciennes and Tor tambroides Bleeker) was carried out in lotic and
lentic habitats in Lake Kenyir, Malaysia.
The fish distribution and habitat profi le of the Malaysian mahseer were
studied to investigate the ecological condition and their relationship with the
environment and to determine the present spatial distribution and abundance in the
lake system. The results showed that there is a habitat selection by fish of different
sizes, (fingerl ing 2.0 - 7.0 cm, juveniles 7.1 - 20.0 cm and adults >20.0 cm TL) in
relation with size of stream, water depth, current velocity, substrate, water
temperature, water transparency, dissolved oxygen, and habitat types.
The adults of Tor tambroides were most abundant in deeper parts or pools in
upstream reaches of large streams (26-60 m width) of Sg. Tembat and Sg.
Terengganu and medium-sized stream ( 1 2-25 m width) of Sungai Kiang. The
XIV
juvenile were found in all sizes of sampled streams in the lake. The adult of T. sora
were found in less abundance in small and medium-sized streams of Sg. Buluh
Nipis n, Sg. Mandak I and n, Sg. Siput, and Sg. Lancang. However, the juveniles
and fingerlings were mostly found in the small stream reaches and were most
abundant at water depths ranging from 10 to 187 cm with velocity ranging from 1 to
118 cm.s·l. The adults occurred in habitats where the water depth was about 5.4 m
and current velocity ranged from 1 to 66 cm.s·l. The fingerling and juvenile of both
species were frequently found in streams where pools represented from 3 to 9%,
runs 5 to 32%, riffles 61 to 91 % of the total area. The fingerlings and juveniles were
mostly found in habitats where boulders were predominant followed by bedrock,
sand, gravel, cobble and pebble. The adults mostly occurred in habitats where the
substrate comprised of boulders and rock. The young mahseers were frequently
found in clear-running water, while the adults occurred in slow-running and more
turbid water as compared to the young mahseer. The temperature profile ranged
from 23.0 to 2S.3°C. the dissolved oxygen varied from 6.7 to 8.8 mg.rl. The water
hardness of the mahseer habitat nullifies the effect of toxic metals to the fish.
The microhabitat and macrohabitat analysis of habitat use and preference of
T. soro in the two small stream reaches of Sg. Buluh Nipis IT and Sg. Mandak IT
showed that T. soro preferred depths between 52 em and 120 em and water velocity
between 0 and 35 cm.s·l. Different size classes of T. sora used different mean
depths at both sites. The seasonal use of depth and velocity by T. sora were
significantly different at both sites (p<O.OS). T. sora preferred sand and gravel as
substrate. T. sora preferred cover up to 70% and the fish of all size had similar
preference for cover at both sites (p>O.OS). T. sora generally aggregated in groups
xv
ranging from 1 to 7 fish and were found to associate with Acrossocheilus dearatus
(C & V) and Osteochilus vittatus (C & V). The adults of T. sora were found in
pools . The juveniles were quite well spread in all habitat types, pools , runs and
riffles, while the fingerlings were most abundant in riffle habitat.
It was found that T. soro fed mainly on algae and other available fauna and
flora at the stream of Sg. Buluh Nipis II. Examining their feeding apparatus , the
teeth of T. sora (7.0 -26.0 cm in TL) and T. tambroides ( 17 .0 - 25 .0 cm in TL) were
not developed on the lower and upper jaw, but there is a presence of pharyngeal
te€th on the upper and lower pharyngeal arch. Their mouths were protracted and
slightly inferior. The l ips of both fish species were thick. Being a typical cyprinid,
both fish species had no conventional stomach and possessed an extended long
intestine. The fish employed suction feeding in adaptation with their feeding
apparatus. The relative length of gut (R.L.G.) for the T. sora with the size range
from 7.0 to 26.0 cm in total length has been found to vary from the lowest 0.77 to
the highest 2.85. The value of R.L.G. for T. tambraides with size ranging from 1 7.0
to 25.0 cm in total length also varies, ranging from l.11 to 2 .50. Both fish species
were omnivores as evident from gut content analysis and the relative length of gut .
I t could be concluded that the mahseer is a highly territorial fish species . The
physical and chemical parameters are significant in determining spatial distribution
and abundance of the Malaysian mahseer and also important in the application of
habitat-based management of the mahseer population in Lake Kenyir.
XVI
Abstrak tesis dikemukakan kepada Senat Universiti Putra Malaysia sebagai memenuhi syarat untuk mendapatkan Ijazah Master Sains.
TABURAN DAN EKOLOGI MAHSEER MALAYSIA DI TASIK KENYIR, MALAYSIA
Oleh
LIENGSOPHA
October 1999
Pengerusi: Prof. Dr. Hj. Mohd. Azmi Bin Ambak
Fakulti: Fakulti Sains Gunaan dan Teknologi
Satu kajian terhadap taburan dan ekologi ikan kelah (T. sora Cuvier &
Valencies dan T. tambroides Bleeker) telah dijalankan di habitat lotik dan lentik di
Tasik Kenyir, Malaysia
Kajian terhadap taburan ikan serta profil habitat ikan kelah telah dijalankan
untuk mengkaji keadaan ekologi ikan kelah serta perhubungannya dengan
persekitaran dan untuk menentukan taburan spatial dan kelimpahan terkini di dalam
sistem tasik. Hasil kajian mendapati terdapat pemilihan habitat oleh ikan yang
berbeza saiz (fry 2.0 - 7.0 em, juvenil 7.1 - 20.0 em dan dewasa >20.0 em panjang
total) terhadap saiz anak sungai, kedalaman, kelajuan arus, substrat, suhu air,
kejemihan, oksigen terlarut dan jenis habitat.
Ikan Kelah dewasa ban yak terdapat di kawasan yang lebih dalam atau lubuk
di bahagian hulu (20-60 em lebar) sungai Tembat dan Sungai Terengganu serta di
kawasan sungai yang mempunyai kelebaran sederhana ( 1 2-25 em lebar) di Sungai
XVlI
Kiang. Ikan juvenil dijumpai dalam pelbagai SaIZ di kawasan persampelan .
Kel impahan ikan dewasa adalah rendah di sungai keeil dan sederhana di sungal
Buluh Nipis IT, Sungai Mandak I dan IT, Sungai S iput dan Sungai Laneang.
Walaubagaimanapun, kebanyakkan ikan fri dan juvenil oi dapati di sungai keei l dan
kerap terdapat di kawasan yang mempunyai kedalaman berjulat di antara 1 0 hingga
1 87 em dengan kelajuan arus di antara 1 hingga 1 1 8 em. s·1 • Ikan dewasa dijumpai
di habitat dengan kedalaman 5 .4 em dengan kelajuan arus berjulat dari 1 - 66 em.s·l .
Fri dan juvenil bagi kedua-dua spesies kerap dijumpai di kawasan sungai di mana
lubuk mewakili di antara 3 hingga 9%, runs diantara 5 hingga 32%, jeram di an tara
61 hingga 9 1 % daripada keseluruhan kawasan. Fri dan juvenil banyak dijumpai di
habitat di mana terdapat banyak balak diikuti dengan kawasan berbatu, berpasir,
gravel , cobble dan pebble. Ikan dewasa dijumpai di kawasan air perlahan dan keruh
berbanding dengan ikan yang muda yang kerap dijumpai di kawasan air jemih .
Seeara keseluruhan, suhu di kawasan kajian berjulat diantara 23 .0 hingga 25 .3 °C
dengan nilai oksigen terlarut di an tara 6.7 hingga 8 .8 mgTI .
Berdasarkan analisis mikrohabitat dan makrohabitat bagi T. sora di kawasan
sungai kecil di Sungai Buluh Nipis II dan Sungai Mandak II, T. soro lebih memilih
kawasan yang mempunyai kedalaman di antara 52 em hingga 1 20 em dengan
kelajuan arus di antara 0 hingga 35 em.s· l . Kajian juga menunjukkan bahawa saiz
ikan yang berbeza menggunakan kawasan min kedalaman yang berbeza di kedua
dua kawasan. Pemil ihan kawasan kedalam dan arus bagi setiap musim oleh T. sora
di dapati mempunyai perbezaan yang bererti di kedua-dua kawasan (p<0.05). T.
sora lebih memilih kawasan berpasir dan gravel sebagai bahan substrat. T. sora dari
XVlll
pelbagai SaIZ di dapati gemar tinggal di kawasan yang mempunyal tempat
berlindung yang hampir mel iputi 70% di kedua-dua kawasan (p>0.05) . T. sora
kebiasaannya tinggal berkumpulan dalam kelompok di antara 1 hingga 7 ekor
dalam satu kumpulan bersama dengan Acrassocheilus dearatlls (C & V) dan
Osteochilus vittatus (C & V). T. sora dewasa dijumpai di kawasan lubuk manakala
ikan juvenil lebih tersebar hampir ke semua habitat seperti jeram dan lubuk
manakala anak jej ari banyak terdapat di kawasan jeram.
Ikan T. sora memperolehi makanan daripada alga dan lain-lain flora dan
fauna yang terdapat di kawasan Sungai Buluh Nipis ll. Ikan T. sora (7 .0 - 26.0 em
panjang total) dan T. tambraides ( 1 7.0 - 25.0 em panjang total) mempunyai mulut
inferior dengan bibir yang tebal . Ia tidak mempunyai gigi di bahagian rahang at as
dan bawah tetapi mempunyai gigi faring di bahagian at as dan bawah kawasan
faring. Kedua spesies ini tidak mempunyai perut tetapi mempunyai usus yang
panjang. Spesies ikan ini memakan seeara menghisap sebagai satu adaptasi terhadap
struktur mulutnya. Panjang relatif usus T. sora berjulat di an tara 0.77 hingga 2.85
bagi ikan yang bersaiz di antara 7 .0 hingga 26.0 em panjang total . Panjang relatif
usus T. sora berjulat di antara 1 . 1 1 hingga 2.50 bagi ikan yang bersaiz di an tara 17.0
hingga 25 .0 em panjang total .
Seeara keseluruhannya, ikan kelah adalah ikan yang bersifat territorial .
Taburan dan kel impahan ikan kelah ban yak bergantung kepada parameter fizikal
dan kimia. Pengetahuan parameter in i sangat penting dan berguna dalam
pengurusan populasi ikan kelah berdasarkan habitat di Tasik Kenyir.
XIX
LIST OF ABBREVIATIONS
°C Degree Celsius
% Percentage
uS/cm Microsimon/ centimetre
cm Centimeter
C.V. Cuvier and Valenciennes
E East
E"" Expectation Frequency
FFRC Freshwater Fisheries Research Centre
GPS Global Position System
ha Hectare
Ko-::;, Kilogram
m meter
m3 Cubic meter
mg Milligram
mg/J Milligram per litter
N North
0 Observation Frequency
ppm Parts per million
R .L.G. Relative Length of Gut
SD Standard Deviation
xx
Sg.
SL
TL
TWL
US$
Malaysian language abbreviation for "Sungai" means River
Standard Length
Total Length
Top Water Level
Unit of the Currency of the United States
xxi
CHAPTER I
INTRODUCTION
Background of the Study
Fishes are important to mankind as a source of protein (Biswas , 1 993,
Philip et al . , 1 993). In Malaysia fish and other seafood are the major diet which
makes up at least 20% of the per capita consumption of all protein. This is almost
equal to the amount of protein taken from other meats such as poultry, pork, beef
and mutton which together contribute about 23% of the required protein (Ishak et
al . , 1 986). Thus, fish is a vital source of food.
Fish is not only a source of vital protein to the population, it also provides
employment for the rural people, gaining some of foreign exchange and creating
opportunity for recreation (Khan, 1 992). In 1 996, the fisheries sector produced
1 ,239,434 tones of total fish production valued at RM3 .84 bill ion contributing
about 1 .54% to the national Gross Domestic Product (GDP) . In this total
production , the marine fisheries landed 1 , 1 25 ,689 tones or 90.90% of the total
production, the inland fisheries landed 3,683 .2 1 tones or 0.30% of the total
production and aquaculture production was 109,062 tones or 8 .80% of the total
production . Exclusively, ornamental fish production ornamental 278 ,462,210
2 pieces. These fisheries provided direct employment to 99,578 people consisting of
79,616 fishermen and 19,902 aquaculturist. This employment constituted about
1.18% of the total labor force in the country (DoF, 1998). Thus the fisheries sector
plays a significant role in providing protein and employment, especially in rural
areas, as well as supports the country economic growth .
Although recreational fisheries have not been well developed, Malaysia has
the potential for recreational fisheries development, both marine and inland. The
existing recreational fishing is sti ll in the form of some nature preservation, the
development and management of sport fish is very rudimentary. In fact, its potential
is enormous (Ambak, 1984). The Malaysian coastline is 3,400 km with about
160,000 square nautical miles of inshore and offshore (Anon, 1989). However the
development of marine sport fisheries needs more precaution and more complicated
than freshwater. On the other hand, freshwater sport fisheries have received high
popularity in the world. Besides this , many natural or man-made freshwater water
systems in Malaysia exist in many forms with existing-sport fish that can be
promoted to sport fisheries. Reservoirs estimatedl y cover an area of about 91,680 ha
(Anon, 1983). In Peninsular Malaysia alone, there are 15 major reservoirs (DoF,
1982). Disused mining pools cover 16,680 ha (Arumugam, 1991). There are more
than 100 river systems in the country (Baluyut, 1983). Large tracts of freshwater and
peat swamp forests cover some 2.5 million ha (Parish and Davies, 1991). These are
the available natural resources potential. With these natural resources, recreational
fisheries have existed in many places and anglers throughout the country have
caught many species. There are many media including New Straits Times, Rod and
Line, and Pancing discussed about fisheries recreation, experiences, guides,