- Needs more sources from primary literature
- Images, e.g. of the absorbance of light of different wavelengths in water
- Neurobiology
- Interface between land and water (E.g. archerfish)
- Fish with little or no vision, e.g. in habitats with little light/turbid water e.g. deep ocean; caves; turbid water/mud
- Reliance on other sensory systems e.g. electroreception
- Coloured oil drops? (Which species?