07/27/2021
I've gotten similar questions a few times, so I figured I would put together a little post about it.
Gills.
What is normal?
Are they supposed to do that?! π
An axolotls gills are a good indicator of overall health, and there are a few major things that can directly effect them.
Water parameters - if they are out of whack, or if your tank is uncycled or the cycle has crashed, can quickly have an effect on the gills. Continuous exposure to improper water parameters can leave your lotl with shorter gill stalks and sparse, stubby filaments. Properly maintained water can produce fluffy, full gills. (Please note that genetics also plays a role in the length of the stalks).
Stress - a stressed out lotl can often have a very distinct look about them. Tightly curled forward gills and a candy cane like hook to their tail are both signs that your axolotl is highly stressed and the causes should be identified and remedied immediately. Axolotls that have longer gills stalks can have a slight curl forward to them, and this is ok! They generally look otherwise healthy and happy and it is something that you will come to recognize is a normal for your lotl.
Sickness - Fungus will often manifest on the gills first. This can look like cotton fluff under water that is attached to the gill stalks, filaments, or both. This can be caused by improper temperatures (too hot!), water parameters, injury, and even stress. This requires moving your lotl to a tub for treatment (usually with clean, dechlorinated, cool water & a treatment dependent on the individual case).
Toxins - Sudden shedding of the gill filaments can indicate that your axolotl has come in contact with a toxin. Such as chlorinated water, or tank contamination. This may also be followed by changes to their slime coat. Tubbing for treatment is required.
Activity - A resting lotl will likely have paler gills that will become brighter colored (such as pink in a leucistic lotl) when they start becoming more active. This is totally normal! Pale gills that do not color up with activity can indicate sickness.
Movement - Flicking of the gills from time to time is completely normal :)
In the attached video this juvenile has long gills that curl slightly, but is otherwise healthy and is shown flicking the gills. They are a nice deep pink color because they were recently fed and have been super active.