Title Page
Contents
Abstract 9
Introduction 11
Materials and Methods 15
2.1. Experiment on Visual sensitivity 15
2.1.1. Light source 15
2.1.2. Light intensity 18
2.1.3. ERG recording 20
2.1.4. Visual spectral sensitivity 23
2.2. Experiment on behavior 24
2.3. Statistical analysis 26
Results 27
3.1. Visual sensitivity of Oreochromis niloticus 27
3.1.1. Light emitting diode (LED) output 27
3.1.2. ERG signal 31
3.1.3. Visual threshold 35
3.1.4. Spectral sensitivity of Oreochromis niloticus 37
3.2. Behavior of Oreochromis niloticus 41
Discussion and Conclusion 48
4.1. Visual sensitivity in Oreochromis niloticus 49
4.2. Activity of Oreochromis niloticus under varying wavelength and temperature 51
References 56
Table 1. Specification of LEDs for lighting system 16
Table 2. Discrete steps used to vary light intensity 19
Table 3. Relationship between LED intensity radiated to Oreochromis niloticus and... 33
Table 4. Difference in Oreochromis niloticus reaction (movement distance) to wavelengths... 45
Figure 1. Measured relative spectral sensitivity curves of LEDs used in the experiment. 17
Figure 2. Arrangement of LED packages attached on an epoxy board. 17
Figure 3. Circuit diagram of a prototype automatic light controller. 19
Figure 4. Schematic representation of equipment setup for ERG recording. 22
Figure 5. Measured relative spectral power curves from 428 ㎚ LED package. 28
Figure 6. Relationship between LED light intensity and electric current used in the... 29
Figure 7. Relationship between LED light intensity (irradiance) and the electric current... 30
Figure 8. Sample of measured ERG waveform in dark-adapted Oreochromis niloticus. 32
Figure 9. Relationship between response amplitude and log intensity of dark-adapted... 34
Figure 10. Visual threshold of Oreochromis niloticus from LED wavelength of weight and... 36
Figure 11. Averaged spectral sensitivity of Oreochromis niloticus. 39
Figure 12. Relative spectral sensitivity of Oreochromis niloticus, White circles indicate... 40
Figure 13. Movement distance of Oreochromis niloticus with varying temperature under... 42
Figure 14. Swimming speed of Oreochromis niloticus with varying temperature under the... 43
Figure 15. Effect of temperature and wave length on moved distance of Oreochromis... 46
Figure 16. Effect of wavelength and temperature on Oreochromis niloticus activity in... 47