Its invasive relative The newly identified species is related to the Rio Grande Cichlid, sometimes called the Texas Cichlid, a fish native to the river it’s named after that forms the southern border of Texas. About the size of a human hand, its scales show off bright bluish-green spots over a gray-green background. But that attractive coloring also makes the Rio Grande Cichlid (Herichthys cyanoguttatus) a popular pet. So the fish most likely escaped or was dumped into the water by their owners. It’s now found throughout Texas, Louisiana and Florida. Scientists have documented that the Rio Grande Cichlid can dominate the waters by being aggressively territorial with other fish, especially bluegill.