Covered Species Information
Authored by Connor Helsel
The fountain darter is located in the Comal and San Marcos spring systems within the Edwards Aquifer region of Central Texas and depends on a combination of sufficient habitat and adequate springflow. The Edwards Aquifer Habitat Conservation Plan (EAHCP) implements Conservation Measures such as submerged aquatic vegetation (SAV) restoration to improve fountain darter habitat by the removal of invasive plant species and planting of native aquatic vegetation. Additionally, the EAHCP has established programs for springflow protection through incentive-based water conservation in times of drought – the Aquifer Storage and Recovery (ASR) program and the Voluntary Irrigation Suspension Program Option (VISPO).
Endangered Species Act status
Reaches a size of 35.5 mm (1.40 inches) standard length (Carla Hassan-Williams et al., 2013).
Physical description and Life History
The fountain darter is the smallest darter in the Percidae family (Page & Burr, 1979). Some species of Percidae have a swimbladder (an organ that helps a fish regulate buoyancy in the water column), yet the fountain darter does not (Collete, 1963). Other distinguishing features include an olive upper body with a band of small, black blotches running mid-laterally. These lateral-body spots are more prominent in males. Additionally, males have five colored bands of black, clear, red, clear, and black on the first dorsal (top) fin. Females have a mostly clear dorsal fin with light brown banding, matching the second dorsal fin (Bonner & McDonald, 2005; Schenck & Whiteside, 1977b).
The life cycle of a fountain darter is 1-2 years (National Academies of Sciences, Engineering, and Medicine [NASEM], 2018).
Females lay batches of adhesive eggs onto aquatic vegetation that are then fertilized and receive no further care (Phillips et al., 2011). Spawning occurs almost year round with peaks in late winter and early spring but, will cease if water temperature rises above 26ºC (Bonner et al., 1998).
The fountain darter is found in the springs and upper reaches of the Comal River, including Landa Lake, and the San Marcos River between Spring Lake and the City of San Marcos wastewater treatment plant outfall (NASEM, 2018).
Habitat and Diet
Fountain darters are most abundant among concentrations of native aquatic plants and bryophytes (a group of flowerless, spore-producing species). Aquatic plants such as Ludwigia, Sagittarria, Cabomba, Potamogeton, and Vallisneria are actively planted to restore native aquatic vegetation populations (NASEM, 2018).
Prefers water temperature of 21-24ºC (Carla Hassan-Williams et al., 2013).
Visual feeders with a diet comprised of aquatic insects and minute crustaceans (Schenck & Whiteside, 1977a).
Bonner, T. H., Brandt, T. M., Fries, J. N., & Whiteside, B. G. (1998). Effects of Temperature on Egg Production and Early Life Stages of the Fountain Darter. Transactions of the American Fisheries Society, 127, 971–978. https://doi.org/10.1577/1548-8659(1998)127<0971:EOTOEP>2.0.CO;2
Bonner, T. H., & McDonald, D. L. (2005). Threatened fishes of the world: Etheostoma fonticola (Jordan & Gilbert 1886) (Percidae). Environmental Biology of Fishes, 73(3), 333–334. https://doi.org/10.1007/s10641-004-4132-6
Carla Hassan-Williams, Timothy H. Bonner, Chad Thomas, & Bobby G. Whiteside. (2013, January 23). Texas Freshwater Fishes. http://txstate.fishesoftexas.org/etheostoma%20fonticola.htm
Collette, B. B. (1963). The Subfamilies, Tribes, and Genera of the Percidae (Teleostei). Copeia, 1963(4), 615. https://doi.org/10.2307/1440961
National Academies of Sciences, Engineering, and Medicine. 2018. Review of the Edwards Aquifer Habitat Conservation Plan: Report 3. Washington, DC: The National Academies Press. https://doi.org/10.17226/25200
Page, L., & Burr, B. (1979). The Smallest Species of Darter (Pisces:Percidae). The American Midland Naturalist, 101(2), 452-453. https://doi.org/10.2307/2424613
Phillips, C. T., Alexander, M. L., & Gonzales, A. M. (2011). Use of Macrophytes for Egg Deposition by the Endangered Fountain Darter. Transactions of the American Fisheries Society, 140(5), 1392–1397. https://doi.org/10.1080/00028487.2011.623992
Schenck, J. R., & Whiteside, B. G. (1977a). Food Habits and Feeding Behavior of the Fountain Darter, Etheostoma fonticola (Osteichthyes: Percidae). The Southwestern Naturalist, 21(4), 487–492. http://www.jstor.com/stable/30054031
Schenck, J.R., & Whiteside, B. G. (1977b). Reproduction, Fecundity, Sexual Dimorphism and Sex Ratio of Etheostoma fonticola (Osteichthyes: Percidae). The American Midland Naturalist, 98(2), 365-375. https://doi.org/10.2307/2424987