What Trees and Fish have in common

Did you know fish have a specialized calcified bone called the otolith that let's you estimate how old your aquatic friend is?

Not only can you determine age, but researchers can also roughly determine which oceanic regions have been visited by the fish due to the accumulation of different mineral compositions.

When I was little, I used to  ask my parents how old the fishes in our tank were.  Now I have reason not to ask anymore.

However, looking at the otolith requires removing the head from the body.