1. VISION IN CICHLIDS Optical quality and visual perception in Cichlidae (Pisces)

6. Spherical aberration

7. Chromatic aberration

8. Accommodation

9. Optical resolution Little spherical aberration Accommodation by movement of the lens (b) Optical relation: 1/f = 1/v + 1/b Focal distance f = 2,3 r (r is lens-radius) Image distance b = 2,55 r (mean vallue; Matthiessens ratio)

11. VERTEBRATE RETINA Rods & Cones Bipolar & amacrine cells Ganglion cells

12. PHOTORECEPTORS

13. ontogenetic cone size

15. Incompatability of photopic sensitivity & resolution

16. Spatial resolution

17. Retinal resolution & sensitivity Angular density: H = (2,55 – v). /360 } 2. D number / o Minimum separable = (H -1 ) 0,5 60 min of arc Unit photon catching ability (threshold value) V c = (2S d + S s ) 1,5

18. Colour vision

19. Photoreceptor absorption spectra

20. Spectral distribution in various aquatic environments (Levine et al., 1979)

21. Transformation parameters of double cones and cone mosaic

22. square or row mosaic

23. sympatric speciation

24. The End