I think it belongs to family Cymothoidae, genus Nerocila. I would refer to the following citation for more potentially helpful information about this family and genus.
Smit, N. J., Bruce, N. L., & Hadfield, K. A. (2014). Global diversity of fish parasitic isopod crustaceans of the family Cymothoidae. International Journal for Parasitology: Parasites and Wildlife, 3(2), 188-197.