The bluefin killifish has a laterally compressed body, usually around 3 centimeters in length. It has a fin above and below the body, pelvic fins, and a tail fin. Fins of females are clear, while males exhibit bright blue and orange colors. Its distinguishing characteristic is a black stripe that extends along the body from the head to the tail.
RANGE, HABITAT, and BEHAVIOR
Bluefin killifish are freshwater fish but may tolerate brackish and marine environments. Their native range includes Florida, southern Alabama and Georgia, but have spread along the Atlantic coast to South Carolina. They prefer densely vegetated ponds and streams and are commonly found in the springs, swimming well below the surface of the water.
Although their native habitat is in and around the Florida peninsula, introduced populations are found in Texas and up the Atlantic coast. This dispersal is primarily the result of the release of fish or eggs that are transported with aquatic plants from Florida, due to their popularity as aquarium fish.