The Texas cichlid (Herichthys cyanoguttatus, formerly Cichlasoma cyanoguttatum) is a freshwater fish of the cichlid family. This is the only cichlid species that is native to the United States. The fish, also known as Rio Grande cichlid, originates from the lower Rio Grande drainage in Texas near Brownsville and Northeastern Mexico. Herichthys cyanoguttatus can grow to be over 13 in (33 cm) and are differentiated by their distinctive characteristics and specific habitat needs. This cichlid is known for its cream and turquoise spots. Adult males also develop a nuchal hump on their head. This cichlid also prefers the water temperature to be between 68 and 82 °F (20–28 °C) and are negatively affected by rapid changes in temperature. The distribution of the Rio Grande cichlid in Texas appears to have originally been limited to the lower reaches of the Rio Grande. However, a number of populations have been established in river drainages of Central Texas Edwards Plateau including the San Marcos, Guadalupe, San Antonio and Colorado rivers. Minimum temperature tolerances in the Colorado River have been measured at 57-66°F.
