Encyclopedia Trivia--
Fish breathe with gills, what is the use of the nostrils?
The nostrils of fish are used to provide a sense of smell and do not have a breathing function.
Fish nose is generally born with a pair, there are front boundary hole (that is, water hole) and posterior boundary hole (that is, water outlet), the fish nose and the mouth are not connected, otherwise the pressure pump effect of oral pressure and gill pressure can not be fully exerted, breathing and bait can not be carried out smoothly.
Fish have tiny sacs in their nostrils that allow them to feel the smell stimuli that occur with food and look for food.
It can also help identify the smell of the same species of fish and different species of fish, avoid being infestationed by predators, and also use it to identify water quality and carry out return movement.
Fish have severe myopia, dim environment and natural eye structure, so that fish vision is extremely poor, usually can only see objects within four or five meters, fish sense of smell, make up for the lack of vision.
