[Photo: Texas Parks and Wildlife]
Description: The fountain darter is the smallest of all darters, reaching only 1.4 inches (3.5 cm) in length. It is olive and white, with dark spots scattered throughout its dorsal and ventral surfaces. The males exhibit red, black, and clear banding on their first dorsal fin and both males and females display light brown banding on their 2nd dorsal fin.
Life History: The fountain darter breeds in pairs year round, peaking in August and late winter. Females are mature at 3.5 months and lay 760 eggs at a time, on average, on filamentous algae and plants. Fountain darters feed mostly during the day on immature insects (mayfly and "true" fly larvae) and small crustaceans including water fleas, copopods, and amphipods.
Habitat: The fountain darter lives in the thermally stable (70-75 degrees F [21-24 deg C]) freshwater lakes, springs, and rivers associated with the Comal and San Marcos rivers in the Edwards Aquifer. It prefers to live in murky, densely vegetated waters among bottom-growth plant species such as algae, hydrilla, and water primrose.
Distribution: Etheostoma fonticola
is found in Spring Lake, San Marcos Springs, and the upper portion of the San Marcos River in Hays County, TX. It is also found in Landa Lake, Comal Springs, and the entire length of the Comal River in Comal County, Texas.
The map below depicts the critical habitat for this species, as designated by the US Fish and Wildlife Service pursuant to the Endangered Species Act.
NOTE: No warranty is given, expressed or implied, as to the accuracy, reliability, or completeness of these data. Data do not represent a legal description of the critical habitat boundary; refer to the textual description in the appropriate final rule for this species as published in the Federal Register.
Federally Designated Critical Habitat for the Fountain Darter
[Figure: Houston Advanced Research Center using US FWS data]
Status: The fountain darter is a state and federally listed (1978) endangered species. There is a refugium for this species at the San Marcos National Fish Hatchery and Technology Center. Although this species is robust within its habitat, it is considered endangered due to the population's sensitivity to a single major event, such as drought. The fountain darter is reliant on the aquatic vegetation in the San Marcos and Comal Rivers. A reduction in the water quality or quantity in these springs or rivers that may affect the growth of these aquatic plants, has profound effect on the fountain darter population. The Edwards Aquifer Authority defines prime habitat for the fountain darter at flows >150 cfs in Comal Springs and associated river ecosystem and >100 cfs at San Marcos Springs and associated river ecosystem. The US Fish and Wildlife Service defines "take" for this species at flows of <200 cfs for the Comal system and <100 cfs for the San Marcos system. There is a legitimate risk to the fountain darter population at flows of 80 and 60 cfs in the Comal and San Marcos Rivers, respectively. The fountain darter is also threatened by exotic species and parasites.
US Fish and Wildlife Service, Critical Habitat Final Rule
Edwards Aquifer Authority, Draft Edwards Aquifer Habitat Conservation Plan
Schenck, John, R. and Whiteside, B.G. 1976. Distribution, Habitat Preference and Population Size Estimate of Etheostoma fonticola.
Vol, 1976, No. 4, pp 697-703.