Do those things have rings?

Tree rings are not unique to trees, and many animals also have them.

Mammals, such as horses, cows, sheep, camels, mules, etc. They all leave rings in the process of tooth calcification. Therefore, many experienced old farmers in rural areas can accurately tell their age just by looking at the teeth of cattle and horses.

The annual rings of reptiles such as turtles and turtles are engraved on the carapace. The annual rings of coelenterates (such as corals) are characterized by regular stripes with different thicknesses on their surface walls.

Fish circles are scaly. Due to the high water-saving temperature in spring and summer, sufficient bait and rapid growth of fish scales, a wide concentric circle is formed; In autumn and winter, the water temperature is low, the bait is less, and the scales grow slowly, leaving only narrow concentric circles. There is an obvious annular boundary between the wide concentric circle and the narrow concentric circle. How to judge the age of fish?

A simple method is to take a fish scale that has been growing for many years and observe it under a microscope or a magnifying glass. You will see black and white annular stripes on the scale surface, much like the annual rings on the cross section of trees. At this time, you only need to carefully count the number of circles of the black ring stripes of the fish scales, plus 1, which is the actual age of the fish. For example, if there are four black circles on the fish scale, the actual age of the fish is five years old. But not all fish's rings grow on scales. For example, salmon's rings grow on gill cover, flounder's rings grow on spine, shark's rings grow on dorsal fin, and yellow croaker's rings grow on ears.

The age of most animals is not easy to judge, but corals are an exception, because corals pile up to form loose or tight bones due to seasonal changes. If the bone is further sliced, X-ray photography can reveal that it has tree-like annual rings, from which scientists can calculate the age of corals.