Cardinal fish
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Biology
The cardinalfish is a nocturnal fish, which spends the day hidden in the holes and recesses of rocks, going out at night to feed on small fish and invertebrates. They live at depths of nearly 30 meters, but it is thought that they spend the winter in even deeper waters, up to 200 metres.
Curiosities
The males are zealous parents and after fertilisation (which is internal), they incubate several thousand eggs inside the mouth until hatching. Throughout this period, they do not eat.