This is called a Tule Perch (Hysterocarpus Traskii) I caught this one (about 6") while fishing for Striper bait last Fall. Very odd little fish, which actually use there pectoral fins for propulsion. They fight decent.... but not as good as a Bluegill :-)
I'm sure they are a very distant relationship to Bluegill. I mean, they are brackish water fish, and not even Centarchids... but kind of cool anyway, huh ? The big males get darker striping, and a lavender metallic sheen on there backs, and sides. Stripers hammer them BTW ;-)
Hey Creekx, the biggest ones I've caught, have only been about 6".... but I have a fishing buddy who swears he caught a giant one over 1 lb... like 9" or 10", and fat too.
On the other hand, I've used tiny ones... like 1 1/2", and caught Stripers on them in the 15 to 20 lb range :-)