Tag Archives: Hays County

Gambusia georgei Hubbs & Peden

San Marcos Mosquitofish (Gambusia georgei)  

The San Marcos Mosquitofish was described in 1969.  

The species was restricted to the San Marcos Spring, a large vegetated spring, and its effluent in Hays County, Texas, USA.  

The San Marcos Mosquitofish reached a length of about 4 cm, the species was live bearing, a large female could give birth to up to 60 young.  

The species disappeared due to a mix of influences, including the pollution of the water by sprayed herbicides along the San Marcos River, and the introduction of another Gambusia species, the Western Mosquitofish (Gambusia affinis (Baird & Girard)), with which it hybridized.  

The last pure San Marcos Mosquitofish were seen in 1983.  

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edited: 23.06.2020