Some of the world's most unusual sharks and rays are threatened with extinction due to threats such as commercial fishing.
A shark that stuns prey with its tail, and a beam that is half of a bus are on the list of 50 species.
Scientists say sharks have a bad image and people do not understand how important and threatened they are.
And losing just one of these "living fossils" would wipe out millions of years of evolutionary history.
"The biggest myth about sharks is definitely the perception that they are dangerous, that they are man-eating machines ̵
"There have been some negative interactions recorded, but they are very rare and unintentional."
This is the first time that sharks, rays, and chimeras (fish with cartilage instead of bone) have been evaluated for the Edge (Evolutionially Distinct and Globally Endangered) of the Existence Program.
Most sharks are at the top of the food chain, making them crucial to ocean health.
Losing them would have a big impact on other fish stocks and ultimately on people's livelihoods.
"They have very few relatives on the tree of life, so they are very unique – great loss," said Fran Cabada.
The assessment found that both targeted and accidental fishing were responsible for the steep decline in many of these populations, along with the loss of habitats due to coastal development, mangrove forest degradation and water pollution and trawling.
"Edge's Shark and Ray list includes some of the most interesting and unique fish we have on this planet," Dr. Matthew Gollock of ZSL.
"The modern extinction of a single species from this list would cause the loss of millions of years of evolutionary history."
Here are some of the species on the list:
The Largetooth Sawfish (Pristis pristis)
This ray ranks first on the list. It is endangered by unsustainable fishing and unintentionally caught in nets. The biggest feature of the large sawfish is the rostrum, which is lined with sharp teeth to cut up the prey. Cowboy boots were once made from sawfish skin.
The Caribbean Electric Jet (Narcine bancroftii)
This jet may cause an electric shock, which may cause it to stun its prey. The fish hide in sand or mud during the day and look for worms and other small prey animals at night.
The Zebrahai (Stegostoma fasciatum)
This shark changes in appearance lifetime. The boys are born with crosswalks that turn into spots with age. He lives on the seabed and has a lifespan of 25 to 35 years.
The whale shark (Rhinocodon typus)
The largest fish in the sea, which is up to 20m high (65ft) long, it is a filter feeder that focuses on plankton and small fish supports to survive.
The basking shark (Cetorhinus maximus)
The giant shark is the second largest shark species (and species of fish) in the world behind the mighty whale shark.
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