I am curious as to what the opinion is on aging aquarium fish. I know through my current reseach that fish can be aged using otoliths, scales and opercula. My question is: Since the changes in the otolith and scales used to age the fish are brought on by environmental changes (ie. dietary changes, seasonal changes, ect.). Do you think that an aquarium fish can be aged this way or do you think that they wouldn't show their actual age due to the stability of aquarium life? I am going to check this out in the lab on Tuesday on 2 angelfish and an oscar that I picked up at the local LFS (they were frozen after they died). The LFS owner says he has had the oscar for about 3 years and the angelfish for about 5 years, so it should be interesting.
Aging Aquarium fish
- Thread starter philliptobin
- Start date
I checked both the scales and the otoliths of the 3 aquarium fish today. 
The oscar was suppose to have been 3 years old, according to the scales and otoliths (checked both the right and the left), he wasn't even a year old. 
The angelfish were suppose to have been 5 years old, their scales and otoliths showed that they to weren't even a year old. 
Now, there is two possible conclusions: 1) the owner lied about the age or 2) aquarium fish are not exposed to the same environmental conditions as their wild counter parts and therefore continue to age with out recording a yearly seasonal change (winter). This would really make for an interesting study if a person had the time. As for me, it is back to pond demographics, sampling starts on April 2.
The oscar was suppose to have been 3 years old, according to the scales and otoliths (checked both the right and the left), he wasn't even a year old. The angelfish were suppose to have been 5 years old, their scales and otoliths showed that they to weren't even a year old. Now, there is two possible conclusions: 1) the owner lied about the age or 2) aquarium fish are not exposed to the same environmental conditions as their wild counter parts and therefore continue to age with out recording a yearly seasonal change (winter). This would really make for an interesting study if a person had the time. As for me, it is back to pond demographics, sampling starts on April 2.Someone who knows what those words mean should do a test on a fish that they know the age of already. 
Modest_Man;1644758; said:
Don't know. Interesting question though.
I may try to do some more on aging aquarium fish as time and dead aquarium stock allows (I refuse to kill any of my water kids). I don't know any of the ages of the fish population I am currently studying. The ageing is all being done by otolith and scale examination.