Peacock Mantis Shell issue?

[FreshwaterConvert]

Hi all. Disclaimer, this is not my personal mantis but it is the one we currently have at the LFS I work at. We’ve had it for a little while but today I noticed this spot on its back, is this shell rot? Something else? I’m gonna be bringing in a PVC burrow for it and am working with the saltwater staff to help determine what to do, I’m sort of the mantis expert/enthusiast on staff.

 

[LosReef]

Watching as I have a mantis but not a peacock. I'm no expert by any means. For mine, I feed it soaked halved clams or raw shrimp in Selcon with all other fish food. It might help heal if it's some kind of wound. It might just go away during the next molt also. Nutrition might expedite both. Just an assumption. Good luck! Such a cool animal!