Wednesday, February 08, 2017Register
 Endangered Spotlight

Photo: Texas State University at San Marcos
[Photo: Texas State University at San Marcos]

Fountain Darter
Etheostoma fonticola

Description: The Fountain Darter is the smallest of all darters, reaching only 35.5 mm in length. It is olive and white with dark spots scattered throughout its dorsal and ventral surfaces.

Life History: The Fountain Darter breeds in pairs year round, peaking in August and late winter. 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 (21-24 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 several bottom-growth plant species.

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.

Status: State and Federally Listed (1978) Endangered Species. There is a refugium for the Fountain Darter 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 spring flow defined as "take" for this species, as defined by USFWS, is 200 cubic feet per second (cfs) for Comal Springs and the associated Comal River ecosystem, and 100 cfs for San Marcos Springs and the San Marcos River ecosystem.

Resources:

Edwards Aquifer Authority, Draft Edwards Aquifer Habitat Conservation Plan

Fountain Darter Page

Schenck, John, R. and Whiteside, B.G. 1976. Distribution, Habitat Preference and Population Size Estimate of Etheostoma fonticola. Copeia. Vol, 1976, No. 4, pp 697-703.

US Fish and Wildlife Service, Endangered Species Profile


 Print   
 Precipitation in the Edwards Aquifer

Precipitation is very important to the ecosystem of the aquifer; the chart details the yearly sum total precipitation over the area for the past 100 years. Note the drought period of the 1950's and low rainfall in recent years. Fifteen National Weather Service weather stations located throughout the Edwards Aquifer area were used for all precipitation analysis. Click on map or chart to see larger image.

 

The fifteen National Weather Service weather stations used to calculate precipitation over Edwards Aquifer; figure by the Houston Advanced Research Center

The fifteen National Weather Service weather stations used to calculate precipitation over Edwards Aquifer; figure by the Houston Advanced Research Center.

Chart displaying yearly sum total precipitation in Edwards Aquifer; figure by the Houston Advanced Research Center

Chart displaying yearly sum total precipitation in Edwards Aquifer; figure by the Houston Advanced Research Center.

 

Edwards Aquifer Seasonal Precipitation

Seasonal changes associated with precipitation can have an impact on the threatened and endangered species in Edwards Aquifer. As niche species, they are very sensitive to changes in flows and groundwater and surface water quantity and quality.

Monthly sum total precipitation in the Edwards Aquifer - comparing the drought years of 1954, 1955 and 1956 with average rainfall; figure by the Houston Advanced Research Center

Monthly sum total precipitation in the Edwards Aquifer - comparing the drought years of 1954, 1955 and 1956 with average rainfall; figure by the Houston Advanced Research Center.

Monthly sum total precipitation in the Edwards Aquifer - comparing the recent years of 2007, 2008, and 2009 with average rainfall; figure by the Houston Advanced Research Center

Monthly sum total precipitation in the Edwards Aquifer - comparing the recent years of 2007, 2008, and 2009 with average rainfall; figure by the Houston Advanced Research Center.


 Print   
Privacy StatementTerms Of UseCopyright 2011 Houston Advanced Research Center

BorderBoxedBlueBoxedGrayBlueSmall width layoutMedium width layoutMaximum width layoutMaximum textMedium textSmall textBack Top!