As far as I'm aware, they don't. Maybe you are thinking of tree rings?
Gills
fishs eddy
Some of the adapataions that allow fishs to live in the water are gills, fins, and a streamlined body shape. The gills allow the fish to live in the water. The gills allow the fish to extract oxygen from the water. Its stream lined shape allow the fish to swim quickly through the water without having major problems. The speed of the fish helps it to out run its predator. The fins allow the fish to swim through the water and help it stear itself. Fishs also have many other adaptaions such as specilized eyes that can see in the depths of the ocean with very little or no light. it also has scales which dont allow water to go in its body
The gills move after every they open their mouth to intake water. Gill rakers, located along the anterior margin of the gill arch, strain water that is passed ove the gills and exchange the water for gasses (oxygen and carbon dioxide).
NO
deers or fishs
Some of the adapataions that allow fishs to live in the water are gills, fins, and a streamlined body shape. The gills allow the fish to live in the water. The gills allow the fish to extract oxygen from the water. Its stream lined shape allow the fish to swim quickly through the water without having major problems. The speed of the fish helps it to out run its predator. The fins allow the fish to swim through the water and help it stear itself. Fishs also have many other adaptaions such as specilized eyes that can see in the depths of the ocean with very little or no light. it also has scales which dont allow water to go in its body
Red Gills are not neccessarily a sign of problems. It all depends on many things. However, if your fish is showing signs of rapid breathing, dashing around the tank, scratching against objects in the tank etc, then your fish may well have a problem. There are many propritry brands and treatments available in pet shops for gill flukes. Just follow directions if required.
bass, bream,
The Indian & Pacific Oceans .
chalk goby
You can determine the freshness of a fish by looking at its eyes, gills, and skin. Fresh fish will have clear, bright eyes, red gills, and shiny, firm skin. Additionally, fresh fish should have a mild ocean smell, not a strong fishy odor.