cute bta

I recently got this BTA anenome and have noticed a white flesh or cut next to its mouth. Any idea what this might be thanks.

this may seem like an idiotic question, however, wild imaginations love to inquire the possibility— backstory (optional read): i acquired an rbta from a close friend of mine. they were getting stationed overseas and bwere breaking down their tank. they said it was healthy, happy, doing great...