Cartilaginous fishes have an internal skeleton made of cartilage and their skin is covered with placoid scales.
While, The bony skeleton of bony fishes is harder and heavier than cartilage. Bony fishes have either lungs or a swim bladder and hard, thin scales.
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Cartilaginous fishes have an internal skeleton made of cartilage and their skin is covered with placoid scales.
The bony skeleton of bony fishes is harder and heavier than cartilage. Bony fishes have either lungs or a swim bladder and hard, thin scales.
