Sharks (Selachimorpha), are considered to be the most dangerous sea animal. They are a type of fish with highly streamlined body. They are known to have their existence 420 million years ago. They are found in numerous varieties growing from the size of 17 cm to 12 meters.
Habitat and Behavior
They are found in the sea at a common depth of 2000 meters and generally they do not live in fresh water. They have seven gills to breathe. Their skin is covered with dermal denticles and these denticles protect their skin from damages and parasites. They feed on squid, plankton and small deep sea fishes. The most interesting fact about these sharks is that their tooth gets replaced several times throughout their life span.
Reproduction and Behavior
The sea sharks produce well-developed young ones, which are few in number. The maturity rate is quite low in the sharks. The smaller sharks like cat sharks mate with the male by curling around the female. They swim parallel to each other and then the male inserts a clasper into female's oviduct. The bite marks can be often seen on the female's body as a sign of mating.
Mythological Relation : Tiger Shark Vs Great White Sharks
Facts about sea sharks
- They do not have true bones and swim bladders
- Their teeth get replaced throughout their life span
- Their skin is covered with denticles in order to protect them
- They are killed for the oil of their liver known as "squalene"
- The total numbers of sharks are just 10% of what they were in 1950
- They are also killed for their fins in order to prepare soup
- The oil of the sharks is used in cosmetic industry
The cosmetic companies talk about corporate social responsibility. But, what they are doing is just opposite to that. They use the oil of the shark's liver to make cosmetics and thus large numbers of sharks are killed daily. The shark is included in the red list of IUCN endangered species. The government should take essential steps to stop killing sea sharks.
Types Of Shark