Fishes
FishesThere 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 fishes of the class Ostechithyes. The apparent similarities between each speech are only skin deep. They have similar dapperly solely because of convergent evolution and not because of any close evolution connection.
There paired fins can identify class Chrondrichthyes, which comprises namely of sharks and rays, their completely cartilaginous skeletons and biting jaws characteristic of the group. Chrondrichthyes are mainly carnivorous, and the sharks have highly adept senses for vision, olfaction, and hearing. They even posses a system of microscopic organs which can detect changes in water pressure around the shall. Sharks do not possess gills flaps like a fish so a shark must continuously move in order to obtain enough oxygen to survey. The large teeth of a shark are evolutionarily derived from jagged skin scales. 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 uses to crush mollusks and crustaceans.
Class Osterrichhthyes has the most...
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