I was wondering if anyone here knew anything about a purple iridescence that shows up on the underside of the jaw of yellow bass (Morone mississippiensis)? To illustrate the iridescence that I'm talking about;
![Posted Image](http://i145.photobucket.com/albums/r237/NateTessler13/purpleunderyellowbassjaw.jpg)
This fish was collected in a small detention pond in the Chicagoland area. The purple coloration wasn't apparent when the fish was in the livewell. However, when the fish was transferred to a smaller bucket (awaiting preservation), the fish became stressed and the underside of its jaw showed the purple iridescence. This wasn't unique to this one fish. All three of the yellow bass collected at this site showed the same coloration. I've never seen this before on yellow bass and I was wondering if anyone had any experience with this.