Question: what is the major similarity between osteichthyes and chondrichthyes?
Answer: Similarities Between Chondrichthyes and Osteichthyes Chondrichthyes and Osteichthyes are the two classes of fish, who are aquatic chordates. Both fish belong to the superclass Pisces. Both have both endoskeleton and exoskeleton. Breathing of both fish occurs through gills.