- Federal Status: Not Listed
- FL Status: State Species of Special Concern
- FNAI Ranks: G5/S1 (Globally: Demonstrably Secure/State: Critically Imperiled)
- IUCN Status: Not ranked
The harlequin darter is a smaller member of the darter Family Percidae that can reach a standard length of 2.5 inches (6.4 centimeters). This species is greenish, with six or seven brown saddles, and seven to 11 dark green or brown spots. Harlequin darters also have a green and black dorsal (back) side, a yellow belly with dark markings, and a clear first dorsal fin with a red boundary (Boschung and Mayden 2004, Florida Natural Areas Inventory 2001).
Little is known about the reproduction of the harlequin darter; however, spawning capable adults have been found in February and March. Females reach sexual maturity at one year (Gilbert and Yerger 1992, Steinberg et al. 2000, Bass et al. 2004, Kuhajda and Warren 1989). Females lead the search for nesting sites and will pick the site as the male follows her lead. Snags (a partially or completely dead standing tree) are used as primary nesting habitats. When released, eggs attach to detritus (decomposed organic matter) components in deep waters.
Harlequin darters inhabit snags and debris build ups in rivers and creeks (Florida Natural Areas Inventory 2001). They can be found from Illinois, Indiana, and Kentucky, south to Florida, and west to Texas (Boschung and Mayden 2004, Etnier and Starnes 1993, Page 1983). Harlequin darters only occur in the Escambia River watershed in Florida.
Harlequin darters are restricted to one watershed in Florida, which makes the species susceptible to disasters in the watershed, such as oil spills. The removal of snags (standing dead trees), which are spawning sites, and impounding flowing waterways are also threats to the harlequin darter (Bass et al. 2004, Boschung and Mayden 2004). Impounding waterways causes habitat fragmentation and water quality levels to decrease. Other threats include high turbidity (cloudiness of water due to sediment particles) in waterways, which decreases water quality.
Bass, G., T. Hoehn, J. Couch and K. McDonald. 2004. Florida Imperiled Fish Species Investigation. Final Report to the U. S. Fish and Wildlife Service. Federal Grant R-3. Florida Fish and Wildlife Conservation Commission, Holt, Florida. 59 pp.
Boschung H.T., and R. L. Mayden. 2004. Fishes of Alabama. Smithsonian Institution Press, Washington D.C. 736 pp.
Etnier, D.A., and W.C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press. Knoxville TN. 681 pp.
Florida Natural Areas Inventory. 2001. Field guide to the rare animals of Florida. https://www.fnai.org/FieldGuide/pdf/Etheostoma_histrio.PDF
Gilbert, C.R., and R.W. Yerger. 1992. Harlequin darter, Etheostoma histrio. Pp. 84-87 in C.R.Gilbert (ed.). Rare and Endangered Biota of Florida. Vol. II Fishes. University Press of Florida, Gainesville, FL.
Kuhajda, B.R,, and M.L. Warren, Jr. 1989. Life history aspects of the harlequin darter, Etheostoma histrio, in western Kentucky. ASB Bulletin. 36(2):66-67.
Page, L.M. 1983. Handbook of Darters. T.F.H. Publishers, Neptune City, NJ.
Steinberg R., L.M. Page, and J.C. Porterfield. 2000. The spawning behavior of the harlequin darter, Etheostoma histrio (Osteichthyes: Percidae). Ichthyological Exploration of Freshwaters 11 (2):141-148.