Question: Variation in gills

[akiso914]

So I got my first axolotl about 6 months ago in the spring as a couple month old juvenile, and she had beautiful feathery gills. Within a month of having her, the long red frills shrank to stubs and remade that way over the summer. She has always been otherwise healthy and eats well. its november now, and I just noticed that in the past month her gills have regrown to long and feathery again... What is going on here? Why did her gills shrink and then grow feathery again after months of being reduced?

 

[AxolotlChris]

Usually gills shrink to stubs due to poor water quality.

Sounds like your tank may not have been cycled for a period of time so high levels of Ammonia and Nitrites would damage the gills causing them to shrink.

You should purchase a liquid test kit to check the levels of your Ammonia, Nirites, nitrAtes, and PH regularly.This kit is recommended: Welcome to API Fishcare: FRESHWATER MASTER TEST KIT

During cycling Ammonia is produced by your Axolotls waste and decomposing food, this is then broken down by a nitrogen fixing bacteria into Nitrites, and then broken down by the bacteria into NitrAtes. Ammonia and Nitrites are lethal so your tank needs to establish colony's of this nitrogen fixing bacteria which will breakdown your Ammonia and Nitrites into less harmful NitrAtes. This bacteria colonizes on various surfaces within your tank such as ornaments, rocks, filter, and substrate. 'Cycling' to establish these colonies can take several weeks. The beneficial bacteria acts as a 'biofilter' keeping your water safe, all you have to do is weekly water changes of 20-30% to keep the NitrAtes down.

Read these links on cycling and water quality:
Caudata Culture Articles - Water Quality
Caudata Culture Articles - Cycling

 

[akiso914]

That makes sense, her gills were smaller in the 2-3 months after I set up a new tank. Thank you for the input!