'''Fish''' are aquatic cold-blooded [[vertebrates]] with fins and scales. Many [[species]] of fish are often kept as pets in containers known as [[aquarium]]s. Fish are generally divided into two groups: [[freshwater]]-dwelling and [[saltwater]]-dwelling, and fish from one group are generally unable to survive in the environment of the other. There are, however, a small number of species that move between saltwater and freshwater at different stages of their lives. Humans consume several types of fish, which is a source of animal protein.
The largest freshwater fish ever found was a 646 -pound giant [[catfish]] found in the Mekong River in [[Thailand]] in 2005. [http://news.nationalgeographic.com/news/2005/06/photogalleries/giantcatfish/]
[[Image:LemonTetra.jpg|thumb|right|Lemon Tetra tropical fish]]
== Types of fish ==