INS/81/008/MANUAL/15   October 1989 PROPAGATION OF SEABASS, LATES CALCARIFER IN CAPTIVITY CONTENTS

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Project Document Indentification

Part II F. Activities

Prepare seafarming manuals and other technical information serials.

ACKNOWLEDGEMENTS

This manual has been revised based on the data recently obtained from hatchery trials at the National Seafarming Development Centre in Hanura, Teluk Betung, Lampung. The authors are grateful to the Project personnel for their review of the manuscript, particularly to Dr. Albert Tacon, feed and nutrition advisor, and Mr. Peter Gaiger, marketing advisor, for their constructive comment. Appreciation is also extended to Mr. Kisto Mintardjo, the Project Co-Team Leader for his cooperation and support. The manual is possible only because of excellent job and hard work of the colleagues of the hatchery unit of the National Seafarming Development Centre and results contributing to the document.

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CONTENTS

1. INTRODUCTION

2. TAXONOMY AND NOMENCLATURE

3. BROODSTOCK DEVELOPMENT
3.1. Farm raised brood fish
3.2. Wild brood fish

4. BROODSTOCK MAINTENANCE

5. SEX DETERMINATION

6. STAGE OF MATURITY

7. SELECTION OF MATURE BROODER

8. INDUCED GONADAL MATURATION

9. PROCESS OF HORMONE INJECTION

10. SPAWNING IN CAPTIVITY
10.1 Natural spawning
10.2 Induced spawning
10.3 Artificial fertilization
10.4 Environmental manipulation

11. FACTORS AFFECTING SPAWNING
11.1 Food
11.2 Water quality
11.3 Salinity
11.4 Stress
11.5 Size of broodstock
11.6 Age of broodstock
11.7 Lunar cycle

12. EGG COLLECTION
12.1 Seine net
12.2 Water overflow method

13. CARE OF FERTILIZED EGG AND HATCHING

14. EMBRYONIC DEVELOPMENT

15. LARVAL DEVELOPMENT

16. CARE OF HATCHLINGS

17. REARING OF LARVAE
17.1 Indor phase
17.2 Outdoor phase

18. FRY REARING
18.1 Nursing in pond
18.2 Nursing in netcage

19. NURSERY MANAGEMENT
19.1 Temperature
19.2 Salinity
19.3 Aeration
19.4 Light intensity
19.5 Stocking density
19.6 Feed and feeding
19.7 Water quality
19.8 Grading
19.9 Cannibalism

20. GROWTH

21. HARVESTING

22. SURVIVAL RATE

23. DISEASE CONTROL
23.1 Diagnosis
23.2 Preventive measures
23.3 Treatment

24. LIVE FOOD
24.1 Tetraselmis
24.2 Chlorella
24.3 Rotifer
24.4 Marine yeast
24.5 Brine shrimp
24.6 Moina

25. ENRICHMENT OF LIVE FOOD

26. INERT FOOD
26.1 Micro-encapsulated egg particles
26.2 Artificial plankton
26.3 Compound feed

27. PACKING AND TRANSPORT
27.1 Preparing fish for transport
27.2 Packing fish
27.3 Preparing for the arrival of the fish
27.4 Acclimatization of the fish
27.5 Treatment of diseases

28. SPERM PRESERVATION TECHNIQUE
28.1 Preparation of diluent
28.2 Mixing and freezing milt
28.3 Thawing and fertilization

29. ELEMENTS IN THE SUCCESS OF SEABASS HATCHERY OPERATORS

30. REFERENCES

LIST OF TABLES

Table 1. Netcage spesification and stocking density in relation to fish size

Table 2. Suitable ranges of water quality of the broodstock tank

Table 3. Stage of Gonadal Development in Seabass, Lates calcarifer

Table 4. Effects of salinity on hatching rate of seabass eggs

Table 5. Embryonic development of seabass eggs at 27°C

Table 6. Rate of absorption of the yolk

Table 7. Types and relative amounts of food given at different stages of seabass larvae and fry

Table 8. Survival rate of seabass fry from days 21–34 rearing in 20 ppt at different temperatures

Table 9. Survival rate of seabass larvae and fry from days 1–30 at different salinities

Table 10. Stocking density and survival rate of seabass larvae and fry at different ages

Table 11. Pore size of grader and retained size of fish

Table 12. Normal growth of seabass larvae and fry in 30 days

Table 13. Treatment of diseases commonly found in seabass fry and fingerlings

Table 14. Treatment of diseases in young and adult seabass

Table 15. Ingredients of Conway medium

Table 16. Nutrients for 1 - liter stock culture of Tetraselmis

Table 17. Nutrients for 3-liter culture of Tetraselmis

Table 18. Nutrients for 200-liter and 1 -ton culture of Tetraselmis

Table 19. Nutrients for 1-ton culture of Chlorella

Table 20. Nutrients for marine yeast culture

Table 21. Content of W3-HUFA of the rotifer fed on different diets

Table 22. Survival rate of seabass fry packed in 40 × 60 cm plastic bags at different age, size and density

LIST OF FIGURES

Fig. 1. General scheme of seabass culture as practiced in Indonesia

Fig. 2. Floating netcages used for broodstock development

Fig. 3. Mature seabass brooder

Fig. 4. Checking the readiness of broodfish by pressing on abdomen of the fish

Fig. 5. Checking the maturity of eggs using polyethylene cannula

Fig. 6. Intramuscular injection of hormone

Fig. 7. Collecting seabass eggs using a small seine net

Fig. 8. Diagram of a fish-spawning tank with an egg collecting system

Fig. 9. Embryonic development of seabass

Fig. 10. Larval development of seabass

Fig. 11. Number of rotifers consumed by a seabas fry/day corresponding to size

Fig. 12. Feeding schedule and water management for seabass larvae and fry in nursery during the first 40 days period

Fig. 13. Number of brine shrimp nauplii consumed by a seabass fry age between 11–17 days old

Fig. 14. Dropping feeding technique

Fig. 15. Survival rate of seabass larvae kept in 20 ppt at different temperatures

Fig. 16. Strainer box to facilitate water exchange

Fig. 17. Grading of seabass fry

Fig. 18. Growth of seabass fry during the first 30 days period

Fig. 19. Rotifer culture showing a blooming peak of rotifer after inoculation

Fig. 20. Artemia hatching tank

Fig. 21. Conditioning seabass fry before packing

Fig. 22. Sequence of packing fish in plastic bag

Fig. 23. A device for gradual changing of water in a transport bag

LIST OF APPENDIXES

Appendix 1. Taxonomic classification

Appendix 2. Production of prepared inert food for seabass larvae and fry

Appendix 3. Instruction for use of selected enrichment diets

Appendix 4. Abbreviations

Appendix 5. Conversions