How to tell how old an axolotl is

I recently bought Aristotle, this little leucistic:
I'm completely in love, but I do believe that what the pet shop told me (him being a year old) is totally wrong. He seems to be just too small for that age, so if I could get some experienced axolotl carers to give a more accurate estimate of this little guy's age, I would be greatly appreciative.
To be specific, he is 12cm long.
(sorry if this is in the wrong place, but as I didn't know where to put it, where better than general)

Sent from my GT-N7100 using Tapatalk

Definitely not a year I'd say. Looks a few months. I usually judge by length, looks to be about 4 inches which is still very young. I'd say axolotl "teen years" would be 6-8", so still very much a young axolotl.

Yeah, he's 4.7 inches long

Sent from my GT-N7100 using Tapatalk

4.5 inches should be around 4-6 months.

So tiny and so cute! Your axolotl is definitely a baby, I'd say maybe 4 months old

I see, I had no idea he was that young. That's very different from the year age I was given by the "axolotl expert" in my local fish store. Is that too young to be putting him on sand?

Sent from my GT-N7100 using Tapatalk

No he's fine on sand. If he were a bit younger then yes it could potentially cause problems but he's fine.

You can't judge age by size, at 4.5" your axolotl would most likely be 4-5 months old with a decent growth rate. However it could easily be a year old, axolotl growth rate is retarded by regulating their food supply so they maintain body mass without growing. Commercial breeders and shops can do this to save on feeding costs, to reduce required water changes and save cash on labour. Unless you can contact the breeder you can't be certain of how old your axolotl is.

I can only speak from my experience with my own axie, but I felt like she grew an inch every month. At three months she was three inches, four at four, etc. She's now nine and a half months and nine and a half inches

Cute little guy!

Thanks for that information everyone, I will ask at the LFS and hopefully I can contact the breeder, but it could be difficult to trace. It is quite likely that they mistreated this little guy. They have a lot of axolotls in very small and very few tanks. Almost all the albinos had missing limbs and chewed off tails. I bought him as a rescue more than anything.

Sent from my GT-N7100 using Tapatalk

Another question, specifically to xxianxx, if his growth has been stunted by low feeding or poor conditions, will he start growing now he's being fed more? Or will he remain this size?

The first twelve months of an axolotls life is where they grow the most, they continue to grow throughout their lives but at a much lower rate, if they miss this initial window of opportunity they can't catch up and will stay smaller than siblings who were fed more and allowed to grow. This doesn't appear to be a problem, growth retarded axolotls can still be healthy viable pets , if anything being small can actually be an advantage as they wont damage water quality as much as bigger axolotls in the same sized tank and for the same reason they will have relatively more room to swim about. I haven't seen any evidence which proves there would be any long term damage to this kind of axolotl.
Wether or not you axolotl grows more is dependant on how old it actually is, if its a year old it won't grow much bigger, if its four months old it still has eight months.

Mini-lotls are cuter anyway.