Several of our group undertook a night snorkel at Airport Beach last night. The moon was full, the water was warm and the corals were busily fluorescing. We spent an hour swimming between coral bommies looking at the fishes that were active during the night, including iridescent cardinal fishes, squirrelfishes and a curious porcupine fish that came to investigate the dive lights. We also saw several invertebrates that we had not observed on the reef during the day, including some photophobic sea 
cucumbers and a couple of species of shrimp.
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I’m curious to know why some fish are drawn to lights the way bugs are to a light. Is it all fish? Just some kinds? Inquiring minds want to know.
Just different fish. Some like the cardinal fish have big eyes and can see well in the dark, so then tend to avoid bright light. Others are attracted to moonlight or starlight and so are attracted to bright lights. A classic case of the problems that can ensue is the situation with too much light pollution (e.g. hotel lights) on sandy beaches where sea turtles nest.