Splendid Darter

The splendid darter is found only in the Barren River system of southern central Kentucky and northern central Tennessee; this system is a part of the Ohio River drainage. The range of this species is between 5000 – 20,000 square kilometers, which is relatively small. E. barrenense is not thought to have either spread or shrunk its distribution since it was described in 1982, but very little data are available on its dispersal and other movements; some larvae may drift along with the current, but ultimately, the species has remained in its small range. The splendid darter has a tendency to spend most of its life in deep, rocky pools and the riffles of small creeks and rivers, as well as streams. The geographic distribution of E. barrenense and other darter species is extremely important to the way the species passes on its genes to subsequent generations. Much of the isolation that remains between closely related species of darters is due to brilliant nuptial coloring and behavioral isolation, ensuring that mates of the same species are attracted to one another. Since many of these species live in sympatric populations, there must be a mechanism such as this, allowing the genes of different species to remain isolated. Without the occurrence of this phenomenon, the very genes which define the species could be compromised, endangering its existence.

The splendid darter is a benthopelagic fish that occupies a freshwater habitat . Research has not yet revealed the specific dieting habits, competitors, or predators of this darter, but studies of other darter species indicate the splendid darter is likely insectivorous and at times consumed by larger predatory fish. These invertivorous fish spend most of their time feeding on the bottoms and sides of streams.

E. barrenense reaches sexual maturity around one year of age, but the majority of breeding individuals sampled are between two and three years old. Typical mating pairs include a two-year-old female and a three-year-old male. Breeding occurs once a year, normally from March to June in Kentucky and March to May in Tennessee. The average lifespan of this species is only three years, so most individuals may breed once or twice before they die. No individuals have been known to live beyond three years. Most species of Etheostoma exhibit unique nuptial coloration and E. barrenense is no exception. It Reproductive isolation and sexual selection between species is thought to maintain these diverse color patterns, as these fish are often found in sympatric populations. Breeding is an interesting phenomenon; males establish floating territories in deep pools and females approach these microhabitats where both fish will press against inclined stones to lay their eggs. Many eggs are laid at one time, but they are usually produced individually on separate, vertical rocks in slightly flowing currents. This dispersing of the eggs increases the chance of survival for at least a few of the offspring. The eggs are spherical, translucent, and adhesive, providing them a greater opportunity to survive as they are attached to a vertical wall and often difficult to detect.