Freshwater fish used as food in many parts of the world.
The respiratory system is responsible for the intake of oxygen and the release of carbon dioxide.
Many freshwater fishes are also popular as food.
The life cycle of vertebrates starts with the production of the reproductive cells of an individual and ends with the production of the reproductive cells...
A group of fish characterized by a cartilaginous skeleton, well-known species include the great white shark and the hammerhead shark.
Smoking severely damages the respiratory system, it may cause COPD or lung cancer.
Extinct species of fish which had thick ´armor´ protecting the head.