Header illustration public domain by Kristin Simanek/USFWS.
Appearance
Public domain photo by Ryan Hagerty/USFWS.
The Okaloosa darter is a small darter that reaches a body length of only two inches (5.1 centimeters). This darter species has a green-yellow to red-brown coloration with five to eight brown spots along the lateral surface of its body, and a well established spot above the base of its pectoral fin. Male Okaloosa darters develop an orange band along the edges of its first dorsal fin (Florida Natural Areas Inventory 2001). As an obligate bottom dweller, they have no swim bladder, which enables a fish to control its buoyancy.
Behavior
The diet of the Okaloosa darter primarily consists of mayfly nymphs, caddisfly larvae, and midge larvae (Ogilvie 1980).
Okaloosa darters breed between the months of March and October, with most breeding activities occurring in April and a peak breeding period in October. In one Okaloosa darter study, a mean average of 79 ova (eggs), of which 29 were mature, were found among 201 females sampled. Eggs attach to vegetation once they are released. Female Okaloosa darters reach sexual maturity when a standard length of 1.2 inches (3.1 centimeters) is reached (Ogilvie 1980).
Habitat
The Okaloosa darter inhabits small streams that are fed by ground water seepage from the surrounding sandhills (U.S. Fish & Wildlife Service 1998). The majority of Okaloosa darter habitat is located within Eglin Air Force Base’s (Eglin AFB) boundaries, but they can also be found in adjoining portions of Okaloosa and Walton counties in Boggy and Rocky bayou of the Choctawhatchee Bay drainage (Burkhead and Williams 1992).
Threats
The main threat to the Okaloosa darter is the introduction of the brown darter (Etheostoma edwini) to its habitat. Brown darters are thought to out-compete the Okaloosa darter for food and other resources (Burkhead and Williams 1992). Sedimentation of streams is also a threat to the Okaloosa darter as the sediments can cover sites where eggs are laid. Other threats include an increase of pollutants in streams. With Eglin AFB committed to continued conservation of the Okaloosa darter, the secondary threats will occur primarily as a result of off-base development and land-use conversion.
Conservation and Management
Eglin Air Force Base's Jackson Guard Unit has made on-base conservation a priority. Eglin AFB has reclaimed clay pits near stream headwaters and improve road crossings to reduce sedimentation and improve habitat for the darter.
The U.S. Fish and Wildlife Service removed the Okaloosa darter from the federal Endangered and Threatened Species list in 2023. Rule 68A-27.0012, F.A.C., states that species removed from the federal Endangered and Threatened Species list shall receive a biological status review by a Biological Review Group. In December 2024, the FWC Commissioners approved the convening of a Biological Review Group to review the species' status against state-listing criteria. The findings of the Biological Review Group and staff recommendation that the Okaloosa darter did not meet criteria to be listed as State-designated Threatened were approved at the February 2026 Commission Meeting. The species was removed from Florida's Endangered and Threatened Species List effective June 10, 2026.
References
Burkhead N.M. and Williams J.D. 1992. Okaloosa Darter Etheostoma okaloosae. Pages 23-30 in C.R. Gilbert, editor. Rare and Endangered Biota of Florida. Volume II. Fishes. University Press of Florida, Gainesville, Florida, USA.
Florida Natural Areas Inventory. 2001. Field guide to the rare animals of Florida. https://www.fnai.org/PDFs/FieldGuides/Etheostoma_okaloosae.pdf
Ogilvie, V.E. 1980. Unpublished Florida Game and Freshwater Fish Commission Endangered Wildlife Project E-1. Annual Progress Report. Tallahassee, Florida. 19 p.
U.S. Fish and Wildlife Service.1998. Okaloosa Darter (Etheostoma okaloosae) Recovery Plan (Revised). Atlanta, Georgia. 42 pp.