Part 1 of Essay
There are two classes of fishlike creatures in the Chordate Phylum. The first is Chondrichthyes Class, which comprises mainly of Sharks and Rays. The seconds is the common Bony of the class Ostechithyes. The apparent similarities between each speech are only skin deep. They have similar dapperly solely because of converge ....

Part 2 of Essay
.... Which are apparent on shark’s ancestor’s Placodermi class. The digestion system of a shark contains a “spiral valve” intestinal system, which increases the surface area and lengthens the time food is digested in the unusually short intestine system of a shark. Sharks sexually reproduce. Unlike a shark, rays have flattened bodies so they can hide themselves in the sand at the bottom of any shallow water area and wait for a meal. Rays also have a whiplike tail for defense and jaws, which it ....