Rock Bass is a fish with very big bones and rib cage cavity. The fish looks huge but often times yields little meat. Especially compared to a Bluegill fish.
It's kind of like, catching bullheads. A fish that's got a really big head and not much meat for it's size and body.
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The really big Rock Bass that I've caught, also have not been in any rocky places...They don't seem to roam with the other Rock Bass.