I'm not sure about snail and fish, but earthworms have eye cells on their skins that are sensitive to light waves except blue. In my past research I used blue light chambers to observe earthworms at the soil surface. 

Thank you Hala I Chaoui, We had also conducted a study in which the earthworm Hyperiodrilus africanus was exposed to artificial lighting generated by energy saving bulbs of varying colours (red, blue, green, white), varying frequency and wavelengths and total darkness. The Effect of light colour on cast productivity and worm emigration was measured. It was recorded in the study that earthworm cast biomass was significantly higher under red light whereas the rate of emigration was higher under blue and green light. That generated my curiousity to study the response of other animals to light exposure (monochromatic lights). An understanding of how light of varying wavelengths affects melatonin, serotonin, acetylcholinesterase and other biological parameters in animals might give a clue as to the responses observed in this organisms