Everything about fish is amazing, but to me, the most fascinating thing about fish (beside their taste) is their lateral line system. The lateral line is the most important thing fish possess because without it, they wouldn’t be able to get around. All fish have a lateral line, and you can usually see it. It is a line of scales that are slightly different from the rest of the fish’s scales, and they run from near their mouth, around the eye, to the tail. That line is made up of epithelial cells, which are basically modified skin cells. They are mucus-filled canals that have hair cells in them—kind of like what we have in our ears to help us determine which direction our spouse is yelling at us from.
Notice the lateral line on this Anthias in my tank
For our participation in this hobby, we don’t need to know exactly how all this works, but you can delve into it if you desire. Basically, the lateral line system allows the fish to know what is around it, what it is chasing, and how close it is to anything solid, including other fish, which is how millions of fish can swim in a school and never touch each other MORE