San Marcos gambusia

Taxobox | name = San Marcos Gambusia
status = EX | status_system = IUCN2.3
extinct = 1983
regnum = Animalia
genus = "Gambusia"

The San Marcos Gambusia is an endangered species of fish, found only in the San Marcos Springs of central Texas. The fish has not been seen since 1983, and so it may be extinct.

Description

The San Marcos Gambusia is typically less than 1.6 inches (4 cm) in length. It frequently has a dark body with a slight blue tint, although the median fins are often yellow. The scales are strongly crosshatched, and the dorsal fin usually has a dark stripe along its edge. The species’ exact diet is not known, but other poeciliids typically eat insect larvae and other small invertebrates.

The fish are live bearing, and have been known to give birth to a few dozen young at a time.

Habitat

The San Marcos Gambusia has only been identified in a 0.6 mile (1 km) stretch of the headwaters of the San Marcos River. They appear to need clean and clear water, with little temperature variability. The apparently also prefer shallow, quiet water, along with partial shade.

External links

* [http://www.tpwd.state.tx.us/huntwild/wild/species/sanmarcosgambusia/ San Marcos Gambusia (Gambusia georgei)] page from the Texas Parks & Wildlife Department
* [http://www.edwardsaquifer.net/species.html#San%20Marcos%20Gambusia%20(Gambusia%20georgei) San Marcos Gambusia] page from [http://www.edwardsaquifer.net/ EdwardsAquifer.net]
* Information from the [http://ecos.fws.gov/docs/life_histories/E021.html U.S. Fish & Wildlife Service]