Crystallaria is a genus of freshwater ray-finned fish which is classified in the subfamily Etheostomatinae, commonly known as the darters, part of the family Percidae which also includes the perches, ruffes and pikeperches. They are found in the Mississippi River basin from Ohio to Minnesota and in southern Mississippi, northern Louisiana, and southeastern Oklahoma, and on the Gulf Slope of Escambia, Mobile Bay, and the Pearl River drainages. They have now been extirpated from Ohio, Kentucky, Indiana, and Illinois.

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