What signs are there that a betta fish is in old age?

[Binky/Carol]

My blue female who is about 2.5 yrs old seems to not be moving much.
She has a small fish keeping her company. She has no visible problems, or gill issues. She eats, but for the last week or so.. hasn't moved from one or two spots..
How can you tell your fish is getting old??
:?

 

[RoachGirlRen]

Unless your betta was bought from a good breeder, it was probably already a good 6 months old when you purchased it, though females are sometimes sold younger. Lifespan normally falls between 2 and 6 years, with 3-5 common with proper husbandry (something few bettas receive). 2.5 is not a bad age for a pet store betta, so I wouldn't be shocked if she's getting on in years and slowing down. Older bettas tend to become less active, less responsive, may dull somewhat in color, are usually very large, and may have a diminishing apetite. The males often stop bubble-nesting, and the females are less receptive to mating attempts. However, it is always good to check your water parameters/temperature and rule out any possible stress or illness before chalking up a change in behavior to old age.

 

[Toady]

I agree with RoachGirlRen, check the water parameters. 2.5 is very good for a petshop betta! Most of mine I know the hatching date (from other breeders) and they last about 12 months with very good care. It sounds like you've given her a very good home and good on you, so many are stuck in containers smaller than a small bottle of soda (or even a can) and are expected to florish.