Go Natalie! Great answer to a great question.
I've never thought to try and figure out the age of a fish I acquired as an adult.
That info could be very useful though.
Wait...aren't the rings caused by periods of slow and rapid growth? Why would aquarium specimens show ridges when conditions are basically stable all year?
Wait...aren't the rings caused by periods of slow and rapid growth? Why would aquarium specimens show ridges when conditions are basically stable all year?
Hmm, good point... I can ask about that one. The rings in the scales are called "annular rings" so I always assumed that each ring would count annually. You're right, most cultured/grown food fish are raised outdoors where the warm season triggers the faster growth, then winter is slower. I'll check up on that!
Old Jack Dempsey are very easy to recognize. They get very tall and their back gets curved. Bit hard to describe, but yours isn't old. Of course he could be 5-6 years I don't know.