Shark

Contents • Anatomy, Diversity & Evolution • Anatomy • • • • Diversity • • Evolution • • • • • Ecology & Behavior • Distribution • Life Cycle and Reproduction • • • • In the Food Web • • • Conservation • Fishing For Sharks • Ecosystem Effects • Shark Protections • Cultural Connections • Books, Film and Media • Additional Resources There are more than 500 species of sharks swimming in the world’s ocean. Yet when most people think of these cartilaginous fish, a single image comes to mind: a large, sharp-toothed and scary beast. That generalization does sharks a huge disservice, as they have far more variety than that. They range in size from the length of a human hand to more than 39 feet (12 meters) long; half of all shark species are less than one meter (or about 3 feet) long. They come in a variety of colors (including bubble gum pink), and some feed on tiny plankton while others prefer larger fish and squids. They are found in just about every kind of ocean habitat, including the deep sea, open ocean, coral reefs, and under the Arctic ice. Wherever they live, sharks play an important role in ocean ecosystems—especially the larger species that are more “scary” to people. Sharks and their relatives were the first vertebrate predators, and their prowess, honed over millions of years of evolution, allows them to hunt as top predators and keep ecosystems in balance. But sharks are in trouble around the world. Rising demand for shark fins to make shark fin soup, an Asian delica...

Long portrayed in pop culture as remorseless people-killers, sharks in reality are no Hollywood monsters. Sharks are a diverse group of mostly predatory fish, including the largest living fish, with skeletons made of cartilage. They have plied the seas since before the dinosaurs lived and play vital ecosystem roles. Sharks' long evolutionary history includes reaching tremendous size, when one of Earth's biggest apex predators, the gigantic megalodon ( Otodus megalodon), hunted the oceans. At high risk of extinction, these marine creatures as a group face far more dangers from humans than any surfer does from a great white shark. Because cartilage skeletons rarely fossilize, establishing the natural history of sharks can pose a challenge, according to the American Museum of Natural History in New York City. But sharks' impressive teeth, along with scales, leave enough of a record to estimate that the animals first evolved more 450 million years ago, according to the Natural History Museum in London. That timeline means sharks prowled the primordial seas around 200 million years before the first dinosaurs, even predating the first forests, which didn't appear until 385 million years ago, Live Science previously reported. Over those eons, sharks survived "the big five mass extinctions." They even enjoyed a "Golden Age" beginning around 360 million years ago, when a tremendous global die-off claimed many fish, leaving sharks to dominate — and proliferate into new species, acco...

With fossil records dating back 400 million years, sharks have outlived the dinosaurs and many other forms of life currently on earth. There are more than 1,000 species of sharks and rays, with new species discovered every year. These majestic top predators that are so essential to the natural order of marine ecosystems now face their most severe threat from overfishing. Many species are threatened with extinction, with some families of rays such as sawfishes in peril. While sharks and rays have been an irreplaceable resource for coastal communities in the developing world for centuries, this unique balance is in danger of being lost forever. With our oceans severely degraded, restoring sharks is key to improving the resilience of these water bodies to climate change. While sharks' diverse range of species adds complexity to our conservation efforts, the dwindling numbers of these amazing creatures from overfishing and demand for their fins and meat increases the urgency of the task. Through our multi-pronged strategies, and guided by the Global Priorities for Conserving Sharks and Rays - A 2015-2025 Strategy, we strive to restore the balance between humans and sharks. Overfishing and illegal fishing of sharks for their fins is depleting populations worldwide. There is often a general lack of even basic management monitoring, control, and surveillance of many fisheries. Improving the capacity to combat pirate fishing (illegal, unreported and unregulated fishing) of sharks ...

We Know Sharks LEARN ABOUT SOME OF THE 400+ SPECIES OF SHARKS. All organisms have scientific names, a name that is unique for each species. Every species has two Latin names which allow people to be certain they are talking about the same creature no matter what language they speak. For example, the scientific classification of the shortfin mako shark goes like this: • Kingdom: Animalia (all animals) • Phylum: Chordata (all chordates) • Class: Chondrichthyes (cartilaginous fish) • Order: Lamniformes (mackerel sharks) • Family: Lamnidae (mackerel sharks) • Genus: Isurus • Species: oxyrinchus Every shark belongs to the classification Chondrichthyes which identifies them as cartilaginous fish, fish whose internal skeletons are comprised of flexible cartilage rather than bone. Chondrichthyes consists of two groups, Holocephali and Elasmobranchii, and within Elasmobranchii are eight (8) orders of sharks. Each order tells us about the biology, physical characteristics and behavior of sharks in that order. Provided here are a number of sharks within each of the eight (8) orders. To further your learning about these truly amazing animals, we highly recommend Sharks of the world. An annotated and illustrated catalogue of shark species known to date . by CARCHARHINIFORMES Also known as “ground sharks,” carcharhiniformes is largest order of sharks. Their characteristics include five (5) gill slits, moveable eyelids which protect their eyes from injury, two (2) spineless dorsal fins, ...