Chondrichthyes (; from Ancient Greek: χονδρ- chondr- 'cartilage', ἰχθύς ichthys 'fish') is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or bony fishes, which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm (3. 9 in) finless sleeper ray to the 10 m (32 ft) whale shark.
Chondrichthyes. Retrieved November, 05 2021, from en.wikipedia.org/wiki/Chondrichthyes.