I wanted to find out what was inside the fish and what the brain looked like. We went to a supermarket and bought a fish. The name of this fish was Bass. He was a beautiful fish. He was gray and green on the top and white on the bottom. He had stripes along his body.
He had two fins onthe top of his back. He also had two fins on the sides behind his gills, two fins on the bottom and one fin near the tail. Some goldfish have two tails but this one had only one.
In his mouth he had teeth which are very small, but there are a lt of them and a tongue. I knew fishes had tongues because I know of that shrimp that gets inside a fish an sucks the blood out its tongue and it replaces the tongue with itself and serves as its new tongue. This is very strange. But it is not about this fish.
Behind the covers on the sides of its head there are its gills. He uses gills for breathing. The fish opens and closes the covers to pump water through them. But sharks can't. So they have to always keep swimming so that they can breathe.
Then we cut the fish open. I didn't know this but there were only a few things inside the fish. They were intestines, stomach, heart, liver and gonads. There was also kidneys but they were small. And there was a swimbladder. And also pyloric caeca. And spine.
This is the fish's heart. It was small. It was hiding between its head and liver. It had the blood in it.
This is the stomach, pyloric caeca and intestines all in one pile. They were hard to separate. We opened the stomach and found there a half-digested worm.
This is a picture of the liver. It makes enzymes that help digestion. Enzymes are chemicals that help chemical reactions in the body. Enzymes break down food and turn it into energy. Livers also cleans up the body by filtering the junk out of blood.
These are the gonads.
Gills.
Penguins are small birds, but they cannot fly. The biggest penguins are Emperor penguins. Emperor penguins can get 4 ft tall. The Emperors are black birds with white and yellow markings. Other penguins are black birds but they only have white markings. They don't have wings - they are called "flippers", and flippers help them swim. Some penguins like the Adelie penguins can go up to 40 or even 100 miles per hour, while a few others are a bit faster. 15 miles per hour or higher depends on the penguin species.
Eagles eat mice and berries. Bald eagles eat fish, turtles, small rodents and snakes. They catch fishes with downward looking eyes like catfish because they catch them by snatching them off the surface. 
Behind the covers on the sides of its head there are its gills. He uses gills for breathing. The fish opens and closes the covers to pump water through them. But sharks can't. So they have to always keep swimming so that they can breathe.
Then we cut the fish open. I didn't know this but there were only a few things inside the fish. They were intestines, stomach, heart, liver and gonads. There was also kidneys but they were small. And there was a swimbladder. And also pyloric caeca. And spine.
This is the stomach, pyloric caeca and intestines all in one pile. They were hard to separate. We opened the stomach and found there a half-digested worm.
Crabs are Crustaceans. Crustaceans don't have backbones and wear their skeletons on the outside. This group includes 52000 species - lobsters (which are bugs), barnacles and crabs. They live on land and in the water. But most - in the water. Once I ate a crab and found cartilage inside the claw. 
This picture on the right is the platypus’ foot with the venomous spur. Platypus does not make a good pet because it has a venomous spur, it eats a lot and its poop smells. When animals flex their muscles they send electric signals.That’s how the platypus finds its prey. It is called “electrolocation”. Platypus find its food by digging with its bill at the bottom of streams where he dives. It swims only by its front feet. And it uses its rear feet to steer.
