Quitobaquito

Along the US-Mexico border, about 15 miles west of the border crossing between Lukeville, Arizona and Sonoyta, Mexico is the small oasis of Quitobaquito in Organ Pipe Cactus National Monument. The shortest route to the site is a dirt road that, for much of its length, parallels the international border. In fact, in places it is no more than 20 meters from the metal fence on the US side, a barrier less formidable than many backyard fences. The saguaros and desert scrub take no notice of the artificial line in the sand so important to humans.

At Quitobaquito, perhaps a half kilometer north of the border, a tiny creeklet finds its origin in a spring that itself seems to just emerge from the base of a small non-descript slope of dry Sonoran Desert soil. The Park Service has lined the creeklet with concrete, no doubt to preserve the integrity of the waterway, because so minute is the flow that it seems like the desert dust could consume the trickle of water with no effort. As I walked along the creeklet, looking for its source, I could see signs of researcher presence – a short submerged PVC tube that I’m guessing houses a temperature sensor or other device, and some red plates underwater about which I cannot surmise their purpose.

Arriving at Quitobaquito (left) and some saguaro cacti near the oasis (right).

The creeklet ends in a rather large shallow pond to the south which is encircled by a narrow but dense band of sedges (just like Schoenoplectus americanus of west coast wetlands, though I’m not positive it is the same species). It looked like there was widgeon grass (Ruppia) in the water. The pond and creeklet were lined with colorful flowering species that I had not seen elsewhere in the Monument.

The pond at Quitobaquito. Sedges line the edge of the pond.

Why the effort to protect flow in the creeklet? This little oasis is home to an endangered fish species, the Quitobaquito pupfish (Cyprinodon eremus). I saw quite a few fish in the creeklet that led to the pond. The species is dimorphic in color – larger blue fish are reproductively mature males and females and immature males are smaller and light grey-brown, blending in well with the substrate. Incredibly these pupfish can tolerate high salinity, very high temperatures, and low oxygen conditions. The fish I observed were skittish and apparently territorial, chasing one another in short bursts of activity.

Quitobaquito pupfish. A arrow points to the female or immature male at left since these fish
blend in much better with the mud than the blue reproductive males.

Flowering plants near the pond: Heliotropium curassavicum (left) and Funastrum cynanchoides (right).

References

Reistad, A. 2012. Pupfish. In: National border, national park: A history of Organ Pipe Cactus National Monument, at: https://organpipehistory.com/orpi-a-z/pupfish/

Spellenberg R. 2012. Sonoran Desert Wildflowers. 2^nd ed. Falcon Guides, Guiford, MT.

Flowering plants near the creeklet: Anemopsis californica (left) and unknown pink-flowered species (right).