There are many different types of fish in the world. Some live in the ocean, while others live in freshwater lakes and rivers. Some fish are small, while others are very large. Fish come in all sorts of shapes and sizes. They can be long and skinny, or short and fat. Some have scales, while others do not. Fish can be brightly colored, or they can be dull and drab. Fish are found all over the world. They live in both cold water and warm water. Some fish live in salt water, while others live in freshwater.
Fish are a very important part of the ecosystem. They provide food for many other animals, including humans. Fish are also a major source of income for many people who live in coastal areas. There are many different types of fish in the world. Some are more popular than others. Some of the most popular fish include salmon, tuna, and bass.
Salmon is a type of fish that is found in the ocean. It is a popular food fish and is also used in many different dishes. Tuna is another type of fish that is found in the ocean. It is a popular food fish and is also used in many different dishes. Bass is a type of fish that is found in freshwater lakes and rivers. It is a popular food fish and is also used in many different dishes.
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic craniate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Most fish are ectothermic ("cold-blooded"), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white sharks and tuna can hold a higher core temperature. Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., cusk-eels and snailfishes), although no species has yet been documented in the extremely cold and hydrogen-based environments of Europa or Enceladus. Fish are an important resource for humans worldwide, especially as food.
Commercial and subsistence fishers hunt fish in wild fisheries (see fishing) or farm them in ponds or in cages in the ocean (see aquaculture). They are also caught by recreational fishers, kept as pets, raised by fishkeepers, and exhibited in public aquaria. Fish have had a role in culture through the ages, serving as deities, religious symbols, and the subjects of art, books, and movies.
The word "fish" descends from Old English fisc (plural: fiscas) which was literally a basket, container, or vessel used for carrying fish, or for storing them while they were being caught. The word later became fossilized in English as the word for fish in general. It can be used singly (as a noun) or in plurals and is one of a small number of English words that can still be used both ways.
In biology – the Linnaean taxonomy – fish are classified as a paraphyletic group, rather than a natural group because they exclude the tetrapods (i.e., the amphibians, reptiles, birds, and mammals which all descended from within the fish). In previous centuries, even biologists did not always make a distinction – sixteenth-century natural historian Ulisse Aldrovandi believed for example that salmon spawn in the air and that swallows picked up the fish in their beaks and delivered them to land. However, since the 19th century scientists have increasingly recognized that tetrapods emerged from within a group of fishes known as the lobe-finned fishes and that this group constitutes a natural (monophyletic) group, even though they are paraphyletic with respect to the teleosts, among which are the ray-finned fishes.
There are many different types of fish in the world. Some people keep fish as pets, while others eat them as part of their diet. Fish are a popular food choice because they are low in calories and fat, and high in protein. Fish live in both fresh and saltwater environments. They breathe using gills, which extract oxygen from the water. Fish are vertebrates, which means they have a backbone. Most fish are ectothermic, meaning their body temperature is determined by the surrounding water temperature.
There are over 32,000 different species of fish in the world. The largest fish is the whale shark, which can grow up to 60 feet long. The smallest fish is the goby, which only grows to be about 1 inch long. Most fish are predators, and they typically eat smaller fish, insects, or crustaceans. Some fish are herbivores, and they feed on plants. Fish are an important part of the food chain. They provide food for larger animals, such as birds and mammals. Fish also play an important role in the economy. They are a major source of food for humans, and they are also used for recreation, such as fishing and swimming.