What is this?

[DeCypher]

My Axolotl's [Toki] 2 gills have white, dead ends. They were like that when he arrived in the mail a couple weeks ago, but one got worse. What is this? How is it fixed? Is it a problem? Note: Other than the gills, he/she is very healthy. A ravenous eater and very active.
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[Kaysie]

You're right. It's the death of the gill stalk. Sometimes it's from poor water quality or injury, other times they just atrophy because they don't need as much gill as what they have.

Keep an eye on them to make sure they don't advance too much. Keep the water cool and clean, and keep it well-fed, and your axie should be fine.