it is invariable that any time we visit Old Town Aquarium in Chicago, we are bound to not only come across some cool fish, but some rare oddballs which we’ve never seen, and rarely even thought about. On this visit to Old Town Aquarium the Wrasse Blenny, Hemiemblemaria simulus, was that fish. The Wrasse Blenny may not be winning any particular fancy coloration contests but it is unique for being a mimic of the Caribbean bluehead wrasse, Thalassoma bifasciatum, throughout several stages of coloration! The Wrasse Blenny mimics the white back juvenile stage, the yellow back adolescent stage and the the color of adult females. The only color stage of the Bluehead Wrasse that the Wrase Blenny doesnt mimic is the terminal phase of adult males with the namesake blue head coloration. The Wrasse Blenny may be a good mimic but the brilliant red eye is a tell tale sign to divers and aquarists that it is not the Blue Head wrasse. Lots more pics of the unusual Wrasse Blenny after the break.