Kalahari Desert northwest, forming marshes that are rich in wildlife. Ancient dry riverbeds—called omuramba—traverse the central northern reaches of the Kalahari and provide standing pools of water during the rainy season. A semi-desert, with huge tracts of excellent grazing after good rains, the Kalahari supports more animals and plants than a true desert, such as the Namib Desert to the west. There are small amounts of rainfall and the summer temperature is very high. The driest areas usually receive of rain per year, and the wettest just a little over . The surrounding Kalahari Basin covers over extending further into Botswana, Namibia
Desert pupfish finished spawning, she will flee in a "panicky" style with the male in pursuit. This chase lasts for about 5 minutes before the male swims to the bottom and both fish begin foraging. "C. macularius" are euryhaline and eurythermal, tolerating temperatures between approximately 4º and 45 °C and salinities ranging from 0 to 70 parts per thousand, exceeding the tolerances of virtually all other freshwater fish. The desert pupfish can also survive dissolved-oxygen concentrations as low as 0.13 ppm. The desert pupfish has been noted to be more abundant in environments with high vegetative cover, pH and salinity, and low