Lump on my baby axolotl

[appshan]

Hi, everyone! I recently bought a baby melanoid axolotl. It’s my first time keeping them as pets so I could use some advice. Yesterday, while feeding him, I noticed a bump on his side (see pictures). Should I be worried about him? He is in a betta cup and gets his water changed daily. He has been pretty active and eating well as well. Today, the bump is still there. Any suggestions?

 

[wolfen]

because of his/her size this is most likely just from having food in his/her system.