The tessellated darter (Etheostoma olmstedi) is a fish belonging to the genus Etheostoma. It was formerly considered a subspecies of the johnny darter, which it greatly resembles in general appearance. Both species are rather pale with small X or W shaped markings on the back and upper sides. Both have only a single anal fin spine whereas all other darters in our area have two. Tessellated darters have somewhat sharper snouts than johnny darters, more dorsal soft rays, and more pectoral fin rays. The suborbital sensory canal is complete in most tessellated darters, usually broken into two sections in johnny darters. Their nape is usually naked, and their cheeks are partly to completely scaled. The breast is usually naked and the belly partly scaled. The body of the tessellated darter is el