difference between placoid and cycloid scale ?

Please find below the solution to the asked query
 

Placoid scales	Cycloid scales
They are hard and tough	They are comparatively flexible
They are mainly present in cartilaginous fishes	They are mainly present in body fishes
They have rough posterior margins and give rough appearance to the skin of fishes	They have smooth posterior margins and give smooth appearance to skin of fishes
They are modified teeth covered by enamel.	They are not modified teeth.
They are packed tightly with their tips facing backwards.	They are arranged in an overlapping pattern.

Hope this information will clear your doubts about the difference between placoid and cycloid scale.

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