LOl..I must be the only honest dude here (just teasing). I called in an order today with liveaquaria. They had credited me for my goby/shrimp order because I had emailed them that it looked DOA. Well..they both survived, but, the favites didn't make it. So..they had overcredited me. I brought it to their attention (my order today would have been free). Well..they gave me a $25 credit for being honest.
Anyway, I'd call that fish a hitchhiker and as such..it is clearly yours. Amazing sometimes, like the my yashia goby, how resilient some of these animals are. On the flip side, also how sensitive. Beautiful fish. SH