Bony Fish

How are they unique, what are some attributes?
One of the biggest unique features of fish is the fact that they can breath underwater. They do this by breathing through their gills, which will be covered later. Bony fish are known for their bone structure. Some of those structures are the spine and skull. Bony fish are also the last survivors of world's first vertebrate, meaning that they are backed boned. To add being the first vertebrate, they date back over a 100 million years.

Bony Fish

Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclass (Scientific Name): Osteichthyes

What is their habitat and food?
They live in the water all over the world, both in fresh and salt water. Fish adapt well to many different environments. They can tolerate many different conditions, including various temperatures. The habitat of bony fish can also change due to migration as a result of spawning or just to go to a better environment because of the seasons. Food sources vary depending on the location and type of fish. Some bony fish are herbivores; some are carnivores, and even some omnivores. They can range from plants and bugs to even other fish.
(See pictures to the bottom and right)

How do these animals digest their food? Do they have a complete digestive system?
Fish, like people, have complete digestive systems. They have a short and expandable esophagus, a stomach, and a blind sac. They have different gastric glands that digest their food. They also have a pancreas, which excretes enzymes into the intestines to aid with digestion.
(See diagram to the lower right)

What type of circulatory system do these animals have?
The circulatory system is no different than any other animal. There is the basic parts such as the arteries, veins and capillaries. The heart structure of bony fish has two basic parts. One part is the atrium, which is considered the collecting chamber for the blood. The other part is the ventricle, which is the pumping chamber for the heart. To add to that the heart structure has a system in how it processes blood. The atrium receives oxygen depleted blood, then pumps it into the ventricle. After that the blood flows the blood flows through the bulbus arteriosus. Once that happens the blood flow to the gill filaments, then the blood is finally oxygenated.
(See diagrams to the right)

What it their nervous system like? Do they have specific sensory structures?
The nervous system of a fish is poorly developed compared to other vertebrates. The brain of a bony fish has three sections to it. The first part is the forebrain, which controls the sense of smell. The second part is the hindbrain. What it does is control movement of the fish, the muscle tone, and the balance. Last but not least is the midbrain, which processes vision, learning and motor responses. One of the sensory structures is the lateral line. The lateral line is just below the fishes skin. It runs on the head and all along the sides of the body. What it contains is a number of sensory cells. The hair like structure propels out of the canal. The current and vibrations of the water causes stimulation and projects nerve impulses to the brain.
(See diagram to the right)

How do they support their shape? Do they have a skeleton?
Bony fish support their shape by having the structure know as a skeleton. In this skeleton is a backbone, skull, ect. The purpose of the bones is that it provides protection, assists in leverage, and is a site of red blood cell production. The rest of the bony fishes structures are made a cartilage. Some of those structures are the fins and other bones. But it is the bone structure that separates them from other species of fish.
(See the picture to the bottom)

How do they get oxygen and get rid of Carbon Dioxide?
They way that bony fish get oxygen is through their gills. What happens is that the fish gulps in water, then which is pumped through their gills. The oxygen that is in the water is then replaced by Co2. After that the water is pumped out through the gill slits.
(See diagram right of the fish gills article)

How do these animals reproduce? What is the life cycle like?
In Most bony fish, the sperm and eggs the fish are separately developed in the male and the female. The way that bony fish reproduce is through external fertilization. What occurs is the female will lay her eggs in the open water. After that the male will come in and then fertilize the eggs with his sperm. Then it is up for the eggs to develop. The eggs are usually hidden or even are guarded. In some other cases, the eggs will actually develop internally in the female. When the eggs do hatch there is very little parental care. This is mostly because parenting is not needed. Their lifecycle is pretty simple. They simply hatch and grow then reproduce, then eventually die.
(Watch the video below)

What is their excretory system like? How do they eliminate the wastes we get rid of urine?
Fish have kidneys that filter impurities and toxins out of the blood. They also have intestines, which take the nutrients out of the food that they eat. The wastes then exit through the anus. Most fish release wastes that are full of ammonia, and therefore are toxic. Some fish also excrete some wastes through the gills.
(See diagram to the right)

What is external fertilization?
This is the process by which fish mate. The female makes a sort of nest in the sand on the bottom of whatever body of water they are in. She then proceeds to lay her eggs into the nest. The male releases his sperm onto the eggs, which then the eggs get fertilized by them and then the female buries them. Then soon after the eggs develop and hatch into baby fish. This is the process of external fertilization.
(Watch the video to the right)

How do fish gills work?
Fish gulp in water, which is then pumped over the gills. The oxygen in the water is then replaced by the carbon-dioxide from the fish. At the same time the oxygen comes in contact with the blood of the fish in the gills. The blood flow of the gills will flow in the opposite direction of the water flow. This is because oxygen will tend to flow from the site of highest concentration to the place of lowest concentration; this arrangement ensures that oxygen will always flow from the water into the blood. After that the water is then pumped out through the gill slits, which on most fish are protected by the gill covers. That is how gill work for a fish.
(See diagram to the bottom and right)

What are some examples of this group of animals?
Trout, bass, cod, tuna, bluegills, and most other commonly known species of fish are bony fish. This is because of their obvious structure they have. That structure is made of bone, which makes up most of their body. Overall, there is over 20,000 species of bony fish.
(See pictures to the right)

What is their importance?
Fish are important to humans for several reasons. They provide a source of food to people all over the world. Some people also keep fish as pets, and they are also kept on display in large aquariums. Fish are also important to the environment. They provide food to many different species of animal, and they eat other creatures, helping to keep other populations under control. Fish are an important part of the food chain in any environment.
(See Picture to the left)