Osteichthyes

Author: Leah Miller
__**EXAMPLES**__:

Ocean Sunfish: The Largest known Osteichthyes

Bonfish: Part of the Actinopterygii class

**Osteichthyes (Bony Fish) are the most species-rich and morphologically diverse lineage of all vertebrates.**
__**HABITAT**__: Osteichthyes are a very diverse group of bony fish. They are Ectothermic, which means they depend on the surrounding environment for their body temperatures. Osteichthyes live in all types of fresh and salt waters. Mild temperature waters are desired but not necessary. Some osteichthyes, such as swordfish, are endothermic and can produce their own body heat.

__**TYPE OF COELOM:**__ There is a coelom present among all osteichthyes. Each Osteichthyes' coeloms vary slightly, but all have a coelom, which allows them to move more freely through the water.

Osteichthyes have an exoskeleton, meaning they have an external skeleton that helps protect the internal organs. Bony fish differ from the Chondrichthyes because the bony fish have skeletons actually made of bone. Most bony fish have scales, however, some have armor plating, while others such as catfishes lack any kind of covering over the exoskeleton and thus are considered "completely naked".
 * __ENDOSKELETON or EXOSKELETON__:**

>> light >> fish's snout; keenest sense is smell; fish >> actually smell the water that enters the >> olfactory sacs
 * __TYPE OF NERVOUS SYSTEM__:**
 * brain
 * spinal cord
 * cranial nerves
 * spinal nerves
 * sensory organs -
 * eyes - good eyesight. no eyelids, thus permitting a maximum amount of
 * ears - no external opening. sensitive to vibrations
 * olfactory sacs - small pouches behind the nostrils on a
 * tongue - taste and touch (taste - rather dull sense)

__**FEEDER**__: Osteichthyes have a typical GI tract + glands: liver, gall bladder, pancreas. Several Osteichthyes' diets were studied at several Southern California Universities and many different things were found to be common among all fish that were tested. Some of the things found were: phytoplankton, zooplankton, algae, insects, plant like matter, decapod appendages, debris and unidentified matters. Most are carnivores;but there are also many that are herbivores.

__**SYMMETRY**__: Osteichthyes (bony fish) have bilateral symmetry, if you were to cut the fish exactly in half, the right and left side would be equal. they would have the same number of eyes, fins, gills, etc.

__**REPRODUCTION**__: Osteichthyes produce externally outside of the body. the female carries an egg and it can only be fertilized by milt which is produced by the male. The vast majority of bony fishes are oviparous (eggs), although some well-known groups are viviparous (live birth, e.g. mollies).

__**CIRCULATORY SYSTEM**__: Bony fish have a 2 chambered heart that helps move Oxygenated blood throughout the fish's body. The oxygen enters the operculum-covered gills and is transported with the blood by means of the 2 chambered heart.

__**ENDOTHERMIC or EXOTHERMIC**__. Osteichthyes are Exothermic, however some such as the swordfish are Endothermic. Osteichthyes' have different kinds of skin to help them conserve body heat, since they can not produce it on their own.

__**SEGMENTATION**__: Osteichthyes have no segmentation.

__**WORKS CITED**__: "Bonefish & Tarpon Conservation Research Center Annual Report." //Bonefish Facts//. Bonefish&Tarpon Conservation Research, June 2009. Web. 29 Mar. 2011. .

Class: Osteichhyes." //SeaWorld/Busch Gardens ANIMALS - HOME//. Sea World/ Busch Gardens, Jan. 2002. Web. 29 Mar. 2011. .

Helfman G.S., B.B. Collette and D.E. Facey. The Diversity of Fishes. Blackwell Sciences, 1997

Ocean Sunfish, Open Waters, Fishes, Mola Mola." //Ocean Sunfish, Open Water Fishes//. Monterey Bay Aquarium, California, 2001. Web. 29 Mar. 2011. .