Forms of life cannot survive if they do not reproduce. Different species have different means of reproducing, and different means of reproduction have different advantages and disadvantages. Asexual reproduction is the most common type.
The size of a shark depends on its species. The largest living shark, the whale shark, averages 31.82 feet long. The extinct megalodon was even bigger at about 60 feet long. The smallest shark is the dwarf lanternshark, which is only 6.7 inches long.
More than 450 shark species have been documented as of 2014. Sharks have been around since prehistoric times, with evidence of their existence dating back hundreds of millions of years. The first sharks appeared in the world's oceans around 420 million years ago.
Sharks are found in every ocean in the world and are sometimes found out of their habitat in rivers and streams. There are around 368 species of sharks in the world.
There are approximately 470 known species of shark in the world, but it's impossible to count the exact number of individual sharks on the planet. World Wildlife Fund estimates that more than 100 million sharks are killed each year for their fins.
Sharks live in every ocean of the world, with most species occupying waters no deeper than 7,000 feet. The Portuguese dogfish is the deepest-living shark and can be found at a depth of 12,000 feet. Some sharks, such as the bull shark, are capable of surviving in fresh water.
Sharks move through the water with the help of their tail fins. The body of a shark is light as it is made of cartilage and not bones. It has a perfectly streamlined body. Its dorsal fins help it steer through the water.
A great white shark, or Carcharodon carcharias, is a large shark that inhabits the coastal waters of all oceans. It is the largest macro-predatory fish on Earth.
Though sharks are considered apex predators, they are often eaten by humans and are sometimes eaten by killer whales. Shark embryos from different fathers will also eat each other in utero, with the largest embryo of the bunch usually winning out.
There are over 400 species of sharks currently prowling the world's oceans. The smallest shark is the dwarf lantern shark, which has a maximum length of 6.8 inches at maturity. The largest shark is the whale shark, which can reach a length of approximately 40 feet at maturity.