Your wish list — the plush you mean to keep.
Press Add to a collection on any plush in the shop: start a collection of your own, or keep it on your wish list. Sign in and both follow you to any device.
Open my wish list →There are more than 500 kinds of shark. They share some surprising features.
Sharks, like skates and rays, have skeletons made of cartilage and connective tissue. Unlike bony fish, they have no gas-filled swim bladder to help them float.
SourceSharks keep making new teeth all their lives. When an old tooth breaks or wears down, it falls out of the front of the mouth. Depending on its kind and diet, a shark can produce between 20,000 and 40,000 teeth.
SourceSharks have special sense organs called the ampullae of Lorenzini. They use them to detect the electromagnetic fields that all living things produce.
SourceMermaid's purse
Some sharks, skates and rays lay their eggs inside a case. It is often called a mermaid's purse. The case is made of a natural material called collagen. Catshark egg cases have long tendrils at the corners. These anchor them to things on the sea floor. Bullhead sharks lay egg cases with two spiral flanges, so the cases can become wedged in cracks in rocky sea floors. Inside the case, the baby grows. This can take anywhere from a few months to over a year. Bullhead shark eggs usually hatch after 7 to 12 months.
SourceVery old family
Sharks have been around for hundreds of millions of years. The earliest fossil evidence for sharks or their ancestors is a few scales dating to 450 million years ago. That means they appear in the fossil record before trees even existed. Over all that time, sharks have survived five mass extinction events. Most of a shark's skeleton is soft cartilage, which needs special conditions to be preserved. Their teeth are made of dentin, which is harder and denser even than bone. So the vast majority of shark fossils found are teeth.
SourceRhincodon typus
The whale shark is the largest known fish alive today. It lives in the open waters of all tropical oceans and feeds mainly on plankton, krill, fish eggs and small fish. Its pattern of pale spots and stripes is different on every whale shark.
SourceSomniosus microcephalus
Greenland sharks live in the cold North Atlantic and Arctic Oceans. They are thought to have the longest lifespan of any known animal with a backbone, estimated at between 272 and 510 years. They grow only 0.5 to 1 centimetre a year.
SourceSphyrna tiburo
The bonnethead is the smallest of the hammerhead sharks, with a broad, smooth, spade-shaped head. It lives in shallow bays over seagrass, mud and sand. It was the first shark found to eat plants as well as animals, and it eats large amounts of seagrass.
Source