The largest fish in the ocean is the whale shark, the only species of the genus Whaleshark in the family Whalesharkidae. It is enormous and the largest fish in the world, usually measuring around 10 meters, and the largest can reach 20 meters. It can weigh up to 20 tonnes and has 2 large skin ridges on each side. The mouth is enormous and positioned forward, with labial folds on the upper and lower jaws. The nostrils are located on both sides of the snout and the water outlet opens into the mouth. Little eyes. The vent is small and located behind the eye. The teeth are small and numerous, conical in shape, with the tooth heads inclined backwards and are used in several rows. The gill openings are very wide. 2 dorsal fins, no spines. The caudal fin is broad, short, and forked; there are folds on each side of the caudal peduncle, the axis of the caudal vertebra is turned over andthere is a depression above the base of the tail. The pectoral fins are broad. The body is gray-brown, rufous or green-brown, with numerous yellow spots and stripes.
The endoskeleton of Chondrichthyans is made entirely of cartilage, but is often reinforced by calcification without real bone tissue. The surface of the body is covered with shield scales. Bare spines or scales. The brain has no seams and there are gill slits on either side of the head, opening to the outside of the body. The intestine is short, with spiral valves and no swim bladder. Males have specialized organs called fins inside their pelvic fins. Internal fertilization, oviparous, ovoviviparous or viviparous, with twisted tail. We now know that there are 12 orders, 40 families, 130 genera and more than 650 species of cartilaginous fish in the world.
Manta ray? It is a huge tropical fish whose namescientist is manta ray. Its size and strength often frighten divers, because when it becomes angry, it can break a person's bones and kill them with a single beat of its powerful wings. So people call it “devil fish”. Sometimes the manta ray clings to the boat's anchor chain with its main fin, dragging the boat quickly out to sea, leading fishermen to mistakenly believe that it is the devil at work, when It is actually the manta ray. “Manta rays” like to swim in groups, sometimes submerged on the seabed, and sometimes males and females come to the surface in pairs. During the breeding season, manta rays sometimes strike the water with their double fins, jump into the air and can "glide" as high as a person above the water. the sound is like that of a cannon, spreading for miles, which is very spectacular. Manta rays can appear intimidantes, but they are actually very gentle, feeding only on crustaceans or schools of small fish and shrimp. There are two fleshy legs on its head, which are its cranial fins. The cranial fins face forward and can rotate freely. The manta ray uses these cranial fins to hunt food and push it into its mouth for swallowing.