Rays

Sciencedog is back. Today I'm talking about rays. Yeah, these fish are really similar to sharks because they're both cartilaginous fish. That means they don't have real bones.  Instead they have bones made out of cartilage. That's the stuff our noses and ears are made out of.

They can grow up to 6.5 ft. long and can weigh up to 790 lbs. Their bodies are smooth, unlike sharks that have sandpaper skin. They flap their arms to hover and swim over the ocean floor. They can also hide in the sand so predators can't find them.

Some sting rays and rays use their electric and venomous tails to fight off predators. Their tails are also really sharp and strong and can go through wooden boats.



These guys have to eat so let me tell what they eat. They eat mollusks,crustaceans and sometimes small fish, but most of the time they don't eat small fish because their eyes are on top of their heads and their mouths are at the bottom. They eat their prey by swooping down on them and surrounding them with their tails.

                                                    Like that video? cool right!!!

You have a better idea about how they look and what they do. Now it's time to name my favorite type of ray, the Thorn Back Ray.

This ray can be as much as 3ft. long and can weigh up to 9lbs. He is called the thorn back ray because he has a strong and thick spine.  It eats shrimp, crab, crustaceans and small fish using it's tail and ability to surround fish. It rests in seabeds like mud, gravel or sand.

Before I go I want to compare rays to skates. A lot of people think they're the same thing, but they're different.  Rays have kite shaped bodies and light tails.  Skates have triangular shaped bodies and heavy tails.

Bye and Have a happy Halloween! 

Sharks

Hey guys! Today I'm talking about sharks.Yeah, I know you think sharks are bad and only want to kill, but some sharks don't attack humans.

There's a bigger amount of humans that kill sharks than sharks that kill humans. It's really sad because now most sharks are endangered and some of them are harmless to humans.

Sharks have an awesome operating system with their teeth since they have three rows of teeth. When they lose a tooth, they replace it with another one.

Their skin feels like sand paper when you stroke it tail to head, but their skin is smooth head to tail. Sharks also have different talents like camouflaging, sensing electricity, jumping in the air, sucking up tons of water or glowing light.

Sharks can come in different types of colors like blue, orange, yellow, brown or leopard.

Now that I've talked about the sharks in general, it's time to talk about the different types of sharks. There are 400 species of sharks. My three favorite sharks are the hammerhead, short fin mako and whale shark.

 The short fin mako shark: This shark is one of the fastest sharks so far and it's really powerful.

This shark eats tuna, squid ,sea turtles, sword fish, marine mammals and other sharks. They live in warm waters and don't have good eye sight.  Instead they use their senses and their fast torpedo shaped body to hunt.

They can be found in the Gulf of Mexico, Argentina and Canada and can live up to 32 years old.

Hammerhead sharks have six senses. Their extra sense is to sense electricity or pulses in people's or animal's bodies.

This shark uses it's head to kill prey and there are eight species of them. The most dangerous ones are the great, smooth and scalloped hammerhead sharks.They can grow up to 23 ft. long and live in warm waters, but cold waters during the summer.



The whale shark is the largest fish because whales are marine mammals.

                                                                                                                                                                              

Whale sharks can go up to 80 ft. and 27,000 pounds. His mouth can suck up 1,500 gallons of water an hour. The whale shark is not dangerous to humans and eats small fish like shrimp.

That's all guys... bye.