The below mentioned article provides short notes on Class Chondrichtyes. 1. The fishes of this class bear cartilaginous endoskeleton. They are cold blooded (poikilothermous or ectothermic). There are about 600 species of cartilaginous fishes. 2. The skin is tough, containing minute placoid scales, which are dermal in origin. 3. Except in the Chimaeras, the gills […]