Blue Tilapia
Blue Tilapia are native to Africa and has become established in Texas and Florida and possibly Arizona, as a result of accidental releases from aquaculture operations.  It is found in fertile lakes, ponds, rivers, streams, and canals and is saltwater tolerant.  They prefer tropical environments with water temperatures over 75 degrees Fahrenheit and relatively intolerant of temperature below 50.  Tilapia are primarily herbivores, but will occasionally consume zooplankton and small invertebrates.
 
Tilapia are compressed, deep bodied fish, similar to our native sunfish.  Adults are generally a blue-gray along the back, fading to white on the belly. Sides may have vague irregular markings, or be unmarked. Dorsal and caudal fins have reddish borders.  The spiny dorsal fin is joined with the soft dorsal fin. They may live over five years.  Fish over 20 inches and approaching ten pounds are possible.
 
Spawning occurs when the water temperatures near 70 degrees Fahrenheit. Large circular nests are dug by the males in shallow water over a sandy bottom. Males lead passing females to the nest for courtship. After the eggs are laid and fertilized, the female takes the eggs into her mouth and swims off.  The eggs are hatched in the female's mouth, over a period of three weeks or so, the female releases the fry occasionally to feed.  When threatened they return to her mouth. This is referred to as mouth-brooding.
Introduced through aquacultural operations, tipalia have become established in the Rio Grande, San Antonio, Guadalupe, and parts of the Colorado River drainages.